Sack Lunch Seminar (SLS)

Congener Copepods in the northern Atlantic Ocean: an inter-regional analysis on the response to changes in environmental conditions



As the investigation of key copepod species gained a special interest within GLOBEC several population models have been used within different regional projects. Copepods of the genera Pseudocalanus, Centropages and Calanus are widespread in the northern Atlantic Ocean and are stockforming in different areas. While some species are present in the whole North Atlantic Pseudocalanus is separated into habitats of congener species of which P. newmani and P. moultoni are found in the Gulf of Maine whereas P. elongatus inhabits the European Continental Shelf. Population dynamics of these copepods are investigated within three-dimensional ecosystem models using different stage grouped population models. Within the U.S. GLOBEC program a population model was developed and applied to the Gulf of Maine. The model estimates temperature dependent developmental rates calculating the abundance of four stage groups where development is controlled by their mean age. Using temperature data from climate models potential biogeographical boundaries are determined for different species. As food concentration can limit growth rates in certain species, the uptake of food was considered in another model, in which individual growth is controlled by the mean mass. Investigations in the North Sea within the German GLOBEC project provide the interaction with other trophic levels. Using both approaches developmental rates under changing conditions are compared to time series at single stations. The population life history, its structure, growth and distribution are examined in the context of seasonal and inter-annual climate variability.