Shrimp up, fish down, and vice-versa: Fishers’ strategies and long-term changes in small-scale fisheries landings at two spatial levels in Southern Brazil

Abstract

Fisheries are complex adaptive systems, requiring due consideration of temporal and spatial scales for their understanding and management. In this study, seemingly contrasting long-term fish and shrimp production trends at two spatial levels prompted us to analyze 50 years of small-scale fisheries landing data in Southern Brazil. We applied time-series analyses and mixed-effect models to identify interannual fishing trends at the regional and local levels. Results confirmed an overall decrease in fish landings and an increase in shrimp landings at the regional level. However, a contrasting trend was observed at the local level, with fish landings increasing while shrimp landings decreased. Such patterns suggest that fishers responded differently to the constant changes in the institutional environment. Therefore, in order to identify and discuss possible drivers of change, other than stock availability, we reviewed the literature and institutional documents (laws, government programs, etc.) as well as qualitative information from almost 30 years of research on the local and regional fisheries. The following drivers were found: technical change and innovation; changes in legal restrictions to fishing and resource protection; asymmetrical access and use of government incentives, particularly financial credit, to foster the fish supply chain; market conditions; and local culture and ecological knowledge. The analysis stresses the importance of a more comprehensive, interdisciplinary approach to fisheries science and management. Fishing landings data integrated to human dimensions of fishing (e.g., social organization, laws, and institutions) provide a better means to understanding the complex dynamics of fishery systems.