The effect of anthropogenic change and protection on fish movement patterns
The Eastern Mediterranean Sea suffers from multiple stressors, including an unprecedented increase in the number of non-indigenous species, one of the fastest rates of warming water temperatures, and fishing. I will present a summary of recent studies, mostly conducted using acoustic telemetry, aiming at understanding how these immense changes are impacting fish behavior, and discuss the role of marine protected areas in buffering these changes. We show here, using several different examples, how behavioral changes may impact MPA function and the interaction with surrounding fished areas. First, we examine whether fish home ranges differ between MPA and surrounding areas. Home range size will define the probability of remaining safe within that MPA or crossing its boundaries and being exposed to mortality. We find evidence that home range size is reduced close to MPA borders. Second, we find that while MPAs contain the same biomass of invasive species as fished areas, invasive impact is reduced inside MPA. We attribute this to behavioral changes associated with the presence of large predatory grouper within MPA which induce fear in the invasive prey which reduces feeding rates. Finally, we examine how fish behaviors change in response to warming waters and extreme weather events. The results will dictate the size and shape of MPAs needed to secure fish populations under changing climates. Taken together, the results have strong implications for understanding how anthropogenic change modifies fish behaviors and impacts MPA function.