Combining Knowledge Systems Helps Understand the Spatial Dynamics of Data-Limited Small-Scale Fisheries Systems in Brazil: A Methods Analysis

Rebecca Borges,Marion Glaser,Karin Boos,Roberta Sá Leitão Barboza,Indira A L Eyzaguirre,Priscila F M Lopes

doi:10.3389/fmars.2021.760535

Abstract

Mangrove habitats provide nursery, shelter, and feeding sites for many economically relevant fish, and invertebrates, such as crabs. Given the highly artisanal character and the patchy spatial distribution of small-scale fishing in mangroves, there is often little data available to inform management, potentially threatening the sustainability of this livelihood-supporting activity. This study assesses the combination of different data collection methods and of including published data in the analysis of the spatial dynamics. We examine crab fisheries in two sustainable-use protected areas as a case study to understand use patterns as indicated by a specific combination of mapping methods. Mangrove crab fishing grounds were mapped by overlaying crab gatherers’ tracked routes with maps produced during participatory-mapping-centered interviews. Information from the literature was used to spatialize crab carapace width and relate it to distance traveled by fishers. Results show that crabs tended to be larger if caught farther from the villages where fishers live. In terms of collection methods, even though GPS tracking is relatively time- and resource-consuming, incorporating some GPS tracking into participatory mapping helps overcome a downside of this type of mapping (e.g., lack of geographical precision) and identifies information that can be accessed through participatory techniques. This highlights the importance of linking different approaches in order to understand small-scale fisheries spatial dynamics.

Highlights

Small-scale fisheries are mainly associated with and known to support subsistence production (Hall et al, 2013) and are often responsible for food security in local communities which strongly depend on mangrove ecosystems (Glaser, 2003; UNEP, 2014)
This could indicate that the GPS tracking method failed to capture these longest distances traveled, either because they are rare among fishers or because participants refrained from taking the GPS on these longer trips
This is possible because, even though the GPS tracking covered 16 months, the sampling was done to some extent in an opportunistic fashion because the fishers’ willingness to participate in the research varied among the villages and throughout the different seasons

Summary

Introduction

Small-scale fisheries are mainly associated with and known to support subsistence production (Hall et al, 2013) and are often responsible for food security in local communities which strongly depend on mangrove ecosystems (Glaser, 2003; UNEP, 2014). Mangroves have been disappearing, with losses of 35% of area in some parts of the world, largely attributable to human activities (Valiela et al, 2001). These negative trends might still be reversible (Worm et al, 2006; Fulton et al, 2019), and protected areas (PAs) are widely advertised as a tool to restore these depleted resources (Worm et al, 2009; Vandeperre et al, 2011; UNEP, 2014; Campos-Silva and Peres, 2016). Careful consideration is needed of the role these ecosystems and the resources they provide play for livelihood support in order to help conserve fishery resources in mangroves (UNEP, 2014)

Methods

Results

Conclusion