MANAGEMENT

Current and recent management measures as well as those being developed that are applicable to various aspects of wild seed fisheries associated with CBA are summarized and discussed. Regulations on marine and freshwater invertebrates and vertebrates from around the world are selected to provide a cross-section of the types and extents of protective measures (Table 6). The selection is illustrative, rather than exhaustive.

The development of management measures has been a response to problems noted in various fisheries, usually declining catches but sometimes concern over bycatch or damage to substrate. In some cases the cause of the problem is clear or can be reasonably attributed to a specific cause or causes, but in others, the reason for problems is not necessarily clear and management is precautionary or based on the best available scientific information. Management measures to address overfishing that have been introduced or are under discussion range from gear controls to catch quotas (e.g. total allowable catch), limited fishing seasons and export controls, size controls, permit issuance, rights of access to fishing grounds, to genetic pollution and disease controls.
In cases where habitat damage is a major concern because seed capture methods involve removal of habitat, fishing gears that move closely over the substrate, or poisons, measures used include bans, modification of fishing gear and protection of larval and juvenile settlement or nursery areas. Where there are concerns about possible impacts on biodiversity of non-target stocks, largely because of bycatch, measures address gear characteristics and may involve training fishers in better handling techniques for reducing mortalities. Example include, more careful transfers during transport, lower densities of storage and transit, more oxygenation as needed, etc. Other measures tackle concerns about disease transfer, as seed have increasingly been traded (exported or imported) or exchanged as part of a valuable seed market, with possible genetic “pollution” from reintroductions or escapes of genotypes into non-native areas.

Typically and not surprisingly, wild seed fisheries for CBA often begin with no management and are practised for decades, sometime generations, with little or no controls. Examples range from molluscs, catfish, mullets and milkfish to groupers and eels. Seed fisheries were largely excluded from formal legislation in the past. This is possibly because of their low perceived value and impact and limited information availability. It may also be because of a general perception that taking seed was somehow getting “something for nothing”; that removal of larvae and small juveniles did not affect adult populations because most would die naturally if not fished – indeed CBA is more likely to be viewed to be a means to gain a net increase production. When fishing pressure was low, this may well have been the case. As fishing pressure and demand for seafood increased there has been a general intensification of fishing, including on seed fisheries. In the case of mussel from New Zealand, it is quite possible that highly targeted collection of large numbers of spats could significantly affect population regeneration since a high proportion of settlers are removed for CBA each year. It is only in the last decade or so, often only after stocks have been very severely reduced, or where there are conflicts identified between users of different life history stages of a species (e.g. in the cases of lobsters, shrimps, shark catfishes, eels and tunas) that management is discussed and legislation developed, and the biological and ecological links formally acknowledged. The high value luxury seafood seed fishery sector,

including for southern bluefin tuna, lobster and grouper, have provided much incentive for sustainability. Management has developed quickly that explicitly addresses the links that exist between adults and pre-adult phases taken by different fisheries.
As fishing, in general, has intensified, it is not surprising that the potential for adult capture fisheries and seed fisheries to affect each other has been realized to the extent that there are now management initiatives that seek to ensure that the two fishing sectors are not in conflict by using stock analyses. This will have to be one of the approaches to management in future if stocks are to be sustained, if equity is to be considered between fishing sectors, and if conflicts over resource use are to be minimized and management aims for sustainable practices realized. This balancing of differential life history phase use is referred to under the general name of “biological neutrality” (Gardner et al., 2006).
For insight into some of the complexities and issues involved in conserving seed fisheries, the long-standing European eel fishery serves as a good example. Declines in European eel catches, including glass eels, elvers and adults, have occurred throughout the range of the species; the exact cause is unknown. Likely causes are a combination of over-exploitation, oceanographic or climate change, freshwater habitat degradation and pollution, and disease, although overexploitation is clearly one important factor (Knights, 2003; Starkie, 2003; Van Ginneken and Maes, 2005). Since so little is known about the life history stages of the European eel, planning for its sustainable management is a difficult challenge and it is only very recently that serious discussions have started to address the long-recognized, albeit little acknowledged, declines in catches (Table 6). Most recently, a study demonstrated genetic differentiation in the European eel indicating that the species consists of several stocks and not just one, as previously thought (Wirth and Bernatchez, 2001). This information is important for assisting protection because it identifies the geographic scale at which management might be most effective and indicates that the massive transfers of seed that have occurred widely within Europe should be restricted or carefully controlled.
Shrimp seed fisheries can be extremely complex; many have a long history of fishing with the involvement of many different user groups. In one area of Bangladesh, for example, the interest groups for shrimp production range from shrimp farmers, biologists and government, to the fishers and hatcheries that supply the farms and exploitation on both adult and seed stocks all have very different needs and opinions on how to deal with the marked declines noted in one of the two shrimp species they commonly exploit (SAPB, 2002). The long history and complexity of this situation makes management extremely difficult and provides a lesson that management should start early in fishery development rather than long after major conflicts and resource declines have occurred and many users or user groups become involved and dependent.
In summary, the management experience for seed fisheries is extremely varied, most is very recent, and little appears to have been effectively implemented to date.
There is little evidence of monitoring of seed fisheries in general, which is essential for understanding the effects of management, or of enforcement. It is clear that many of the management challenges stem from the complexities of understanding and assessing fisheries acting at different life history stages, especially when one of these, the early life history “seed” stage is little understood (either biologically or as a fishery). The general assumptions surrounding the impacts, or, rather, the lack thereof, of removing early life history phases, on later adult stages or wild populations have precluded management discussions until recently.
Regulations that address seed fisheries must focus on specific aspects of the problems encountered and not just treat them as fisheries of “undersized” individuals, except, perhaps in cases such as of the humphead wrasse and bluefin tuna. The problems are compounded when other factors, such as habitat degradation, destruction or water pollution may also be major factors in declines noted. What is clear is that seed fisheries are important and likely to be important for a long time since HBA (i.e. full-cycle aquaculture) is only viable for a small subset of aquatic species. Even in species for which hatchery-reared seed are available, issues of seed “quality”, HBA production volumes and costs may mean continued pressure on wild stocks to provide high quality, inexpensive seed. Farmers may prefer wild-caught seeds in some areas, such as milkfish in the Philippines, shark catfish in Viet Nam, shrimps in Bangladesh, or economic factors might mean that wild-sourced seeds are sometimes cheaper than those of the same species that are hatchery produced, as in the case of several grouper species in the Taiwan Province of China culture sector (Sadovy, 2000). The issue of management of wild populations in CBA, therefore, must be addressed, and must specifically seek to tackle the characteristics of “seed” fisheries.