22  MANAGEMENT OF SHARK FISHERIES OFF THE WEST COAST OF THE USA
D.L. Hanson

10149 SW Erie St., Tualatin
Oregon 97062, USA

1.  INTRODUCTION

The shark fisheries of the West Coast of the United States of America (USA) are limited in scope and area. Major directed fisheries are prosecuted for only two species, spiny dogfish (Squalus acanthias) and the common thresher shark (Alopias vulpinus). The spiny dogfish fishery occurs in the internal waters of Puget Sound in the state of Washington and, to a lesser extent, off Oregon. The thresher shark fishery occurs primarily off the coast of California but does extend at times off the coast of Oregon. These, and other sharks, are also taken incidentally in other fisheries but at very low levels.

These fisheries are managed under the individual authority of each state even though the fishery may occur in waters managed under federal authority. The individual state management systems are unique and will be discussed in subsequent sections of this report. The need to manage at least some shark fisheries under the Magnuson Fishery Conservation and Management Act (MFCMA) at a federal level has been discussed at various times, but it has generally been agreed that state authority is sufficient to manage and protect these stocks.

A limited number of these and other sharks are taken as bycatch in fisheries managed under authority of the MFCMA. They are not, however, directly managed or assessed under this authority. These and other shark species are also taken in sport fisheries off Washington, Oregon and California. They occur primarily as bycatch in Oregon and Washington sport fisheries, but there are directed sport fisheries for sharks in the waters off California.

The thresher shark fishery has been controversial at times since the primary gear used is drift gill nets (DGN). The bycatch of marine mammals has also brought this fishery under increasing public scrutiny in the USA.

The largest, most consistent shark fishery off the West Coast of the USA started as a target fishery for the common thresher shark (Alopias vulpinus) in California. Prior to 1979, thresher sharks were occasionally taken in near-shore gillnet fisheries in California (Hanan et al. 1993). The population was probably unexploited prior to this time.

2.  THE RESOURCE

2.1  Species composition of the fishery

The species composition of the shark resources off the West Coast of the USA is diverse. Numerous species are relatively abundant and widespread, while others characteristically are found primarily off southern California. Some species such as the common thresher shark appear to have seasonal movements up and down much of the West Coast. Little is known about the biology of the populations of sharks found off the West Coast and fishery dependent data provides the largest source of knowledge concerning these stocks. The limited number of species of commercial or sport importance and the disjunct nature of the management jurisdictions require that this report address selected species. Note that some species may be taken directly or indirectly in the same fishery, or even the same net.

The DGN fishery for sharks targets primarily the common thresher shark and to a much lesser extent the shortfin mako shark. The same fishermen and gear can also catch swordfish (Xiphias gladius) on the same trip but rarely in the same net set.

2.2  Distribution of the fishery

The thresher shark fishery started in California and is still most heavily prosecuted of that state. The fishery moves northward to the waters off Oregon, and rarely, Washington during some years. Oregon and Washington have also allowed an experimental DGN fishery off their coast in some years.

2.3  Associated species either as bycatch or discards

The DGN fishery has had limited onboard observer coverage under state and/or federal programmes in most years since 1980 (Hanan et al. 1993). The concern over bycatch of species important to recreational, or other commercial, fisheries and marine mammals (pinnepeds and cetaceans) has kept this fishery under more scrutiny than perhaps any other West Coast fishery of the USA. The observer data has consistently demonstrated that the DGN does take marine mammals and sea turtles, both of which are protected under various federal laws (Table 1).

Fishermen have voluntarily tried numerous techniques to reduce bycatch. They have hung their nets further under the surface, increased mesh size above what is legally required and tried different types and sizes of twine. Some have even tried to place materials on the nets in the hope that they would assist cetaceans to avoid the net. Individual fishermen have reported that some of these methods have reduced the bycatch of pinnepeds and cetaceans.

The bycatch of fish other than thresher sharks and marine mammals have resulted in numerous time and area closures. The US congressional re-authorization of the Marine Mammal Protection Act (MMPA) in 1994 brought another challenge to the DGN fishery. It classified the fishery as a Category I fishery which meant it was taking an unacceptable number of marine mammals (cetaceans) which had been classified as strategic stocks. In most cases, these takes were at low levels (Tables 1 and 2). Strategic stocks are those which are below their optimum sustainable population size (OSP). The MMPA required that National Marine Fisheries Service (NMFS) form a take reduction team (TRT) that would recommend measures to bring the DGN into compliance with the MMPA. This brought further attention to the DGN fishery which was identified by the NMFS as having unacceptable bycatch of marine mammals in 1989.

The Take Reduction Team recommended that an experimental fishing regime be set up in 1996 (NMFS 1997). They recommended that fishermen install “pingers” on their nets, and fish the nets only below 36 feet. The pingers significantly reduced the take of strategic stocks in 1996 and the TRT recommended that NMFS require them on all nets in the 1997–98 fishery. The NMFS accepted this recommendation, and it is currently being implemented. The TRT meets annually and reviews the efficacy of its recommendations and reports the results to the NMFS.

The MMPA re-authorization by Congress in 1988 provided appropriations to federally fund an observer programme for the DGN fishery off the Washington and Oregon Coast. The observer programme, which was administered by the Pacific States Marine Fisheries Commission (PSMFC), demonstrated that marine mammals and sea turtles were being taken by the DGN fishery off the Washington and Oregon coasts in sufficient numbers to be of concern to the state management agencies (PSMFC 1990).

Observations for the 1980–81 through 1982–83 seasons are combined as they represent the first sampling method used by the CDFG. The 1990–91 data were collected by the NMFS (from Hanan et al. 1993).
^a There were 262 net pulls observed during the period October 1980 to April 1983 when the fishery wasallowed year-round. Bycatch-rate data are presented for only the May through January period to allowcomparison to subsequent years when the fishery was closed February through April. There was anadditional closure within 75 miles of shore 1 May through 14 June 1990, but all data for the 1990–91season are presented.
^b This represents one animal, which was released alive.

The fishing year is 1 April -31 March.

The experimental DGN off the Washington and Oregon coasts was closed for 1989 due to concerns over bycatch. The states were also concerned over the status of the thresher shark resource and the potential impact that the DGN fishery could have on the spawning adult segment of the thresher shark resource. The Oregon Department of Fish and Wildlife (ODFW) was directed by its governing Commission in 1995 to again issue experimental fishing permits for swordfish. The ODFW issued ten swordfish permits in 1995. The permits were acquired, however, by fishermen who, for the most part, resided in California. It is known that thresher sharks are taken incidentally by DGN fishermen off Oregon fishing for swordfish on the experimental permits, but they cannot be landed in Oregon. It is thought that the shark bycatch is most likely landed in northern California where it is legal. The at-sea observer programme mandated under the MMPA results in some observation of sets off the Washington, Oregon and Californian coasts. A directed thresher shark fishery in this area would most likely have a higher bycatch of marine mammals than a directed swordfish fishery if it is conducted closer to shore as occurred in the prior fishery. The management agencies of the states of Washington and Oregon are considering allowing the landing of incidentally caught thresher sharks in the future.

The West Coast DGN fishery has bycatch of numerous other species than the target species (Table 3). Other than the marine mammal bycatch previously discussed, the only other potential biological bycatch problem is for shortfin, mako and blue sharks.

Blue sharks are not marketed from the DGN fishery in the USA as rapid spoilage after death occurs (Hanan et al. 1993) and usually they are discarded at sea. The DGN fishery caught an estimated 6706 to 16743 blue sharks per year during 1990–1994 (Julian 1996). This was lower than the estimated 20 000 blue sharks per year taken during the years 1980–1983 (Holts et al. 1996). The authors noted, however, a decreasing trend in the alternate length (AL) over the period 1990–1994.

Shortfin mako sharks are not thought to be sufficiently abundant to support a directed fishery. But, they do occur as bycatch in the DGN fishery in sufficient numbers to provide a marketable resource for that fishery. The market price for shortfin mako sharks continues to be high enough to ensure that they are landed. Holts et al. (1996) demonstrated a decline in average size for landed shortfin mako sharks. The data are highly variable, however, and may be the result of changes in fishing patterns and time and area regulatory changes. The average size of landed shortfin mako sharks does not appear to be declining at present.

2.4  Development and current status of means of prosecuting the fishery

2.4.1  The harvesting process

The California Fish and Game Commission which regulated these fisheries allowed the landing of sharks caught incidentally to other species such as California barracuda (Sphyraena argentea)and white seabass (Atractoscion nobilis). As the market for thresher shark developed, fishermen started adapting their drift gillnets and fishing techniques to take thresher sharks. They also found they could catch swordfish with the same techniques. Landing these incidentally caught swordfish initially was not permitted. The Commission did, however, allow the landing of incidentally caught swordfish in December 1979 through March 1980. The Commission subsequently denied a request to authorize the use of drift gill nets to catch swordfish. The California legislature then exercised its authority to regulate fisheries to allow special permits for drift gillnet fishing.

The primary species taken in the DGN fishery are also of interest to recreational fishermen. Striped marlin (Tetrapturus audaxs) were taken by recreational fishermen, and swordfish were taken by commercial harpoon and hook-and-line fisheries. The legislature initially limited the DGN fishery to an incidental catch of 25% of the number of swordfish taken by the commercial harpoon and hook-and-line fisheries by month and 10% of the catch of striped marlin taken in the recreational fishery. The DGN could be no longer than 6000 feet and must utilize twine of size #18, or larger, with a mesh size of 8" or larger. The fishermen were required to keep daily log books and fish only between two hours before sunset and two hours after sunrise.

The California legislature in 1981 enacted new legislation to allow the DGN fishery to target swordfish during selected months, and removed the percentage landing restriction. A limited entry programme was also established with a maximum of 150 permits. This effectively prohibited new entrants since the actual number of permits at that time was, in fact, 300 in 1985. The mesh size for the fishery was also increased to a stretch mesh measurement of 14" or greater.

In 1981 the Legislature enacted the first of many closures and restrictions to reduce the bycatch of marine mammals. It also regulated the fishery by a number of time and area closures. The California Department of Fish and Game was given authority to close the DGN fishery if either the shark, or swordfish, landings exceeded 1.5 million pounds during any 12-month period. The DGN fishery continued to develop and expand northward from southern California. The Legislature responded in 1984 by granting 35 new permits for taking swordfish north of Point Anguello. A portion of the fishery actually was conducted, at times, off the coast of Oregon outside the three mile state water limit.

During the 1980's the Legislature added a number of time and area closures which moved the fishery further offshore in some areas and closed it in areas of higher bycatch, or perceived conflicts with other fisheries. In 1989 this culminated in the prohibition by the legislature of the DGN from fishing within 75 nautical miles of the coast from 1 May to 14 July. The nearshore DGN fishery was thus effectively closed from the end of January through mid-July. The legislature has continued to move opening and closing dates in the 1990's. The passage of the federal Marine Mammal Protection Act of 1988 brought increasing scrutiny of the bycatch of the DGN fishery. A federally funded observer programme was instituted for the fishery off California and, for the first time, off Oregon and Washington.

The DGN fishery off Oregon and Washington had started in 1983 when the states offered experimental fishing permits. By 1986, 647 000lb (PSFMC 1990) of thresher shark were landed in Oregon and Washington ports. The states of Oregon and Washington ceased issuing permits in 1989, but California fishermen could still fish off these states' waters outside of three miles. Only 294lb of thresher shark were landed in Oregon in 1996, and 82431b in Washington (PSMFC 1997). These fish are most likely bycatch from the groundfish trawl fishery which operates under federal authority.

2.4.2  Evolution of catch

The reported landings of thresher sharks has fluctuated due to many factors, including regulatory changes but the fishery has not shown the dramatic fluctuations seen in other Washington, Oregon, and California coastal fisheries, e.g. groundfish and salmon. The catch has been limited in some areas and times by regulatory processes which required certain ratios by species in landed catch.

The landings of thresher sharks in California peaked in 1982 at 1087t (Table 4). Landings subsequently declined but have been relatively stable at 150 to 200t since 1992. The DGN fishery accounts for approximately 80% of the catch of thresher shark off the WOC. Vessels fishing with set gill nets have landed 12–20% of the catch in recent years (PSMFC 1997), longline vessels and other gears account for the rest of the catch. Landings of thresher shark off the Washington and Oregon coasts beginning in the 1980s (Table 4) reflect experimental fisheries which opened and subsequently were closed by these states. Landings of shortfin mako sharks peaked in 1987 (Table 4) and have declined to less than 100t in the 1990s. Landings of blue shark peaked at 92t in 1981 (Table 4) and quickly declined to minimal levels as the fishery was unable to develop a market for human consumption.

1 Preliminary.

2.4.3  Fleet characteristics, evolution of the fleet, and fishing effort

There was limited interest in commercial fishing for shark off the Washington-Oregon-California coast prior to the 1970s. Sharks were taken incidentally by vessels fishing set nets or longline gear. Hanan et al. (1993) reported that early in the development of the fishery, DGN vessels tended to be made of wood or fiberglass and ranged from 30 to 75 feet in length. As the fishery has developed, vessel size has increased, and steel or aluminum construction has become more common.

The development of the drift gill fishery brought a rapid expansion in fishing effort to catch sharks off the Washington, Oregon and California coasts. Fishermen's log book, which were required by state, and for later years by federal laws, permit the calculation of effort and catch-per-unit effort. Hanan et al. (1993) reported that compliance with the log book reporting requirements was estimated to be greater than 90% and concluded that total effort estimates based on log books were accurate. A unit of effort is effectively one overnight set of a net since they are set out in the evening and must be out of the water by two hours after sunrise. Annual effort for the DGN fleet peaked in 1986 at 11 243 sets (Table 5). It has declined to near 4000 sets annually in the 1990s. Much of this decline is due to regulatory changes.

Catches of blue sharks are estimated.

Gill nets, set or drifting, were banned from state waters (to 3 miles off shore) by a vote passed by California in 1990. This action, effective 1 January 1994, dislocated a substantial number of smaller vessels which could not safely fish further off shore. Some of these vessels have converted to other gear, including different hook-and-line configurations.

2.5  Markets

2.5.1  Introduction

The vast majority, perhaps all, of the sharks taken in the Washington, Oregon and Californian coast thresher shark fishery are consumed in the USA. The USA also imports thresher and limited amounts of other sharks from Mexico since Washington, Oregon and Californian coast fisheries cannot fill the market demand for shark flesh. The market has played a limited role in the management of the thresher shark fishery. Shortfin mako sharks are also readily marketed in the USA and are not exported to any extent. Thresher shark can commonly be found in the fish markets along the entire West Coast of the USA.

Efforts have been made to market blue shark in the USA, but blue sharks deteriorate and spoil rapidly after death. The DGN fleet thus discards almost all blue sharks taken. At least one California longline vessel attempted to develop a market for blue sharks in 1979 and 1980 (Holts et al. 1996). It was able to market 25 and 50t of blue shark in 1979 and 1980 but it ultimately failed to provide consistent supplies of sufficient quality to continue. The low market price obtained for blue shark also apparently contributed to the demise of this fishery.

2.5.2  Revenues from the fishery

No analyses of the net economic benefits of the Washington, Oregon and Californian coast thresher shark fishery could be located. Hanan et al. (1993) reported swordfish ex-vessel prices ranged from $1.00 to $2.00/lb for shark. Ex-vessel prices for thresher shark in 1997 at $1.50 to $1.75/lb were still in that range. The ex-vessel price for shortfin mako sharks averaged around $1.25/lb in 1997. The CDFG estimated that landings by the DGN fishery have averaged $7.2 million (US) in exvessel value for swordfish, mako, and common thresher shark in recent years (NMFS 1997). A large majority of fishermen on the West Coast of the USA also prosecute other fisheries such as groundfish, crab, and albacore, thus diversifying their income.

2.6  Economics of the fishery

While an economic analysis of the fishery is unavailable, a good indirect measure can be gained by examining participants willingness to continue fishing. The cap on the number of permits prohibits new entrants and restricts the ability to transfer permits. The proportion of fishermen who continue to make annual or near annual landings remains high. They are also active politically in protecting their fishery from challenges by other groups who would eliminate or greatly reduce the fishery. The fishermen continue to find willing buyers for the product and additional product is imported from Mexico. These facts would argue that this is a profitable fishery since it is highly unlikely that all these individuals are performing these functions for pleasure.

The thresher shark fishery is not subsidized. There are no development programmes and limited expenses are involved in management of the fishery at this time. DGN fishermen pay an annual fee of $330 to participate in the fishery. There is also a $1500 fee to transfer permits between fishermen. Processors are required to pay a $0.11/lb privilege tax on thresher and shortfin mako shark purchases.

2.7  The fisheries workforce

The majority of the participants in the Washington, Oregon and Californian coast thresher shark fishery are professional fishermen. Many move to other fisheries when the swordfish/thresher shark fishery is closed. Experimental longline fisheries for shortfin mako and blue sharks were authorized for short periods, but they were quickly terminated due to higher than acceptable catches of shortfin mako sharks and high discard rates of blue sharks. Active participation in the DGN fishery has declined from 210 in 1986 to 124 in 1994 as permits are not renewed. Even though over 150 permits were issued in 1996, only 100 permits were really actively fished. Crew sizes on the DGN vessels ranged from one to six between 1981 and 1991 (Hanan et al. 1993).

3.  MANAGEMENT OBJECTIVES

3.1  The fisheries within the context of national fisheries policies

As previously stated, the shark fisheries on the West Coast of the USA are managed by the individual states of Washington, Oregon, and California. The MFCMA, with all of its National Standards and policy direction, does not apply to these fisheries. There are, however, federal laws which protect interstate commerce and prevent discrimination between fishermen of different states. The states have worked together with the PSMFC to develop an Interjurisdictional Fishery Management Plan (FMP) for Thresher Shark which was completed in 1990. All three states endorsed the FMP, but reserved management jurisdiction over their respective areas.

3.2  Objectives for the management of shark fisheries

Each of the state agencies responsible for shark fisheries have legally established objectives that provide for sustainable fisheries management. They are generally broad guidelines without extensive guidance for individual species fisheries management.

3.3  The objective setting process

Each of the states of California, Oregon, and Washington has a different process for establishing management objectivies. All three states also have an active public initiative process which is somewhat characteristic of the western USA. In the initiative process, an individual can attempt to gather a legally set number of signatures to place an initiative on the ballot. If they are successful, the issue is voted on by the electorate and can become law without needing approval by the legislators. This process was used to ban gillnetting in state waters off California.

Each state has an entity to manage the fish and wildlife resources for the citizens of the state. The ability of these entities to establish broad objectives is controlled by one or more governing bodies. The Washington Department of Fish and Wildlife and the Oregon Department of Fish and Wildlife receive broad policy and/or objective guidance from a Commission which is appointed by the governor of that respective state. Washington has nine citizen commissioners and Oregon has seven citizen commissioners. These commissioners are appointed for six and four year terms, respectively, and do not receive compensation for the time they work for the Commission. The commissioners of Washington and Oregon are usually individuals with strong interests in the fish and wildlife resources of the state. The California Fish and Game Commission has five members who are appointed by the Governor for six-year terms. The appointees are subject to confirmation by the Senate and receive $100 for each day served. The powers of the Commission are delegated to it by the legislature. The California legislature has not delegated authority over many aspects of commercial fisheries to the Commission.

The Commissions conduct their work in open public forums. Proposed changes in broad policies and objectives are subject to intense public scrutiny through the review process which includes the opportunity to provide written comments and public meetings where oral testimony can be directly presented to the Department and Commission. The process is designed to ensure that any individual with an interest in the issue can be heard. This does not, of course, guarantee that everyone will be pleased with the final decision.

4.  MANAGEMENT POLICIES AND THE POLICY SETTING PROCESS

4.1  Identification and evaluation of policies

Management policies discussed in this section include season length; gear limitation in type, size, or number; and limited entry types. They are generally called “regulations” in the USA. Oregon and California have implemented different forms of limited entry for the DGN fishery. Most of the gear regulations such as net length and mesh size have been developed in the California fishery and ultimately implemented by the other states. Gear restrictions are discussed in Section 3.2.2.

4.2  Policies adopted

4.2.1  Resource access

In 1981 the California legislature enacted new legislation which allowed shark fishermen to target swordfish during selected months. It established a limited entry programme with a maximum of 150 permits. The actual number of permits was greater than 150, however, and all permit holders were allowed to continue fishing. Thus there were still 3000 permits by 1985. The legislation prohibited new entrants and the number of permits has gradually declined as fishermen left the fishery due to retirement, death, etc.

A California DGN permit can be transferred for a fee of $1500. The annual cost for the permit is $330, but applicants must also obtain a general gillnet/trammel net permit. Permits have been sold between fishermen for $3500 to $5000 (including the transfer fee) in 1996.

Washington and Oregon began granting experimental DGN fishing permits in 1983. These permits were granted to any fisherman requesting one through 1988. Both states stopped issuing permits in 1989. There was little resistance to this change since it only closed fishing inside three miles, and most of the fishermen also had a valid California fishing permit. Oregon issued 10 swordfish DGN permits in 1995 but does not, at present, allow the landing of thresher sharks which are taken as bycatch in Oregon waters. It is unusual, however, for substantial numbers of both swordfish and thresher sharks to be taken in the same net set. While fishermen will most likely land the sharks taken in the Oregon fishery in California, a few have been landed in Washington. These permits are issued on a first-come first-served basis and are not transferable.

4.2.2  Gear restrictions

DGN fishermen in California are restricted to a net with a stretch mesh size of 14' or larger and no longer than 6000 feet in length. The net must be constructed with twine size #18 or larger. Data gathered from the NMFS observer programme has demonstrated that most fishermen use a larger mesh size and twine size than is required. In 1996 the average mesh size was 19'. The 1994 re-authorization of the MMPA ultimately brought additional restrictions to the fishery to reduce the take of cetaceans. An experiment was conducted in 1996 in which a randomly selected number of nets fished with “pingers”. These pingers were sound-producing devices which had been shown to reduce the incidental take of cetaceans in fisheries off the East Coast of the USA. The nets were also fished at least 6 fathoms below the surface. The 1996 experiment demonstrated a significant reduction in the rate of take of cetaceans in nets with pingers. The pingers were then made mandatory for the 1997 season. The final regulations also required the nets to be fished at least 6 fathoms from the surface.

4.2.3  Vessel regulations

Vessel length and tonnage have not been restricted by the three states for the DGN fishery. The economics of the fishery are apparently sufficient to control vessel size and configuration. A vessel is restricted to one net of the specified size so there is little incentive to increase vessel size for other than safety or quality (refrigeration) considerations.

4.2.4   Biological regulations

The DGN fishery has been restricted in time and area to reduce bycatch and the catch of juvenile sharks. In 1994 there were indications that the thresher shark resource was declining because of fishing pressure. The California legislature passed legislation which, coupled with previous legislation, closed the area within 75nm of the California coast to DGN fishing (south of Pt. Arguello) from 1 February to 14 August (previously 15 July). This closed the area in which juvenile thresher sharks had been taken and resulted in a fishery primarily targeting swordfish.

There are no size limits on landed thresher shark. Since the sharks are generally dead upon retrieval by the vessel, such a restriction would serve little purpose. Time and area restrictions have been effective in reducing the take of juvenile thresher sharks. In addition, pelvic fins must be left attached until the sharks are landed.

4.2.5  Catch/quota allocation

The Washington, Oregon and Californian coast thresher shark fisheries and, in particular, the DGN fishery are not regulated by Total Allowable Catch or Individual Transferable Quotas but the states of Washington, Oregon, and California did agree to a coastwide harvest guideline of 750 000lb dressed weight of thresher sharks in 1990 (PSMFC 1990). The states agreed that landings in excess of this amount would trigger a discussion on the fisheries and of potential actions to be taken to reduce the total coastwide catch.

4.2.6  Discussion

The regulatory processes of the three states provide ample opportunity for public input. The primary criticism that can be made is that there is no single regulatory body which can control the three-state area. This potential problem has been mitigated to date by the willingness of the three states to act cooperatively in managing a fish stock which straddles state boundaries. Without such cooperation, the states realize that any one state's management programmes can be totally frustrated by another state's action. This should provide a continuing incentive for cooperation. The authority of the federal government under the FCMA could also be implemented if it became apparent that the individual states were unable to successfully manage this resource.

A second potential criticism is that each state's unique regulatory process is subject to political pressures which could result in precipitous actions such as the banning of gill nets within 3nm of the coast such as by public initiative as in California. Federal management could prevent such actions, but they are likely to be ineffective in doing so after they have occurred in an individual state.

The state of California is unique in retaining much of the regulatory authority over commercial fisheries in the state legislature. The fact that any action in the legislature is open to amendments which could drastically affect the fishery makes fishermen reluctant to introduce, or support, changes in the fishery which would require changes in the legislature.

5.  THE MANAGEMENT PLANNING PROCESS

5.1  Provision of resource management advice

The process for providing annual input to regulations is described in Section 3.3.

None of the three states have prepared Fishery Management Plans (FMP) for shark fisheries. The states did, however, participate with the PSMFC in developing an interjurisdictional FMP for thresher shark in 1990 (PSMFC 1990). That plan provided a harvest guideline for all thresher shark fisheries on the West Coast of the USA. It also established an annual meeting of the states to review past years' landings and proposed regulatory changes. The FMP also provided for the establishment of an industry advisory panel to comment on management proposals when needed. The FMP clearly stated that catches of juvenile thresher sharks would be discouraged. While the FMP recommendations are not binding, the states have continued to participate in the process and abide by the agreements reached therein. The FMP also provided a process to recommend changes to thresher shark management and to coordinate the changes with the three states. It also recognized that each state retained its sovereignty and unique management structure and processes.

5.2  Fishery statistics

5.2.1  Methods used for collection of catch and effort data

The gathering of catch statistics is a highly organized, consistent and efficient process on the West Coast of the USA. The acquisition of effort data and biological data on catch and bycatch is much more variable and subject to limited funding and/or interest.

The states of Washington, Oregon, and California all require that a fish ticket be completed for each landing and sale of commercially caught fish. This provides a record of the catch, the price paid, and the individual and/or vessel landing the fish. The states use this data to monitor the catch of target species and to tax the fishing industry. The data thus collected are compiled and entered into a coastwide database, Pacific Fisheries Information Network (PacFIN). This database is administered by the PSMFC, which then shares the data in accordance with confidentiality agreements with the states, the NMFS and others who have a legitimate need for the data.

The California DGN fleet has been required since 1980 to maintain daily log books describing their catch. Compliance with this log book requirement was high (greater than 90%), and California scientists have stated that the total effort estimates are assumed to be accurate (Hanan 1993). An observer programme was also mandated by the California legislature. This programme provided verification on catch and bycatch data between 1980 and 1985. The low level of coverage in this programme limited its value for management.

The NMFS established a mandatory observer programme under the authority of the MMPA during the 1990–91 fishing season. This programme provided another independent source of catch and bycatch data of the DGN. The programme resulted in systematic observations on a preset proportion of the fishing trips and was designed to sample 20% of the fishing effort in recent years but has never fully achieved that goal (Table 6). It has, however, gathered substantial amounts of data on the DGN fishery. The continuation of the programme is dependent on federal appropriations by the US Congress and the budget priority process of the NMFS. Biological data on the DGN fisheries have been gathered on a much less systematic basis. Funding for this type of programme has been intermittent which resulted in large gaps in the total database for the fishery, particularly fishery-dependent biological data on the thresher shark resource.

5.2.2  Evaluation of the data collection process

The PacFIN database system has proven to be highly accurate and provide real-time landings data for managers. PacFIN supplies data summaries on the internet through the PSMFC home page (http://www.psmfc.org). State and federal agencies receive data summaries on a timely and accurate basis. This PacFIN programme is now being used as the data collection model for other coastal fisheries in the USA.

The state-mandated skipper log book programme was an effective tool for monitoring effort in the DGN fishery (Hanan et al. 1993). These log books did not, however, require the fishermen to list bycatch. The fish ticket requirement for landed fish provides another measure of the catch of target species in the skipper log books. The bycatch data derived from skipper log books required by the MMPA have been subjected to some criticism after the NMFS observer programme was implemented. Bycatch rates were shown at times to vary in a significant manner between observed and unobserved boats (NMFS 1994). Non-reporting of the capture of marine mammals can subject the fishermen to monetary fines. However, the reporting of takes of marine mammals can result in increased political pressure to close, or severely limit, fisheries. It is felt, however, that the majority of DGN fishermen report the majority of the bycatch. An independent, federally funded observer programme will likely be an ongoing need and presence in the DGN fishery. The MMPA requirements to reduce or eliminate marine mammal bycatch will not be accomplished in an acceptable manner for many environmental groups without this independent review of bycatch.

The collection and assessment of biological data on the landed thresher shark catch is perhaps the weakest link in the data for the DGN fishery. CDFG sampled from less than 5% of the thresher shark catch to a peak of near 20% of the catch between 1981-1982 and 1991. The sampling of the shortfin mako shark catch was similar for the years 1981-1982 through 1991. The CDFG sampling peaked in the 1989-1990 season and has been at a low level since. The CDFG reported only 48 thresher sharks were sampled for sex and size in 1996. The NMFS observer programme has been sampling from 5% to 17% (10-14%) of the vessel trips in the years 1990 to 1995. The actual percentage of the thresher shark and shortfin mako shark sampled is likely less.

5.2.3  Data processing, storage, and accessibility

The Pacific Fishery Information Network (PacFIN) data reside on a mainframe computer (ORCA) at the Northwest Regional Office of the NMFS. The data are managed and controlled, however, by PSMFC. PacFIN utilizes servers running the UNIX operating system and a Oracle Relational Database Management System (DBMS).

PacFIN receives vessel, permit restrictions, and fishery-specific data from numerous sources (Table 7). Some of the fishery landing data is supplied to PacFIN from the Washington, Oregon and Californian region on a weekly basis. This real-time data is used to manage many of the West Coast fisheries which are controlled by quota management regulations.

W. Daspit (pers. comm.) reported that all data destined for the PacFIN central database arrives on the ORCA by one of five methods: (1) internet FTP directly to the ORCA system, initialed at either the sending or receiving end; (2) a 9600 BPS (or faster) Kermit file transfer from a data source bulletin board to a PacFIN office computer system and then on FTP to ORCA; (3) a diskette containing a MS-DOS ASCII file(s) sent or delivered to the PacFIN office; or (4), an 8 mm Unix tape containing an ASCII file with the transfer performed by the ORCA operations staff.

The frequency of data update depends on the data source and the need for in-season fishery management. The Washington, Oregon and Californian state agencies update their data monthly and other data sources provide updates on varying schedules. All the data updates are validated by PSMFC staff before storage in the permanent database tables. PacFIN supplies summary tables of fishery data either in hard copy to those who request it or through the PSMFC home page on the internet (http://www.psmfc.org). The staff also provide some specialized summary reports to fulfill specific requests, though this ability is not unlimited.

The PacFIN database is confidential. It contains economic data from individuals and individual vessels. Therefore, PacFIN by agreement of all its parties follows the confidentiality rules set by the NMFS in NOAA Administrative Orders. These rules state that only data which does not reveal the economic history of individuals or corporations can be made public. Individual access to the database is highly restricted and only available to selected employees of PSMFC, the NMFS and other member agencies such as those from the Washington, Oregon and California states. Certain private individuals (contractors) contracted to perform projects for these agencies may be given electronic copies of selected portions of the confidential data necessary to complete their projects. They receive this data only by signing the same confidentiality agreement that is completed by those with direct access to the database. They are also required to destroy the data once their project is completed.

CDFG - California Department of Fish & Game;
ODFW - Oregon Department of Fish and Wildlife;
WDFW - Washington Department of Fish and Wildlife;
ADFG - Alaska Department of Fish andGame;
AFSC - Alaska Fishery Science Center, National Marine Fisheries Service;
DFO - Department of Fisheries and Oceans, Canada;
USCG - United States Coast Guard, USA;
MWR - Northwest Regional,National Marine Fisheries Service.

5.3  Stock assessment

5.3.1  Stock structure

The fishery data from the Washington, Oregon and Californian coasts strongly suggest that there is a single coastwide stock. This stock is also found at times off the coast of Mexico (Hanan et al. 1993, PSMFC 1990) though. Recent data suggest that there may be two distinct genetic stocks off the West Coast (PSMFC 1997). This hypothesis will be examined in greater detail in the next few years.

The stock appears to move northward from southern California and Mexico in the summer and fall. Large, mature thresher sharks can be found as far north as Vancouver Island, British Columbia, by late summer. Biologists presume these adults return to southern California and Mexico in the winter months, presumably to give birth in March to June. The westward and southward extent of this migration is unknown, but limited data suggest it may be extensive. Common thresher sharks are distributed throughout all tropical and temperate oceans so it is conceivable that many separate oceanic stocks could exist.

To date, all stock size distribution and biomass for thresher sharks and shortfin mako sharks have come from fishery dependent data. Methodologies have not been developed to perform any independent large-scale resource surveys of the shark resources of the Washington, Oregon and Californian coast of the USA.

The fact that thresher and shortfin mako sharks are often taken as bycatch in swordfish fisheries as well as in directed fisheries makes the assessment of CPUE data difficult. The DGN fishery has also undergone numerous regulatory changes which affect both effort and catch relations. In almost all cases, these regulatory changes have increased the restrictions on gear and area fished. In some cases, regulations have been implemented to directly reduce the catch juvenile sharks.

5.3.2  Measures of stock abundance

Cailliet and Bedford (1983) reviewed the biology of selected sharks in California waters and the fisheries which were starting to affect them. The analysis of data for 1977 to 1982 did not lead them to conclude that the thresher shark population was in jeopardy at that point. Further analysis of the data in the 1980s and the declining thresher shark landings and CPUE led Bedford (1987) to conclude that the thresher shark resource was declining. The decline in landings and the average size in the catch declined from 1984-85 through 1990.

Fishing effort peaked in 1986 at an estimated 11 243 sets (Table 5) and rapidly declined to less than 5000 sets by 1994. Much of the effort in these years had been directed primarily at swordfish. Landings of thresher sharks declined during the same time period. Total thresher shark landings peaked at over 1000t in 1982 and rapidly declined to less than 300t by 1986. Landings have been relatively stable and under 200t per year from 1992 through 1996 (Table 4). Common thresher sharks account for over 91% of the thresher shark landings for this time period (Table 8).

The limited biological samples taken in recent years have not demonstrated any substantial change in the size of thresher sharks being landed. These data have led CDFG to conclude the thresher shark population is now relatively stable.

Landings of shortfin mako sharks peaked in 1982 at 242.1t and again at 277.6t in 1987 (Table 4). Landings quickly declined to less than 100t by 1992 and have remained there since Holts et al. (1996) stated that market samples of shortfin mako sharks demonstrated a decline in size from 58cm AL in 1981 to 35cm AL in 1985. The average AL then increased between 1986 to 1990 to 47cm. He also noted that at-sea NMFC observer data for 1990-94 reported averages of about 50cm.

5.3.3  Biological advice review process

Research scientists and managers from CDFG, NMFS, and numerous universities have reviewed shark fishery data and fisheries as described in the attached bibliography. A formal annual process to review the biological data of these populations is, however, somewhat limited. CDFG provides annual reports on landings and intermittent reports on effort and bycatch. The NMFS's primary interest has been to describe and limit bycatch in the DGN fishery. The NMFS also has researchers who have an interest in sharks and routinely follow developments in fisheries which take sharks.

The legislative process by which California regulates many of its commercial fisheries also provides an informal review of the fisheries, but is, at times, a highly emotional public process. The PSMFC sponsors an annual meeting of its Thresher Shark Management Panel. Scientists from CDFG, NMFS, ODFW and WDFW review each year's data and provide recommendations to the states on management of the coastwide thresher shark resource.

5.3.4  Biological management reference points

Hanan (1984) reported that sustainable mortality rates were likely low for the thresher shark population. His preliminary estimate based on the limited data available, of sustainable rates of F=0.007 to 0.049, has proved too optimistic as the subsequent decline in landings and average size shark landed has demonstrated. Limited funding has prevented greater gathering of biological data upon which to base a better stock assessments. Hanan (1993) stated, “There are no estimates of natural and fishing mortality rates for the shortfin mako.” and concluded that “Stock structure and abundance of shortfin makos in the eastern Pacific are poorly understood.”

5.3.5  Sustainability of the resource

The data available on the Washington, Oregon and Californian coast thresher shark resource imply a fishery that developed rapidly and was likely fished at unsustainable rates. Numerous restrictive regulations have been placed on the DGN fishery which takes the vast majority of the thresher sharks. These restrictions have closed large areas, reduced the take of juveniles (off California) and adults (off Oregon and Washington), and provided additional protections.

The 1997 meeting of the Thresher Shark Management Panel sponsored by PSMFC concurred with the CDFG that the available data indicates the thresher shark population is stable or increasing. While not commenting on the sustainability, Holts et al. (1996) noted that the mean size of thresher sharks observed in the NMFS programme had stabilized at 52 cm AL between 1990 and 1994. The numerous changes in the regulations directed at the DGN fishery makes it difficult to evaluate the decline in CPUE data since the fishery was, at times, moved into times and areas known to have fewer thresher sharks. Even less is known about the sustainability of the shortfin mako shark resource. As was previously stated, the average size of shortfin mako caught dropped rapidly, increased again and then somewhat stabilized, although at a smaller size than in the earliest years of the fishery. It is likely that shortfin mako sharks are not currently being fished at a rate that would cause a precipitous decline in the population and may, in fact, be sustainable.

Blue sharks are not landed in Washington, Oregon and California due to the lack of a market. Data on bycatch is somewhat limited, but estimates provided by Julian (1996) and others indicate that catch of this species has declined substantially since the early 1980s and has recently been estimated to be less than one-fourth that taken during 1985–1986. Holts et al. (1996) noted, however, that the mean size of blue sharks measured by NMFS onboard observers was declining in the DGN fishery in 1990–1994. It is extremely difficult to judge whether blue sharks are being taken at a sustainable rate at this time.

5.4  Discussion

5.4.1  The managers perspective

CDFG is managing a relatively small thresher shark fishery inside a larger and more lucrative swordfish fishery. This situation created considerable conflict in the early years of the DGN fleet. Regulations were promulgated which resolved many of the conflicts between commercial fisheries but conflicts still occasionally arise between sport and commercial fishermen. This will likely continue as the pressure grows from too many fishermen pursuing too few fish.

Real and perceived problems with bycatch will continue to cause frustration for management. Marine mammal stocks under the MMPA often receive protection usually afforded only to threatened or endangered stocks under the Endangered Species Act. Managers may be forced to take measures to protect marine mammals such as the California sea lion, while they are continue to be castigated for their inability to deal with the damage caused by the overabundant sea lion population. The take of some cetaceans is extremely low (Table 2), yet managers are required to achieve lower rates or close all, or part, of the fishery. Closure of a fishery to achieve a rate which is politically driven can cause a great deal of frustration for managers.

California is the only state on the west coast that regulates its fishery through the legislative process. While the Commission and Department have been delegated some emergency authorities, the vast majority of the regulatory issues are resolved by the legislature. Representatives from the entire state of California are thus involved in what may be viewed by some as relatively local issues. The marine resources belong to the entire state, so it can be argued that this process ensures that everyone can express their views through their elected representatives. The result is that a great deal of political pressure can be injected into management which strives to manage on a biological basis.

The legislative process generally prevents a quick action being taken before the public or the fishing industry becomes aware of its necessity which provides some protection from arbitrary actions. Generally, all factions on an issue are offered the option of developing compromises. The CDFG can, and does, interact in the legislative process. In the past, the CDFG has opposed regulatory actions proposed and enacted by the legislature. This can be an uncomfortable position since the legislature also controls the CDFG's annual appropriations. Managers are continually frustrated by the lack of adequate funding for monitoring the fisheries. The lack of funds for research on the shark stocks has frustrated managers and researchers alike. Without adequate research funding, the fish and fishermen will continue to be at risk.

The Legislature and the CDFG are managing the shark fisheries with limited data. This has resulted in a substantial level of uncertainty in promulgating regulations. The process appears to work, as evident by data which shows thresher shark and shortfin mako shark stocks as stable, or increasing. The process cannot be described as being risk-averse as some claim these stocks exhibit relatively low productivity.

The stocks pursued by the DGN fleet cross state and national boundaries. The NMFS has been pursuing agreements with Mexico to provide enhanced data sharing and research and these efforts have been more successful in recent years. But, the lack of funding for research and management hinders the abilities of these two governments to manage transboundary stocks. The states of California, Oregon, and Washington have a great deal of history in cooperative management of West Coast fisheries. Management differences are usually resolved amicably on an informal basis. The Thresher Shark Management Panel also provides an annual opportunity to discuss thresher shark management and research and to provide management recommendations.

5.4.2  Users' perspective

Shark fishermen and, in particular, those fishermen who use DGN feel like they are almost an endangered species. A voter initiative previously discussed closed state waters within three miles of the coast to gillnets. The DGN fleet is well aware of other efforts in the USA to ban all gillnets. They are concerned that a similar effort could be initiated in the heavily urbanized state of California. The small numbers of commercial shark fishermen have little political influence which may be necessary to fight such a challenge.

The DGN fleet has made substantial efforts to reduce bycatch, particularly of marine mammals. However, each time the MMPA is reauthorized (generally every five years) a new and more restrictive management regime is implemented. Fishermen and their dependent industries have not had the political power to prevent these changes to the MMPA. They may be able to soften the more onerous restrictions desired by animal-rights organizations, but they cannot prevent all new restrictions. The management of selected species at the national level in the USA becomes a very politically charged process. Biology of the selected species may not totally dictate all the restrictions that can be placed on the fishing industry. This leaves fishermen feeling threatened and frustrated.

The state processes in general allow fishermen a balanced forum to deal with management issues. The state fish and wildlife commissions of Washington and Oregon are more directly concerned with fish and wildlife management and are, by design, more removed from the political process. The DGN fishery has been conducted as an experimental fishery in these two states and has been closed in some years. These closures only affected landings and fishing within three miles of the coast so they did not elicit much resistance from the fishermen. This is partially the result of the majority of the fishermen also holding California licences.

The management process in California, which involves the state legislature, leaves the fishermen at increased risk when new bills are introduced. Recent changes to the MMPA resulted in discussions of the need to change state laws. The DGN fishermen were reluctant to see new bills introduced in the legislature since the bills could be amended in numerous ways to their disadvantage. The fishermen feel that politics could control the process, rather than the resource's biology. The capture of even one marine mammal is unacceptable to some animal rights groups on the West Coast and elsewhere in the USA.

The DGN fleet has resisted efforts to reduce the numbers of permittees in the past. They have felt their small numbers already place them at significant risk in the political process. Programmes to reduce the number of fishermen, therefore, will continue to remain generally unpopular for these fishermen. California commercial fishermen also are concerned by growing sport fisheries in southern California. As sport fishing pressure increases, the interest in what were marginal species such as sharks also increases. The increased sport interest has resulted in more restrictive commercial regulations in the past. The commercial fishermen feel they are at a disadvantage when the issue becomes sport versus commercial fishing.

The huge supermarkets and rapidly increasing urbanization of the USA has resulted in a lack of public knowledge as to where their food comes from. This makes it easier for activist groups to target a particular industry and present distorted views of what is happening. The result has, at times, been the closure, or severe restriction of a USA fishery, while a foreign fishery with much higher environmental impacts continues to export its product to the USA. This is also a frustrating position for Washington, Oregon and Californian coast fishermen.

6.  FISHERY MANAGEMENT REGULATIONS

6.1  The regulations

As of this time, California does not restrict the number of sharks which can be landed by individual fishermen. The shark fisheries are regulated by time, area, and gear restrictions. Oregon and Washington do not permit the landings of sharks taken by DGN gear but do permit sharks to be landed that are incidental in other fisheries. This has resulted in a very limited number of landings from the groundfish trawl fishery off Oregon and Washington.

California has a large array of gillnet mesh sizes for various fisheries under its jurisdiction. The primary gear for the targeted shark fishery are DGNs. DGNs may be no longer than 1000fm and constructed with #18 twine, or larger, and have a mesh size of 14" or greater. Oregon and Washington have usually adopted identical regulations when they have allowed an experimental DGN fishery.

The DGN fishery is restricted by numerous time and area closures. It is closed from 1 February through 30 April. It is open from 75nm from the mainland out to sea. The open area extends from the USA/Mexico border to a line drawn westerly from the boundary line between Oregon and California. A fisherman with a valid permit may land thresher sharks if taken more than 75nm offshore. DGN fishermen may fish for and land sharks taken inside 75nm from 15 August to 31 January, but there are numerous areas which remain closed inside of the 75nm line.

California does not presently permit the use of commercial longline gear to take sharks in its waters. Oregon has provisions to provide permits for an experimental longline fishery for sharks, but no interest has been expressed by fishermen for this potential fishery. The legislature established an additional 35 experimental swordfish permits to be fished north of Point Arguello, California. These actions resulted in over 210 permittees fishing and landing fish in the 1986–1987 season. At present, the CDFG cannot issue new DGN permits. The existing drift net permits which have not expired due to retirement, death, or for other reasons can only be transferred to individuals who were prior drift net permittees and also possessed a general gillnet and trammel net permit and a valid DGN permit or valid swordfish limited entry permit during the previous season. The permittee must also have landed at least 2500lb of swordfish or 1000lb of shark, or landed sharks or swordfish for which the permittee was paid $1000 or more. There are also other requirements and fee payments needed to maintain the general gill and trammel net permits.

Additional restrictions also limit the times and/or conditions under which a permit can be transferred. A permit can be transferred only when: (1) the permittee has paid for, and validated, the permit for three years; (2) the permittee is injured or has a serious illness and hardship will result if the permit cannot be transferred; (3) a marriage is dissolved and the permit is held as community property; (4) the permittee has died and the surviving family wishes to transfer the permit. These requirements resulted in a reduction in the number of valid DGN to 172 eligible permittees by the 1996–1997 season. Of these, approximately 100 active permit holders account for most of the fishing effort.

Oregon holds an annual lottery for 10 unlimited landing permits which allow the holders to land swordfish in Oregon ports. This is a policy, not a regulation. Oregon also offers an annual limited landing permit which permits individuals to make up to five landings in Oregon ports. These permits are not transferable and fishermen have shown little interest in them. Most of the Oregon permittees also hold valid California DGN permits. Washington, at present, does not permit the landing of any fish taken by DGN in its ports.

6.2  Regulations and the communication process

All three West Coast states require the legal posting of all regulations to give them the force of law. Summaries of all applicable regulations are printed booklets and arereadily made available. If a state does not meet all of the legal requirements for posting regulations, they may not be enforceable in the state court system.

As has been discussed, all three states have a very public process for changing regulations. This also helps to inform fishermen that changes in regulations may be coming. There is usually a delay of 3 to 12 months before a newly passed regulation in these fisheries takes effect. Once regulations have been legally made available to the public it is the individual's responsibility to ensure they are informed and in compliance with the law. Generally, ignorance of the law is not a valid legal defense in the USA in these cases.

7.  THE LAW AND ENFORCEMENT

7.1  Legal status

Shark fisheries on the West Coast are not managed under the federal authority of the MFCMA but are managed by each of the three states. Under federal law an individual state can regulate its fishermen wherever they fish, unless they are participating in a fishery which is conducted under federal law. Each state also has the authority to manage its fisheries within three miles of its shoreline regardless of the residency of the fisherman. Each state can also control the landings of fish in ports within the state, even if they were taken outside of state waters, although this principle has lately come under legal challenge in some jurisdictions of the USA.

All three states have an agency (or department) established under state law which is responsible for managing the fish and wildlife resources of the state. They also exert enforcement authority to ensure compliance with laws and regulations through state officers authorized under state law. The ability of these officers to ensure compliance with regulations has been limited in recent years due to reduced funding and manpower. The states generally have very limited ability to perform at-sea patrols. They receive some assistance from the NMFS and the U.S. Coast Guard, but the majority of enforcement activities occur shoreside at the time of catch landing.

7.2  Enforcement problems

Shark fisheries on the West Coast do not present unique enforcement problems. Rather they present the same types of fishery enforcement challenges seen in most fisheries in the area. Only a small portion of the enforcement of state laws and regulations occur at sea, most checking for compliance with laws and regulations occurs at dockside at off loading. The most serious problem for fisheries enforcement authorities is their minimal and declining financial resources. The number of officers has declined in the three states and their equipment budgets have not kept up with their needs. This is the primary factor which limits at-sea enforcement by the state agencies. The at-sea presence of the U.S. Coast Guard and, to a lesser extent, NMFS enforcement assists states to deter violators. Compliance with fishery rules and regulations by fishermen is generally reported to be high by most West Coast enforcement agencies.

7.3  The legal process

Fishery law enforcement officers are empowered to issue citations, or a notice of violation, to suspected violators. The cited individual, in less serious cases, has the option of paying a preset monetary fine (essentially an admission of guilt) or appearing before a judge or magistrate to contest the citation. This process is generally used in cases which involve lower-class violations which do not carry the threat of confinement in a custodial facility or the loss of a fishing permit. More egregious violations involve more formal legal processes involving grand juries and jury trials. These types of violations can result in substantial monetary fines and incarceration and, in some cases, the loss of a fishing permit. In all cases, culpability is ultimately determined by the justice system which is independent of the fishery management and enforcement agencies of the state.

8.  MANAGEMENT SUCCESS

8.1  Profitability of the fishery

No separate economic evaluations of the shark fisheries on the West Coast have been done. The willingness of fishermen to pursue these fisheries and defend them in the regulatory and legislative process would indicate that they are profitable. As noted, most West Coast fishermen are involved in many fisheries throughout the year and it is unlikely that fishermen rely on shark fisheries alone for their entire annual income. The most lucrative shark fishery (thresher shark), at least in total ex-vessel value, is actually a bycatch, or a supplemental, fishery for swordfish.

California has estimated that the total economic value of the California drift gillnet fishery when all economic multipliers are applied exceeds $36 million per year (NMFS 1997). The landing of shark species which are highly valued by consumers also helps to reduce the US reliance on imported fish species which has increased in recent years.

8.2  Issues of equity and efficiency

The DGN fishery is typical of many limited entry fisheries on the West Coast. Typically, almost all fishermen who make landings at the time the limited entry programme was implemented received a permit. The programmes were thus initially inclusive. Generally, in limited entry programme the total number of vessels decrease only by attrition. No one is usually forced out of the fishery. New entrants must buy an existing permit, as well as meet other requirements.

DGN permits are not particularly expensive by US standards if an individual is interested in entering the fishery. Virtually all species of commercially valuable fish on the West Coast are fully exploited or overexploited. Since few single fisheries are sufficiently lucrative to provide a year-round adequate income, fishermen tend to participate in a number of fisheries. The present situation of fully exploited fisheries reduces the incentive for new individuals to enter the fishery which has helped to maintain the profitability of the DGN fishery.

Management of the DGN fishery has been relatively stable since the mid-1980s. Thus fishermen have not had to make significant investments or lose resource access due to management. While changes in safety regulations by the US Coast Guard and, to a lesser extent, gear modifications resulting from changes in the MMPA, have resulted in increased costs to the fishermen, it is unlikely that these changes by themselves have forced anyone out of the fishery.

9.  MANAGEMENT COSTS

Management costs attributable to shark fisheries are at present low. These fisheries are not managed by quota so day-to-day management information is not required. Almost all dockside sampling and gathering of fish ticket information is done for a number of fisheries at the same time and in the same port. Shark landings are a relative small percentage of the total landings for most ports.

There are numerous state permits, licences, and stamps which must be purchased by commercial fishermen on the West Coast and, in particular, in California. The funds collected help to pay for marine fish management, but much of the revenue collected may be diverted to other state programmes. Shark fisheries are a very small part of the total marine management programme.

California reported the landing of over 400 000lb (dressed weight) of thresher shark in 1996. Only 48 of the thousands of thresher shark landed were sampled for size and sex. The lack of funding for even this basic type of data has prevented fishery managers from developing a more accurate picture of the existing shark population in recent years.

Thus, it can be argued that insufficient funds are spent on research of West Coast shark populations, for example, fishery independent data on total population size and age structure of shark populations are extremely limited. The fishery-dependent data which are available indicate the shark stocks of commercial importance are at least stable. Current management of directed shark fisheries is considered sufficient to ensure the populations do not decline below self-sustaining levels, but only circumstantial evidence supports this view.

The NMFS, Southwest Fisheries Science Center has recently funded genetic analysis of the thresher sharks off the Washington, Oregon and Californian coast which will expand upon previous work performed by the University of California, Davis. The NMFS is also planning feasibility studies on the use of archival satellite tags to study the distribution and movement of thresher sharks. It is hoped that these studies will answer some of the basic biological questions and serve to direct more intensive research in the future.

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