Movements of aquatic predators within the Shark River estuary (FCE LTER), Everglades National Park, South Florida, USA, June 2007 - ongoing

In South Florida, the allocation of freshwater resources is a constant source of debate. Stakeholders competing for freshwater include agriculture, rapidly growing urban populations, and the natural environment with its associated ecosystem services. Among these services, one of the most valuable is the provisioning of coastal recreational fisheries, which generates roughly $8 billion annually in angler expenditures in Florida alone. Yet, the interplay between freshwater allocation and the sustainability of these coastal fisheries remains poorly understood. One pathway of influence is through the availability of resources and food. Seasonal rainfall and freshwater management drive pulses of freshwater marsh prey into estuaries, creating short-lived but abundant foraging opportunities. Previous research has shown that these prey pulses occur primarily in the inland reaches of the estuary, providing resources for recreationally and ecologically important consumers such as the Common Snook (Centropomus undecimalis), Florida Largemouth Bass (Micropterus salmoides), Red Drum (Sciaenops ocellatus), Atlantic Tarpon (Megalops atlanticus), Bull Shark (Carcharhinus leucas), and American Alligator (Alligator mississippiensis). However, it is unclear how far these species move to exploit this subsidy, or whether such pulses increase reproductive output and long-term population stability. Further, sea level rise is changing how economically and ecologically important taxa use estuarine environments. To address these questions, we use acoustic telemetry to track the multi-year (2007–present) movements of key estuarine taxa, including Common Snook, Florida Largemouth Bass, American Alligator, and Bull Shark, within the Shark River Estuary of Everglades National Park. This multi-species approach expands our focus from freshwater and estuarine predators to include apex predators that link freshwater, estuarine, and marine ecosystems. From a science perspective, our research provides novel insights into how highly mobile consumers respond to pulsed prey resources across patchy landscapes, and how these ephemeral resource subsidies may boost consumer populations in the wake of global change. More broadly, quantifying the value of pulsed resources to consumers fills an important information gap in population and community ecology, while also informing freshwater management decisions critical to South Florida’s ecosystems and economies.