Assistant Professor University of New Hampshire, United States
Small-scale fisheries are largely understudied and are often omitted from global harvest counts. They provide vital nutrition for millions of people and are some of the most vulnerable fisheries to anthropogenic impacts such as urbanization and climate change. As a case study into these issues, we studied Madagascar’s southern coast, where local people have deep cultural ties to fishing. Recently, international export markets have contributed to overfishing of many species in the area, especially cephalopods. Despite being the largest export from Madagascar’s fisheries, very few population modeling studies have been conducted on the cephalopod population of Madagascar. This project aims to understand how this cephalopod community dynamics act under different levels of harvest and protection. We will fit stage-based matrix population models to existing catch data in order to predict changes in population growth rate with the aim to identify key spawning seasons for Madagascar’s cephalopods. We predict that, contrary to their temporal counterparts’ biannual spawning pattern, this fishery actually spawns continuously throughout the year, which will help inform when fishing protections should be implemented. Further, we plan on incorporating different fishing methods and gender dynamics into existing socio-ecological models to better reflect Madagascar’s fishing population.
Our estimated parameter values (e.g., survival and fecundity) were in line with past work on cephalopod population dynamics. With these models, we predict declining cephalopod stocks in the area and with a potential collapse of the fishery in the next ten years. We are now examining the potential for management strategy, such as temporary closures, to prevent such a collapse. We also plan to incorporate a socio-ecological modeling framework to improve the sustainability of conservation methods in Madagascar. Specifically, we plan to update the “buy in or buy out” assumption of previous models where people in a community are either fully in support of fishing or fully against it. As our study population is a culture deeply rooted in fishing and therefore can’t simply “buy out” of fishing practices, we plan on implementing what is called a continuous strategy space to our model to incorporate more nuanced opinions of fishing practices. This project aims to change how we approach studying small-scale fisheries, as we hope to take into consideration the specific community and ecological aspects of our study site, instead of implementing a blanket model for all cultural and fishing norms.