Sustainability in small-scale fisheries: An analysis of ecosystem impacts, fishing behavior, and spatial management using participatory research methods

Anthropogenic impacts to ocean ecosystems have been well documented throughout the globe, highlighting commercial fishing as a primary threat to marine life populations and habitats. Small-scale commercial fishing operations provide more than half of the world's seafood, employ over 90% of all fishermen, and take place along a vast proportion of the world's coastline. Their local, decentralized nature poses unique challenges for research, data collection, and management, particularly in developing nations. As a result, a focus on large, industrial fisheries has discounted the potential impacts of small-scale fisheries, leading to an assumption that they are generally more sustainable. My research on two remote fishing cooperatives in Baja California Sur, Mexico asks to what extent these small-scale fisheries are sustainable, and in cases where significant ecological impacts do occur, I offer and compare several distinct conservation approaches. While engaging fishermen to participate directly in the data collection, I begin by conducting a series of studies that examine how small-scale fisheries interact with marine ecosystems. I quantitatively assess potential ecological effects including bycatch of non-target species and damage to seafloor habitats resulting from several common fishing practices and find that the type and magnitude of impacts are significantly different across small-scale fishing gears. Set gillnets have higher bycatch and habitat impacts than other fishing gears, representing a major priority for small-scale fishery conservation. I also analyze fine-scale fishing behavior in the lobster fishery to help explain why some fishermen are more successful than others and how marine habitat characteristics and resource distribution influence their gear placement strategies. Observable trap movement behaviors on a limited number of fishing trips significantly explained differences in overall catch success among fishermen throughout the entire season. My findings are helping fishing cooperatives maintain a certified Marine Stewardship Council eco-label while highlighting areas for improved performance in terms of profitability and sustainability. Meanwhile, I suggest that the future of ecolabeling efforts in small-scale fisheries should address the full suite of fishing activities rather than single species, actively seek and train fishermen to collect data required for assessments, and use data gathered in assessments articulate specific improvements in the social and ecological context of each fishing community. To provide management options to reduce the ecological impacts of set gillnets I identified, I develop and analyze the outcomes of a spatially-explicit bioeconomic model that reduces those impacts by redistributing fishing effort across different spatial zones, converting to alternative gear types, closing certain areas to fishing, and reducing total fishing effort. I use the model to construct a series of implementable, cost-effective management alternatives and compare them based on their ecological and economic outcomes. Overall, this thesis provides a framework for a participatory conservation paradigm aimed at making small-scale fisheries more sustainable while providing broadly applicable tools for other fisheries as well.