Catches
Fishing techniques and gear
Fisheries management
Environmental aspects
Historically, rich and diverse fisheries have developed in the Tonle Sap ecosystem, with fishing strategies and techniques based mostly on fish behaviour and the flood regime. A large variety of gear is used, over 150 different types of gear have been inventoried (P. Degen, personal communication, 2000). Many of the techniques and gear used are of the passive type whereby no active effort is involved in the act of capturing the fish. Floodwater recession and migration patterns of fish are exploited in these fisheries.
The catches from the Tonle Sap make up about 60 percent of the total inland catch of the country (World Bank, 1995; Csavas et al., 1994). According to the most recent official catch figures, this corresponds to 138 600 tonnes, though the most recent MRC estimates (van Zalinge et al., 1999) put the Tonle Sap catch at between 177 000 and 252 000 tonnes.
Different classification systems are traditionally used to characterize the catch. Biological species are rarely used as a criterion in this. Different classifications were devised for different purposes. Some of the most commonly used systems are described here.
Mekong Secretariat (1992) provides a detailed description and review of a classification system that defines categories of fish based mainly on their water quality requirements and usual distribution patterns. Four categories are widely used:
Csavas et al. (1994) provide a description of the classification system used for official statistics which grades fish according to size and species based on local taxonomical knowledge. Freshness also plays a role in the sense that it can downgrade less-fresh fish. Grade 1 fish are 1 kg or more in weight, even though some high-quality smaller fish can be included. Grade 2 fish are between 0.5 and 1 kg, and fish weighing less than half a kilogram are usually classified as Grade 3. This classification system has primarily a commercial use. Generally, the price and utilization of the fish will depend on their grade. First-grade fishes fetch the highest prices, and they are often transported to urban areas or exported. Second-grade fish will be mostly consumed locally, being more affordable for the generally poorer rural population. Fish of the third grade is usually not directly consumed but processed or transformed into prahoc, or used as animal feed. Grade 1 fish include notopterids (Notopterus chitala and N. notopterus), cyprinids (Balantiocheilos melanopterus, Morulius chrysophekadion, Cyclocheilichthys enoplos, Puntioplites proctozysron, Barbodes altus, B. schwanefeldi, Osteochilus melanopleurus, Hypsibarbus lagleri, Cirrhinus microlepis, Leptobarbus hoeveni, Paralaubuca harmandi), pangasids (Pangasius sutchi, P. larnaudi), bagrids (Mystus numerus), silurids (Belodontichthys dinema, Micronema apogon) and channids (Channa micropeltes).
There are about 120 commercially important species in the lower Mekong (Jensen, 2000a). Ten species make up almost two thirds by weight of the total catch from inland waters in Cambodia and over half of its total value (Table 2.1). Since most of the inland catches originate from the Tonle Sap ecosystem, this is expected to reflect the species composition of the Tonle Sap catches as well.
Catch data have traditionally been collected by the provincial offices of the Department of Fisheries. Only data on the formally licensed (i.e., large and medium-scale) fishing operations are systematically collected. Data collection is based on the mandatory reporting of catches by fishing operators. In these reports, catches are categorized according to the three grades described earlier. There is usually no independent sampling or verification of the data presented to the Department of Fisheries. No information about catch efforts or on species composition or any other biological information is included in this yearly exercise. Even though the quality of these data is generally considered good (Jensen, 2000c*), there is only limited use for them. This system of data collection is prone to underreporting by fisheries operators as licence prices are in part determined by the previously reported catches and revenues from the same fishing operation. The permanent presence of data collectors at the large-scale fishing operations has not proven to provide more complete and accurate catch data. As a consequence, the catch and revenue from the inland fisheries have been systematically underreported, to the point where the sector risks to becoming marginalized.
* Lamberts:
Page: 3 embargoed
Table 2.1 Ranked relative species composition and value of the 1995/1996 catch (top-ten species only) from different types of large and medium-scale fisheries in Cambodia.
|
Rank |
Species |
Khmer name |
Percentage of total catch by large and medium-scale
fisheries |
|
|
by weight |
by value |
|||
|
1 |
Henicorhynchus1 spp. |
trey riel |
21 |
9 |
|
2 |
Channa micropeltes2 |
trey chhdaur |
9 |
19 |
|
3 |
Cyclocheilichthys enoplos |
trey chhkok |
9 |
8 |
|
4 |
Dangila spp. |
trey khnawng veng |
6 |
2 |
|
5 |
Osteochilus melanopleurus |
trey krum |
4 |
2 |
|
6 |
Cirrhinus microlepis3 |
trey pruol |
3 |
4 |
|
7 |
Pangasius4 spp. |
trey pra |
3 |
3 |
|
8 |
Barbodes gonionotus |
trey chhpin |
3 |
2 |
|
9 |
Paralaubuca typus |
trey slak russey5 |
3 |
1 |
|
10 |
Channa striata |
trey raws |
2 |
6 |
|
Total of 1-10 |
|
63 |
56 |
|
1 Includes three, possibly five, different species.The lack of complete catch data from all segments of the fisheries has caused or contributed to a number of problems. The fact that the reported data are only partial is in most cases neglected when these data are used, resulting in secondary data of poor quality. As mentioned earlier, the contribution of the inland fisheries sector to food security is probably grossly undervalued. The share of the GDP originating from fish, fish products and employment in the fishery sector has never been accurately assessed, resulting in an underestimation of the GDP and underperforming collection of taxes and fees for the national budget. The general impression among Department of Fisheries officials and many fishers about the decline of stocks and catches and the disappearance of larger species is likely to be accurate but cannot be substantiated without comparable data. The undervaluation of the licensed fisheries sector and the non-quantification of the subsistence and small-scale fisheries risk to contribute to the situation where the fisheries sector cannot withstand critical challenges, e.g., from proposed dam construction and subsequent alterations to the hydrology of the main fishing grounds. Other critical issues include land use and natural resource management of the floodplain of the ecosystem. Reasonably good and complete data are essential for the proper management of the fisheries and its preservation as one of the main natural resources of Cambodia.2 It is not clear whether this includes juveniles of this species, for which a different Khmer name (trey diep) is used.
3 It is not clear whether this includes juveniles of this species, for which a different Khmer name (trey krawlang) is used.
4 Includes possibly Pangasianodon hypophthalmus.
5 See note on the identification and use of the Khmer name on page 107.
Source: Deap et. al., 1998
In the past seven years, there has been a considerable effort by the DANIDA funded MRC project for the management of the freshwater capture fisheries of Cambodia to upgrade the quality and scope of the fisheries catch data. Details on the methods and results can be found in Deap et al. (1998) and Sensereivorth et al. (1999). The systematic sampling and collection of data has resulted in a more complete and accurate picture of what inland fisheries in Cambodia produce. The collection of data was refined to the level where information is collected for individual genera or species. This will allow the creation of time series of the catches and consequently a substantiated assessment of trends in the catches. It will also contribute to remedy some of the negative consequences of the current problematic data collection and presentation. The most important achievement to date is probably the capacity and awareness that has been built at all levels in the Department of Fisheries.
Consequently, the department has for the first time included figures on the other segments (family and on-farm fishing) in the official fisheries data for 1999. However, the collection of data from the licensed fishery sector has not changed. The recent creation of so-called “research lots” might contribute to an improvement in this part of the sector as well.
There appears to be a consensus in the scientific community studying the inland capture fisheries of Cambodia about the perceived declines in fish stocks and catches (e.g., van Zalinge and Thuok, 1999; Gum, 1998; Loeng, 1999). The human population increase of the last two decades has resulted in an increased fishing effort, overcapitalization and more mouths to be fed from the catches (Csavas et al., 1994; Mekong Secretariat, 1992; NIS, 1999; Ahmed et al., 1998; Demuynck, 1995). Undoubtedly these factors contribute to a trend widely perceived as a decline of the inland fisheries. In addition, a number of indicators do suggest that the fishing effort has reached levels where overfishing is likely, at least for part of the stock. From the anecdotal data and information available, it is evident that the largest species such as Mekong giant catfish (Pangasianodon gigas) and giant barb (Catlocarpio siamensis) have become less common and those specimens that are caught are generally smaller than in the past (van Zalinge and Thuok, 1999; Rainboth, 1996). Catches of large specimens of these species are headline news nowadays. There are less clear indications for the medium-sized species, although the catches have probably gone down. These include the most valuable species, which are specifically targeted. Some species have become rare or endangered (Rainboth, 1996; Ministry of Environment, 1998). The small species are still very abundant and probably more fish are being caught than ever before in this category. The reproductive biology of these species makes them less vulnerable to overfishing.
The lack of data does not allow to conclude any overall trend in the total inland catch. However, there is concern about the impact of overfishing of part of the stock on the ecosystem as a whole, and the productivity might well be affected by the decline or disappearance of species. Other major threats to the productivity come from impacts on the parameters of the ecosystem that determine its productivity and thereby the potential catch.
i. Large-scale fisheries (fishing lots)
ii. Medium-scale fisheries
iii. Subsistence (small-scale) fisheries
Based on legal and practical requirements, the inland fisheries of Cambodia have been divided into three categories: large, medium and small-scale fisheries. Apart from a number of general rules that apply to all, each category is subject to specific regulations concerning gear, fishing grounds and timing of fishing and related activities.
The large-scale fisheries are also referred to as industrial fisheries, even though there is very little industry or mechanization involved in the fishing or subsequent processing of fish. Large-scale fishing is practised in areas for which exclusive access and exploitation rights are acquired. These areas are generally referred to as “fishing lots”, and their acquisition is subject to public auction. The conditions of the lease are specified in a standard-format contract. The information contained therein stipulates the precise location and boundaries of the fishing lot, the timing and kind of fishery activities allowed and additional conditions for the lessee. Typically, a fishing lot is leased for two years, after which the lease of the lot is auctioned again. By leasing the fishing lots, and this particularly applies to the lots covering large areas, the Department of Fisheries de facto cedes control over the area of the lot, allowing the lessee to set up his own militia and use force to control access, to detain people who unlawfully enter the lot, to confiscate and destroy unauthorized fishing gear, and to regulate all other fishing activities taking place inside the lot. The fishing season is officially open from 1 October until 31 May; during the closed season, no activities are allowed in the fishing lots. In 1999, there were 239 fishing lots in the country, 139 of which are situated inside the Tonle Sap ecosystem (Table 2.2).
There are three major techniques used in the large-scale fishing operations, depending on their location in the ecosystem. Inside the Tonle Sap lake and the surrounding floodplain, fishing is mainly done by seining. In order to prevent the fish from escaping from the fishing lot exclusive area, the lessees install an extended system of bamboo fences that are being erected when the floodwaters have considerably receded. Subsequently, the fish are systematically chased out of parts of the area and collected in a large fenced holding area. In this area, the main installations of the fishing lot are built. They include a landing platform for the catches, and installations for the loading of the catch onto boats of fish buyers who dock at this platform. Usually a part of the catch is sold directly, while the rest is stocked in large floating cages. These fish are transported to Phnom Penh where generally higher prices are fetched, or they are kept for sale later when the markets are less saturated. This kind of fishing operation targets primarily fish of the first grade, many of which are black fish, like Channa, Pangasius, Cirrhinus and Kryptopterus. Juvenile Pangasius are sold not for consumption but are used for stocking in cages for further culture. There is little information available about the internal functioning of the fishing lots, but sub-leasing of parts of a lot seems to be common practice. There are reports of social problems related to some fishing lots, in particular with respect to their boundaries and the access of communities to local open-access fishing grounds (e.g., van Zalinge and Thuok, 1999; Demuynck, 1995; Gum, 1998).
Barrage fisheries are the second type of operation used in the large-scale fisheries. This technique is mainly found in the delta formed at the point where the Tonle Sap channel connects to the lake. It targets mainly longitudinally migrating fish. The composition of the catches depends on the precise location in the ecosystem and they usually contain both white and black fish. The barrages are constructed from wooden poles and bamboo fencing and block the entire width of a branch of the channel. Depending on the size of the barrage, one or more catch chambers or long net funnels are attached to openings in the barrage. The barrage operation is combined with seining. Towards the end of the water recession, seine nets are pulled downstream across the channel and the fish are trapped between the net and the barrage.
The third type of large-scale fisheries practised under the lots system is the bag net - locally called dai - fishing lots on the Tonle Sap channel. The dais are located in the southernmost 30 km of the channel. Large cone-shaped bag nets of about 100 m long and with a mouth diameter of 25 m are suspended from floaters and anchored in the channel, where they are held open by the current. Mesh size is 15 cm at the entrance and 1 cm at the bag (Loeng, 1999). Each net is considered a fishing lot. The nets are connected in series of four to nine in rows across the channel, sometimes leaving only a small opening for navigation. The bag can be winched onto a wooden platform anchored near the net end; there the catch is sorted and transferred onto boats for transport. Dais are operated from the end of September until March.
The dai fishery specifically targets migrating fish leaving the Tonle Sap lake and floodplain when the water levels begin to recede and in the months after that. There is a pronounced peak in the catches in January. The migration out of the lake towards the Mekong occurs in well-known and regular waves, reaching its highest levels six to three days before full moon (Loeng, 1999; Fily and d’Aubenton, 1966). During these migration peaks, the bags are lifted every 20-25 minutes day and night, and 500 kg of fish may be collected with each lift, to the extent that the handling and transport capacity at the dai becomes a limiting factor for the volume caught (H. Hy, personal communication, 1999). Outside these peaks, lift frequency is much lower.
The dai catch consists mainly of migrating white fish, with a majority of third-grade fish that is mostly used for the production of prahoc. Loeng (1999) reports strongly reduced catches (9 000 tonnes compared with 15 000 tonnes the previous season) from the dai fishery in 1998/1999 when the highest flood levels were considerably below normal, possibly as a result of El Niño. This supports the hypothesis that the area that is flooded is determining the productivity of the ecosystem.
Some of the fishing lots have not been leased out but were reserved for research by the Department of Fisheries. In an attempt to improve data collection from the commercial fishing lots, in 1999 some of the leased fishing lots were additionally converted into research lots. In 2000, 70 lots, or about one third of all, have been given this new status. The lot owners have the obligation to maintain the flooded forest, to allow physical demarcation of the lot area, and to allow research on species and catch data within the lot to improve fisheries statistics. However, capacity of the Department of Fisheries to effectively carry out this research is insufficient, and the previous public auction system has been replaced by less transparent direct agreements between the fishing lot lessees and the Department. Under the new status, lots can be assigned for four to six consecutive years (Department of Fisheries; Seilert and Lamberts, 2000). It is not clear what the impact of this policy will be on revenue collection for the government or on the management of the fishing lots.
Table 2.2 Type and number of fishing lots in the Tonle Sap ecosystem per province, 1999 (Department of Fisheries)
|
Province |
Fenced and barrage lots |
Dai |
Total |
|
|
Auctioned |
Research |
|||
|
Phnom Penh |
- |
1 |
25 |
26 |
|
Kampong Chhnang |
9 |
10 |
- |
19 |
|
Siem Reap |
- |
7 |
- |
7 |
|
Pursat |
- |
7 |
- |
7 |
|
Battambang |
7 |
5 |
- |
12 |
|
Kampong Thom |
2 |
5 |
- |
7 |
|
Banteay Meanchey |
4 |
- |
- |
4 |
|
Kandal |
2 |
17 |
38 |
57 |
|
Total |
24 |
52 |
63 |
139 |
The open-access areas are shared between the medium-scale fisheries and subsistence fisheries. The medium-scale fisheries are subject to yearly licensing by the Department of Fisheries. The licence restricts the activities in regard to number and kind of fishing gear and area and period of fishing. A large variety of gear is used in the middle-scale fisheries and details of the specifications for each gear type are indicated in the fisheries law. The most important gear types used are large arrow-shaped traps with bamboo fences, gillnets, traps, encircling seines and long lines. As for the large-scale fisheries, fishing is only allowed during the open season. Gillnets make up a large part of the gear used in the middle-scale fisheries; 63 percent of the households in fishing communities use gillnets (Ahmed et al., 1998).
The arrow-shaped traps are mostly used in the floodplain of the lake and are moved as the water levels recede. The gear targets fish that are migrating out of the flooded forest area and the catches are dominated by black fish, about one quarter of it giant snakehead (Channa micropeltes) (Roth and Sea, 1999). Migrating fish are guided by up to 2-km-long bamboo fences to the arrow-shaped head of the gear where they are gathered in large submerged drum-shaped traps. Although such fence lengths are illegal (the maximum length allowed is 500 m), in places the fences of traps are combined and form a large system with several traps, effectively sealing off a part of the inundated area in a way similar to the system of fences erected around the exclusive-access fishing lots. Traps are operated in the open-access fishing areas with a licence issued by the provincial office of the Department of Fisheries, or inside the fishing lots under agreements with the fishing lot lessee. Recently, there is a trend to replace the bamboo for the fences with much cheaper and more effective nylon netting (Roth and Sea, 1999). This is likely to have a negative impact on the ecosystem as nets are lost in the environment and the fishing pressure is likely to increase.
The small-scale fisheries are the third main category. All fishing activities not included in the large and medium-scale categories are considered here. Small-scale fishing, which is also referred to as subsistence or family fishing, is allowed throughout the year and in all fishing grounds, except in fishing lots during the open season and in the fish sanctuaries. Most of the fishing in this category is done for subsistence by individuals or at household level, or for cheap complementing and variation of the diet. Some of the fish caught are traded but this is usually not the main objective.
There are no accurate figures available on the importance of the small-scale fisheries in the total inland fisheries catch. One of the few studies that include the small-scale fisheries (Ahmed et al., 1998) provides some data on the species composition of the catch, albeit based on interviews with fishers rather than on sampling. One third of the fishing households (i.e., households of which at least one member is involved in fishery as a main activity in a commune that has access to a fishing ground and where inhabitants are involved in fishing) reported trey riel (Henicorhynchus spp.) as the most important species caught. Other important species are black fish. Table 2.3 provides an overview of the results of the same study on small-scale fishing in fishing grounds of the Tonle Sap ecosystem.
Table 2.3 Percentage of households engaged in small-scale fishing during the open (o) and closed (c) season in various fishing grounds in the Tonle Sap ecosystem by province (1995-1996). n = total number of fishing households questioned in the survey. (based on data from Ahmed et al. 1998)
|
Fishing ground |
Phnom Penh |
Kampong Chhnang |
Siem Reap |
Pursat |
Battambang |
Kampong Thom |
Total |
|||||||
|
o |
c |
o |
c |
o |
c |
o |
c |
o |
c |
o |
c |
o |
c |
|
|
Tonle Sap lake |
0 |
0 |
2 |
2 |
16 |
17 |
1 |
2 |
0 |
0 |
6 |
0 |
4 |
4 |
|
Tonle Sap channel |
14 |
30 |
58 |
53 |
6 |
3 |
0 |
0 |
0 |
0 |
0 |
6 |
15 |
15 |
|
Flooded rice field |
22 |
45 |
23 |
30 |
47 |
53 |
7 |
86 |
49 |
39 |
38 |
43 |
31 |
50 |
|
Small river/lake |
28 |
38 |
48 |
48 |
72 |
46 |
66 |
53 |
85 |
76 |
67 |
69 |
65 |
56 |
|
Inundated forest |
17 |
28 |
26 |
30 |
40 |
39 |
13 |
14 |
69 |
52 |
28 |
30 |
36 |
34 |
|
Others |
0 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
|
Gear type |
Percentage of all households |
Average number of gear per household1 |
||
|
open season |
closed season |
open season |
closed season |
|
|
Harpoons |
4 |
4 |
2.5 |
2.3 |
|
Bamboo/rattan traps |
26 |
29 |
10.6 |
9.4 |
|
Cast net |
32 |
25 |
1.1 |
1.1 |
|
Scoop net |
2 |
2 |
1.4 |
1.4 |
|
Gillnet |
50 |
50 |
3.2 |
3.0 |
|
Small handled drag net |
1 |
1 |
5.6 |
6.6 |
|
Single-hook line |
15 |
17 |
67.3 |
70.6 |
1 Including data from Kandal and Kampong provinces.Gillnets are the gear type most widely used in small-scale fisheries and half of the fishing households use them in addition to other gear. Gillnets are the most commonly held fishing gear in non-fishing households (Ahmed et. al., 1998).
There are reports of widespread illegal fishing operations such as the use of explosives, electro-fishing, poisoning, fishing with unauthorized and oversized but otherwise legal gear, expansion of boundaries, use of brush parks, etc. In part, this reflects the changing reality and requirements of the fisheries and the need for an update of existing legislation and rules. For example the catch per unit effort of gillnets is low (read on) and the legal limitation of 10 m length for gillnets used in small-scale subsistence fisheries is usually too low to make this operation worthwhile. On the other hand, it demonstrates the lack of enforcement capacity of the Department of Fisheries. The continued use of samrah or brush park fisheries is an example of this. This small-scale fishing practice has been classified as illegal since 1987. However, in 1998 there were still 165 of these brush parks operating in the Tonle Sap channel. The technique of the brush parks consists of the creation of an artificial habitat for fish in the open water, resembling the nearby inundated forest. To this effect, large amounts of trees and branches are cut in the flooded forest and placed in the stream in December-January, together with bamboo and wooden sticks that mark the boundaries of the brush park. These brush parks have an average area of 400 m2 (Ho, 1999). Starting in February, when the water level has sufficiently receded, the brush parks are encircled by a seine net and the branches are removed. In this way all the fish present in the artificial forest are caught. The branches are reused for a new samrah and the operation is repeated about every two months until the floodwaters come up in the channel. The catch consists of a variety of black and white fish. It is clear that this type of fishing technique has a number of detrimental consequences for the ecosystem. A considerable amount of wood is cut from the flooded forest to form the brush parks. Their presence in the channel slows down the current and increases siltation, and the parks trap floating vegetation coming down from the Tonle Sap lake. Often, navigation in the channel is hampered. Ho (op. cit.) states that the lack of enforcement in this case is due to the government ignoring the problem, despite indications of the environmental impact of the brush parks.
The fisheries of Cambodia are regulated by law, issued by the Council of State on 9 March 1987 (Fiat-Law No. 33 KRO.CHOR on Fisheries Management and Administration) and completed by two additional sub-laws (No. 66 OR.NOR.KROR of 5 November 1988 and No. 26 OR.NOR.KROR of 9 May 1989). The fisheries legislation used to be one of the most developed and extended systems of fisheries regulation found in the world (Mekong Secretariat, 1992). The law applies to all “wild” plants and animals found in the fishery domain. The inland fishery domain as defined by the law includes practically all inland waters except man-made ponds and reservoirs, and includes the areas that are only temporarily aquatic, such as the flooded forests. The fishery domain includes both the fishing lots and the area outside the lots, called the protected fishery domain. The latter includes flooded forest areas and the fish sanctuaries where all fishing is prohibited. In 1999, the World Bank made a number of recommendations for a revision of the fisheries laws (Swan, 1999).
The Department of Fisheries of the Ministry of Agriculture, Forestry and Fisheries is the agency that holds the authority over the fishing domain. The Department of Fisheries is charged with the enforcement of the fisheries law. In 1999, 1 855 cases of illegal inland fishing were taken up by the Department. Almost 150 million Riel or about US$40 000 worth of fines were imposed in a total of 638 cases, while 103 cases were referred to the courts. In 1 227 cases, illegal fishing equipment was confiscated and destroyed (Department of Fisheries).
At the provincial level, the institutional settings tend to weaken the authority of the Department of Fisheries. The provincial offices of the Department are managed under the provincial offices of the Department of Agriculture, resulting in a double hierarchy and at times conflicting interests and policies. This weakens the ability of the Department of Fisheries to implement its management activities.
The objectives of the Department of Fisheries in fisheries management are:
1. to maintain the resource for food security for all rural people;There is no elaborated overall fisheries management plan apart from the general rules and regulations given in the fisheries law (World Bank, 1995). Reforestation and restoration of the natural inundated forests and development of the aquaculture sector are the two issues that are put forward by the Department as priorities for long-term planning.
2. to use additional production for income generation from export; and
3. to assure that fisheries provide substantial input for the national economy.
The management tools at the disposal of the Department of Fisheries for the enforcement of the law and implementation of the policies are primarily licensing activities for the large and medium-scale commercial fisheries, enforcement of gear and timing regulations and research and data collection.
Table 2.5 Management issues for Cambodian inland fisheries
|
Issues |
Required management tools |
Assessment |
|
|
Objective 1: To maintain the
resource (...) |
|||
|
Exogenous |
Credible data on the value and importance of the inland fisheries
sector for use as an argument in relevant national and regional decision
making |
The present data are improving but still fragmentary. There is no
accurate valuation of the inland fisheries sector |
|
|
· Alterations to the hydrology of the Tonle
Sap |
Evidence of the importance of the present hydrological cycle for the
productivity of the inland fisheries in general, and the vulnerability
of the Tonle Sap ecosystem in particular |
Increasing amount of supporting data available but still no clear demonstration
of the importance of the hydrological cycle. Mechanism of production in
the floodplains not demonstrated |
|
|
Appropriate forums |
ASEAN, MRC |
||
|
Endogenous |
Effective regulation and enforcement |
Extensive regulation but weak enforcement |
|
|
Threats to the parameters of the inland fisheries ecosystem: |
|
|
|
|
|
· clearing of flooded forest |
Protection and restoration of the flooded forest |
Lack of enforcement capacity and insufficient integration with the multiple
functions of the flooded forest for local communities |
|
|
· hampering of fish migration |
Regulations and enforcement to ensure migration paths remain clear |
There is concern in the Department of Fisheries about the collection
of large amounts of fry in the Mekong, and about the possible impact of
heavy and noisy boat traffic on the migration paths. Use of illegal fishing
methods in migration ways (e.g. brush parks) not effectively stopped.
Construction of obstructions is forbidden |
|
|
· bad fishing practices |
Regulations specifying permitted fishing practices and effective implementation
including policing and awareness building among the fishers |
Extensive and detailed regulation exists but somewhat outdated; update
with recent information and developments required. Problematic enforcement |
|
Overfishing of specific stocks |
Quota/specification of catch limitations for vulnerable species |
No effective limitation or awareness building among fishers. Insufficient
data on the condition of most stocks |
|
|
Loss of biodiversity |
Conservation measures like the creation of protected areas Awareness
building |
Eight fish sanctuaries have been established in deeper sections of the
lake where all fishing is forbidden but poaching reported. Their boundaries
are reportedly unmarked. Some awareness building efforts ongoing but limited |
|
|
Objective 1: (...) for food security
(...) |
|||
|
Availability of food |
Effective management of the fish stocks in a durable manner and at high
levels |
Exploitation at high levels but probably not durable for at least part
of the fish species |
|
|
|
Data on per-caput fish consumption and availability |
Some data available from recent surveys but the inaccurate total production
and fish availability figures do not allow assessment of fish consumption |
|
|
|
Data on regional variation in fish consumption |
There are considerable variations in fish consumption but no specific
data available |
|
|
Objective 1: (...) for all rural
people. |
|||
|
Access to fishing grounds for subsistence fishers |
Demarcation of open-access areas and reservation of fishing rights for
subsistence fishing. Mediation and mitigation in case of conflicting interests |
Problematic in many areas due to illegal expansion of exclusive fishing
areas; open- access areas at times unlawfully occupied for private (commercial)
use. Overall weak judicial system, undermining authority of the Department
of Fisheries, and powerless fishers and local communities |
|
|
Access to food/transport and distribution |
Facilitation of transport, distribution and processing; improvement of
market transparency |
Poor but improving infrastructure (roads). Limited distribution to rural
areas away from fishing grounds. Processing is widespread but generally
of low quality and limited preservation time |
|
|
Objective 2: Use additional production
(...) |
|||
|
Assessment of surplus production |
Data on local consumption, production and availability |
Insufficient at present |
|
|
Objective 2: (...) for income
generation (...) |
|||
|
Contribution to the national budget and the operating budget of the Department
of Fisheries |
Effective collection of export taxes and fees |
Incomplete |
|
|
Contribution to trade balance |
Private sector |
Well developed |
|
|
Objective 2: (...) from export. |
|||
|
Preservation and processing techniques and subsequent food quality. |
Food quality control and assurance facilities. |
Exports to neighbouring countries ongoing and well organized. Lucrative
overseas markets inaccessible because of insufficient food quality control
and assurance |
|
|
Transportation |
Infrastructure |
Poor road infrastructure limits the amount and quality of fish and fish
products for export |
|
|
Objective 3: (...) provide substantial
input (...) |
|||
|
Establishment and collection of licence and auction fees |
Administration |
The administration is in place and well functioning. Fees are sub-optimal.
One third of the fishing lots are no longer auctioned under the new research
lots status |
|
|
Objective 3: (...) for the national
economy. |
|||
|
Contribution to GDP |
Catch data collection and market information |
Inadequate catch data, although improving. Large sectors of the inland
fisheries are not included in the production data |
|
|
Contribution to national budget |
Reliable catch data and effective tax/fee/fines collection |
Inadequate catch data. Collection of moneys inadequate |
|
Table 2.6 Formal and informal licensing agents in the inland fisheries sector
|
Licensing agent |
Nature/description of licence |
Licensing/Management objective |
Licensees |
|
Central Department of Fisheries, Phnom Penh |
Formal. Fishing lots. Licences award exclusive exploitation
rights to clearly defined and delineated fishing lots. |
· Maximizing catch |
Fishing lot lessees |
|
Provincial offices of Department of Fisheries |
Formal. Medium-scale gear licences |
· Access control |
Medium-scale gear operators |
|
Fishing lot lessees |
Informal. |
· Catch and profit
maximization |
· Individual subsistence
fishers |
|
Local military authorities |
Informal. Fishing rights for certain fishing grounds |
· Income generation |
Mainly subsistence fishers |
|
Village chiefs |
Informal. Sub-lease of parts of fishing lots. Subsistence
fishing grounds allocation |
Access for subsistence fishers |
Subsistence fishers |
In order to achieve the overall fisheries management objectives, the short-term objectives would need to include the following:
The use of the fishing lots is probably one of the most effective ways of fisheries management. Because of demand (subsistence, commercial) and the common property nature of the fisheries, most developed fisheries are overcapitalized, i.e., the users are not optimizing the use of their gear and efforts. Through the auctioning of the lots, the character of the fisheries shifts from a common property to that of a privately owned property, resulting in an adjustment of the fishing effort to minimize costs and maximize yields and profits (Laevastu, 1996). However, the short duration of the lease (two years) does not provide much incentive to the lessees to maximize yield and profit in a medium or long-term perspective, and investments in habitat conservation and other long-term measures are generally low. Since nearly all the fish catches from the lake do have a market value, the present exploitation is optimized towards as large quantities as possible, regardless of long-term considerations.
From detailed descriptions of fishing lot operations by lessees (e.g., Mekong Secretariat, 1992; Vibolrith, 1999; Loeung, 1999), it appears that these are efficiently run, and that operations are effectively focused on minimizing of costs and maximizing immediate profits.
However, the current implementation of the fishing lots system, particularly in the Tonle Sap lake, gives rise to a large number of conflicts with other, mostly local, users of the common property resources. These conflicts usually arise when the exploitation of the lots is done at the expense of the local community, by affecting its livelihood or even food security. In developing countries, the privatization of a common property resource is expected to generate benefits for the community, at all levels. Unless these issues are adequately dealt with, the lot system is counterproductive and does not contribute to the achievement of the fisheries management objectives.
For the management of the inland fisheries to be effective, action is required at regional, national and local levels. The most urgent issues are found at the local level: equitable access to common property resources, local-level food security, habitat conservation and good fishing practices.
The very nature of its productivity, the ecosystem is affected by changes in the wide environment. There are a number of significant environmental developments affecting the fisheries of the lake, events and processes that are both natural and man-made or aggravated by human activities. On the other hand, fishing activities in the Tonle Sap have environmental impacts as well.
· Siltation
Siltation of the Tonle Sap is a natural process. The rate of siltation is reported to have considerably increased in the past century, from 2-8 mm per year in 1900 to 40 mm per year recently (Mekong Secretariat, 1992; Csavas et al., 1994). However considerable, there are no differential data available for the areas of the ecosystem that are subject to local sedimentation rates. Sedimentation is more pronounced in places where differences occur in water flow speed such as the junction of the Tonle Sap channel with the Mekong at the Quattre Bras, at the mouth of rivers and canals and in the inland delta formed at the junction of the Tonle Sap channel and the lake.
Clearing of flooded forest and deforestation in the catchment areas of the Mekong and the Tonle Sap have been widely blamed for the rise in siltation. Mining for gems and deforestation have contributed to an increased sediment load of tributaries to the lake (e.g., the Sangkae river in Battambang).
The effects of the presumed increased siltation on the fisheries are mostly indirect. The flow of water to the Tonle Sap from the Mekong is reduced, resulting in a smaller area that gets flooded and therefore reducing the input in the ecosystem by the flooded forest and reducing the habitat area for the fish. A direct consequence of this is a lower productivity of the ecosystem and a reduction in potential fish catch. The average water depth in the lake during the dry season has decreased, and this has probably led to slightly higher water temperatures. The assumption that this has been the cause of reported dry-season mortalities of fish (Mekong Secretariat, 1992; Csavas et al., 1994) is unsubstantiated. Other factors such as reduced transparency would negatively impact on the capacity for planktonic photosynthesis; on the other hand, with the higher silt loads there is an increase in nutrients, and the net outcome of the two effects is unpredictable. The increased deposit of silt at the Quattre Bras and at the inland delta of the Tonle Sap could reduce the flow of fish eggs and larvae into the lake and hamper the migration of fish out back to the Mekong when the water recedes.
Proposals have been made for dredging parts of the ecosystem, particularly at the Quattre Bras junction to improve navigation, enhance the water flow and facilitate fish migration. At this point, there is a lack of understanding both of the sedimentation process in this dynamic area and fish migrations, and any assessment of positive effects of such activity seems premature (Mekong Secretariat, 1992). The dredging process itself would likely cause serious temporary problems.
· Changes to the hydrology of the ecosystem
Apart from the natural siltation process, there are a number of human activities which would have an important impact on the hydrology of the Tonle Sap ecosystem. As all other floodplain fisheries, those of the Tonle Sap are particularly sensitive to water regulation. Water regulation in the ecosystem was the subject of some proposals in the past but is nowadays discounted. Changes in the hydrology nowadays would be a secondary effect of other development plans like dams and irrigation schemes.
In the past, proposals were worked out to increase the water depth of the lake and to block the return of the floodwaters to the Mekong for two months by means of dams and a barrage on the Tonle Sap channel to increase the production time of the floodplain (Bardach, 1959; Fily and d’Aubenton, 1966). Nowadays, such proposals seem grotesque and contrary to all understanding and knowledge of the functioning of the ecosystem.
However, plans for upstream dams on the mainstream Mekong and major tributaries still are a reality. The impacts of such constructions would be lower flood levels, less flooded area and higher dry-season flow rates. The timing of the flood cycle would likely be altered, which might result in the loss of the synchronization between the reproductive behaviour of (migratory) fish species and the hydrological events. This could seriously impact on migrations and the distribution of eggs and fry (van Zalinge et al., 1999). Most previous assessments of the impact of dams construction on the fisheries of the Tonle Sap seriously underestimate the consequences. This is mostly due to the way in which these assessments are made but it is also brought about by the persistent underreporting of the inland fisheries production. Furthermore, most of the alterations to the hydrology of the ecosystem would not only affect the fish production but would also have considerable social implications. A reduction of the flooded area not only means lower production and catches but also reduced access for fishers to the stocks. This is particularly relevant for places where the fishing lots take up most of the area of the common property resources. Proposed mitigation for the loss of lake fisheries such as alternative reservoir fisheries are usually not realistic (Mekong Secretariat, 1992).
Downstream water control in the Mekong delta may also affect the Tonle Sap ecosystem, resulting in higher water levels.
· Irrigation
The development of irrigated rice culture schemes could reduce wild fisheries production (Mekong Secretariat, 1992). On the other hand, the irrigated rice fields could produce considerable amounts of fish, especially when enhanced stocking of the rice fields is carried out.
· Agro-chemicals
Intensification of rice culture and agricultural expansion in parts of the floodplain of the ecosystem lead to an increased use of agro-chemicals such as pesticides and fertilizers. Various unregulated pesticides are used and enter the ecosystem. Apart from an impact on fish production, this forms a threat to public health through the accumulation of pesticides in the fish. There is a continuing reduction of the area in the floodplains that is covered by original vegetation as more land is converted for agriculture purposes. Fertilizers used will partly run off and be taken up in the ecosystem. Given the size and hydrology of the ecosystem, this is likely to have only a limited effect on the fisheries and on productivity.
· Pollution
At present, the little-developed industry of Cambodia causes only few pollution problems. However, recent cases of illegal importation of toxic waste show that there is a danger to public health and to the Tonle Sap ecosystem. The potential impact of pollution is large, especially if migration paths were polluted (Mekong Secretariat, 1992). Urban and domestic liquid waste is not treated but directly discharged into water bodies. Especially around centres of human population (Phnom Penh, floating villages), this has an impact on water quality, particularly during the dry season, when the shallow waters are stagnant and temperatures can be high.
· River transport
Pollution at ports is a greater risk, as there is more traffic. Oils spills are a real risk and waste oil, sludge and bilge are usually discarded in the water. There is concern about the impact of busy motorized boat traffic along the channel on migration of fish.
