by Ross Shotton *
INTRODUCTION
The commercial fisheries of the Northwest Atlantic, particularly those for cod, have been important for five centuries. Area 21 has a total surface area of 6.26 million km2of which 1.29 million km2is shelf area. The region's (Figure B1.1) marine environment is dominated by the cold Labrador Current, which flows southward to the Grand Banks, and by the warm Gulf Stream, which flows north-eastwards from Cape Hatteras, seaward of the continental shelf; it supplies relatively warm water to West Greenland. The freshwater influence from the St Lawrence River is also important. The major fisheries resources occur on the broad continental shelves, particularly Georges Bank, the Scotian Shelf, the Gulf of St Lawrence and the Grand Banks of Newfoundland. While the principal grounds are under the national jurisdictions of Canada, the United States, Greenland and France (for St Pierre and Miquelon), the Flemish Cap and the “nose” and “tail” of Grand Bank lie in international waters.
Figure B1.1 - The Northwest Atlantic (Area 21)
Most of the demersal resources which long supported the major Northwest Atlantic fisheries were severely depleted in the late 1980s and early 1990s by a combination of heavy fishing, cold conditions linked to stronger Labrador Current flows and other factors, such as poor feeding conditions, lack of capelin (Mallotus villosus ), seal predation and low oxygen concentration. In 2002, many demersal fisheries remain either closed or operating under strict regulatory limitations, even after almost 10 years of such management. In contrast, the lobster (Homarus americanus) resources expanded in the 1980s, supporting catches not seen in the previous hundred years. On Georges Bank, the declining gadoid resources that were replaced by dogfish (Squalus acanthias) and skates (Raja spp.) in the 1980s, have begun to recover. Similarly, yellowtail flounder (Limanda ferruginea) have also begun to recover. Off Newfoundland, shrimp (Pandalus borealis), also known as northern prawn, and snow crab (Chionoecetes opilio) resources expanded in the late 1990s, supporting catches which drove total landed values to record highs, despite the loss of the traditional demersal fisheries. Other resources, such as scallops (Placopecten magellanicus) and herring (Clupea harengus ), continue to support healthy fisheries in some areas. Georges Bank herring, at last, recovered from the overfishing of the 1970s.
Figure B1.2 - Annual nominal catches ('000t) by ISSCAAP species groups in the Northwest Atlantic (Area 21)
Source FAO
PROFILE OF CATCHES
Nominal catches in the Northwest Atlantic doubled from 2.3 million tonnes in 1950 to 4.6 million tonnes in 1968 (Figure B1.2 and Table D1). Catches decreased rapidly from 4.4 million tonnes in 1973 to 2.8 million tonnes in 1978, they remained relatively stable around 2.7 million tonnes until 1984 when they started to increase slowly, reaching 3.3 million tonnes in 1990. Catches subsequently decreased steeply, as a result of the groundfish collapse off Eastern Canada, to about 2 million tonnes in 1994. A slight recovery has been evident since 1998, when 1.96 million tonnes were reported, to 2.24 million tonnes in 2002.
Figure B1.3 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 32, Northwest Atlantic (Area 21)
Source FAO
Figure B1.4 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 35 & 37, Northwest Atlantic (Area 21)
Source FAO
The development of the fishery in the Northwest Atlantic after 1950 followed a pattern of pulse fishing with groundfish, mostly cod (Gadus morhua) but also haddock (Melanogrammus aeglefinus) and silver hake (Merluccius bilinearis ), being the first target (Figure B1.3) followed by herring and mackerel (Scomber scombrus ) (Figure B1.4). Flatfishes catches peaked at 303 000t in 1968 (Figure B1.5), they then declined slowly and irregularly to 189 000t in 1992, then more than halved to 78 600t in 1995. By 2002 catches of these fishes had recovered to 116 400t, just over half of which consisting of Greenland halibut (Reinhartius hippoglossoides ), for which new fisheries have developed in the early 1990s. Fisheries for invertebrate have fared better (Figure B1.6) showing increases from the mid 1970s to the early 1990s when more than 600 000t were caught. Catches of sea scallops, ocean quahog and surf clams decreased during most of the 1990s, but have increased during the last part of the decade. Shrimp and lobster catches have generally increased. Total catches in 2002 were again above 600 000t. In 1998, catches of snow crab passed those of American lobster for the first time, and in 2002 snow crab catches were 30 percent higher than those of lobster.
Greenland
Both East (FAO Statistical Area 27) and West Greenland are included in this description. Northern prawn continues to be the major species in Greenland with 2001 catches being an all time high of 85 450t or 51.7 percent of reported catches. Greenland halibut catches in 2001 were almost 21 000t, a sizeable decrease from the maximum of nearly 40 000t reported in 1999. Catches of capelin of 18 600t were also substantially lower in 2001 compared to that reported in 2000, a 24.4 percent reduction. These three species comprise 75.4 percent of total reported catches. Catches of cod in 2001 (5 614t) show a considerable increase over the 2000 all time recent low of about 3 000t, but this remains well below catches in the recent past, e.g. almost 110 000t in 1989. The presence and abundance of cod in offshore waters off Greenland is believed to be related to environmental conditions, and periodically to influx of larvae from Iceland that subsequently migrate back to Iceland to spawn (Buch, Horsted, and Hovgård, 1994).
RESOURCE STATUS AND FISHERY MANAGEMENT
Canada
For most of the past five centuries, the predominant fisheries in what are now Canadian waters produced exclusively salt cod, the fish usually being caught by hook-and-line from small vessels and salted ashore. The adoption, by the Canadian industry, of trawler technology, producing frozen fish from a wider variety of target species, has largely occurred in the last fifty years. Indeed, fixed-gear demersal fishing remains important in many areas. However, the most significant event for the resources, in recent decades, was the arrival of foreign factory-trawler fleets, beginning in the late 1950s. The resulting overfishing provoked the extension of national jurisdiction in 1977. At that time, there was considerable optimism that Canadian catches would increase substantially through better fishery management and the replacement of foreign fishing effort with a national one. Some improvement in stock status was seen up to the mid-1980s but thereafter a combination of expanding fishing capacity (which drove increased effort despite the supposedly-conservative management system) and a succession of weak year-classes in many stocks led to increases in fishing mortality and decreases in stock sizes. Most of the demersal fisheries, including some of the world's most renowned, were closed in 1992 or 1993, while others saw sharp reductions in catch quotas (Murawski et al., 1997).
The drastic management measures have had mixed results (further information on stock status and fishery management in the Canadian area can be found at http://www.dfompo.gc.ca/csas/Csas /English/Index_e.htm). In their 2003 report to the Minister, the Fisheries Resource Conservation Council noted that spawning biomass of the cod stock in NAFO Divisions 2J3KL continued to be very low, with low recruitment, high mortality from seals and exposure to bycatch. Grand Bank substocks comprised only 3 percent of 1980s biomass with few fish older than 5 years old. Cod stocks in Scotian Shelf and Bay of Fundy (Div. 4VsW), under a moratorium since 1993, show the lowest spawning biomass ever recorded, with recruitment, growth, condition and age structure below average. The stock of Division 4Vn (May–November), closed to fishing since 1993, shows little sign of recovery, largely due to weak recruitment. For 4×5Y cod stock, recruitment has improved starting with the 1998 yearclass and although biomass has increased since the late 1990s, it remains low. Gulf of St. Lawrence cod stocks (Div. 3Pn4RS) show further decline in the spawning stock biomass, with age 3 cod showing a historic low. Natural mortality remains high - with seals attributed as the major cause - though energetic condition and growth have improved (Fisheries Resource Conservation Council, 2003a,b,c). Thus it is unsurprising that on 24 April, 2003, the Government of Canada announced the fishery closure of three cod stocks in the Gulf of St.Lawrence and north-east of Newfoundland and Labrador. In addition, on 2 May, 2003, two populations of the Atlantic Cod were designated as threatened and endangered following assessments by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The population units used by COSEWIC do not correspond to those used traditionally for fishery management. As a result, the Laurentian North population of the Atlantic Cod was assessed as threatened because, although cod remains abundant in the eastern part of the region (southern coast of Newfoundland), they have declined substantially in the northern Gulf, where the fishery is now also closed. The Maritimes population of the Atlantic Cod remains in the special concern category (http://www.cosewic.gc.ca/eng/sct7/sct7_3_1_e. cfm), even though the 4VsW cod stock is at the lowest spawning biomass recorded, as indicated above.
Figure B1.5 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 31, Northwest Atlantic (Area 21)
Source FAO
Figure B1.6 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 43, 45, 55, 56, Northwest Atlantic (Area 21)
Source FAO
The failure of most East Coast cod stocks to recover in the more than 10 years since they collapsed has puzzled and disappointed those working on and interested in these fisheries. When the moratoria were placed on these stocks in the early 1990s, some expected that they would recover quickly. However, some of the collapsed stocks were smaller than ever seen before and thus had far to rebuild. Other stocks had been as low before but this time the recovery failed to occur. A number of likely explanations have been proposed by a recent review organized by the Canadian Department of Fisheries and Oceans (http://www.dfompo.gc.ca/media/backgrou/2003/cod(3)_e.htm).
The environment: Cod in Northern Atlantic Canada have lower productivity than cod further south or in the eastern Atlantic Ocean because they live in colder environments. During at least the first half of the 1990s, the ocean climate was unusually cold, which was particularly unfavourable to the stocks’ productivity, and therefore, to recovery.
Fish growth and survival: The harsh environment in the 1990s reduced survival and growth. When the fishing moratoria were applied in the early 1990s, most of the cod were small for their age and in poor condition with little energy reserves to survive the winter months or critical stages of their life cycle. The energetic condition of cod following spawning was particularly low in the early 1990s, perhaps low enough to cause high mortality in some of the cod stocks. In addition, reduced cod stocks being preyed upon by an increasing number of seals, sufficient to have affected recovery. In the Gulf, increasing abundance of mackerel and herring may also have resulted in high predation on cod eggs and larvae. Taken together, environmental conditions and increased predation resulted in poor growth and poor survival for cod.
Reproduction: When the cod stocks collapsed, they had few older fish and a high proportion of first time spawning fish. This contributed to a reduction in the reproductive potential in cod stocks. In view of the high mortality experienced on many cod stocks, this condition has continued. In certain cases, there was a severe reduction of the size of some spawning components or a reduction of the area where spawning occurs. Also, the spawning biomass on many cod stocks was so low that the number of young fish was much lower than in the past contributing to continued low production.
Fishing: While catches from fishing have been reduced in comparison to the 1970s and 1980s, in some stocks, they appear to have remained sufficiently high to generate significant mortality. There was also evidence of under-reporting or non-reporting of cod catches, discarding small fish and poaching.
In summary, the lack of recovery was concluded to be the result of several factors working simultaneously or in turn that affected fish growth, reproduction and fish survival. Taken together, these factors strongly suggest that there will not be a prompt recovery in any of these stocks in the near future.
As opposed to cod, lobster, which is the mainstay of inshore fisheries in much of Atlantic Canada, supported near-record catches in the 1980s after being depleted for half a century. It seems that ecological changes led to the increased production, though there is no agreement as to the specific cause and increased fishing efficiency is also believed to have played a role. Lobster catches, managed through 40 Lobster Fishery Areas in Atlantic Canada, reached a peak of 48 500t in 1991, declined through the following decade, climbed to 51 400t in 2001 and declined again to 45 111t in 2002.
United States
The fisheries of the Northeast United States have a long tradition based on the highly productive demersal fisheries of Georges Bank and, to a lesser extent, the lobster fishery of the Gulf of Maine. There have also been significant fisheries for many other species, some of which were more prominent in earlier years while some have become important only in recent years (further information on stock status in the US area can be found at http://www.nefsc.noaa.gov/nefsc/saw/ and information on fishery management can be found at: http://www.nefmc.org). A variety of fishing gears including otter trawls, gillnets, traps, and set lines have been employed, but otter trawls are the preferred gear. Except for a period of intense distant water fleet fishing from the early 1960s until the mid 1970s, the fishery in United States waters has been domestic. The distant water fleet fishery, conducted mainly by Eastern European factory trawlers on Georges Bank, can best be characterized as a pulse fishery which sequentially targeted and then severely reduced the abundance of species such as haddock (peak in 1965), silver hake (peak in 1965), herring (peak in 1968), and mackerel (peak in 1973).
Fishery management since the establishment of a 200-mile exclusive economic zone (EEZ) by the United States in 1977 initially achieved limited success. Since the mid 1990s, particularly with the adoption of the Sustainable Fisheries Act and the adoption of stronger management actions, fishing mortality has been reduced substantially on most groundfish stocks, and some have started to rebuild relatively quickly (Groundfish Facts & Figures at http://www.nefmc.org).
Demersal species
Demersal species have been the traditional mainstay of the fisheries off the United States Northeast coast. About 35 species/stocks are included in this category, dominated by gadoids, flounders, goosefish (Lophius spp. also known as monkfish), spiny dogfish (Squalus acanthias ), and skates in the New England area, and by summer flounder (Paralichthys dentatus ), scup (Stenotomus chrysops ), goosefish (Lophius americanus) and black sea bass (Centropristis striata) in the Mid-Atlantic region. The average yield over the last decade of the principal groundfish and flounders group, which includes species in the cod family, such as cod, haddock, silver and red hake (Urophycis chuss ), and pollock (Pollachius virens ), yellowtail flounders (Pleuronectes ferrugineus ), summer and winter flounder (Pleuronectes americanus ), witch (Glyptocephalus cynoglossus ), windowpane (Scophthalmus aquosus ), and American plaice (Hippoglossoides platessoides ), averaged 61 218t (37.5 percent flatfish, 62.5 percent gadids).
This amount is less than one-third of their combined long term potential yield. Overall abundance of these principal groundfish and flounders, as measured by the National Marine Fisheries Service (NMFS) research vessel bottom trawl survey catch-per-tow indices, declined by about 70 percent between 1963 and 1974 as a direct consequence of distant water fishing. Some recovery occurred in the late 1970s following catch and effort reductions implemented by the International Commission for the Northwest Atlantic Fisheries (ICNAF) prior to 1977 and the establishment of the United States EEZ in 1977, but was short-lived owing to increased fishing pressure by United States fishermen. Overall abundance reached a record low in 1992.
However, since the mid 1990s, as a result of stringent management measures (including a moratorium on new vessel entrants, drastic reductions in days at sea for trawl and gillnet vessels, increased mesh sizes, several year-round large closed areas), fishing mortality rates have been drastically reduced and stock biomass rebuilding begun for stocks such as haddock on Georges Bank, yellowtail flounder on Georges Bank and Southern New England, and summer flounder. United States catches for most of these species have declined substantially since about 1994 and, for cod, were the lowest on record in 1997 (12 982t). By 2001 there had been a slight recovery to 15 100t, but catches dropped again to 13 128t in 2002. Haddock catches had recovered to 7 553t by 2002, up from 328t in 1994.
Pelagic species
Abundance of Atlantic herring and Atlantic mackerel has been monitored using spring survey data, since both species occur primarily within the boundaries of the survey area in March and April, when this survey is conducted. In general, survey catch-per-tow data for these species have been more variable than those for principal groundfish and flounders, although the aggregate index adequately depicts overall trends. The index dropped in the mid-1970s, reflecting pronounced declines in abundance of both herring and mackerel (including the collapse of the Georges Bank herring stock). Since 1983, the index has markedly increased with the 1994 value the highest in the time series. This trend is supported by virtual population analyses (VPA) which indicate high abundance of both the coast-wide herring stock and the north west Atlantic mackerel stock in recent years. There is also evidence for recovery of the Georges Bank herring stock, (http://www.nefsc.noaa.gov/sos /agtt/). Herring and mackerel were heavily exploited by distant water fleets in the late 1960s and early 1970s and abundance of both species declined in the early 1980s before subsequently rebuilding in the absence of intensive fisheries. Catches of mackerel in 2002 were 70 456t (61.2 percent Canada, 38.8 percent United States), while at the high end for the decade, remain still far below the long-term estimated potential of 383 000t. Total US catches of herring from the coastal stock complex (Gulf of Maine, Georges Bank, and Nantucket Shoals stocks) reached a peak of 106 600t in 2001 then declined abruptly to 67 652t in 2002, the lowest recorded catch since the 1994 low for the decade of 48 700t. US catches comprised 26.1 percent of total herring harvest in 2002, the remaining being taken by Canada.
Anadromous species
This is a diverse group including river herrings such as alewife (Alosa pseudoharengus) and blueback (Alosa aestivalis ), American shad (Alosa sapidissima ), striped bass (Morone saxatilis ), Atlantic salmon (Salmo salar ), Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) and shortnosed sturgeon (Acipenser brevirostrum ). The composite average yield from 2000 to 2002 is only about 3 978t, far below the historic maximum of 32 443t in 1959. All of these species, except striped bass, are overexploited and their abundance is low.
Commercial catches of striped bass peaked at 5 900t in 1973 (estimates of recreational catches were not available until 1981), but dropped steadily to only 63t in 1987. Combined commercial and recreational catches reached a record low of 423t in 1989. Because of low stock abundance and poor recruitment, highly restrictive regulatory measures were imposed in the mid 1980s. Stock rebuilding followed the recruitment of several improved year classes, and the stock was declared restored in 1995. The 2002 catches of striped bass were 2 847t.
The last two decades mark a period of decline in stock status for all Atlantic salmon populations of the North Atlantic. Indices and complete measures of population abundance indicate that overall survival plummeted as much as fivefold for some stocks during these years. This has intensified concern over the additive effects of natural mortality in the marine environment and habitat issues that persist in U.S. rivers. The US Atlantic Salmon Assessment Committee produces an annual report that includes an index of minimum documented returns to US rivers. In 1999, only 1452 adults returned to US rivers, one of the lowest returns in a time-series that dates from 1970. At present, these data provide the best index to US stock abundance. This value is dominated by returns to the Penobscot River, which typically comprise more than 60 percent of total returns on an annual basis (http://www. nefsc.noaa.gov/sos/spsyn/af/salmon).
Invertebrate species
Offshore fisheries for invertebrate species including lobsters, surfclams (Spisula solidissima ), ocean quahogs (Arctica islandica ), longfin squid (Loligo pealeii ), shortfin squid (Illex illecebrosus ), sea scallops, northern shrimp and red crab (Chaceon quinquedens) are among the most valuable in the Northeastern United States. Fisheries for invertebrate species in nearshore and estuarine waters such as blue crabs (Callinectes sapidus ), oysters (Crassostrea virginica ), hard clams (Mercenaria mercenaria ), sea urchins (Strongylocentrotus spp.), softshell clams (Mya arenaria ), sea worms (including primarily sandworm (Nereis virens) and bloodworm (Glycera dibranchiata )) commonly harvested for use as bait in recreational fisheries, conchs (Busycotypus canaliculatus, Busycon carica, and Busycon sinistrum ), and blue mussels (Mytilus edulis) provided additional income for this fishery.
United States catches of lobster, the most valuable species of this group, underwent an almost steady increase since 1940, reaching a peak of 37 730t in 2000, declining only slightly to 32 390t in 2001, and increasing again to 37 309t in 2002. These recent increases in catches have resulted from both increased effort as well as apparent increases in abundance due probably to favourable environmental conditions. However, fishing mortality rates are 2 to 3 times in excess of overfishing definitions, and catches are almost totally dependent on newly-moulted and sexually-immature animals. Consequently, there is a need to greatly reduce fishing mortality rates, but recent regulatory measures (i.e. limits on the number of traps per fishermen) may not be sufficiently stringent to achieve this.
Since 1982, the Atlantic Sea Scallop Fishery Management Plan (FMP) has regulated the fishery for scallops throughout the range on the Atlantic coast of the U.S. Initially the major regulations required vessels to land scallops that averaged less than 35 to 40 meats (i.e. the adductor muscle) per pound or if landed in-shell, to have a minimum shell width of 3 to 3½ inches (about 7.5 to 9.0 cm). Fishing effort increased to unsustainable levels in the late 1980s and 1990s, prompting the New England Fishery Management Council (NEFMC) to develop Amendment 4 that became effective in 1994. Amendment 4 radically changed the management of the sea scallop fishery to achieve a maximum fishing mortality threshold equal to F 5%, a reference point believed to ensure recruitment by attempting to keep spawning stock biomass above five-percent of virgin conditions, a biomass thought to be sufficient to prevent a recruitment-caused stock collapse for a fecund species like sea scallops. Implemented with this management change were limited access permits, annual day-at-sea allocations, dredge ring-size minima, restrictions on gear configuration to improve escapement of small scallops and a minimum top mesh size to improve finfish escapement. US Sea scallop catches from the Georges Bank - Mid-Atlantic area, averaged 88 896t during the last decade with a high of 186 336t in 2002, indicating a recovery of the stocks. The large areas closed to protect groundfish stocks have also greatly contributed to the recovery of sea scallops.
Surfclams and ocean quahogs, regulated by an individual transferable quota (ITQ) system implemented in 1990, are harvested by dredges primarily in the Mid-Atlantic and Southern New England region and are currently underexploited. Catches of both species have remained relatively stable in recent years, with catches of 175 709t and 149 767t, respectively in 2002 (decadal averages were 159 965t and 163 367t respectively).
Domestic fisheries for longfin and shortfin squid, although existing since the 1800s primarily to supply bait markets and generating catches of about 1 000t or less per year for each species until the 1970s, expanded greatly in the 1980s and 1990s in response to growing human consumption markets. Longfin squid are fished primarily between Cape Hatteras, North Carolina and the Gulf of Maine, while shortfin squid have been fished from Cape Hatteras to Newfoundland and are assumed to constitute a unit stock throughout that range. Distant water fisheries for these two species existed between 1964 and 1986, with catches from United States waters peaking for longfin squid at 36 500t in 1973 and for shortfin squid at 24 700t in 1976. Catches of shortfin squid from Canadian waters between Nova Scotia and Newfoundland, primarily by distant water fleets, rose sharply to a peak of 162 100t in 1979 before collapsing in the early 1980s. The decadal average yields of squid for 1992–2002 were 17 796t for longfin and 13 197t for shortfin. But, by 2002, catches of Illex illecebrosus were down to 2 750t.
NAFO area
Resources beyond the EEZ of the three countries in the region are managed under the aegis of the North Atlantic Fisheries Organization. Summary information on the status of the stocks in their area (which includes redfish, yellowtail flounder, American plaice, witch flounder, cod, Greenland halibut and capelin) is given in their annual report (NAFO, 2001) and through their web site (http://www.nafo.ca/publications/annrep/AR01. pdf). Given the concern over the status of cod, it is of interest to note that in the case of the single NAFO stock of the Flemish Cap, the fishery was closed in 1999, though non-contracting countries continued to exploit these stocks. The biomass at the beginning of 2000 remained low, consisting mainly of fish of 6 and 7 years of age. Younger fish were scarce due to low recruitment during the period 1995–1999 and it was recommended that there be no directed fishery for this species.
REFERENCES
Buch, E., Horsted, S.A., & Hovgård, H. 1994. Fluctuations in the occurrence of cod in Greenland waters and their possible causes. ICES mar. Sci. Symp . 198: pp. 158–174.
Fisheries Resource Conservation Council. 2003a. 2003/2004 Conservation Requirements for Groudnfish Stocks on the Scotain Shelf and in the Bay of Fundy (4VWX5Z), in Subareas 0, 2 + 3 and Redfish Stocks. Report to the Minister for Fisheries and Ocreans. FRCC R.1. January 2003. 107p.
Fisheries Resource Conservation Council. 2003b. 2003/2004 Conservaton Requirements for 2J3KL Cod Stocks. Report to the Minister for Fisheries and Ocreans. FRCC R.2. March 2003. 18p.
Fisheries Resource Conservation Council. 2003c. 2003/2004 Conservation Requirements for Groundfish Stocks in the Gulf of St.Lawrence. Report to the Minister of Fisheries and Oceans. FRCC R.3. April 2003. 47 pp
Murawski, S.A., Maguire, J.-J., Mayo, R.K. & Serchuk, F.M. 1997. Groundfish stocks and the fishing industry. pp. 27–70 In Boreman, J., Nakashima, B.S., Wilson, J.A. & Kendall, R.L. (eds.) Northwest Atlantic Groundfish: Perspectives on a fishery collapse. American Fisheries Society, Bethesda, Maryland: xxii+242p.
NAFO. 2001. Annual Report of the Northwest Atlantic Organization (NAFO) 2000. 216p.
* FAO, Marine Resources Service, Fishery Resources Division
by Jean-Jacques Maguire *
INTRODUCTION
The North Atlantic features a large subpolar gyre that plays a central role in the distribution and ecology of fish stocks in the Northeast Atlantic area (Figure B2.1). The presence of this subpolar gyre was illustrated by the “Great Salinity Anomaly”, when a huge volume of cold, low salinity water travelled around the gyre from 1968 to 1982 (Dickson et al., 1988). Some fish stocks in its path experienced poor recruitment, possibly due to reduced food supply and the colder temperature of the anomalous water delayed primary production blooms (Dickson and Brander, 1994). Other oceanographic features of the Northeast Atlantic include the extended shelf area off Northern Europe, the semi-enclosed Baltic Sea, and summer upwellings off the coast of Spain and Portugal. The total area is 14.3 million km2, of which 2.7 million km2are shelf area.
Figure B2.1 - The Northeast Atlantic (Area 27)
Most of the traditional fishery resources of the Northeast Atlantic are fully exploited, overexploited, or depleted. New fisheries have developed for deep-sea species, and although their status is not precisely known, there are reasons to believe that most likely these resources will not be harvested sustainably as they are notoriously sensitive to exploitation. In this area, some deep-sea species/stocks have become depleted before appropriate management could be implemented (ICES 2002).
Figure B2.2 - Annual nominal catches ('000t) by ISSCAAP species groups in the Northeast Atlantic (Area 27)
PROFILE OF CATCHES
The fisheries of the Northeast Atlantic expanded rapidly in the late nineteenth and early twentieth century as fishing became mechanized and motorized. World Wars I and II provided short periods of relative fishing inactivity during which stocks rebuilt. Nominal catches increased from 5.2 million tonnes in 1950 to peak close to 13 million tonnes in 1976. Catches have declined thereafter to 8.5 million tonnes in 1990 but they have subsequently increased more or less steadily to 11.7 million tonnes in 1997. They have subsequently fluctuated around 11 million tonnes (Figure B2.2 and Table D2). The increase in total catches masks the ups and downs of traditional species such as North Atlantic cod (Gadus morhua ), haddock (Melanogrammus aeglefinus) and herring (Clupea harengus ), the development of fisheries for formerly lower-valued species such as sandeels (Ammodytes spp.) and blue whiting (Micromesistius poutassou ), and the shift from mackerel (Scomber scombrus) in the North Sea to the Western area.
Figure B2.3 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 32, Northeast Atlantic (Area 27)
Source FAO
Figure B2.4 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 32, Northeast Atlantic (Area 27)
Source FAO
Figure B2.5 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 35,37, Northeast Atlantic (Area 27)
Source FAO
Catches of Atlantic cod have consistently made the largest contribution to the total of cods, hakes and haddocks until 1998 when blue whiting caught up with cod (ISSCAAP Group 32 species - Figure B2.3). A persistent downward trend in cod catches is evident from the peak of the late 1960s. Catches of blue whiting have been greater than those of cod since 1999. The total Northeast Atlantic catches of species other than cod and blue whiting in ISSCAAP Group 32 peaked in the early 1970s and then showed a general decline (Figure B2.4).
Catches of Atlantic herring and particularly capelin (Mallotus villosus) have shown greater short-term variability than those of many other species, including other pelagics (Figure B2.5). This is partly due to the influence of a few large stocks such as Norwegian spring-spawning herring that collapsed in the late 1960s, and of North Sea herring in the late 1970s. Similarly, the decline in capelin catches in the mid-1980s was due to the collapse of the Barents Sea capelin fishery, which was closed from 1986 to 1991. The Norwegian spring spawning herring recovered in the 1980s, and it sustained the growth in catches of the group in the 1990s. North Sea herring also recovered in the 1980s, suffered another set-back in the mid-1990s, but the stock is now considered rebuilt. Catches of mackerel and European sprat show less variability in the last twenty years.
The small-mesh fishery for sandeels (in ISSCAAP Group 33) has expanded substantially since the late 1960s. Catches since 1985 have shown no trend and have varied between 0.65 and 1.24 million tonnes (Figure B2.6). Significant fisheries exist for Atlantic redfishes (various deep-sea and oceanic stocks of Sebastes mentella and S. Marinus, ISSCAAP group 34) mostly in international waters in the Irminger sea. Catches of shrimps and prawns (ISSCAAP Group 45) have increased since the early 1980s. This increase is mostly attributable to northern prawn (Pandalus borealis) while the combined catches of other shrimp and prawn in ISSCAAP Group 45 species has declined slowly since the mid-1950s.
RESOURCE STATUS AND FISHERY MANAGEMENT
The origins of modern fisheries stock assessment science can be traced to late nineteenth century studies of North Sea fisheries leading to the creation of the International Council for the Exploration of the Sea (ICES) in 1902. Currently, ICES provides assessments and/or management advice for over 100 stocks or sub-stocks in the Northeast Atlantic through its Advisory Committee on Fisheries Management (ACFM) http://www.ices.dk/committe/acfm/comwork/report/asp/acfmrep.asp. The majority of these stocks (approximately 70) are analysed each year using age structured stock assessments. The quality of the stock assessments varies for a number of reasons, including unreliable commercial catch data, particularly since the 1990s due to misreporting, uncertain stock identity, conflicting trends in catch-per-unit-of-effort (CPUE) series and/or an absence of corroborative data from fishery independent surveys and insufficient catch-at-age data.
ICES has implemented the Precautionary Approach by defining limit reference points in terms of spawning biomass (SSB) and fishing mortality (F) for the majority of the stocks it provides advice on. There should be a high probability that limit reference points are not reached and therefore management action must be taken before the thresholds are approached. The point where management action is necessary is related to how precisely the reference points and the current stock status are estimated but also to the risk that fishery management agencies are willing to accept. ICES has suggested fishing mortality (Fpa) and biomass proposed action (Bpa) reference points, where action is needed in order to avoid reaching the limit reference points. These have been used to define safe biological limits that are more restrictive than previously: before, it was sufficient for SSB to be above a minimum biologically allowable level (MBAL), now it is also necessary that F be less than a pre-agreed value.
The status of the main resources and stocks is summarized below, based on reports of the ICES Advisory Committee on Fisheries Management in 2002 (ICES, 2002).
Northeast Arctic fisheries (ICES Sub-areas I and II)
Since 1997, assessments of Northeast Arctic cod have consistently indicated that the stock was smaller than estimated in previous assessments. Fishing mortality is estimated to have increased considerably compared to the late 1980s and early 1990s when stringent management measures had been implemented. The large change in the perception of the stock between the 1996 and the 1997 stock assessment provides a striking example of the difficulties of estimating stock size while the steep increase in F demonstrates the ability for fishing mortality to increase quickly in situation of excess fishing capacity. The stock is currently considered to be overexploited and outside safe biological limits, because F is substantially above the fishing mortality where ICES proposed action should be taken (proposed Fpa = 0.42) to avoid Flim.
ICES summarizes the status of stocks in this area as follows: “the stocks of cod and Sebastes mentella are outside safe biological limits, haddock is harvested outside safe biological limits, while saithe is within safe biological limits. The status of the Greenland halibut stock is not precisely known. SSB shows signs of improvement but is still among the lowest in the time-series, and recruitment in recent years is also estimated to be well below the historic average. The available information on Sebastes marinus is insufficient to assess the stock properly, but there are strong signs in the surveys of reduced recruitment, and both the coastal survey and commercial CPUE indicate a decrease for larger fish. The capelin stock is within safe biological limits although the recent stock increase has culminated and the stock has decreased slightly in the last year. Norwegian spring-spawning herring is harvested at or slightly above safe biological limits. The spawning stock is declining, but is still considered to be within safe biological limits.”
Figure B2.6 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 31, 33, 34 & 45, Northeast Atlantic (Area 27)
Source FAO
The Baltic (ICES Divisions IIIb-d)
The conditions for marine fish populations in the Baltic are highly dependent on inflows of saline and oxygenated water from the North Sea. These inflows are irregular, infrequent and vary in strength. Large inflows occurred in 1970, 1974, 1976 and 1979, with a prolonged stagnant period throughout the 1980s before a medium sized inflow in 1993. Since 1993, there have been no major influx.
Recruitment to the Eastern Baltic cod stock is poor during stagnant periods because the cod sperm cannot survive in low salinity, poorly oxygenated water. The strong year classes associated with good environmental conditions in the late 1970s led to SSB peaking in the early 1980s at close to 700 000t before declining steadily to about 100 000t in 1992, the lowest in the series that begins in 1966. Agreed total allowable catches (TACs), first set in 1989, have consistently exceeded those advised by ICES and have in turn consistently been exceeded by reported catches during 1989–1994, although since 1995, the estimated landing are less than both the agreed TAC and the ICES advice. Both cod stocks in the Baltic (Eastern and South-western) are considered outside safe biological limits. The cod stock in the Kattegat is presently considered to be overexploited and outside safe biological limits. Sprat (Sprattus sprattus) is considered within safe biological limits.
Table B2.1 Stocks status and management areas
Herring Unit | Proposed Management area | Status |
Herring in Subdivisions 22 & 24 | South-western Baltic, Subdivisions 22, 23, 24 | Biomass relatively stable, but fishing mortality too high |
Central Baltic Herring | Subdivisions 25, 26, 27, 28, 29 and 32 (excl. Gulf of Riga) | Stock size uncertain, fishing mortality too high |
Gulf of Riga herring | Gulf of Riga (part of Subdivision 28) | Within safe biological limits |
Herring in Subdivision 30 | Bothnian Sea (Subdivision 30) | Biomass relatively high, but fishing mortality too high |
Herring in Subdivision 31 | Bothnian Bay (Subdivision 31) | Stock size considerably lower than in the 1980s |
ICES revised its definition of the stock structure of herring in the Baltic in 2002. Table B2.-1 provides the stock structure and the proposed management area, along with the status of the stocks.
The North Sea (ICES Sub-area IV), Skagerrak (Divisions IIIa) and Eastern Channel (VIId respectively)
The cod stock assessment now includes the Skagerrak and Eastern Channel stocks in addition to the North Sea stock. The combined stock is considered to be outside safe biological limits. ICES recommended “closure of all fisheries for cod as a targeted species or by-catch. In fisheries where cod comprises solely an incidental catch there should be stringent restrictions on the catch and discard rates of cod, with effective monitoring of compliance with those restrictions. ” (ICES, 2002).
Haddock and whiting are presenting opposite situation: for haddock the biomass is relatively high, but fishing mortality is excessive. For whiting, the biomass is low, but fishing mortality is also low. In both cases, ICES recommended no fishing in order to protect cod. In the revised stock definition, saithe is considered within safe biological limits.
North Sea plaice (Pleuronectes platessa ) and sole (Solea solea) are the major components of the mixed flatfish fishery. With the exception of four outstanding year classes (1963, 1981, 1986 and 1996), North Sea plaice recruitment has been remarkably stable since 1956. However, fishing mortality increased steadily from the beginning of the time series. The stock is considered to be outside safe biological limits. The very strong year classes in 1987 and 1991 of North Sea sole did not result in sustained increases in SSB because fishing mortality was too high. The stock is also considered to be outside safe biological limits.
The main stocks of sandeels and Norway pout (Trisopterus esmarkii) targeted by the small-mesh fishery are considered fully harvested or fully exploited and within safe biological limits.
The European Union (EU) and Norway have agreed reference points for fishing mortality and SSB for North Sea herring in order to have a high probability of maintaining the SSB above 800 000t (Blim) because below that biomass, recruitment seems to be impaired. Thanks to swift management response to mid-year advice in 1996, the status of the North Sea herring stocks has improved and the stock is now considered within safe biological limits. SSB has increased gradually since the low stock size in the mid 1990s in response to reduced catches, strong recruitment and management measures that reduced exploitation both on juveniles and adults.
Iceland (ICES Divisions Va), the Faeroe Islands (Vb), the Irminger Sea/Greenland (Sub-areas XII and XI)
The fishery in the Faeroe area is multi-fleet and multi-species. A quota-based management system was imposed in 1994 but it led to substantial increases in discarding and misreporting, and a new management system based on individual transferable (within same-gear categories) fishing days started in June 1996. As a result of the combined effect of poor recruitment in the last decade and high fishing effort, the SSBs of Faroe Plateau cod and Faroe haddock decreased markedly. During 1993–1995 ICES considered them to be outside safe biological limits and advised no fishing. Both stocks have since increased due to improved recruitment and growth with SSB above Bpa but with fishing mortality on both estimated to be above Fpa since 1996. The Faroe Bank cod stock seems to be at or slightly above average. The SSB of Faroe saithe has been increasing from the record low in 1992 to above the Bpa in 1998–2001, but the fishing mortality is above Fpa.
Icelandic demersal fisheries (excluding oceanic redfish) have been managed by an individual transferable quota (ITQ) system since 1984. SSB estimates of the Icelandic cod decreased from 1.4 million tonnes in 1955 to about 400 000t in 1966. Except for two brief periods of increased biomass because of strong year classes, the SSB has subsequently followed a downward trend to less than 200 000t in 1988. The cod stock showed some biomass increase due to better recruitment (1997–2000 year classes) after a long period of poorer recruitment. The Icelandic saithe stock is considered to be outside safe biological limits while Icelandic haddock has been exploited at a very high fishing mortality for more than ten years. Haddock biomass has been increasing in recent years. Several strong year classes have entered or are expected to enter the fishery.
The offshore cod stocks around Greenland remain severely depleted since the 1990s, ICES recommends that no fishing should take place and that recovery plans be developed for both the inshore and the offshore components which are considered depleted.
The other main demersal resources in the Northwestern area are Greenland halibut and redfish. The Greenland halibut is considered to be harvested outside safe biological limits (i.e. fishing mortality is above Fpa), but there are indications that fishing mortality may have decreased and biomass increased in recent years. The redfish resource is made up of two species, Sebastes marinus and S.mentella, with S.marinus supporting a shelf fishery down to 500 m while S. mentella supports both a pelagic oceanic fishery (0 to 500 m) and a deep-sea fishery in the Irminger Sea (below 500 m). The ranges of the three stocks differ, and different fisheries exist on different parts of the ranges. The catches of oceanic S. mentella in ICES Sub-areas XII and XIV are almost all taken in international waters, although the same stock is found, at least at certain times, within the EEZs of Greenland and Iceland. S. marinus is considered to be outside safe biological limits. The status of the complex of deep-sea and oceanic S. mentella is uncertain and its stock structure is not fully understood. ICES advised that the TACs should not exceed recent catches.
Fishing mortality has decreased steadily since 1988 for Iceland summer-spawning herring and SSB is currently amongst the highest observed historically since 1949. Following the collapse of the stock in 1968 a ban on fishing was enforced from 1972 to 1975 and the SSB has increased nearly continuously since 1971. Recruitment has also been increasing and the stock is healthy. The stock is considered fully exploited and within safe biological limits. Good recruitment has lead the capelin stock to recover very quickly from the unsafe low of 1990 to a record high in 1995, it returned to average in 1996 and 1997, and increased again in 1998–99. ICES recommended that areas of high juvenile abundance be closed to commercial fishery. The stock is considered fully exploited.
The West of Scotland and Rockall (ICES Divisions VIa-b) the Irish and Celtic Seas (VIIa-c and VII e-k), and the Bay of Biscay (VIIIa-b)
The cod stocks of the West of Scotland, Irish Sea and Celtic Sea are all considered to be overexploited and outside safe biological limits to varying degrees, and ICES advises reductions in fishing mortality of 60 percent for the Celtic Sea fishery and closures for the Irish Sea and West of Scotland. There is no information on the status of Rockall cod and recent catches are considered unreliable due to misreporting. The saithe stock for West of Scotland is now included with the North Sea and Skagerrak.
Irish Sea plaice is considered to be fully exploited, within safe biological limits and F should not be increased. Irish Sea sole is considered to be within safe biological limits. The Celtic Sea plaice is considered to be outside safe biological limits and a 40 percent reduction if fishing mortality is advised. For sole fishing mortality should be reduced below Fpa, but the biomass is above Bpa.
Iberian Region (ICES Division VIIIc and Sub-areas IX and X)
Hake (Merluccius merluccius) is the major demersal resource of the Iberian region, together with anglerfish (Lophius spp.) and megrim (Lepidorhombus spp.). The SSB of southern hake decreased steadily from 1982 to 1997. It is estimated to have increased slightly since. The SSB of the larger stock of northern hake (found from the Bay of Biscay to the Celtic, Irish and North Seas) has decreased more gradually from 1978 to 1990, and it has remained relatively stable since. Both stocks are considered overexploited and ICES advised a recovery plan for the northern stock and a fishing mortality as close to zero as possible for the southern stock. The status of both species of megrim is unknown in relation to reference points, but fishing mortality should not be allowed to increase. The combined stocks of anglerfish (Lophius piscatorius and L. budegassa ), are outside safe biological limits with ICES advising a 5 percent reduction in fishing mortality. The Southern horse mackerel (Trachurus trachurus ) stock appears to have been stable over the last 20 year, the status of sardine (Sardina pilchardus) SSB is unknown because different assessment methods provide different absolute biomass, but biomass appears to have been increasing since 2000. Anchovy (Engraulis encrasicolus) is inside safe biological limits.
North Atlantic and Baltic salmon stocks
There are over 1500 salmon (Salmo salar ) rivers in the North Atlantic Salmon Conservation Organization's (NASCO) Northeast Atlantic Commission (NEAC) Area. Monitored rivers suggest that there is no significant trend in smolt production in the Northeast Atlantic as a whole. Northern European (Scandinavia and Russia) 1 sea-winter (1SW) and multi-sea-winter (MSW) stocks are considered to be fully exploited and within but close to safe biological limits. Southern European (Ireland, UK and France) 1SW stocks are considered to be fully to overexploited when considered as a stock complex. Southern European MSW stocks are considered to be overexploited and to be outside or close to safe biological limits.
ICES 2002 summarizes the status of Baltic salmon as follows: “There are 04–50 rivers in the Baltic Sea with wild salmon smolt production. Many rivers have been dammed and spawning and nursery areas have been completely or partially destroyed. To compensate, hatcheries have been built on these rivers where fish are reared to the smolt stage before release. These fish feed in the sea mainly in the Baltic Main Basin and migrate back to rivers as spawners, where they are used as broodstock to a varying extent. In some rivers with compensatory releases, some homing salmon succeed to reproduce so that there is small amount of natural reproduction. A major part of wild and reared smolt production takes place in the Gulf of Bothnia.” The International Baltic Sea Fisheries Commission has the objective of increasing the production of wild Baltic salmon to 50 percent of the natural production capacity by 2010.
Widely distributed, deepwater and migratory stocks
Blue whiting are caught from the Barents Sea to the Straits of Gibraltar. Reported catches in 2001 were almost 1.8 million tonnes, the highest ever recorded, while in 2002 catches were close to 1.6 million tonnes. Mackerel, now assessed as a single stock for the Northeast Atlantic, is considered to be inside safe biological limits but F should be decreased to below Fpa. The development of the fishery exploiting western horse mackerel has been supported by an extraordinary strong year class produced in 1982. The stock is considered to be inside safe biological limits.
Deepwater species such as the argentine (Argentina sphyraena) or greater silver smelt (Glossanodon leioglossus ), roundnose grenadier (Coryphaenoides rupestris) and Atlantic orange roughy (Hoplostethus atlanticus ), along with more than 20 other species of bony fish and more than 10 species of sharks, are now caught in deepwater fisheries. The long life-span and associated low growth rate of most of these species means that catches can be sustained for a number of years as the stocks are “mined” before suddenly collapsing. ICES has advised a precautionary approach where effort is kept as low as possible until the response of these species to fishing is better understood. A first step in gaining such an understanding is reporting catches by species. ICES notes that species/stocks in its area have been depleted before appropriate management measures could be implemented.
Environmental issues
The previous issue of this Review (FAO, 1997) stated that: “Trawling with heavy gears is thought to have a major impact on the sea bottom, altering and degrading marine habitats and possibly causing loss of species diversity. Demonstrating statistically significant causal links between sea bottom degradation and fish production will be difficult, even if such links may exist, but a comprehensive impact assessment has not been carried out.” A search of the 1978–1999 Aquatic Sciences and Fisheries Abstracts (ASFA) database using the keywords TRAWLING and BOTTOM and IMPACT yielded 73 references. Of those, 29 were not relevant, dealing with exploratory fishing, mesh size studies, or the effect of salinity and oxygen concentration on the success of cod spawning. Of the 44 remaining references, 4 were personal accounts and experiences which although undeniably valuable cannot be scientifically evaluated. Of the 40 references that might be scientifically evaluated, 34 identified an effect. Of the 34 references (some reported the same study) that identified effects, 12 were negative, two were positive impacts such as increased snow crab abundance, and the remaining 20 were non-committal on the sign of the impact.
Jones’ (1992) abstract probably provides the most accurate description of the situation: “Research has established that the degree of environmental perturbation from bottom trawling activities is related to the weight of the gear on the seabed, the towing speed, the nature of the bottom sediments, and the strength of the tides and currents. The greater the frequency of gear impact on an area, the greater the likelihood of permanent change. In deeper water where the fauna is less adapted to changes in sediment regimes and disturbance from storm events, the effects of gear take longer to disappear. Studies indicate that in deepwater (>1 000m), the recovery time is probably measured in decades.” The situation is undoubtedly complex and will continue to generate debate for years to come. An expert consultation on the Precautionary Approach convened by the FAO and Sweden in 1995 states “Different fishery technologies will have different effects on the ecosystem, the social structure of fishing communities, the safety of fishery workers and the ease, effectiveness and efficiency of management of the fishery. It is the amount and context in which fishery technology is used (e.g. when, where and by whom) that influences whether the objectives of fishery management are reached, and not the technology” (FAO, 1996).
Concern has been expressed over possible damage to the spawning grounds of Celtic Sea herring caused by gravel extraction along the Irish coast. Other environmental concerns arise out of the growth of mariculture and sea ranching of Atlantic salmon and the potential negative impacts on the genetic make-up of wild populations.
Management issues
The majority of the commercial fish resources of the Northeast Atlantic are either fully exploited, overexploited, or depleted despite substantial human and financial investments in fishery management, including science, monitoring, control and surveillance. As indicated earlier, scientifically based fishery management originated in the Northeast Atlantic, and arguably the current fishery management processes are amongst the most elaborate, involving the provision of scientific advice and the establishment of Total Allowable Catches (TACs) on a yearly basis for most species/stocks. The process also includes extensive discussions and consultations with interested parties. Despite this elaborate process, the situation of the stocks in the NE Atlantic cannot be described as better than in the Mediterranean, where the fishery management processes are considerably less elaborate, and often considered lacking (in non-Mediterranean fisheries circles). Possible explanations for the absence of substantial differences between the two areas could be that in the Northeast Atlantic fishery management has not been properly implemented, that scientific assessments have not been sufficiently reliable, that decision makers have set TACs above the advice, that fishers have caught more than the TAC (either through under reporting or misreporting of their catches), and that enforcement of the regulations and of the TACs has been ineffectual.
REFERENCES
Dickson, R.R., Meincke, J., Malmberg, S.-A., & Lee, A.J. 1988. The “Great Salinity Anomaly” in the northern North Atlantic, 1968–1982. Prog. Oceanogr., 20: 103–151.
Dickson, R.R. & Brander, K.M. 1994. Effects of a changing windfield on cod stocks of the North Atlantic (an extended abstract). ICES mar. Sci. Symp., 198: 271–279.
FAO. 1996. Precautionary approach to capture fisheries and species introductions. Elaborated by the Technical Consultation on the Precautionary Approach to Capture Fisheries (Including Species Introductions). FAO Technical Guidelines for Responsible Fisheries, No. 2: 54p.
FAO. 1997. Review of the state of world fishery resources: marine fisheries. FAO Fisheries Circular, No. 920: 173p.
ICES. 2002. Report of the ICES Advisory Committee on Fishery Management, 2002. URL: http://www.ices.dk/committe/acfm/comwork/report/asp/acfmrep.asp
Jones, J.B. 1992. Environmental impact of trawling on the seabed: A review. N. Z. J. Mar. Freshwat.-Res., 26 (1): 59–67.
* FAO consultant, Marine Resources Service, Fishery Resources Division
by Kevern Cochrane *
INTRODUCTION
The area under the competence of the Western Central Atlantic Fisheries Commission (WECAFC) extends from Cape Hatteras in North Carolina, United States (35°N), to just south of Cape Recife in Brazil (10°S). It includes an area of nearly 15 million km2of which approximately 1.9 million km2is shelf area (Stevenson, 1981). The major subdivisions in the area are the Southeast coast of the United States, the Gulf of Mexico, the Caribbean Sea and the Northeast coast of South America which includes the Guianas and Brazil.
Figure B3.1 - The Western Central Atlantic (Area 31)
The WECAFC area includes FAO Statistical Area 31 and a portion of Area 41 occurring offshore of northern Brazil. This chapter deals only with Area 31 (Figure B3.1 and Table B3.1). The region is geographically one of the most complex regions of the world, and is split up into a number of deep ocean basins separated by shallow zones, and a large number of island platforms, offshore banks and the continental shelf. The major island groups in Area 31 are the Bahamas and adjacent banks and islands, which account for over half of the islands and banks shelf area, the Greater Antilles (Cuba, Puerto Rico, the Virgin Islands, and Hispaniola), and the Lesser Antilles (Stevenson, 1981).
Table B3.1 Locality and area of the major coastal shelf zones in the WECAF area (Stevenson, 1981).
LOCATION | AREA ('000 km2) | FAO Area | |
Continental Shelf | |||
U.S. east coast | 110 | 31 | |
Gulf of Mexico | 600 | 31 | |
Yucatan - Eastern Venezuela | 250 | 31 | |
Guyana, Surinam, French Guiana | 200 | 31 | |
Northern Brazil | 360 | 41 | |
TOTAL Continental shelf | 1520 | ||
Islands | |||
Islands and offshore banks | 380 | 31 | |
GRAND TOTAL | 1900 |
Figure B3.2 - Annual nominal catches ('000t) by ISSCAAP species groups in the Western Central Atlantic (Area 31)
The Western Central Atlantic area is characterized by anti-cyclonic (i.e. clockwise) flow of currents. The North Equatorial Current flows westwards just north of the equator and meets with the Guiana current to form a western boundary current. Where this boundary current enters the Western Central Atlantic it splits into the Antilles and the Caribbean currents. The Antilles current flows northwards on the Atlantic Ocean side of the Antilles islands, eventually joining with the Florida Current. The remainder of the western boundary current flows through the eastern Caribbean, mainly between Barbados and Tobago, where it forms the “core” of the north and westward flowing Caribbean Current that eventually enters the Yucatan Channel. However, the Caribbean Current also includes significant meanders, filaments and eddies (Appeldoorn et al., 1987; Smith et al., 2002). The water entering the Caribbean then flows through the Yucatan Channel into the Gulf of Mexico where it becomes the loop current that flows clockwise through the Gulf, and through the Straits of Florida to become the Florida Current. The Florida Current and the Antilles Current combine to form the Gulf Stream, flowing northwards along the east coast of the United States of America and Canada (Stevenson, 1981; Smith et al., 2002). The pronounced overall movement of water from south east to north west through the Western Central Atlantic is probably very important for distribution of larvae, for example of the Caribbean spiny lobster, but the area is also marked by substantial variability, with counter currents, meanders and eddies. The region also comes under the influence of runoff from the major rivers discharging into the region: the Mississippi, Orinoco and Amazon Rivers, and of frequent hurricanes.
Figure B3.3 - Annual nominal catches ('000t) of selected species in ISSCAAP Groups 35, 39, Western Central Atlantic (Area 31)
Source FAO
The geographic complexity of the Western Central Atlantic results in equally complex bio-diversity, with at least 1172 species of invertebrates, fish and tetrapods occurring in the region. Of these, 987 are fish species and 23 percent of the fish species are “rare or endemic to the region”. The zones of highest diversity are the waters of southern Florida, eastern Bahamas and northern Cuba. The Caribbean probably has the highest species-richness in the Atlantic (Smith et al., 2002).
PROFILE OF CATCHES
Nominal catches from the region increased steadily from approximately 500 000t in 1950, to a peak of approximately 2.5 million tonnes in 1984. They subsequently declined but showed some increases in the early 1990s, with just under 2.0 million tonnes being landed in 1994 but have been stable at between 1.5 and 1.7 million tonnes since then (Figure B3.2 and Table D3). A worrying feature of records from the WECAFC region continues to be the poor identification of landings and, for example, Group 39 Marine fishes not identified accounted for nearly 163 000t of the total landings in 2002.
The ISSCAAP group making the largest contribution to catches continues to be Group 35 herrings, sardines, anchovies. This group is dominated by the Gulf menhaden (Brevoortia patronus) which occurs from the Yucatan Peninsula to Florida. Catches of the species increased irregularly from about 200 000t in 1950 to close to one million tonnes in 1984 but declined somewhat thereafter and have varied between just under 500 000t and 700 000t in recent years (Figure B3.3). There was also an important fishery for the other menhaden species, Atlantic menhaden (B.tyrannus ), with peak catches of 140 000t in 1981, but the fishery declined steeply in subsequent years to under 4 000t in 1984. Catches have been under 40 000t since 1992 (Figure B3.3).
Including the substantive contribution from Group 35, small pelagics accounted for the largest catches by mass. Fishes from seven families dominate small pelagics catches in the region. These are: Exocoetidae (flyingfish); Clupeidae (herrings and sardines); Engraulidae (anchovy and anchoveta); Carangidae (jacks, bumpers and scads); Hemiramphidae (halfbeaks); Belonidae (needlefish) and Mugilidae (mullet). The round sardinella (S. aurita) is an important small pelagic species and total catches of this species increased steeply from 59 000t in 1990 to almost 200 000t in 1998 (Figure B3.4), mostly recorded by Venezuela. Landings decreased substantially in 2000 and 2001, with catches just over 70 000t, but increased again to approximately 160 000t in 2002. Other small pelagic species occurring in ISSCAAP Groups 33 (Miscellaneous coastal fishes), and Group 35 (Herrings sardines anchovies) include the flathead grey mullet (Mugil cephalus ), unidentified mullets and the Atlantic thread herring (Opisthonema oglinum ), all of which have generated catches under 20 000t in recent years (Figure B3.4). Atlantic thread herring landings fell to 7 000t in 2001 and to 5 000t in 2002, less than half those of immediately preceding years. There has been a substantial increase in landings of the unidentified jacks and crevalles of the genus Caranx. Fished mainly by Mexico and Venezuela, catches of this group approximately doubled from the early 1980s to their 1997 and 1998 values of over 12 000t, although they have fallen to around 9 000t per year since then. The four-winged flyingfish (Hirundichthys affinis )supports locally important fisheries in some of the lesser Antilles islands, including Barbados, Grenada and Tobago. Catches of this species peaked at nearly 6 000t in 1988, but more typically fluctuate between 1 000 and 2 800t, as they have done throughout the 1990s and up to 2002. The common dolphinfish (Coryphaena hippurus )is another pelagic species important to the small island states. It is also landed by the United States and Mexico, and a directed fishery for the species has developed in Venezuela in recent years. Catches of common dolphinfish in the region doubled from 2 014t in 1984 to 4 629t in 1997 but varied between 3 200t and 3 900t over the next few years.
The ISSCAAP Group 33 - miscellaneous coastal fishes also makes an important contribution to the catches of the region (Figure B3.2). This group covers a wide diversity of species, of which the following contribute most to catches: sea catfishes (Ariidae ); groupers, seabasses etc. (Serranidae ), especially the groupers (Epinephelus spp.); grunts, sweetlips (Haemulidae ); snappers, jobfishes (Lutjanidae ), especially the unidentified snappers (Lutjanus spp.) and the yellowtail snapper (Ocyurus chrysurus ); croakers, drums (Sciaenidae ) especially the weakfishes(Cynoscion spp.) and the whitemouth croaker (Micropogonias furnieri ); the ponyfishes (Leiognathidae ); and the snooks (Centropomidae) especially the common snook (Centropomus undecimalis ). The catches made up by members of this group totalled 132 000t in 2002, somewhat lower than during most of the previous decade.
The miscellaneous coastal fish can be subdivided into two broad groups based on habitat: those occupying areas with soft substrata and those typically occurring over reefs. Amongst those occupying areas with soft substrata, unidentified sea catfishes accounted for the highest catches in recent years, showing a substantial increase from under 5 000t in 1988 to over 18 000t since 2000. (Figure B3.5). These species are recorded on the FAO database as being landed by mainland countries, especially Mexico and Venezuela. Unidentified weakfishes peaked at over 20 000t in 1995 but have also subsequently declined (Figure B3.5). Catches identified as spotted weakfish (Cynoscion nebulosus) totalled more than 6 000t in recent years, with the exception of 2001 when catches fell to 4 900t. The whitemouth croaker and common snook were also important contributors to catches of fish from soft-bottomed habitats. Landings of both these species have shown increases since 1950, with the whitemouth croaker generating catches of over 5 000t from 1991 to 1996, oscillating in the following years from 1 900t to 6 800t. The common snook has produced landings of between approximately 5 00 000t and just over 6 000t since 1995 (Figure B3.5).
Figure B3.4 - Annual nominal catches ('000t) of selected species in ISSCAAP Groups 33, 35, Western Central Atlantic (Area 31)
Source FAO
Figure B3.5 - Annual nominal catches ('000t) of selected soft-bottom species, Western Central Atlantic (Area 31)
Source FAO
Amongst the dominant reef fishes in catches, those of unidentified groupers increased markedly in the late 1970s and early 1980s, from under 10 000t, to above 20 000t. Since the peak in the late 1980s, they show a generally decreasing trend (Figure B3.6). Catches of red grouper (Epinephelus morio) fell from a peak of over 12 000t in 1980 to 86t in 2002, while those of Nassau grouper (E. striatus) have fallen from 3 200t in 1967 to well under 500t in recent years. However, at the second meeting of the WECAFC Scientific Advisory Group held in Martinique in April 2003, a member from Mexico quoted from Monroy et al . (2001) that landings of red grouper in Mexico had totalled 8 197t in 2001. These landings had presumably not been reported to FAO under that taxonomic group. The trend in red grouper landings shown in Figure B3.6 would therefore be very misleading as an indicator of the abundance of the species. Catches of the unidentified snappers and jobfishes have shown a substantial increase from under 2 500t in 1950 to more than 25 000t in 1994 although they have declined since then. Catches of northern red snapper (Lutjanus campechanus) and lane snapper (L. synagris) remained relatively constant in the 1970s and 1980s but, after reaching peaks in the early 1990s, showed steady declines from then to 2002, the most recent figures available.
Figure B3.6 - Annual nominal catches ('000t) of Selected Reef species, Western Central Atlantic (Area 31)
Source FAO
Figure B3.7 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 36, Western Central Atlantic (Area 31)
Source FAO
There are also important fisheries for snapper on the Brazil-Guianas shelf, targeting particularly the southern red snapper (L. purpureus) but also lane snapper and the Vermillion snapper (Rhomboplites aurorubens ). Several of the countries of the Brazil-Guianas shelf have local and foreign fleets fishing for snapper in their waters and Venezuelan vessels are particularly active, fishing legally in the EEZs of most countries in the area. Venezuela has reported that between about 3 500 and 5 000t of southern red snapper are landed annually in Venezuela, with over 50 percent caught in foreign waters (FAO, 1999a).
The catches of ISSCAAP Group 36 tunas, bonitos, and billfishes have increased over the last three decades and catches during the 1990s averaged 87 000t, compared to averages of 80 000t in the 1980s and 52 000t in the 1970s. Catches reached 104 000t in 2001, the highest on record, and decreased in the following year to 84 000t. For management purposes, this group is divided into two sub-groups, the oceanic species whose distribution extends beyond the WECAFC region and can be trans-oceanic, and the coastal large pelagics whose distribution is largely confined to the WECAFC region. Amongst the oceanic species, by far the largest catches are for yellowfin tuna (Thunnus albacares ), whose catches increased steeply in the early 1980s, as a result of increasing fishing effort mainly by fleets from within the region. Nearly 30 000t of the species was landed in 2001, compared to about a half of this amount or less for the other major species (Figure B3.7). However in 2002 yellowfin tuna catches fell to just over 18 000t.
The coastal large pelagic catches were dominated by four species of Scomberomorus . In 2002, the recorded landings of these four were: king mackerel (S. cavalla ) 12 131t; Atlantic Spanish mackerel (S. maculatus) 7 361t; Serra Spanish mackerel (S. brasiliensis) 5 250t; and Cero (S. regalis) with 147t in 2001 but no catches recorded in 2002. Catches of Atlantic Spanish mackerel decreased in recent years from a peak in the early 1990s (Figure B3.8).
Sharks (ISCAAP Group 38 - sharks, rays, chimaeras) have attracted considerable attention in recent years, as concerns have been raised about their over-exploitation. Within the WECAFC region, catches of chondrichthyans have escalated spectacularly since 1950, reaching a peak of 37 000t in 1994, but have fallen since then with some oscillation to nearly 25 000t in 2002 (Figure B3.9). The major contributors to the landings in 2002 were: sharks, rays, skates etc nei; requiem sharks nei; and rays, stingrays, mantas etc.; with much smaller landings of shortfin mako, silky shark, smoothhounds nei, nurse sharks, blue sharks and dogfish sharks nei. The dominance of landings in only broadly identified taxonomic categories demonstrates the poor quality of much of the data submitted to FAO from the region. The fact that so little information is available on the species composition of the landings reinforces the need for improved and careful monitoring.
A report by Yegres et al., (1996) on the shark fishery in Venezuela, operating beyond the EEZ of that country in both the Caribbean Sea and the Atlantic Ocean in the south western reaches of the WECAFC area, listed 31 shark species as being caught. The most common, by number, in the industrial fleet included blue shark (Prionace glauca - 36 percent), reef shark (Carcharhinus springeri - 14 percent), and shortfin mako (Isurus oxyrinchus - 12 percent), and in the artisanal fleet, Caribbean sharpnose shark (Rhizoprionodon porosus - 21 percent), scalloped hammerhead (Sphyrna lewini - 14 percent) and smalleye hammerhead (S. tudes - 12 percent). Bonfil (1997) reported that 34 species of shark occur in the Mexican waters of the Gulf of Mexico, of which 14 are important in fisheries and nine of these he described as being of “prime importance”. Of the nine most important, five were Carcharhinus and two Sphyrna species.
Figure B3.8 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 36, Western Central Atlantic (Area 31)
Source FAO
Figure B3.9 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 38, Western Central Atlantic (Area 31)
Source FAO
Some of the most valuable fisheries in the Western Central Atlantic are crustacean fisheries, in particular that for Caribbean spiny lobster (Panulirus argus) and those for a number of shrimp species, particularly penaeid shrimps (Figure B3.10). Landings of spiny lobster in Area 31 (i.e. excluding those from Brazil) reached a peak of 31 000t in 2000 but fell to 25 000t in 2001 and recovered somewhat to 29 000t in 2002. Landings of this species have a high monetary value per unit mass, and the resource is therefore one of the most valuable in the region. Recorded catches of unidentified penaeid shrimps were 48 000t in 2002, varying without meaningful trend, between approximately 40 000t and 58 000t since the mid-1970s. The most productive shrimp species is the northern brown shrimp (Farfantepenaeus aztecus ), with 2002 catches of 57 000t, followed by the Northern white shrimp (Litopenaeus setiferus) with catches of 43 000t in the same year. The genus structure of the penaeid shrimps was recently revised by Pèrez Farfante and Kensley (referred to in Carpenter, 2002). This new system is applied here. Previously the species within these new genera would have been included in the genus Penaeus . One shrimp species where catches have increased in recent years is that for the Atlantic seabob (Xiphopenaeus kroyeri ). Catches were only approximately 5 000t in 1990 but reached over 32 000t in 2001 and declined to 26 000t in 2002.
Figure B3.10 - Annual nominal catches ('000t) of selected species in ISSCAAP Groups 43, 45, Western Central Atlantic (Area 31)
Source FAO
Figure B3.11 - Annual nominal catches ('000t) of Common octopus and Stromboid conchs, Western Central Atlantic (Area 31)
Source FAO
Amongst the molluscs, the highest catches (given in total weight, including shell) in recent years have been of American cupped oyster (Crassostrea virginica ), which varied during the 1990s from less than 59 000t (1991) to a peak of 195 000t in 2000, and ark clams (Arca spp) of which over 45 000t were landed in 2002. Catches of calico scallop (Argopecten gibbus) have been highly variable, peaking at nearly 400 000t total weight in 1984, but with no landings recorded in 1991–1993 and again since 1996.
Substantial increases have been observed in recent years in the recorded landings of common octopus (Octopus vulgaris) and the stromboid conchs (Strombus spp). Catches of both have increased steadily since 1950 (Figure B3.11). Catches of common octopus were slightly over 8 500t in 1983 and subsequently climbed to an average of over 18 000t in the 1990s, with the highest recorded landings of over 28 000t in 1996. Landings of just over 16 000t were recorded in 2002. It was reported at the Second Meeting of the WECAFC Scientific Advisory Group that landings of octopus on the Atlantic coast of Mexico actually consisted of substantial contributions from both common octopus and a local endemic species the Mexican four-eyed octopus (Octopus maya). The increase in catches of stromboid conchs has also been marked. Catches in 1984 were over 13 000t but then fell to approximately 9 000t in 1987. Average annual catches during the 1990s were nearly 30 000t. The highest recorded landings of over 37 000t were registered in 1997. Catches have declined since then to 20 000t in 2002.
All species of Chelonidae, the sea turtles, have been listed on CITES Appendix 1 since 1977. Despite this, landings of the three species recorded on the FAO database for the WECAFC area (green, hawksbill, loggerhead) and those not identified, remained high until the late 1980s and, in fact, peaked at 1 600t in 1985. Thereafter, they declined rapidly, falling to only 31t in 1999, made up mainly of green and hawksbill turtles. The recorded catches in 2002 were 42t. Marine turtles have been harvested and utilized in the WECAFC region for a range of uses from subsistence to provision of luxury items (Fleming, 2001).
RESOURCE STATUS AND FISHERY MANAGEMENT
The capacity for fisheries management differs markedly between the different coastal states of the Western Central Atlantic. In some countries there are appropriate institutions, with fishing and fisheries being monitored and controlled in attempts to ensure sustainable utilization, while in others fisheries are largely unmanaged or managed only in a rudimentary manner. However, even amongst the most advanced fisheries management agencies in the region, there are problems in coping with the high species diversity, and from the region as a whole there is little information on the status of the important resources and even less on the hundreds of species of lesser importance to the region's fisheries. In its 2002 report to Congress (NMFS, 2002), the National Marine Fisheries Service of the United States (NMFS) recorded that of the 57 stocks falling under the jurisdiction of the Gulf of Mexico Fisheries Management Council (GMFMC), the status of 46 (81 percent) was either unknown or undefined. Of the 179 stocks falling under the jurisdiction of the United States Caribbean Fisheries Management Council (CFMC), the status of 175 (98 percent) was unknown or undefined. As stated in earlier reports, it is very unlikely that the state of knowledge is any higher than this in most other countries in the region.
Based on their stock sizes, neither of the two menhaden species, the Gulf and the Atlantic menhaden, are considered to be overfished (according to the USA Sustainable Fisheries Act, a stock is overfished when its size is below a prescribed biomass threshold, regardless of the cause(s), NMFS, 2002). Amongst the small pelagics, the only quantitative estimate of status available was for the round sardinella in Venezuela, based on virtual population analyses (VPA) by Mendoza et al . (1994). They estimated that the stock was lightly exploited at that time, but that may have changed with the increased annual catches showed in Figure B3.4. The high variability in recent years makes this difficult to evaluate. The status of the many other species of small pelagics is largely unknown. Amongst these are the carangids, with 15 genera and 31 species occurring in the region, again indicating the difficulties associated with assessment and management of the resources of the region. The general understanding of the stock status of small pelagics in the region is that they vary from under- to fully-exploited (FAO, 1998).
The groundfish species are dominated by ISSCAAP Group-33 miscellaneous coastal fishes. Of these, the Nassau grouper (Epinephelus striatus) and Goliath grouper (Jewfish, Epinephelus itajara ) are under rebuilding programmes for both the Gulf of Mexico and the Caribbean Fishery Management Councils. In the Gulf of Mexico, fishing mortality has been reduced below the desired threshold, but this is not reported for the stocks under the CFMC. The Red snapper (Lutjanus campechanus) and the Red drum (Sciaenops ocellatus )remain on rebuilding programmes for the Gulf of Mexico stocks, and reductions in fishing mortality are still being recommended or required for both of them. Fishing mortality for another two Gulf of Mexico stocks, Vermilion snapper (Rhomboplites aurorubens )and Gag grouper (Mycteroperca microlepis) is now considered to be above the minimum threshold biomass but a reduction in fishing mortality is recommended. The status of the Greater Amberjack (Seriola dumerili )in the Gulf of Mexico was estimated to be “not overfished”, but NMFS recommend that a rebuilding programme is required for the stock. The Red grouper (Epinephelus morio) is considered to be overfished and to be undergoing undesirably high fishing mortality. A rebuilding programme is under development for the stock. In the coastal waters of Mexico, Red grouper has been estimated to be overexploited (Arenas and Díaz de León, 1998). The status of the remaining reef fishes falling under the jurisdiction of both Management Councils of the USA was unknown.
The latest estimates of the status of the groundfish stocks of the Brazil-Guianas shelf remains those produced under the joint activities of the CARICOM Fisheries Resource Assessment and Management Programme (CFRAMP) and the FAO WECAFC ad hoc Working Group on the Shrimp and Groundfish Fishery of the Brazil-Guianas Shelf. The stocks which have undergone preliminary analyses are primarily soft-bottom dwellers and include some local stocks of whitemouth croaker (Micropogonias furnieri ), Jamaica weakfish (Cynoscion jamaicensis) and green weakfish (C.virescens ), smalleye croaker (Nebris microps ), and king weakfish (Macrodon ancylodon ). As a result of limited data, the results were only preliminary, but using yield and spawner biomass per-recruit reference points, there were indications that the stocks which were examined were being overexploited(FAO, 1999; 2000). A recent assessment of L.purpureus in French Guiana, showed indications of over-exploitation of the stock (Charuau, 2000).
Apart from these scientifically-based estimates, there is a general acceptance of the fact that the inshore reef and groundfish resources of the region are commonly fully exploited and some are overexploited (FAO, 1998). Mahon (1993) reported that “It is generally accepted that reef fish resources of the island platforms are extremely overexploited in most Lesser Antillean countries”.
Interest continues amongst some states of the region for expanding their fisheries for large pelagics, both oceanic and coastal, and in recent years fisheries for these stocks have increased considerably. The stocks being targeted by these expanding fisheries fall under the mandate of the International Commission for the Conservation of Atlantic Tunas (ICCAT), but assessments are only undertaken for the oceanic stocks within their mandate. Recent assessments available (ICCAT, 2002) indicate that yellowfin tuna, which is considered to consist of a single Atlantic stock, is fully-exploited and possibly overexploited. The ICCAT Standing Committee on Research and Statistics therefore recommended that fishing mortality on this stock should not be increased. Some fishing for bigeye tuna (Thunnus obesus ) occurs off the coast of Venezuela. The stock is considered to be overexploited and fishing mortality is above the MSY rate. The stock structure of skipjack tuna (Katsuwonus pelamis) is not well known, but it is treated as two management units, an eastern and a western unit. The most recent assessment for this stock was done in 1999 and ICCAT (2002) estimated the status of the western stock to be “stable”.
Several other large pelagic species fished in the western central Atlantic have also been assessed by ICCAT. The results of the 2002 assessments are: west stock of the Atlantic bluefin tuna (Thunnus thynnus) - overfished to a point where recruitment could be low because of low spawner stock biomass; Atlantic blue marlin (Makaira nigricans) - biomass estimated to be about 40 percent of BMSY and over-fishing is considered to have been taking place for the last 10 to 15 years; white marlin (Tetrapterus albidus) - the stock is considered to be severely overexploited and that over-fishing is continuing; western Atlantic sailfish (Istiophorus platypterus) - current catches are thought to be sustainable; and Northern Atlantic swordfish (Xiphias gladius) - status is considered to have improved in recent years and the biomass is estimated to be just below BMSYand the fishing mortality to be below the MSY rate.
Amongst the coastal species, the status of Serra Spanish mackerel and Cero is unknown. NMFS (2002) consider a Gulf of Mexico “group” of the king mackerel to be have been overfished but that, under a rebuilding programme, fishing mortality is now below the threshold. The Atlantic “group” is considered to be “not overfished”. Marcano et al . (1999) found no signs of overexploitation of King mackerel in their study on a fishery for the species in eastern Venezuela. Neither the Gulf nor the Atlantic “groups” of Atlantic Spanish mackerel are considered overfished by NMFS. Dolphinfish, which does not fall within the ICCAT mandate, is now considered to be a single stock throughout the Western Central Atlantic (Wingrove, 2000 and Prager, 2000, as reported in FAO, 2002a) and has been estimated to be well above BMSY and fishing mortality to be below the MSY rate.
The status of the stocks of sharks in the region is poorly understood, but there is concern due to their vulnerability to over-exploitation. Bonfil (1997) referred to some assessments undertaken on shark in Mexico, suggesting fishing mortalities ranging from approaching that yielding the maximum sustainable yield (FMSY) to above them. However, he stressed the preliminary nature of these assessments. He did draw attention to the concentration of fishing effort on juvenile sharks in Mexico, which he suggested was one of the most important concerns in these fisheries. Many of the stocks of shark in Area 31 are likely to be widely distributed and hence to require regional and international co-operation for adequate fishery management.
The Caribbean spiny lobster is listed in Annex III of the Protocol Concerning Specially Protected Areas and Wildlife (the SPAW protocol) of the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region (the Cartagena Convention). For species listed on Annex III, contracting Parties to the SPAW protocol “shall adopt appropriate measures to ensure the protection and recovery of the species… and may regulate the use of such species in order to ensure and maintain their populations at the highest possible levels”. The status of the species was examined at two workshops held in 1997 and 1998, attended by scientists from all the major lobster producing nations in the region (FAO, 2001), and reviewed at subsequent workshops in 2000 and 2002. The results from these workshops indicated a resource that is being fully or overexploited throughout much of its range, although there were insufficient data from some areas to estimate the status reliably. The workshops concluded that in most countries there is an urgent need to control and in many cases to reduce the fishing effort in the lobster fisheries. As many countries have open access to their lobster fisheries, this may require implementing restricted entry systems into the fishery, ensuring that the resulting total effort is commensurate with the productivity of the resource, and the licensed fishers are able to obtain acceptable economic returns. In some areas, the size of the lobsters being caught was smaller than desirable and in these cases it was recommended that suitable minimum size restrictions should be implemented and enforced.
The other valuable crustacean fisheries in the region are those for shrimp, mainly penaeid shrimp, and also the Atlantic seabob. Stocks of brown, pink (Farfantepenaeus duorarum ), white (Litopenaeus setiferus )and royal red shrimp (Hymenopenaeus robustus )have been estimated by the GMFMC not to be overfished in that region, while the status of seabob (Xiphopenaeus kroyeri )is unknown. The CFRAMP/WECAFC workshops referred to above (FAO, 1999, 2000) have made some progress in assessing the status of important shrimp stocks in the Brazil-Guianas continental shelf, along the coastline of Venezuela, Trinidad and Tobago, Guyana, Surinam, French Guiana and the northern coast of Brazil. The results suggest that in most cases, the national stocks of southern white shrimp (L.schmitti ), southern pink shrimp (F.notialis ) and brown shrimp (F.subtilis) which have been assessed are not being biologically overexploited but were probably being fished above the economic optimum fishing effort. There are indications of high rates of fishing mortality on red spotted shrimp (F.brasiliensis ). However, in the Gulf of Paria that position is estimated to be reversed, with F. subtilis estimated to be overexploited in 2001, while F. brasiliensis is estimated to have been close to BMSYin 2001, indicating a fully-exploited stock (Ferreira, Trinidad and Tobago, pers. comm.).
Amongst the molluscs, the recent catches of Mexican four-eyed octopus (O. maya )have been estimated not to be sustainable (Arenas and Díaz de León, 1998). Another molluscan stock, the Queen conch (Strombus gigas ), is listed on CITES Appendix II which means that international trade in the species is controlled by the national CITES authorities, it is also listed on Annex III of the SPAW protocol of the Cartagena Convention.
At the Queen Conch Stock Assessment and Management Workshop held in Belize in March 1999, it was found that many countries did not have sufficient or suitable data to make reliable estimates of the current status of the stocks (CFMC and CFRAMP, 1999). In those cases where there were sufficient data, the estimated status varied from lightly to overexploited. NMFS (2002) reported that Queen conch is the subject of a rebuilding programme in the CFMC, but that fishing mortality is still too high in that management area and needs to be reduced.
An ecosystem approach to fisheries recognizes that fish resources are dependent on the ecosystems in which they occur. Within the WECAFC region, many ecosystems are undergoing adverse impacts from human activities, and damage to critical habitats is one such concern. Important habitats found in the Caribbean include coral reefs, seagrass beds, mangroves, coastal lagoons, sandy beaches and mud bottom environments. Coral reefs are a cause of widespread concern and are important habitats for many exploited fishery resources. The report Status of Coral Reefs of the World 2002 (GCRMN, 2002) reported that in the northern Caribbean and western Atlantic, coral reefs were continuing to decline although possibly at a slower rate than previously. The main causes of the decline include pollution, disease, overfishing, anchor damage and destructive fishing and tourism practices. In Central America, hurricanes in 2000, 2001 and 2002 caused extensive damage, destroying up to 75 percent of corals in parts of Belize. Intense fishing and overloading by nutrients and sediments from poor land-use are also causing damage. A major effort through a World Bank and Global Environment Facility (GEF) project is working for the conservation of the Mesoamerican Barrier Reef System. The Survey also reported that inshore reefs in the eastern Antilles are degraded while deeper reefs are in better condition. The causes of damage are similar to those for the northern Caribbean.
The Caribbean Environment Programme of the United Nations Environment Programme (UNEP, undated) reports that seagrass beds, mainly turtle grass Thalassia testudinum and manatee grass Syringodium filiforme, provide food for grazing species including some fish, turtles and sea urchins, shelter for many commercially important species such as snappers, grunts, lobsters and conch, and other ecosystem services. Mangroves are particularly important nursery areas for many commercially important marine species. Seagrass habitats are being damaged and reduced by human activities such as eutrophication and other forms of pollution, and poor land use practices leading to increased sediment transport and deposition from land to the sea. A major cause of damage to mangroves is physical clearance of forests for housing and tourism projects and for development of aquaculture sites. Suitable measures need to be taken to conserve these environments if the marine ecosystems of the region are to be conserved, and if their many benefits are to be used in a sustainable manner.
Once again, the most marked feature of the results and trends presented here is the very high uncertainty about the status of even the more important fisheries resources of the region. In general, greater uncertainty about the status of resources and the impact of fisheries on them requires more cautious management, with a resulting loss of potential benefits. In cases where there is little information, fisheries exploitation needs to proceed very cautiously and should be accompanied by concerted efforts to collect adequate, relevant data to enable the resources to be utilized responsibly. Unless urgent steps are taken to collect sufficient information on landings and effort to provide, at least, the minimum information necessary to ensure sustainable utilization, there is a high risk that landings will continue to decline, as this review shows many have already done. This will lead to further erosion of the social and economic benefits currently being derived from the region's marine resources. As so many of the resources are shared between two or more countries, close co-operation between countries at a variety of international levels will commonly be advantageous and often essential in securing this.
An essential first step for most countries of the region is improvements to the existing fishery monitoring and data collection programmes and systems. Different fisheries, ecosystems and species will require different approaches, and monitoring and assessment programmes will need to be designed to optimize the use of limited human and financial resources in order to obtain the most useful information. In a number of cases, it will be important to identify key species, reflecting social, economic or conservation objectives, and to ensure that they are carefully monitored and regularly assessed, including sub-regionally or regionally where the stocks are shared, so as to ensure that the appropriate management action is taken. Obvious examples of these include species such as the Caribbean spiny lobster, the commercially important shrimp species, the species important to fisheries for large pelagics, queen conch, and others. In addition, a useful approach in high diversity communities is to monitor selected indicator species for each major habitat type and taxonomic group, to provide an index of the status and trends in broader species groups and, collectively, on the ecological community as a whole.
Further to improving data collection and generation of information to guide management, consideration also needs to be given to implementing management measures and strategies that are less demanding of high quality and comprehensive data, and that are more robust to uncertainties in the available information. In accordance with the ecosystem approach to fisheries, these measures also need to take into account, and minimize where appropriate, negative impacts on non-target species and sensitive habitats. Management measures that, properly applied, can be relatively robust to uncertainty include strict management of fishing effort and fishing capacity, greater use of closed seasons and closed areas (including Marine Protected Areas, MPAs), and suitable gear restrictions aimed at minimizing bycatch of undesired species or size groups and other undesired ecosystem impacts. Fishing should also be prevented where species pass through particularly vulnerable life history stages, such as dense spawning aggregations. No single management measure or approach will adequately address all the conservation and utilization objectives of fisheries, and an effective management system will usually consist of a suite of complementary management measures that, typically, would include a combination of closed areas and/or seasons, gear and vessel restrictions, an appropriate limited entry system, and input (effort) or output (catch) controls. Adequate enforcement of these measures is, of course, essential.
These efforts may require additional financial commitments in several countries, and these additional financial resources are likely to be hard to find. Where commercial fisheries exist, cost-recovery may be an option. However, in considering the costs of effective management, attention also needs to be given to the severe social and economic consequences of the alternative to effective management, which is almost certain over-exploitation of resources, resulting in their depletion and the loss of the benefits being derived from them.
REFERENCES
Appeldoorn, R., Dennis, G.D. & Monterossa Lopez, O. 1987. Review of shared demersal resources of Puerto Rico and Lesser Antilles Region. In FAO Fisheries Report, No.383: 36–106.
Arenas, F.P. & Díaz de León, A. (eds.) 1998. Sustenabilidad y pesca responsable en México: evaluación y manejo 1997–1998. Secretaria de Medio Ambiente Recursos Naturales y Pesca, México.
Bonfil, R. 1997. Status of shark resources in the southern Gulf of Mexico and Caribbean: implications for management. Fish. Res., 29: 101–117.
Carpenter, K.E. (ed.) 2002. The Living Marine Resources of the Western Central Atlantic . Vol. 1: Introduction, molluscs, crustaceans, hagfishes, sharks, batoid fishes and chimaeras. FAO, Rome.
CFMC & CFRAMP. 2000. Report on the Queen Conch Stock
Assessment and Management Workshop. Belize City, Belize,
15–22 March 1999.
http://www.strombusgigas.com/reports.htm
(last accessed 21/08/2001).
Charuau, A. 2000. Assessment of Lutjanus purpureus in French Guiana. In Reports from the CFRAMP/FAO/FishCode stock assessment workshop on the shrimp and groundfish fisheries on the Guiana-Brazil shelf. Belem, Brazil, 25 May to 10 June 1999. FAO Fisheries Report, No. 628.
FAO. 1998. Report of the Seventh Session of the Working Party on the Assessment of Marine Fishery Resources. Belize City, Belize, 2–5 December 1997. FAO Fisheries Report, No. 576. 39 p.
FAO. 1999. National reports and selected assessment reports presented at the CFRAMP/FAO/DANIDA stock assessment workshop on the shrimp and groundfish fisheries on the Guiana-Brazil shelf. Port-of-Spain, Trinidad and Tobago, 7 to 18 April 1997. In FAO Fisheries Report, No. 600. Rome, FAO. 1999. 200p.
FAO. 2000a. Reports from the CFRAMP/FAO/FishCode stock assessment workshop on the shrimp and groundfish fisheries on the Guiana-Brazil shelf. Belem, Brazil, 25 May to 10 June 1999. FAO Fisheries Report, No.628. Rome, FAO. 2000. 206p.
FAO. 2001. Caribbean Spiny Lobster Stock Assessment and Management Workshops Belize, 21 April – 2 May 1997, Mérida, 1 June – 12 June 1998. FAO Fisheries Report, No. 619. Rome, FAO. 2001. 381 p.
FAO. 2002. Large pelagic fisheries in CARICOM countries. Assessment of the fisheries and options for management. Report of FAO TCP Project RLA/0070. FAO, Rome.
Fleming, E.H. 2001. Swimming Against the Tide: Recent Surveys of Exploitation, Trade and Management of Marine Turtles in the Northern Caribbean. TRAFFIC, North America, Washington. 185pp.
GCRMN. 2002. Status of coral reeefs of the world: 2002. Ed. C. Wilkinson. Australian Institute of Marine Science, Townsville.
ICCAT. 2002 Report of the Standing Committee on Research and Statistics (SCRS), Madrid, Spain - September 30 to October 4, 2002.
Mahon, R. 1993. Lesser Antilles. In Marine Fishery Resources of the Antilles. FAO Fisheries Technical Paper, No.326: 5–98.
Marcano, J.S., Lärez, A., Carrion, A. & Heredia, O. 1999. Pesquería de carite rey, Scomberomorus cavalla, por la flota artesanal cordelera del Estado Nueva Esparta, en el oriente de Venezuela y áreas adyacentes. Mem. Soc. Cien. Nat. La Salle, 58 (149).
Mendoza, J.J., Fréon, P. & Guzmán, R. 1994. VPA estimates of a fishing mortality and exploited biomass from Sardinella aurita catch-at-length data in eastern Venezuela. Naga, 17: 32–36.
Monroy, C., Gimenez, E., Burgos, R. & Moreno, V. 2001. Informe de investigaciones conjuntas Mexico-Cuba sobre mero (Epinephelus morio, Valenciennes 1828) en el Banco de Campeche. Ministerio de la Industria Pesquera, Cuba. 43 p.
NMFS. 2002. Towards rebuilding America's marine fisheries. Annual Report to Congress on the Status of U.S. Fisheries - 2001. NMFS, USA. 2002.
Smith, M.L., Carpenter, K.E. & Waller, R.W. 2002. An introduction to the oceanography, geology, biogeography, and fisheires of the tropical and subtropical Western Central Atlantic. In Carpenter, K.E. (ed.) 2002. The Living Marine Resources of the Western Central Atlantic . Vol. 1: Introduction, molluscs, crustaceans, hagfishes, sharks, batoid fishes and chimaeras. FAO, Rome.
Stevenson, D.K. 1981. A review of the marine resources of the WECAFC region. FAO Fisheries Technical Paper, No. 211. 134 pp.
UNEP. undated. The Caribbean Environment Programme. United nations Environment Programme, Kingston, Jamaica.
Yegres, H., Alio, J.J., Marcano, L.A. & Marcano, J.S. 1996. Biología y pesquería de tiburones en Venezuela. ICCAT Coll. Vol. Sci. Pap., 45(3): 309–315.
* FAO, Marine Resources Service, Fishery Resources Division
by Ana Maria Caramelo and Merete Tandstad *
INTRODUCTION
The Eastern Central Atlantic, off the West coast of Africa, from the Gibraltar Strait to the mouth of the Zaire river (Figure B4.1) covers a total of 14.2 million km2. The continental shelf is generally narrow, with only 0.65 million km2for the entire area. Area 34 encompasses temperate, tropical, and equatorial waters, lagoons anported from the area during the 1950–2002 period by a total of 22 coastal States and 47 distant water fishing nations.
The fisheries in the region are dominated by small pelagics, especially sardine (Sardina pilchardus) and other clupeids (ISSCAAP Group 35) that account for more than 52 percent of total nominal catches in 2002.
Figure B4.1 - The Eastern Central Atlantic (Area 34)
In the late 1980s, changes in Eastern Europe first resulted in the appearance of a number of new distant water fishing nations that started operating in the area. Subsequently, increased emphasis placed on market forces have resulted in a reduction of activities of some distant water fleets that were mainly targeting small pelagic fishes. During the last 5 years the fishing intensity by European Uniom fleets on small pelagics increased in the north western portion of the area.
Figure B4.2 - Annual nominal catches ('000t) by ISSCAAP species groups in the Eastern Central Atlantic (Area 34)
PROFILE OF CATCHES
The total nominal catches reported from area 34 increased almost 12 fold from about 300 000t in 1950 to close to 3.6 million tonnes in 1977. Since then, catches have oscillated in a relatively smooth fashion between 2.5 million tonnes in 1979 and 4.1 million tonnes in 1990 due to changes in markets, in distant water fleets fishing effort, and climate induced changes in stock productivity all affecting mostly ISSCAAP group 35 catches. Catches have remained relatively stable with an average of 3.6 million tonnes being landed since 1995 (Figure B4.2 and Table D4), and 3.4 million tonnes in 2002.
Figure B4.3 - Annual nominal catches ('000t) by Coastal states and Foreign fleets, Eastern Central Atlantic (Area 34)
Source FAO
Figure B4.4 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 35, Eastern Central Atlantic (Area 34)
Source FAO
Figure B4.5 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 37, Eastern Central Atlantic (Area 34)
Source FAO
The major contributor to catches in the area are the species of ISSCAAP Group 35 (herrings, sardines, anchovies, etc.) accounting for about half of the total (Figure B4.2). The landing of this group decreased slightly to 1.7 million tonnes in 2002 compared with 2.2 millions in 1990.
The coastal states steadily developed their national fisheries, increasing from 43 to 72 percent of total catches in the area between 1977 and 2002 (Figure B4.3). Distant water fishing fleets, mainly catching small pelagics and tunas, have made large but irregular contributions since the early 1970s.
Four species categories account for more than 80 percent of the catches in ISSCAAP Group 35 (herrings, sardines, anchovies, etc.): the European pilchard, also known as sardine (Sardina pilchardus) makes the largest contribution followed by other herrings, the round sardinella (Sardinella aurita ), and European anchovy (Engraulis encrasicolus) (Figure B4.4). Sardinella spp. also accounts for a sizeable portion of the area/group total.
Figure B4.5 shows catches of ISSCAAP Group 37 (Miscellaneous pelagic fishes). Trachurus spp. catches, the dominant species, increased sharply in the late 1960s, remained high through most of the 1970s, but declined through most of the 1980s and 1990s. Catches of Chub mackerel (Scomber japonicus) have two exceptional years in 1988–1989 followed by a collapse of the catches in 1993, a recovery in 1997 and fluctuations since.
The Senegalese hake (Merluccius senegalensis) has been the major contributor to ISSCAAP Group32 (cods, hakes, haddocks), with catches above 100 000t in the 1970s and relatively steady but much lower catches since then (Table D4).
The catches from ISSCAAP Group 36 (tunas, bonitos, billfishes, etc.) shown in Figure B4.6 show similar trends with time, reflecting the behaviour of the fleets and the influence of climatic events on resource productivity. Skipjack (Katsuwonus pelamis) has become the main contributor, generally surpassing yellowfin tuna (Thunnus albacares) from 1991 onwards. In 2002, yellowfin catches were slightly higher.
Figure B4.7 shows the main species catches in ISSCAAP Group 45 (shrimp, prawns, etc.). Southern pink shrimp (Penaeus notialis) catches started to become significant in the 1960s and have since increased with oscillations with a sharp peak, reaching 33 000t in 1999 with a value of 17 000t in 2002. The deepwater rose shrimp (Parapenaeus longirostris ) fishery started in 1972 and catches have been variable since then, with a high of 19 000t in 1978. In 1998 deepwater rose shrimp catches of 11 000t were reported from the region. Catches were 6 000t in 2000 and 3 000t in 2002.
The octopus (Octopus vulgaris) fishery from ISSCAAP Group 57 (Squids, cuttlefishes, octopuses) started in 1962 to reach 93 000t in 1975, but catches have since regularly decreased to reach 9 000t in 2002 (Figure B4.8). Catches of cuttlefish have fluctuated with an average of 44 000t from 1990 to 2001, but declined to 16 000t in 2002. Catches of other cephalopods nei show a general increase from 60 000t in 1992 to 152000 in 2001 followed by a sharp decline to 71 000t in 2002.
RESOURCES STATUS AND FISHERY MANAGEMENT
This review of the status of stocks is based on assessments undertaken by recent Working Groups on the evaluation of the major fisheries resources in the region and conclusions of the Eastern Central Atlantic Scientific Sub-Committee, (Lomé, Togo 24–26 February 2004) and the Fishery Committee for the Eastern Central Atlantic (CECAF), Dakar, Senegal 24–27May 2004. The status of many stocks was assessed during Working Groups held during 1998–2004.
Eighteen of the demersal stocks assessed were either fully exploited or overexploited. One of the stocks, Epinephelus aeneus, found mainly in Mauritania, Senegal and the Gambia, was assessed to be so overexploited that it was close to extinction. Sardinella aurita in the northern CECAF region is showing signs of overexploitation (FAO, 2004b).
A general conclusion is that as a precautionary measure, the present fishing effort should be maintained or even reduced for all demersal and pelagic species in the region and also toinclude shrimps
Figure B4.6 - Annual nominal catches ('000t) of selected species in ISSCAAP Group 36, Eastern Central Atlantic (Area 34)
Source FAO
Figure B4.7 - Annual nominal catches ('000t) selected species in ISSCAAP Group 45 Eastern Central Atlantic (Area 34)
Source FAO
Figure B4.8 - Annual nominal catches ('000t) selected species in ISSCAAP Group 57 Eastern Central Atlantic (Area 34)
Source FAO
Northern areas
In general most of the demersal resources off Northwest Africa are considered fully to overexploited (FAO, 2003c; FAO, 2004a, b).
Hakes (Merluccius spp.) on the Mauritania continental shelf have been considered fully exploited. Amongst the other finfish resources assessed, the stock of Epinephelus aeneus was found to be at particular risk, and immediate action is called for (FAO, 2003c).
Three stocks of common octopus (Octopus vulgaris) are caught by the Northwest African cephalopod fisheries, namely Dakhla, Cape Blanc and Senegambia stocks. Both the northern one, off Dahkla and the central one off Cape Blanc, are considered overexploited with recent catches around 50 000t for the Dahkla stock and 19 000t for the Cape Blanc stock. The state of the southern stock off Senegal and the Gambia is uncertain. Catches of this stock are lower than those of the two other (FAO, 2003c).
The exploitation of other species of cephalopods, such as squids (Loligo vulgaris) and cuttlefish (Sepia officinalis ), is less intense than that of octopus: their catches account for 30 percent of the cephalopods landed in 2002. Catches landings of octopus and associated by-catch species from the Northwest African cephalopod fisheries have shifted during recent years from Las Palmas, Canary Islands, to other ports in Northwest Africa. Management measures taken in Moroccan exclusive economic zone (EEZ) include a two month closed season and a reduction in the number of non-Moroccan vessels operating in the area.
The 2002 catches of deep-sea shrimp (Parapenaeus longirostris ) and shallow water shrimp (Penaeus notialis) in the North CECAF area are around 18 000t, and the stocks seem to be intensely exploited or even overexploited (FAO, 2003c).
In the Mauritania area, pink spiny lobster (Panulirus mauritanicus) stocks continue to be heavily exploited. Northern and southern stocks of green lobsters (Panulirus regius) are probably overexploited (FAO, 2003b). Stocks of deep-sea crab (Chaceon maritae ) seem to be heavily exploited.
The biomasses of the large stocks of small pelagic in the North CECAF region - sardine (Sardina pilchardus ), sardinella (Sardinella aurita and Sardinella maderensis ), chub mackerel (Scomber japonicus) and horse mackerel (Trachurus spp.) - are highly variable.
Acoustic surveys carried out off Northwest Africa in November–December during the period 1995–2002 showed that the school density of small pelagic (mainly sardinella, sardine excluded) was very high, particularly off Mauritania, with a biomass estimated at about 3.5 milliontonnes. In addition, the biomass estimated by acoustic surveys for mackerel, horse mackerel and other small pelagic in the area between Morocco and Senegal was around 2 million tonnes in the November–December cruises carried out during the period 1995–2002 (FAO, 2003a).
The sardine biomass estimated by acoustic methods in the region situated to the North of Cape Blanc showed an 80 percent decrease from 1996 to 1997. Sardine biomass in North of Cape Blanc and Mauritanian waters was estimated to range between 3 and 5 million tonnes during the periof 1986–1996. Since 1999, biomass in this region has gradually increased, being estimated at close to 4.5 million tonnes as of December 2002. The Spanish and USSR fleets ceased fishing in Moroccan waters after the Morocco-USSR and Morocco-EU fishing agreements were not renewed (1998). Overall, the exploitation rate is considered to have decreased as a result, but sardine is also exploited in Mauritanian waters (FAO, 2003a).
The combined catch of small pelagics in Northwest Africa should not be increased above the average of the last 5 years, excluding the sardine in Zone C (Sardina pilchardus ), (FAO 2004a). The different species groups of sardinella, horse mackerels and mackerels are intensively exploited (FAO, 2004a).
In the Cape Verde area, the most important fisheries are those for tunas, with mean estimated catch of 4 000t in the last 10 years. Spiny lobsters (Palinurus charlestoni) are now considered to be overexploited and a freeze in fishing effort has been recommended. In 2001 demersal catch was 21 percent of the total catch in the artisanal fishey. The estimated potentials for demersal are 3 000 to 5 000t and for small pelagic 4 500 to 6 500t (Carvalho, Morais and Nascimento, 1999).
Southern areas
The continental shelves of Guinea-Bissau, Guinea and Sierra Leone are characterized by coastal fish assemblages of croakers principally located in the nutrient-rich estuarine and inshore areas.
The exploitation rate applied to cuttlefish stocks in Guinea has been increasing since the 1990s and by 2001 with a catch of 5 800t the stocks were considered to be overexploited (FAO, 2003c).
Current annual production of southern pink shrimp in Guinea and Sierra Leone is around 2 000t. The species is considered moderatly exploited in Sierra Leone whereas in Guinea the species is considered overexploited (FAO, 2003c).
Marine resources of the Gulf of Guinea are mainly exploited by Côte d'Ivoire, Ghana, Togo, Benin, Nigeria, Cameroon and Equatorial Guinea, among others. Multi-species fisheries are common in the Gulf of Guinea. Small pelagic resources are exploited mainly by artisanal and semi-industrial purse-seine in Côte d'Ivoire, Ghana, Togo and Benin and exclusively by small-scale fisheries in Nigeria and Cameroon. Coastal demersal resources are composed of sciaenids (exploited by small-scale and semi-industrial fisheries in Nigeria, Benin, Togo and Cameroon), groupers and snappers (fished in Togo and Ghana with hook-and-lines in untrawlable areas), and sparids (Côte d'Ivoire and Ghana). The white shrimp resources off Nigeria and Cameroon are fished exclusively by artisanal fisheries while pink shrimp is exploited by trawlers of the semi-industrial fishery. Penaeid shrimps in Togo and Benin and in Côte d'Ivoire are caught in lagoon fisheries. The offshore demersal resources of Ghana and Côte d'Ivoire are made up of sparids along with the slope community, while the offshore demersal resources of Nigeria and Cameroon are primarily drift fish (Arioma spp.) and redfishes (Scorpaenidae).
Trawl surveys carried out on the Western Gulf of Guinea continental shelf by the RV Dr. Fridtjof Nansen have shown that between 1999 and 2001 the estimated biomass of demersal resources varied somewhat in the period from 17 500t to 39 500t. In the Gulf of Guinea, from Ivory Coast to Cameroon the potential of shrimps were estimated at 10 000t, and stocks were considered highly exploited (FAO, 1999).
Demersal resources were found to be either fully or overexploited (FAO, 2004a, b). Due to inconsistencies in the input data, the CECAF Demersal Working Group recommended that a precautionary approach, avoiding any increase in fishing effort, should be adopted for all the demersal species in the Gulf of Guinea (FAO, 2003c, 2004 a, b).
Small pelagic species (sardinellas, mackerels and anchovies) are important but unstable resources in the Western Gulf of Guinea shared by Côte d'Ivoire, Ghana, Togo, and Benin which further complicates the management of the fisheries exploiting them. Potentials of small pelagic in the west and central Gulf of Guinea have been estimated at 330 000t and seem to be fully exploited. Many countries have not developed appropriate database and research structures to evaluate the state of the stocks and their explotation
REFERENCES
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FAO. 1997. Rapport du Groupe the Travail ad hoc sur les Céphalopodes. Tenerife, 19–26 mai 1997. M. Lamboeuf ed. COPACE/PACE/ Ser., No.97/63. Rome, FAO. 1997. 103 pp.
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FAO. 2003c Report of the CECAF Working Group on the assessment of demersal resources. Conakry, Guinea, 19–29 September 2003. In press.
FAO. 2004a. Fishery Committee for the Eastern Central Atlantic - Report of the third session of the Scientific Sub-Committee. Lomé, Togo 24–26 February 2004. FAO Fisheries Report/FAO Rapport sur les pêches, No. 750. Accra, FAO. 2004. 35 p.
FAO. 2004b. Report of the Seventeenth Session of the Fishery Committee for the Eastern Central Atlantic. Dakar, Senegal 24–27 May 2004. FAO Fisheries Report/FAO Rapport sur les pêches, No. 754: 57 p.
* FAO, Marine Resources Service, Fishery Resources Division