WORKSHOP AGENDA ITEM 3: STATE OF BYCATCH KNOWLEDGE

NIGERIA

The GEF/UNEP/FAO programme in Nigeria
James Ogbonna, Federal Department of Fisheries, Abuja

Introduction

Nigeria has a long coastline of about 850 km, lying mainly from the Niger-Delta to the border with the Republic of Cameroon. Industrial shrimp activities are limited mainly to the Southeast. Shrimp trawling in Nigeria began in the 1960s. Currently a total of 167 trawlers are licensed to trawl for prawns. The annual prawn production is about 12 000 tonnes of which 8 000 tonnes is exported. The Nigeria shrimp trawling industry is associated with a significant amount of discards and bycatch. The discards consist mainly of small sized fishes and juveniles of commercially important fish species. In the prawn trawl fishery, fish and prawns comprise 75 percent and 25 percent of the total catch respectively

Policy and legislation on shrimp bycatch

The Sea Fisheries Decree No.71 of 1992 requires that all shrimp trawl codends should not exceed 44 mm mesh size. The law also prohibits the dumping of edible seafood in the territorial waters. The law also recommends that the ratio of fish:prawns should be maintained at 75:25. In practice this is never maintained and more fish, relative to prawns is caught. Currently no technology is employed to reduce the capture of juvenile/adult finfish in shrimp trawls. However, in compliance with the Code of Conduct for Responsible Fishing (CCRF), and in order to make the Nigerian shrimp product acceptable in the American market, Turtle Excluder Devices (TEDs) are already installed in the shrimp vessels operating in Nigeria’s territorial waters. One fishing company had voluntarily employed the same type of trawls with 60 mm cod mesh size and they report landings of premium fish and less discards. Data from this exercise have not been analysed independently.

Bycatch utilization

The bycatch comprising adult and juvenile finfish of commercial value is usually sold to fishmongers who in turn retail them at the various marketing outlets. Some of the bycatch, usually juveniles, are also sold at sea by some unscrupulous vessel captains/crews or at the numerous fishing markets of the coastal/riverine communities. From an economic point of view the level of bycatch and discard generated is on the increase. There is also an expanding market for the trash fish at the numerous fishing communities due to the existing high demand for fish. The effect of bycatch on the recruitment vis-à-vis species diversity has not been properly researched.

The GEF/UNEP/FAO programme in Nigeria

From 1999, Nigeria has been participating in the GEF/UNEP/FAO shrimp fisheries project. The focus of this project is the reduction of the environmental impacts of shrimp trawling through the use of Bycatch Reduction Technologies and change in fisheries management regimes. The project is being implemented in two phases viz:

(a) Preparatory phase
(b) Implementation phase (main phase)

Project preparatory phase

This phase consists mainly of wide consultations with all stakeholders and that was after Nigeria had indicated that the problem of bycatch existed and needed to be reduced. Apart from consultations, sensitization/interactive sessions were held with people in the bycatch (discard) trade. There was a lot of anxiety expressed by both traders and fishers over alternative means of making money if the quantum of bycatch was reduced. The project was easily accepted by the stakeholders due to the following factors/issues:

• Trash fish marketers/crew were afraid of losing the lucrative fish bycatch business;

• Marketers/middlemen, especially those engaged in transshipment were eager to cash in on the trash fish business;

• Nigeria’s large population creates consumer pressure for trash fish and therefore the market for trash fish is readily available;

• The sound management of the trawl fishery and utilization of the trash fish was going to contribute positively to the government strategy on poverty alleviation and food security;

• The stakeholders were unanimous about the non-sustainability of the current method of shrimp operations and the need to employ new tested mitigating technologies to reduce bycatch (trash).

At the end of the preparatory phase, an international workshop was held in Lagos with participants drawn from many parts of tropical Africa but with focal points from Cameroon, Tanzania and Nigeria. At the end of the workshop a general work outline/framework was agreed upon which was later reviewed, developed and approved as the shrimp fisheries project

Project implementation

In the approved project, the Federal Department of Fisheries (FDF) of Nigeria, as laid out in a Letter of Agreement, will undertake to implement the following subprojects:

• Improved routine shore-based collection of fisheries statistics (particularly from the shrimp trawler fleet). This includes data on fishing effort, fishing capacity, landing of shrimp, valuable fish, bycatch, etc over an annual cycle.

• Collection through an onboard observer/sampling programme of precise detailed data on actual effort and catches by industrial shrimping.

• Initiation of a campaign for the widespread introduction of appropriate bycatch reduction technologies in the industrial shrimp trawler fleet.

• The compiling of existing fisheries legislation, regulations plus measures for ongoing MCS of shrimp trawlers fisheries.

Under a different letter of agreement, the Nigeria Institute for Oceanography and Marine Research (NIOMR), the marine research arm of the Federal Ministry of Agriculture, is to undertake the following in collaboration with the Republic of Cameroon:

• The design and implementation of a socio-economic survey of the shrimp-trawl fisheries and the trading of their bycatch.

• The development/adaptation of appropriate bycatch reduction technologies for the Nigerian and Cameroonian shrimp-trawl fleets.

• The construction of prototype BRDs for testing in the commercial shrimp trawls fisheries.

• The implementation of a training/outreach session for some commercial fishermen from Nigeria and Cameroon in the construction and operation of these prototypes.

Project achievements

A draft data collection format for the fishery has been developed by the FDF awaiting the ratification of the project steering committee.

• The draft format for the socio-economic survey is nearing completion.

• The Honorable Minister of Agriculture recently approved the review of the sea fisheries act. The composition of the review committee cuts across many disciplines. Nominations are being received from different relevant establishments for the initiation of the review committee. After working internally, the draft paper produced would be reviewed together with the Republic of Cameroon.

• The Letter of Agreement for the implementation of the FDF component of the project in Nigeria has been signed. A dedicated bank account has also been opened. NIOMR is working on the second Letter of Agreement

At the end of the project it is hoped that all shrimp vessels will be employing the adopted bycatch reduction devices. There is close collaboration between Nigeria and the Republic of Cameroon in the implementation of the project.

Constraints

The major impediment to the actual initiation of the project has been funds. The inaugural meeting which precedes the actual project commencement is currently awaiting the release of funds.

KENYA

Gerald Mwatha, KMFRI, Mombasa

Due to bathymetrical, ecological and other environmental factors, the Malindi-Ungwana Bay is the area with the highest concentrations of shallow water prawns within Kenyan marine waters. Shallow water prawns are also found in the mangrove inlets. Mostly they are found in the mangrove inlets up to sub-adult stage while adult prawns are commercially caught by trawlers in the Malindi-Ungwana Bay area. In the mangrove creeks, prawn fishing is mainly at subsistence level and peaks during the rainy season. In the Malindi-Ungwana bay, the prawn fishery ha developed as a commercial fishery since the mid-1970s. Trawlers of various sizes carry out bottom prawn trawling all year round. Over time, the number of trawlers fishing in this area has varied greatly between 5 and 20 each year. However, not all the licensed trawlers are actively engaged in prawn trawling. For example, in 2000, out of the 12 licensed trawlers only 6 were fishing. In the last decade, the average annual landings from prawn trawlers have averaged 334 and 640 tonnes of prawns and fish respectively (Anon, 1999).

There have been limited efforts to quantify or qualify the amount of bycatch associated with prawn trawling activities since commercial prawn trawling began in the Malindi-Ungwana Bay area. Monitoring of the bycatch is also lacking. However, there is some available information on the quantity of high quality fish retained by the trawlers. Figure 1 shows the annual landings of prawns and fish by the prawn industry over the years.

Figure 1: Annual landings of prawns and fish by the semi-industrial prawn trawlers operating in Malindi-Ungwana Bay area (Data from SECO and Alpha fishing companies).

A short evaluation on the impact of trawling on turtle mortality was carried out in 1997 (Mueni, KMFRI, unpublished data). The survey showed that prawn trawling in Kenya has a bycatch of about 70-80 percent bycatch in weight, which includes juveniles of commercial fish species and other marine organisms that include endangered species like sea turtles.

To address the persistent complaint by the artisanal fishermen about the high amount of bycatch generated by the prawn trawlers, among other concerns, the government banned prawn trawling in 2000 to allow for detailed scientific research to be carried out in order to gather correct information and make recommendations on the appropriate management intervention. During the same period, the Food and Agriculture Organization funded a research project to quantify and qualify the amount of bycatch associated with semi-industrial prawn trawling in Kenya. This research work was carried out over a period of one year (2001 to 2003) by the Kenya Marine and Fisheries Research Institute in collaboration with several organizations and stakeholders (Mwatha, KMFRI, unpublished). From this study, it was established that the ratio of total bycatch to prawns is 7:1. On average, each trawler discards about 1.5 tonnes per day. Small sized fish are the most commonly discarded fish in this fishery.

Between 25 and 30 percent (in weight) of the total fish discarded is made up of juveniles of commercially important fish species (Fig. 2). Sciaenidae (especially Otolithes ruber Malindi herring, and Johnius sp.) and Pomadasys sp are the main fish discarded in this category. At larger sizes (>20cm) the same species are retained. Figure 2 shows the spatial distribution of commercially important fish species in Malindi-Ungwana Bay.

Fish discarding has brought to the fore bitter conflicts between the artisanal and the semi-industrial sectors of the fishery. The artisanal fishermen argue that the decline in fish catches is due to the destruction of fish habitats by the trawlers. They also view the discarding of fish as a real case of food wastage and they would like to see it eliminated or reduced. The Fisheries Department, Kenya Marine and Fisheries Research institute and other stakeholders are holding regular consultative meetings to address the problems associated with prawn trawl bycatch, explore new opportunities and build consensus among the interested groups. Further detailed evaluation and monitoring of the bycatch is to be undertaken.

Figure 2: Temporal distribution of commercially important fish species discarded by prawn trawlers in the Malindi-Ungwana Bay area.

MADAGASCAR

Guy Rabarison, CNRE, Antananarivo

This is a brief review of bycatch composition studies done by the former French Oceanographic Centre (ORSTOM) and the National Oceanographic Research Centre (CNRO) at Nosy-bé (Madagascar). The first study was conducted in 1964 in the Ambaro Bay, the most important shrimp fishing ground in the northwest of Madagascar. The aim of the work was to make a survey of benthic resources of the Bay, both shrimp and fishes. The results presented here concern only the information on fish assemblages as bycatch in the trawl fishery. The second study was carried out by CNRO in 1984/85 and was aimed at assessing the importance of bycatch of the industrial shrimp fishery in the northern part, namely Ambaro Bay, Ampasindava Bay and Mahajanga Bay which was named Zone I, Zone II and Zone III in the fishery regulation at that time. Both surveys were done with the research vessel of the Centre.

The survey done in 1964/1965 with the R/V VAUBAN resulted in a description of the fish population on the shrimp fishing ground in Ambaro Bay - northwest of Madagascar (reported in Chabane and Plante, in Cah. ORSTOM, 1964). Two types of substrata were identified, sea grass and muddy-sand bottom. Main families found in sea grass habitats were Lethrinidae, Lutjanidae, Siganidae and Serranidae, while in muddy/sand habitats, Leiognathidae, Gerridae, Mullidae, Clupeidae and Theraponidae dominated. During 1984 and 1985, a preliminary assesment of industrial shrimp trawl bycatch was done by CNRO using R/V TELONIFY. A qualitative and quantitative evaluation was carried out.

Table 1: Sampling with the research vessel B/R TELONIFY

According to the species occurring in the local market, species were classified in two categories: commercial fish (P1) and trash fish (P2). In these groups, species were sorted as dominant (more than 30 percent of positive trawls) secondary (between 30 and 10 percent of positive trawls) and accidental (less than 10 percent of positive trawls).

Table 2: Main species composition (only top four species in each category listed)

Overall species composition in weight was also calculated from 201 trawls (137 in wet season and 64 in dry season).

Table 3: Main fish species in bycatch (by weight)

Estimations of catch rates (kg/hr) of commercial fish (P1) and trash fish (P2) in the 3 zones are given in table 4.

Table 4: Catch rate (kg/h) of bycatch fish species

The ratio of commercial fish over total bycatch, for zone I, II and III are given in table 5.

Table 5: Ratio of commercial fish to total bycatch P1 / (P1+P2)

The relation of bycatch to total catch i.e. shrimp and fishes, varies between 0.858 during the dry season and 0.356 during wet season. Based on this relationship, the biomass of bycatch for 1984 was estimated at 2 221 tonnes. Discarding is about 20 000 - 30 000 tonnes per year (not included in global marine catch statistics). Only 3 000 - 4 000 tonnes are landed and sold for consumption by the population.

MOZAMBIQUE

Barbara Sousa, Instituto de Investigaçao Pesqueira, Maputo

Mozambique is located on the eastern coast of southern Africa between 10^o27´ and 26^o2´S latitude and 30^o12 ´E and 40^o51´E longitude. The Mozambique coastline is 2 700 km long and is characterized by a wide diversity of habitats including sandy beaches, sand dunes, coral reefs, estuarine systems, bays, mangroves and seagrass beds, which offer good conditions for marine animals, such as marine mammals and sea turtles. Total population in 1994 was estimated to be 16.6 million inhabitants (World Bank, 1995). The majority of the population is rural (approximately 76 percent) and the remaining 24 percent live in urban areas (provincial capitals). As a result of the civil war, a large part of the population resettled along the coast and is dependent on marine resources.

Shallow water shrimp occur in the Sofala bank area which is located in the central part of Mozambique, between the latitudes 16^o00´S and 21^o00´S, at depths ranging from 7 to 70 m. Shallow water shrimp are widely distributed along the coast mainly in mangrove areas where shrimp juveniles grow. Bottom conditions are generally good for trawling but, north of 17^o30´S, the continental shelf is very narrow with fringing corals forming a chain of small islands, which makes trawling difficult. South of 19^o30´S, at depths between 40 and 100 m, the corals still present a problem, but trawling can be conducted with caution. (Palha de Sousa, 1996; Fig.1). This resource is exploited by industrial, semi-industrial and artisanal fisheries.

Figure 1: Map of Mozambique and the main trawling grounds

The shallow water shrimp fishery started in 1964 on the Sofala Bank, with a foreign fleet. Until 1973, the national industrial fleet operated between Angoche port and Pebane. From 1974 onwards some trawlers selected Quelimane as a base harbour and fishing area was extended to the Zambezi river delta. During 2001, 80 industrial and freezer semi-industrial vessels representing several companies were licensed to conduct this fishery. All vessels are outrigger trawlers but the boat characteristics such as length, engine horsepower, gross tonnage and number of nets vary among companies. In Beira Bay, 25 ice semi-industrial vessels also operated in the same year (Palha de Sousa et al., 2002).

In 2001, the catch of the industrial fishery (including the freezer semi-industrial vessels) was 8 751 tonnes and for the ice semi-industrial fishery was 218 tonnes (Palha de Sousa et al., 2002). The fishery targets different species of shallow water shrimp such as: Penaeus indicus (white shrimp); Metapenaeus monoceros (brown shrimp); Penaeus japonicus (flower shrimp); Penaeus latisulcatus (marfil shrimp) and Penaeus mondon (tiger shrimp). White and brown shrimp comprise about 70 to 80 percent of total shrimp catches (Palha de Sousa, Schultz and Pacule, 1996). During most of the fishing trip, the shrimp bycatch is discarded. The most valuable fish are sorted and frozen and part of the bycatch may be collected by artisanal fishermen for human consumption (fresh or dried). By catch annual estimates from 1993 to 1996 varied from 21 000 to 29 000 tonnes per annum (Schultz, 1997). Research on shallow water shrimp bycatch started with an ongoing sea sampling programme on board the shrimp trawlers in 1984. Also during shallow water shrimp research surveys, data on bycatch is collected, processed and analysed. Since 1984, data were collected on board to determine the relationship between shrimp and bycatch, and information was also collected from landings to establish species composition and biological characteristics of the main species (Palha de Sousa and Schultz, 1987; Schultz, 1997). From 2000 onwards, data were also collected from the artisanal fishery in Zambézia province. The shrimp species composition is the same in this fishery.

Bycatch comprises about 80 percent of the total catches (Table 1). The most abundant families/groups are Sciaenidae, Trichiuridae, Brachyura (crabs), Engraulidae, Haemulidae and Synodontidae, and the most abundant species include Otolithes ruber (tigertooth croaker), Johnius amblycephalus (bellfish), Johnius dussumieri (bearded croaker), Trichiurus lepturus (largehead hairtail), Arius dussumieri (blacktip sea catfish), Pellona ditchela (indian pellona), Thryssa vitrirostris (orangemouth thryssa) and Pomadasys maculatum (saddle grunt).

Table 1: Annual percentage of bycatch from 2000 to 2002 (Palha de Sousa and Baltazar, 2002)

Catch composition varies depending on the area trawled, and catches may be clean or may include different degrees of mud, sponges, algae, etc. Fig. 2 shows fish catch composition by family for 2000 and 2001.

Figure 2: Main catch composition of fish for 2000 (left) and 2001 (right) (Palha de Sousa and Baltazar, 2002).

SOUTH AFRICA

Sean Fennessy, Oceanographic Research Institute, Durban

The South African prawn trawl fishery is relatively small, catching about 300 tonnes of target species per annum, with a value of about $ 1 million. There are shallow (< 50 m) and deep (> 100 m) water components, and the fishery is managed by means of input controls, i.e. there are no quotas. It is a wasteful fishery, with about 1 000 tonnes of discards per annum.

The deep water component currently has about four vessels operating, and catches about 250 tonnes of pink prawns (Haliporoides triarthrus), crabs (Chaceon mcphersoni), rock lobster (Palinurus delagoae) and langoustines (Metanephrops mozambicus) per annum (Fennessy and Groeneveld, 1997). There is a retained bycatch of about 30 tonnes per annum, mostly comprising fish and cephalopods, and a discarded bycatch of about 1 000 tonnes. The composition of the discards is not well known, although the fish component is dominated by greeneyes (Chlorophthalmus punctatus), coffin fish (Chaunax pictus) and rattails (Family Macrouridae) (Fennessy and Groeneveld, 1997). The shallow water fishery comprises four trawlers, targets penaeid prawns (mostly Penaeus indicus and Metapenaeus monoceros) and catches about 100 tonnes per annum (Fennessy, 1993). The retained bycatch (mostly fish and cephalopods) is about 25 tonnes per annum and the discarded bycatch is diverse, but mostly consists of fish and crustaceans, and is about 400 tonnes per annum (Fennessy, 1994a; Fennessy, 1994b). The fish component of the bycatch mostly consists of Otolithes ruber, Johnius dussumieri, Johnius amblycephalus, Trichiurus lepturus and Thryssa vitrirostris (Fennessy, Villacasting and Field, 1994).

Data on deep water and shallow water retained bycatch has been collected since 1985 (based on skipper’s logbooks), while research on the shallow discards was conducted from 1989-1992 (Fennessy, Villacastin and Field, 1994; Fennessy, 1994a; Fennessy, 1994b; Fennessy, 1995). Investigation into shallow water bycatch reduction was undertaken in 2000 (Fennessy, 2002) and further work is planned in 2003, while investigation into the rationale behind the duration of the shallow water trawling season is currently being conducted. Additionally, observers from the local management agency (Marine and Coastal Management) have been undertaking trips on trawlers since 2002.