Smithsonian Marine Station

When assessing future changes in fishing, research has focused on changes in the availability of the resource. Fishers' behaviour, however, also defines fishing activity, and is susceptible not only to changes in weather but also to changes in the economy, which can be faster and more ubiquitous. Using a novel modelling approach and spatially explicit predictors we identified the current drivers of artisanal fishing activity and predicted how it is likely to change in 2025 and 2035 under two climate and two economic scenarios. The model is effective at explaining the activity of fishers (AUC = 0.84) and suggests that economic variables overwhelm the importance of climate variables in influencing the decisions of fishers in our case study area (Utila, Honduras). Although future changes in the overall incidence of fishing activity are modest, decreases in the number of accessible fishing grounds with projected increases in fuel prices will increase localised fishing effort depleting fish resources near the port. Compelling adaptation strategies in the area require the intervention of the market chain to make the sale price of fish more responsive to fuel price fluctuations and changes in fishing behaviour to improve fuel efficiency, including the revival of traditional ways of fishing.

Marine protected areas (MPAs) are an important ecosystem-based management approach to help improve the sustainability of the spiny lobster fishery (Panulirus argus), but information is lacking concerning levels of lobster population connectivity among MPAs. Given their prolonged (*6 months) pelagic larval duration, population connectivity must be considered in any spatial management plan for P. argus. We used genetic techniques to uncover spatial patterns of connectivity among MPAs along the Mesoamerican Barrier Reef (MBRS) of Central America. We hypothesized that connectivity would be greater and genetic differentiation diminished among lobster populations within MPAs in the southern MBRS, which is dominated by a retentive oceanographic environment, as compared to MPAs in the more advective environment further north. We found that levels of connectivity are high among spiny lobster populations residing in MPAs in Central America, although overall F ST was low (F ST = 0.00013) but significant (P = 0.037). MPAs in the northern MBRS contained significantly more individuals that were genetically determined outliers or migrants than southern MPAs (P = 0.008, R 2 = 0.61), which may have contributed to the higher levels of genetic differentiation observed in northern MPAs. Direct genetic testing of larvae and adults will be required to confirm this hypothesis. The high level of connectivity among MPAs provides additional evidence of the importance of international cooperation in the management of Caribbean lobster fisheries. However, uncertainty regarding the ecological and physical drivers of genetic differentiation in Northern MPAs implies that managers should hedge against uncertainty.