MAP 3.1.3.11 Trophic Level Secondary - Aquatic Fauna Seasonal Characteristics (Wet Season)

This project obtains wet-season monitoring data on aquatic animals and periphyton that play a fundamental role in the food web of the Everglades. Periphyton is the primary source of food for aquatic animals there and it is an excellent indicator of nutrient enrichment, if present. Small fish, crayfish, and grass shrimp are the primary food resources of apex predators in the Everglades, notably wading birds. This project is linked to a companion effort monitoring the same aquatic animals in dry-season drying pools where wading birds and alligators feed on the concentrated prey. These projects are motivated by a Trophic Hypothesis that restoration of hydrological conditions in the Everglades will lead to restoration of historical productivity of apex predators such as wading birds through its impact on the food web. Periphyton is a fast responding indicator (weeks to months) of nutrient and hydrological conditions and small fish and aquatic invertebrates respond in a seasonal to multi-annual (up to 3y) timeframe to changing hydrological conditions; aquatic animals are also affected by nutrient enrichment in predictable ways, but not as quickly and precisely as periphyton.

本项目获取了大沼泽地（Everglades）食物网中发挥核心作用的水生动物与周丛生物（periphyton）的湿季监测数据。周丛生物是该区域水生动物的主要食物来源，同时也是检测营养富集现象（若存在）的优良指示物。小型鱼类、螯虾与草虾是大沼泽地顶级捕食者的主要食物来源，其中尤以涉禽为代表。本项目与一项配套研究相关联，该研究针对旱季干涸塘中的同类水生动物开展监测——这类塘体是涉禽与短吻鳄取食密集型猎物的场所。本系列研究的核心依据为营养级假说（Trophic Hypothesis）：修复大沼泽地的水文条件，可通过影响食物网，进而恢复涉禽等顶级捕食者的历史种群生产力。周丛生物对营养与水文条件的响应速度极快（数周至数月）；小型鱼类与水生无脊椎动物对水文变化的响应周期则为季节到多年级（最长3年）。此外，水生动物也会以可预测的方式受到营养富集的影响，但响应速度与精准度均不及周丛生物。