Focus 2

Process Studies

At the small- and mesoscale, population process studies are of critical importance for the understanding of the functioning and thereby the structure of marine ecosystems. Small-scale processes may be influenced by climatic variations but it is large-scale phenomena, such as distribution and timing of stratification and migration patterns, as well as matching in vertical migration and timing of phytoplankton blooms that are likely to be most important. While much recent research has focused on phytoplankton, particularly through JGOFS, knowledge of the role of zooplankton as grazers, predators and prey is much less well developed. While the protozoan component of the microzooplankton multiply by cellular division, the larger zooplankton most often undergo complicated life cycles with series of larval stages before sexual maturity is reached. This has major implications for the ability of the two groups to exploit rapidly changing situations in the ocean. Feeding processes and choice of food are critical issues for models. New investigations show that zooplankton are much more versatile in their feeding behaviour than earlier believed and, that if they have the choice, they prefer the more nutritive food sources.

Focus 2 Working Group at Rhode Island, USA, July 2004
Focus 2 Working Group at Rhode Island, USA, July 2004

Zooplankton are also a food source for higher trophic levels, and their abundance and species composition may have great implications for the population dynamics of the latter (Cushing, 1995). Thus, fish populations may be strongly affected by zooplankton fluctuations, resulting in significant economic consequences. Such fluctuations may be caused by climatic variability or change and/or by human activity, at least in the coastal areas, and knowledge of the inter-relationships is of fundamental importance for the understanding of when, and where, adverse situations can be predicted.

The process studies in Focus 2 outline experimental approaches to investigating specific mechanisms which are thought to link ecosystem responses with environmental variability. The design of these studies is closely linked to the retrospective studies under Focus 1, and the modelling and observational work of Focus 3. Close integration is essential.

Focus 2 Meetings Location Date Chair Download
1st meeting Roscoff, France 10-13 Sept 2000 Serge Poulet Report / newsletter
2nd meeting Qingdao, China 13-14 Oct 2002 Serge Poulet Report / newsletter
3rd meeting Rhode Island, USA 18-20 July 2004 Roger Harris Report / newsletter
4th meeting Dartington, UK 16-20 Oct 2005 Roger Harris Report / newsletter
Focus 2/3 meeting Marseille, France 2-5 May 2006 Francois Carlotti newsletter