Semester of Graduation

Fall, 2018

Degree

Master of Science (MS)

Department

Department of Oceanography and Coastal Sciences

Document Type

Thesis

Abstract

Nearshore marine fisheries provide the main source of protein for nearly 9 million people in the coastal villages of Tanzania, yet for decades the fisheries have shown signs of overexploitation. These fisheries are small-scale and co-managed by local coastal communities in groups known as Beach Management Units (BMUs). BMUs monitor individual fishing trip data (e.g. gear, vessel, taxa); however, these data have only been analyzed in nationally aggregated statistics and to our knowledge, are not presently used in management decision making. The present thesis aimed to identify the forms of data and information that local fishery monitoring can record about small-scale marine fisheries in Tanzania, and how that local monitoring data may be related to the spatial socio-ecological context of those fisheries. We collected all available fishing trip data from 2014 to 2017 from BMUs in fourteen villages in two spatially, socially, and ecologically distinct districts (Pangani and Rufiji) of the country. Our results found that each village had unique patterns of vessel-use, gear-use, and taxa landed, and that every village was specialized in some measure. Specifically, two villages in Pangani district landed octopus or parrotfish almost exclusively, suggesting potential trophic cascades after years of overexploitation. We then proposed a flexible modeling approach which incorporated the BMU landings data with spatial data to predict the spatial characteristics of the marine fisheries in Tanzania. The spatial models identified relationships between fishery landings and coral reef, seagrass, and mangrove habitat patch attributes, along with fisher density and a hydrologic index. Furthermore, the predicted spatial characteristics matched previously reported fishery characteristics in both districts. The maps developed by our modeling process provide a means for stakeholders and managers to understand the spatial distribution of their fisheries and in turn, focus on explicitly managing what, how, and where fishers operate. Overall, this thesis has shown that the catch data collected by BMUs were able to generate the first descriptions of village-based Tanzanian fishery characteristics. Thus, it is possible that the collection and analysis of local monitoring data can be used to promote the application of fishery regulations that are relevant to their socio-ecological context.

Date

8-13-2018

Committee Chair

Midway, Stephen R.

DOI

10.31390/gradschool_theses.4782

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