Print PageThe coastal ecosystems, harvested species, and commercial fisheries of the Gulf of California Region are characterized by immense spatial and temporal heterogeneity, yet this key feature is rarely incorporated into resource management. We draw upon the results of three case studies that each combine biological, environmental, and fisheries data to demonstrate how fishes, fisheries, and ecosystems interact at several spatial and temporal scales and discuss how such knowledge can be used to inform regional management and conservation strategies.
Results/Conclusions
First, we investigate the spatial structure of commercial marine fisheries of Northwest Mexico to understand how the scale of fishing activity overlaps with those of coastal habitats. Our results demonstrate that NW Mexico, which is currently managed as one fishing region, is actually comprised of five distinct fishing sub-regions that coincide with the locations and geographic ranges of the major coastal habitats (temperate reefs, mangroves and estuaries, etc) of the region. Dividing the NW Mexico into these separate regions would provide a platform to implement conservation initiatives and management policies the same spatial scale.
Next, we examine associations between the timing of fish spawning aggregations and monthly trends in commercial landings and ex-vessel revenues for aggregating reef fishes in the southern Gulf of California. We find that species that form seasonal spawning aggregations comprise the eight most important commercial reef fish fisheries of the region with respect to landings and revenues, and peaks in landings and revenues for five of these eight species occur during spawning aggregation periods. Given the known vulnerability of fish spawning aggregations to exploitation, our results suggest that seasonal fishing restrictions and spatial regulations of aggregation sites should be considered to manage some, but not all, aggregating reef fishes.
Finally, we use satellite remote sensing technology to study daily interactions between the spawning migration of the Gulf corvina (Cynoscion othonopterus) and commercial fishing activities in the Upper Gulf of California. Our results show that the corvina fishery is completely synchronized with the migration and spawning cycle of the fish, which in turn, follows a distinct semi-lunar rhythm. Our results indicate that management strategies could be fine-tuned to create brief, spatially or temporally explicit regulations that may reduce impact of fishing on reproduction while also increasing fishing efficiency, fisheries monitoring, and enforcement.
