MANAGING CAPTURE-BASED AQUACULTURE OF GROUPER

The management of capture-based farmed groupers is complicated by several problems, including shortage of capture-based seed, disease transfer resulting from international trade in seed, high mortality rates in capture and culture, overfishing of grouper adults, etc. (Ottolenghi et al., 2004). Groupers are top predators, sedentary in character and strongly territorial, typically long-lived and slow growing and many assemble in large numbers to spawn. These characteristics contribute to the ease with which over exploitation may occur, and is engendered by the Live Reef Fish Trade (LRFT).

This has already led to calls to include many of the target species in Appendix II or III of the Convention on International Trade in Endangered Species (CITES) (Lau and Parry Jones, 1999). The Nature Conservancy (TNC) has developed a regional strategy in the Asia-Pacific that focuses on developing and applying regional models to sustainable fisheries. Many different approaches have been taken to reduce exploitation, e.g.

the Bahamian government has recently approved the establishment of five no-take marine reserves. All of these sites contain known Nassau grouper (Epinephelus striatus) spawning aggregations. Although stocks of Nassau grouper in the Bahamas appear to be healthy, these closures (coupled with other research activities) are being implemented to ensure that conservative management measures are taken, as a precaution against stock collapses such as those that have occurred in other locations that once held stocks of this species (Johannes, 2000). In Micronesia, Palau was among the first nations in the world to protect their grouper spawning aggregations, enforcing a seasonal closure on the Ngerumekaol (Ulong Channel) aggregation site in 1976, then creating permanent no-take marine reserves at Ngerumekaol and Ebiil (another aggregation site) in 1999. Pohnpei State in the Federated States of Micronesia has also declared permanent no-take zones around its grouper spawning aggregations (Rhodes and Tupper, 2007). Both Palau and Pohnpei have closed their grouper fisheries during the reproductive season and have limited or banned export of groupers and other species involved in the live reef fish trade.
Other regulations should be developed to control the harvest of grouper seed. The availability of capture-based grouper seed is often insufficient and unreliable (both in quality and quantity) to meet demand; low production in farming is mainly attributed to lack of seed supply (Chao and Chou, 1999; Yashiro, Vatanakul and Panichsuke, 2002; Agbayani, 2002). Disease problems due to the high transfer stress can cause high mortality rates in capture and culture. Sadovy (2000) has compiled information on the status of regulations on grouper seed capture and exports that concern capture-based aquaculture (Table 21).
A survey of CBA in Southeast Asia found that while the quantity of seed caught was significant, the production level was very low (Sadovy, 2000). The major causes contributing to this massive mortality are destructive fishing practices and gears, poor post-harvest handling, poor farming practices and conditions, and a generalized lack of experience or knowledge. This review indicated that there is a substantial fishery, and demand, for fish in the 5–10 cm range, but that the removal of this seed could have serious consequences for the future of both adult stocks and the contribution of these adults to the future of the seed fishery itself. Given the likelihood that there will be a significant increase in natural mortality for the smallest settling fish, several researchers have already proposed that fisheries for very early post-settlement (or even pre-settlement) seed is a way of gaining benefit from a resource that does not affect its long-term sustainability.
It is necessary to consider further initiatives to attain a more sustainable use of grouper stocks and greater socio-economic benefits from grouper capture-based aquaculture. One possible approach for grouper management is, as Sadovy (2000) suggests, the establishment of nursery areas where the capture fishery and culture operations occur. Another possibility is to protect key seed settlement areas and nursery habitats, such as mangrove areas, coral rubble and sea-grass environments in river mouths and estuaries, and to ensure seed production by safeguarding spawning adults. Marine protected areas (MPAs) should incorporate key settlement and nursery areas, but to date, there are few (if any) MPAs protecting grouper nursery habitat (Tupper, 2007).
Positive steps to address many of these issues are being taken by the Network of Aquaculture Centres in Asia and the Pacific (NACA) and its partners, the Asia-Pacific Economic Cooperation (APEC), the South-East Asian Fisheries Development Center (SEAFDEC), the Australian Centre for International Agricultural Research (ACIAR), and the WorldFish Center (formerly known as ICLARM), etc. In 1998 the Asia-Pacific Grouper Network (APGN) was established; this organization addresses aquaculture development, in order to:
• reduce the current reliance on capture-based “seed” for aquaculture, as the capture of wild juveniles is sometimes carried out using destructive fishing techniques that can have significant impact on the long-term status of the stock;

TABLE 21
Southeast Asia national regulations

Locality Regulation
China Limits the number of grouper “seed” fishers and the quantities of grouper “seed” captured
A licence is needed for transporting marine “seeds” and their export is
prohibited
There is a management regulation of Guangdong Province for the cultivation
of aquatic products in the shallow sea intertidal zone, which applies to those
engaged in marine cultivation
China Hong Kong SAR Culturists must be licensed and operate in one of 26 gazetted culture zones There are no regulations that apply to the capture of grouper “seeds” or their
import or export
Indonesia There is no management of seed resources
Malaysia Federal legislation prohibits the use of cyanide for fishing
In East Malaysia there are no special regulations for grouper seed capture.
Some regulations may act indirectly, for example some gears that are made
of trawl net are subject to trawl mesh size control. Grouper seeds cannot be
imported for culture
In West Malaysia the fishing of “seeds” is not allowed during November and
December; it is only permitted during the peak season from January to April.
No export of seeds smaller than 15 cm is permitted
Philippines It is illegal to use cyanide or any other poisonous substance for fishing The scissor net is illegal
Fyke net have been banned
The Fisheries Code of 1998 (Republic Act 8550) prohibits the export of “seed”
of milkfish and prawn but its application to grouper is not clear. This Code
regulates gear/structures and operational zones for fish capture and culture
Transportation and export of fish and fisheries products requires permits from
the Quarantine section, including a health certificate from the Fish Health
section of Bureau of Fisheries and Aquatic Resources (BFAR)
Taiwan PC In Penghu Island, fishers are not permitted to catch any grouper seed of <6 cm The use of cyanide for fishing is illegal
Thailand The use of push nets and fyke nets is limited. Push nets and trawlers should not be used within 3 km of the shore and the mesh size of trawlers should be
?2.5 cm.
Viet Nam Government regulations prohibit export of groupers <500 g (ex Ministry of Fisheries)
There is no limit on export volumes. For export a health certificate from a
provincial office, Fisheries Resources and Environment Conservation Sub
Department is needed, and requirements of the importing country satisfied

Source: Sadovy, 2000, as reprinted in Ottolenghi et al., 2004.
• provide an alternative source of income/employment for coastal populations currently engaging in destructive fishing practices;
• protect endangered reef fish from the pressures of illegal fishing practices, through the development of sustainable aquaculture; and
• develop new aquaculture livelihood options and investments that will generate economic benefits for a diversity of stakeholders and employees.
Since 1996, all the above mentioned organizations have conducted workshops, with the aim of establishing a regional mechanism for research cooperation that supports the sustainable development of capture-based aquaculture in the Asian region. Emphasis has been placed on technology transfer and management strategies for the benefit of farmers and coastal populations (Ottolenghi et al., 2004).