Fish Spawning Aggregations: A Reef Resilience Toolkit Module

Fishing Limits

While MPAs (year-round or seasonal protection of FSA sites) are considered the most effective protection for spawning aggregations, gear restrictions, catch limits, and trade restrictions can also be applied, and be used in conjunction with MPAs. Be aware that these other measures may not be as effective as closures, particularly if markets are not centralized, or if enforcement potential is limited. Similarly, permanent MPAs will not work in some areas. For example, in some locales, such as the Solomon Islands, MPAs are used to rebuild stocks or populations following pulse fishing. These temporary MPAs (called tambus) are a traditional form of management, and lobbying for or insistence on promoting permanent MPAs would not be accepted.

Working with both the fishers and the sellers to enforce fishery regulations is essential. Photo © Wolcott Henry 2005/Marine Photobank

• Gear bans can be helpful, but generally are not sufficient. Traps, nets, spears (especially with SCUBA), or poisons are methods that promote rapid overfishing of aggregations. Hand-line fishing, often considered less detrimental to aggregations, have also been implicated in FSA overfishing and loss.
• Catch quotas can be useful tools to manage traditional fisheries at sustainable yield levels. However, catch quotas are not useful for managing FSAs, simply because of the complexity and unknowns associated with aggregating fish populations and FSAs. In addition, quotas are extremely difficult to enforce, and may cause incidental death of fishes caught and released, once the quota limit is reached for a species. Catch quotas are not recommended for FSA management. Indeed, allowing fishing on FSAs is likely to lead to problems both within the FSA itself and among user groups.
• Size restrictions are another form of traditional fishery management, but are usually not considered useful for FSA management. One reason is that many species are sex changing (hermaphrodites), making determination of size limits difficult, with the release of illegal-sized fish often resulting in unintended mortality. As mentioned elsewhere, allowing larger sized individuals to be taken, for example, increases the chances of altering the sex ratio to reduce reproductive output, particularly in hermaphrodites. Size limits are often also difficult to enforce, e.g., many fishing methods are not size selective, fish may be sold as filets, and landing or processing of fishes may occur outside enforced areas.
• While traditional, subsistence use of FSA sites might still be permitted at some limited level, subsistence fishing has also been implicated in FSA loss. Where traditional management is strong and permanent MPAs are not possible, subsistence or pulse fishing may be permitted by traditional reef owners. In these cases, FSAs are closely monitored and fishing made to cease when the FSA abundance is low. Traditional owners may close the FSA to fishing for years to allow populations to gradually increase, while still maintaining traditional user rights at a low level in these areas. These types of FSA fishing are inherent within certain cultures, but are not recommended in areas where such traditions do not already exist.
• Export bans are valuable in areas where export can be effectively controlled, and where there is evidence that FSA-derived fishes are being exported. Export of FSA-derived fishes should be restricted as part of a comprehensive management plan.
• User-permit fees for MPAs should be instituted to support enforcement and maintenance of the FSA. However, access to and use of the FSA for tourism should be discouraged and, whenever possible, prohibited. Managers should ensure that user fees contribute directly to support the maintenance of the resource.
• Market-based bans, such as sales bans, can be an effective tool in reducing the take of fish from FSAs, particularly where markets are centralized and enforcement is strong. If market-based measures are instituted, managers must also consider the effects of such bans on other species, since removing one or more species from the allowable catch may place additional pressure on other local (non-spawning) target species1. Whenever possible, sales bans should be accompanied by catch bans, to reduce the impacts of subsistence fishing and poaching on FSA during ban periods.

Additional measures may be possible to control or stop FSA fishing. In many areas, traditional fisheries management tools simply will not work. Ideally, managers should work with stakeholders to examine alternative methods of FSA protection and enforcement that may be more appropriate for local circumstances. However, it must be understood that any measure that allows continued fishing of FSAs is likely to lead to negative impacts on the FSA, and the reproductive population, and therefore is discouraged.