Abstract
Objective: This study examines the productivity and technical efficiency (TE) of diving operations that target queen conches Aliger gigas in the Commonwealth of Puerto Rico, the largest producer of queen conches in the United States. Currently, there is a proposal to list queen conch as threatened under the Endangered Species Act (ESA). Methods: We use stochastic production frontier methods to investigate the relationship between catch and fishing inputs and the technical performance of diving operations. Result: Our results show that the fleet could increase its catches, on average, by 30% (and, thus, increase its income) by using existing fishing inputs and technology more efficiently. We find that the potential to expand catches was slightly higher from increasing the crew size than from extending the length of the fishing trip. The study also finds considerable heterogeneity across coastal regions and operation sizes. Overall, operations on the east and west coasts and those having three or more crew members were more efficient. Operations that use a single gear and specialize on few species (revenue concentration) were associated with higher levels of TE. We also find that diving operations exhibit decreasing returns to scale. Conclusion: The potential ESA listing of the queen conch poses a dilemma because increasing the efficiency of the fleet may continue to compromise the sustainability of the resource. While a threatened designation does not necessarily result in additional trade or harvest restrictions, further actions may be advisable given the many threats, such as overutilization, habitat loss, coastal pollution, and disruptive environmental change that queen conch populations face. Our model suggests that reducing the size of the crew and/or the length of the trip may increase efficiency, but these restrictions may not be advisable on safety grounds. Thus, management agencies may want to reassess existing trip limits and the length of the closed season and explore the use of closed areas.