What are food webs?
Food webs are useful depictions of how energy, matter, nutrients, pollution, and other things flow through ecosystems. Realizing that a group of animals is just a part of a much larger network opens up a world of predictions about how a change in one part of the web might impact another. This is where I think ecology, or studying interactions, gets really exciting. Knowing who an animal interacts with, the nature of the interaction, and what environmental factors influence these things can help us determine the ecological importance of each component of a food web.
As part of the Florida Coastal Everglades Long Term Ecological Research program, we are using stable isotope analysis, stomach contents, and pollution analyses to investigate the trophic ecology of predators including catfish, bull sharks, alligators, and dolphins throughout the Everglades. These efforts will allow for a more complete picture of the Everglades estuarine food web and give us a deeper understanding of trophic interactions within the system. Having this knowledge may allow us to predict the consequences and benefits of the multi-billion dollar restoration plan to increase water flow back into the Everglades.
I am also studying the ecological importance of alligators, who create and maintain “alligator ponds” in the marsh by repeatedly digging to create an area of deeper water. Many animals including fish and aquatic invertebrates use these ponds as a refuge to make sure they have water in the dry season when marsh water levels drop. This concentration of animals, in turn, makes these ponds prime foraging sites for wading birds and large fish. As hotspots of biological activity, ponds concentrate nutrient-rich excrement and carcasses that enhance the resources available to algae, bacteria, and plants at the base of the food web. My work is looking at the ecology of these ponds and how alligators impact biogeochemistry and food webs in the marsh.