Science Serving Maryland's Coasts

Greer (Anderson) Maier, University of Miami

Class Year: 

Project Title: 

Effects of Varying Salinity Stress on Fecundity, Survivorship and Population Dynamics of the Calaniod Copepod Eurytemora affinis


The calanoid copepod Eurytemora affinis is known to be highly adaptable in the dynamic conditions they encounter in the estuarine environments they inhabit. The geographic and seasonal distribution of the species is restricted, however, and could possibly be linked to osmotic limitations. These limitations involve both lethal and sublethal responses to salinity stress and are possibly related to salinity regime. Questions arise as to how osmotic demands created by different salinity regimes affect E.affinis individuals. These effects include sublethal responses such as reproduction and lethal responses involving maintenance costs. Possible salinity regimes populations encounter in estuaries are both pulsed and chronic and can have high, low, or optimal salinity levels. Under these parameters, E.affinis appears to have greater fecundity and survivorship in high salinity environments and in general, populations have relatively higher growth rates in varying vs. constant salinity regimes. Because salinity stress is often a major factor in many estuarine species' distribution, the response of E.affinis populations and individuals to different salinity regimes could be useful in explaining the factors limiting the distribution of the species in estuaries.