Date of Award


Degree Type


Degree Name

Doctor of Philosophy in Biological and Environmental Sciences


Environmental and Earth Sciences (EVES)


Natural Resources Science

First Advisor

Graham E. Forrester


The failure to sustain fisheries is attributed to simultaneous effects of overfishing and to natural disturbance on fish habitats. Many conservation and management efforts are not successful in sustaining the fisheries. There is a growing need to broaden our understanding of people’s knowledge and their fisheries and to consider new approaches that will lead to effective conservation that enables us to sustain fisheries and protect the environment. This study examines the use of fishers’ local ecological knowledge (FEK) to characterize fishing communities and their practices, to assess the state of the fisheries, and the usefulness of this knowledge for conservation management. I studied the local ecological knowledge of lobster fishers for one of the main ports in Rhode Island (RI), and for fishers across 10 communities in the North East coast of the Dominican Republic (DR), using Grounded theory, Cultural Consensus Analysis, and standard statistical methods.

For the RI study, the FEK was collected through a series of meetings. After the FEK was collected and compiled, it was matched to the corresponding science-based data - when available - in order to analyze overlap and differences that exists between the two forms of knowledge. Furthermore, I looked at the lobster fishers’ arguments that describe their ecosystem view of the fisheries, and their arguments over management implications that affect them in their fisheries. Although in general, the lobster fishers’ FEK corresponded with the best available SEK, the few exceptions regarding reproduction and habitat preference for reproduction could lead the way for collaborations and further study. Scientists and managers could benefit from the ecosystem view that lobster fishers have, one that integrates historical timeframes and the complexities of systems that interact together. Furthermore, collaboration is needed to address differences that hamper management collaborations: from not being included in science and monitoring processes, and also from disagreements regarding standard monitoring practices used to survey areas that the fishers do not consider to be lobster’s habitat.

For the study in the DR, surveys were conducted during two field trips, the survey instruments were designed to compile the ecological knowledge fishers have on the fish that they catch, and perceptions on their fisheries. The assessment of the content of the FEK was completed using a qualitative-quantitative methodological sequence. Furthermore, the methods for coding descriptive responses were also evaluated. The results revealed a shared cultural model of ecological knowledge for four of the eight commonly fished species. The cultural consensus analysis index of fisher’s individual knowledge (competence score) was found to be unrelated to the fishers’ perceptions on the state of their fisheries and how they are managed. These results underline the need to better explain the fundamental basis of fishers’ perceptions.

The usefulness of fishers’ local ecological knowledge on the size-at-maturity relative to the size-at-capture, and the maximum body size were tested as an indicator for overfishing. The comparison of the estimates on the size at capture and size-at-maturity tested whether the fishers perceived themselves to be catching adults or juveniles; comparisons between the FEK and the science based knowledge (SEK) served to assess whether the fishers and the scientists agreed on the composition of the catch. Lastly, comparisons on the maximum body size harvested (FEK) relative to the known maximum size known to scientists (SEK) served to assess whether the largest fish had declined.

The perceived composition of the catch differed between scientists and fishers. Fishers perceiving their catch to be generally comprised of juvenile and adults, when in fact, the scientists would describe them as catching mostly adults. No correlation was found between fishers’ perceptions on the state of the fishery, nor the changes in the fisheries, and the fish size estimates they gave. The majority of the fishers categorized the state of their fisheries as bad and agreed that their fisheries had changed, and that the changes had been for the worst. These results suggest that the potential for overfishing can be estimated from these comparisons, but the use of FEK in the absence SEK is not recommended for fish size estimate values. The FEK that fisher’s posses, in both RI and the DR, attest to the changes in the state of the fisheries indicative of a serious decline, met with adaptations or regulations that either extend the unsustainable fisheries or limits fisher’s ability to sustain their livelihoods.



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