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.

南佛罗里达州的淡水资源配置始终是持续热议的焦点。争夺淡水的利益相关方涵盖农业、快速增长的城市人口，以及依托相关生态系统服务的自然环境。在这些生态系统服务中，最具价值的一项为沿海休闲渔业供给，仅佛罗里达州一地，其每年带来的垂钓者消费规模便约达80亿美元。然而，淡水配置与这类沿海渔业可持续性之间的相互作用机制仍未得到充分阐释。其影响路径之一在于资源与食物的可获得性：季节性降雨与淡水管理措施会将淡水湿地的猎物脉冲式输送至河口，形成短暂却极为丰富的觅食契机。此前研究表明，这类猎物脉冲主要发生在河口的内陆区段，为兼具休闲与生态重要性的消费者提供了资源，包括普通锯盖鱼（Common Snook, Centropomus undecimalis）、佛罗里达大口黑鲈（Florida Largemouth Bass, Micropterus salmoides）、红鼓鱼（Red Drum, Sciaenops ocellatus）、大西洋大海鲢（Atlantic Tarpon, Megalops atlanticus）、公牛真鲨（Bull Shark, Carcharhinus leucas）以及美国短吻鳄（American Alligator, Alligator mississippiensis）。但目前尚不清楚这些物种会移动多远去利用这类资源补给，也无法确认这类猎物脉冲是否会提升其繁殖产出与长期种群稳定性。此外，海平面上升正在改变兼具经济与生态重要性的类群对河口环境的利用模式。为解答上述问题，本研究采用声学遥测技术（acoustic telemetry），对大沼泽地国家公园鲨鱼河河口内的关键河口类群（包括普通锯盖鱼、佛罗里达大口黑鲈、美国短吻鳄与公牛真鲨）开展了2007年至今的多年运动轨迹追踪。这种多物种研究视角将我们的关注范围从淡水与河口捕食者拓展至连接淡水、河口与海洋生态系统的顶级捕食者。从学术层面而言，本研究为理解高流动性消费者如何响应异质景观中的脉冲式猎物资源，以及这类短暂性资源补给如何在全球变化背景下促进消费者种群增长提供了全新见解。从更广泛的视角来看，量化脉冲式资源对消费者的价值填补了种群与群落生态学领域的一项重要信息空白，同时也可为对南佛罗里达州生态系统与经济至关重要的淡水管理决策提供参考依据。