Research ProjectParasites in the Food Web

Parasites in the Food Web

  • Trematode parasite inside shrimp abdomen

    Trematode metacercariae, or larval worms, encysted inside a shrimp. Once the shrimp is eaten, these parasites will likely infect the predator. Photo Credit: Ruth DiMaria

  • Intern looking through microscope

    Intern in the Marine Disease Ecology lab looking for parasites in local bivalves. Photo Credit: Katrina Lohan

  • A hydrobid snail

    A hydrobid snail, the first host of a worm that has to go through the food web to reproduce and survive. Photo Credit: Katrina Lohan

Project Goal

We use genetic methods combined with field sampling and lab and field experiments to understand the role of parasites across trophic interactions in coastal waters.

Description

We use a variety of methods to understand the impact of parasites on trophic interactions across food webs. Parasites are best known for causing mortality, but they can have a range of other impacts on their hosts, such as changing their behavior or decreasing fecundity. For each of these impacts, there are potential implications for the food web – host death provides food for scavengers, such as blue crabs, or releasing nutrients for bacteria; reducing fecundity can decrease the population, meaning less food for predators; and changes in host behavior often increase the likelihood of a host being consumed by a predator, meaning an increase in food availability for predators. Parasites can also be an important food source for some aquatic organisms.

We are using field surveys along with field and lab experiments to understand how changes in host behavior impact food availability. This includes using genetic methods to understand parasite diversity and impacts in phytoplankton and zooplankton assemblages (a vital food source for many important fish and bivalve species) and gut contents of commercially important crustaceans and fishes (e.g., blue crabs, striped bass, menhaden).

Contact

Katrina Lohan

lohank@si.edu