Hypoxia and Macoma balthica: Ecological effects on a key infaunal benthic speciesEPA Grant Number: F5E61380
Title: Hypoxia and Macoma balthica: Ecological effects on a key infaunal benthic species
Investigators: Long, William C.
Institution: College of William and Mary-VA
EPA Project Officer: Zambrana, Jose
Project Period: September 1, 2005 through August 1, 2008
Project Amount: $106,692
RFA: GRO Fellowships for Graduate Environmental Study (2005) RFA Text | Recipients Lists
Research Category: Academic Fellowships
I am examining the effects of hypoxia (i.e., low dissolved oxygen) on community and population dynamics in the Chesapeake Bay. I am focusing on a dominant bivalve, Macoma balthica, which provides an important food-web link between its food sources, detritus and phytoplankton, and its predators, commercially important species such as the blue crab, Callinectes sapidus. I will be examining the effects of hypoxia upon the growth, reproduction, mortality, and predation of M. balthica.
- Determine the effects of hypoxia on mortality in M. balthica.
- Determine the effects of hypoxia on reproduction in M. balthica.
- Determine the effects of hypoxia on the growth of M. balthica.
- Determine the effect of hypoxia on predation on M. balthica.
- Use these observations to create a mathematical model of the system to show the effects of hypoxia on both the population dynamics of M. balthica and the trophic transfer to fish and crustaceans.
I will be using four main methods to complete these objectives. First, a field survey in the York and Rappahannock Rivers will provide large-scale representation of M. balthica population density both within and outside of hypoxic areas, along with information about growth and reproduction. Second, I will use laboratory experiments exposing live M. balthica to various tightly controlled dissolved oxygen levels to measure growth, reproduction, and mortality of M. balthica under a range of dissolved oxygen conditions. Third, I will conduct field experiments with caged and un-caged transplanted clams to measure predation-induced mortality inside and outside of hypoxic areas. Finally, to measure fecundity in M. balthica, I am developing an enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies specific to egg proteins. After quantifying the average amount of protein in each egg I will be able to use this assay to determine the number of eggs in a given female. The information from the various experiments will be used to create a mathematical model that will predict the effect of various hypoxic regimes on M. balthica populations, and its effect on trophic transfer up the food web.