A question of scale; a more regional perspective needed to manage aggregating fishes

As experiences begin to roll in on the outcomes of aggregation protection measures, and as we come to learn more about aggregating species and the fishing pressures they increasingly face, it is becoming clear that management often needs to extend well beyond the time and place of spawning. This, in itself is not new or surprising; while aggregation-fishing is certainly not the only challenge to the sustainable management of many aggregating species, it is only after seeing the realities of attempts at aggregation protection and failures of local piecemeal fishery management that the need for broader measures becomes ever more compelling and, in some cases, urgent. In Belize, for example, numbers of aggregating Nassau grouper continue to decline despite protection of 11 spawning aggregation sites introduced in 2002 throughout the country.

While the apparent lack of recovery may partly be due to the need for more time for it to manifest itself in long-lived species like the Nassau grouper, Epinephelus striatus, continued poaching on protected sites has seriously undermined the effort at management in the country. Moreover, as we learn more about the biology of aggregating species, we have come to know details of nursery areas, migratory routes to and from aggregation sites and movement patterns. This information has alerted us to the need for a broader biological perspective to be taken over larger spatial scales.

The absence of progress in Belize suggests a lack of buy-in by the fishing community and government of the introduced measures, and has led the National Spawning Aggregation Working Group to propose the introduction of additional protection (see above account on Belize). In the Bahamas, annual landings statistics suggest continuing decline of the Nassau grouper, despite long-standing minimum size limits and protective measures during the spawning season over 10 years. A major problem in the Bahamas case is poaching by foreign fishers, but the ad hoc nature of aggregation protection from year to year (see above) and the finding that illegal sales of the species continue during the spawning season, undermine existing measures and leave aggregation protection vulnerable to short-term political changes and influences. In Cuba, an increasingly restrictive cocktail of protective legislation over decades has failed to stem the decline in certain aggregating species, with the intensively aggregating Nassau grouper and mutton snapper, Lutjanus analis, those species most seriously affected.

An example of integrating a wide range of management tools, given uncertainties and possible impacts of fishing or disturbance on different life history phases has developed on the massive Great Barrier Reef, Australia. Here, the reef fish fishery is managed using a combination of total allowable catch, fish size limits and spawning season closures, while the recent rezoning
resulted in the no-take protection of about 30% of reef and shoal habitat, including outer reef and deep-water habitats. Such habitats are important spawning areas for some species. To forestall possible impacts from human disturbance, tourist diving platforms cannot be sited within 200 m of a spawning site.

What is becoming ever clearer is the need for broad regional initiatives to protect aggregating species. Reef fishes that migrate long distances to spawning aggregations are often not well served by the typically small size of marine protected areas, or those that do not extend across national boundaries. The Gulf and Caribbean Institute workshop sessions in 2007, reported on herein, on the Goliath, E. itajara, and Nassau groupers both identified the need for regional collaborations in data collection and management efforts, while the developing initiative by Mexico with Belize is an encouraging sign of moving to a more international approach to aggregation management. In sum, the specific inclusion of aggregations and aggregating species into ecosystem-based management approaches could help to shape linkages across large areas, many habitats and multiple jurisdictions. This broader approach needs to be discussed much more on international agendas in the same way that threatened turtles and mammals have attracted widespread attention and management initiatives.

Yvonne Sadovy (SCRFA) This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Feb 2008