Case Study for Red Snapper
Management of the red snapper (Lutjanus campechanus) fishery is perhaps the most contentious issue in the Gulf of Mexico because it involves two valuable fisheries in the region. Red snapper stocks have failed to recover from overexploitation. Some have attributed this failure to bycatch of juveniles in shrimp trawls, rather than fishing by directed commercial and recreational fisheries (Goodyear, 1995; Schirripa and Legault, 1999). Red snapper fishers suggest that an essentially unfished stock of fish exists offshore, where it is unavailable to the fishery (Schirripa and Legault, 1999). They have argued that this presumed offshore stock provides sufficient spawning activity and that the onus for recovery rests on shrimpers who need to decrease bycatch of young red snapper. Juvenile bycatch represents as much as 70% of the entire fishing mortality of this species (Nichols et al., 1990; Nichols and Pellegrin, 1992; Schirripa and Legault, 1999) although it comprises only 1% of the total incidental take in the shrimp fishery.
However, the shrimp industry finds fault with National Marine Fisheries Service's (NMFS's) bycatch estimates and suggests that NMFS address alternative issues, including large-scale chronic (e.g., global warming) or acute (e.g., harmful algal blooms, hypoxia) events and the effects of the directed fishery on the age structure of the population.
A recent peer review of the red snapper stock assessment indicated that little effective management could be accomplished until basic information on red snapper population dynamics was acquired (Stokes, 1997). For example, the level of bycatch reduction required for stock recovery is uncertain without accurate estimates of natural juvenile mortality rates. It is essential to determine the age structure of the red snapper population in order to estimate natural mortality rates. Although a number of analyses of the red snapper data incorporate changing rates of natural mortality, the level of uncertainty surrounding these values is high (Good-year, 1995, 1997; Schirripa and Legault, 1999), with some arguing for low levels, based on the red snapper's longevity (e.g., Camber, 1955; Wilson et al., 1994), and others for higher levels, based on the exclusion of regulatory discards from the samples (McAllister, 1997). The importance of bycatch reduction as a management strategy for red snapper recovery depends on the value used for the natural mortality rate (Stokes, 1997).
One way to obtain more accurate estimates of natural mortality would be to establish reserves and determine the age structure in these unfished areas. Such reserves also would promote red snapper recovery by protecting a fraction of the stock from fishing. Hence, reserves could play dual roles in promoting stock recovery and providing better estimates for population parameters used in stock assessment. This could serve as an additional incentive for the fishing industry to work on reserves with managers and scientists to make management more effective.
Reserves also can serve important functions in habitat restoration projects. Reserves act as controls (undisturbed sites) for evaluating the effectiveness of restoration projects at disturbed sites. Designation of areas as reserves could be used to protect sites so that restoration occurs naturally. There is a distinction