Critically Endangered totoaba Totoaba macdonaldi: signs of recovery and potential threats after a population collapse

[摘要] ABSTRACT: The lack of long-term monitoring programs makes it difficult to assess signs of population recovery in collapsed marine populations. Fishery-induced changes in the life history of exploited marine fishes, such as truncated size and age structure, local extirpations, reductions in age at maturity, and changes in mortality patterns, have occurred. In the present study, we explored life history aspects of totoaba Totoaba macdonaldi, almost 40 yr after a population collapse, to examine whether totoaba maintained their life history pattern and to identify the potential threats of using fishing gear (hooks, gillnets). The results of the present study indicate that the totoaba size structure was not truncated as expected in overexploited populations; indeed, it was similar to that observed in the past. Totoaba have maintained their known historical distribution range. The spatial size structure and temporal distribution followed the known migration patterns of totoaba. Total and natural mortality were similar. Contrary to recommendations for sustainable fisheries, caught fish contained a large number of juveniles, irrespective of method used. We conclude that the general life history (size structure, distribution, migration, and mortality) has not changed since the fishery collapse. However, the choice of fishing gear could compromise a positive recovery trend of the population. Moreover, poaching is a major ongoing threat to the recovery of totoaba.

[学科分类] 动物科学

[关键词] Totoaba;Totoaba macdonaldi;Fishery collapse;Recovery;Gulf of California