Project Phases


The DEN-SELECT project will investigate two novel approaches for the optimization of copepod culture: the density effects on production as well as the strain selection.

”What are the greatest research challenges you expect to be facing ?

1

Density effects on the productivity of copepod culture

One of the weaknesses in the development of sustainable copepod systems is that, unlike rotifers and Artemia, copepods have not been raised successfully in very dense cultures. The high density in calanoid copepod cultures(1) increases the interactions between growing individuals which may lead to high cannibalism, physical disturbance during food encounters(2), and chemical communication effects which are not well described.
More specifically, in Acartia tonsa cultures, we regularly experience a production of resting eggs. These eggs are made to resist long periods in the sediment and cannot hatch immediately after spawning(3).
The present project will investigate the density effects influencing the production of copepod resting eggs in cultures using a series of laboratory experiments where physical and chemical effects of density in culture will be evaluated. The project will also study the related production loss due to egg cannibalism at different copepod densities. The goal is to find the optimal concentration of copepods that should be used in cultures to successfully develop cost effective and sustainable protocols for copepod cultures.

(1) >3000 ind. l-1; Drillet et al 2006a
(2) Hansen et al. 1991
(3) Drillet et al. 2008a, b

2

Effects of selection on population life history traits in copepod culture

In all food production sectors, production is increased through the selection of populations or groups from one species that have developed particular traits which are required for rendering the production economically valuable (high quality organisms, greater survival, shorter generation time, etc.). In the marine environment, the selective reproduction technique has so far only been applied to a small percentage of the hundreds of fish, invertebrate and plant species exploited in aquaculture, and therefore there is a high potential for improvement of raised species (1).
Like any other, the productivity of copepod culture is greatly affected by the selection of optimal populations for aquaculture purposes. The present project will use a newly isolated population of Acartia tonsa from Øresund to investigate the effects of selection on population life history traits among the developed generations during cultivation.

(1) FAO, http://www.fao.org/biodiversity