Marine Productivity - UK GLOBEC

MARINE PRODUCTIVITY: physical controls on ecosystem dynamics

The aim of the Marine Productivity programme is to develop coupled modelling and observational systems for the pelagic ecosystem, with emphasis on physical factors affecting zooplankton population dynamics. Marine Productivity provides a major UK contribution to the international Global Ocean Ecosystem Dynamics project (GLOBEC) and is funded by the Natural Environmental Research Council, UK (NERC).

Marine productivity aims to answer the following questions:
1) How are basin-scale structures in zooplankton species maintained?
2) How do zooplankton species respond to basin-scale physical forcing?
3) What are the impacts of basin-scale physical changes on secondary production
in Shelf Seas?

Marine productivity will focus on Calanus finmarchicus and C. helgolandicus Meganyctiphanes norvegica in the North Atlantic, Euphausia in the Southern Ocean and in the Shelf Seas - Calanus helgolandicus, Meganyctiphanes norvegica, (C. finmarchicus),plus work on other important shelf sea copepods (eg Temora longicornis, Pseudocalanus elongatus and Acartia clausi) and the interactions of micro- and macro-zooplankton. It will test whether physical factors (oceanographic hypotheses) or biological factors (trophic hypotheses) primarily drive the relationship between climate and population dynamics of key zooplankton species, as expressed through interannual variability and longterm trends.

In the North Atlantic, the following topics will be investigated: winter distributions, spring survival, entry to diapause/overwintering states, coupled physical-biological modelling, in Shelf Seas, the topics will be Advective exchange and winter distributions, Population development and food supply and Process Studies and Modelling. For the Southern Ocean, the year-round survival strategy for Euphausia superba will be investigated.

Six main periods of cruise activity are envisaged, over a two year period beginning in late 2001:
1a: early winter, North Atlantic (Nov-mid Dec 2001; c 6wk)
1b: winter, shelf seas (Jan 2002; 2-3 wk)
2: late spring/early summer, N Atlantic & shelf seas (late April -
early June 2002)
3: late summer/early autumn (August - early Sept 2002)
4: winter (Nov 2002 - Jan 2003)
5: late spring/early summer (late April - early June 2003)
6: late summer/early autumn (August - early Sept 2003)

Each cruise will potentially comprise a mix of broad-scale surveys and more site-specific process studies. For cruises 2, 3, 5 and 6 a 50:50 split between survey work and process studies is likely; however, for cruises 1a, 1b and 4 (the winter cruises), survey work is likely to predominate. The basic framework will be daily CTD/rosette (with lowered ADCP) stations interspersed with tows of a plankton sampling vehicle (probably two per day). It is anticipated that PALACE floats may also be used to track water masses.

This information was taken from the NERC Marine Productivity Homepage "http://www.nerc.ac.uk/funding/thematics/marprod/index.shtml"