Managing Invertebrate Fisheries: Biology, Spatial Structure and Community-based Governance.

摘要

Fisheries scientists and managers often face the challenge of elucidating the spatial patterns in distribution and life history traits of exploited resources and to match the scales of biology, management and governance. This spatial and multi-scale complexity is inversely related to the species mobility and thus particularly important for sedentary invertebrates. A combination of model-based approaches, a meta-analysis through systematic literature review, and simulation testing was applied to different invertebrate resources to tackle four issues specific of these fisheries: (1) determine the environmental processes responsible for spatial aggregation; (2) characterize the spatial structure in biomass aimed at designing spatially-explicit management tools; (3) reveal local ecological and social characteristics of fisheries needed for a successful community-based management and governance; and (4) explore potential benefits of fine-scale spatial cooperative harvesting. Generalized additive models (GAMs) were able to depict non-linear relationships between environmental variables and the distribution and biometrics of the Patagonian scallops. Whereas physiological tolerance to temperature appeared to the driver for the range boundary of this species, food availability was a key explanatory factor of the spatial variations in scallop abundance. The spatial structure in biomass, proportion of females and molting deep-sea red crabs was estimated by using likelihood-based geostatistics. These findings are relevant to determine the potential effect of climate change in both species' distribution and productivity, to manage them at the appropriate scale, and to develop spatially explicit management measures. Fine-scale spatially structured resources also pose a critical challenge to centralized top-down fisheries management and governance. Thus, community-based co-management has been suggested as a complementary approach. Regression trees were used to identify the most important social-ecological attributes of fisheries needed for a successful community-based management, which included leadership, social capital and incentives. Lastly, simulation of a sea urchin fishery through an agent-based model showed that spatial cooperative harvesting allow fishers to optimize the use of the resource in terms of higher gonad yields per unit of effort while maintaining the productivity of the stock. In summary, the spatial heterogeneity of biological and human systems associated with invertebrate resources requires of multi-scale and inter-disciplinary management and governance.