Water Resources Research Act Program

Details for Project ID 2014NJ355B

Parasite biomass and nutrient stoichiometry in a stream ecosystem

Institute: New Jersey
Year Established: 2014 Start Date: 2014-03-01 End Date: 2015-02-28
Total Federal Funds: $5,000 Total Non-Federal Funds: $10,000

Principal Investigators: Rachel Paseka, Michael Sukdeo

Project Summary: Parasitism is ubiquitous in nature, yet the importance of parasites to ecosystem function remains largely unknown. In many ecosystems, parasites are both very common and highly productive, yet the amount of energy and nutrients moving through parasitic interactions has not been quantified at an ecosystem scale. This study measures both the quantity (biomass) and quality (elemental content) of parasites in a stream ecosystem by employing an energetic and stoichiometric framework. Using streams in the New Jersey Pinelands as a model system, I will measure the biomass of all intra-host and extra-host parasites relative to the free-living organisms in the ecosystem. I predict that intra-host parasites make up a portion of total stream biomass rivaling that of many free-living taxa. Most parasites have a huge reproductive output, releasing many more infective stages to the environment than will reach a subsequent host. I predict that the biomass of these extra-host parasite stages exceeds that of intra-host parasite biomass in these streams. If parasites make up a substantial portion of stream biomass, then they also play a direct role in ecosystem energetics. Additionally, I will employ ecological stoichiometry to measure the elemental ratios of parasites, their hosts, and basal resources in these streams. Following stoichiometric patterns observed in free-living communities, I predict that parasites are rich in nutrients relative to their hosts. Nutrient-rich parasites would likely represent a valuable resource to free-living predators or decomposers. This research is a key first step in addressing the full importance of parasitism to ecosystem function.