A major area of interest within the biological oceanographic community is the ability to assess the factors affecting population abundances of marine organisms and the potential role of climate change on marine species. For zooplankton species, it is hypothesized that nutritional regime can profoundly affect zooplankton abundance and survival. However, current techniques to assess nutritional and physiological condition in zooplankton to evaluate this hypothesis are rather insensitive and/or difficult to apply. Additionally, analysis of field data from biological studies usually lags behind the availability of physical measurements. This project will develop shipboard activity (rate) assays for enzymes of metabolism and growth in several species of marine zooplankton including two species (larvae of the cod, Gadus morhua and the copepod, Calanus finmarchicus) which are important components of an of the Georges Bank ecosystem, which is a region of interest in the zooplankton and fisheries community. The assays once developed will be used to test the vertical-stratification hypothesis for zooplankton survival in the Georges Bank region. The objectives will be accomplished by: (1) laboratory optimization of the enzyme assay conditions; (2) correlation of physiological parameters (e.g., respiration rates) with enzyme activities to validate molecular proxies; (3) estimation of physiological condition in field-caught specimens by use of these enzyme activity proxies.
