Author: Amanda L Subalusky,  Assistant Professor (University of Florida)

Designation: 

Description:
Animal movements can transport resource subsidies between terrestrial and aquatic ecosystems, and the impact of these subsidies on recipient ecosystems is highly context dependent. Our research on wildlife resource subsidies in the Mara River, East Africa, illustrates how the quantity, quality, timing, and duration of animal inputs is translated through the lens of both abiotic and biotic characteristics of the recipient ecosystem to influence trophic structure and ecosystem function. The river’s population of hippos contribute over 13,000 tons of feces to the river annually through daily feeding migrations. The Serengeti wildebeest migration contributes 1,100 tons of carcass biomass to the river each year through seasonal mass drownings during annual migrations. These different forms of input interact differently with river discharge to yield important and complex impacts on the river. Hippo inputs are high in particulate carbon that deposits on the river bottom during low flows, driving high rates of ecosystem respiration and providing an important resource to the river food web. Wildebeest inputs are more likely to occur during higher flows, during which time they have minor effects on river metabolism, but they provide an important food resource for a suite of scavenger species, and their influence persists in the river for decades through the slow decomposition of bones. Research in this system highlights the potential influence of animal resource subsidies on aquatic ecosystems and illustrates the challenges in predicting subsidy impacts in dynamic systems.

Category: Scientific Program Abstract > Special Sessions > SS79 New perspectives on the functional roles of fauna in wetlands, lakes, and other aquatic ecosystems