The Marine Productivity (MarProd) programme is a thematic programme of the Natural Environment Research Council. It is funded for a period of five years starting in 2000. Its main goal is "to develop coupled modelling and observation systems for the pelagic ecosystem, with emphasis on physical factors affecting zooplankton dynamics" with the following specific objectives
- To identify the dominant spatial and temporal scales of physical parameters and zooplankton population dynamics, by observation, modelling and retrospective analysis.
- To parameterise the critical processes governing zooplankton dynamics by observations and experiments.
- To construct and validate spatially explicit models of zooplankton and their food and predators, capable of resolving short term changes in population structure.
- To provide data for model validation by developing and applying new interdisciplinary techniques to a wide spectrum of biological and physical parameters.
- To develop a database and information system for historic and new data, and models.
Research projects funded under a first phase (2000-2002) exploited historical data sets and existing biological models, complemented by laboratory experiments, remote sensing analyses and newly acquired field data to gain a better understanding of the dynamics of zooplankton populations in shelf seas. Under this phase, data sets such as the long-term hydrographic and plankton time-series at the L4 sampling station (Plymouth Marine Laboratory), a year-long monthly survey of surface nutrient distribution in the Irish Sea (DARDNI), a synthesis database of published data on growth and fecundity in marine planktonic copepods (Heriot Watt University) have been compiled and are in the process of being archived at BODC.
The second phase (2001-2005) focuses on the open ocean and the North East Atlantic. Its main component will exploit data collected during a major fieldwork campaign of four research cruises on RRS Discovery between November 2001 and December 2002; a total of over 800 gear deployments were performed at 159 stations mainly distributed in the Irminger Sea and Iceland Basin.
The four cruises had a set of common specific objectives which were:
- To map the physical features of the survey region in terms of water mass distribution, velocity field and mixed layer properties
- To collect water samples for plant pigment and microscopic analyses and to estimate the biomass of different taxonomic/functional groups of microplankton (picoplankton, phytoplankton and microzooplankton)
- To measure high resolution profiles of inorganic nutrient concentrations
- To determine the 3D abundance of key zooplankton species (Calanus finmarchicus, Oithona spp. and euphausiids)
Instruments deployed included a multi-sensor CTD profiler and rosette sampler, lowered and shipborne ADCPs, towed multi-instrument and multi-net plankton samplers, profiling and continuous underway Fast Repetition Rate Fluorometers (FRRFs), zooplankton nets, and towed and lowered scientific echo sounders.
In addition, process studies were undertaken to obtain information about factors controlling the reproduction, growth, mortality and behaviour of individual species using physiological studies (feeding experiments, egg production and nauplii development, species interactions) and analyses of biochemical composition (lipids and hormones studies, analyses of C/N and stable isotope ratios composition).
Phytoplankton primary production was measured using carbon uptake on the last two cruises and additional data were collected using a Fast Repetition Rate Fluorometer (FRRF) through continuous surface underway sampling and vertical deployments.
All four cruises were supported by continuous underway measurements of bathymetry, surface hydrography (temperature, salinity, fluorescence and attenuance), meteorology (wind speed and direction, PAR and total incident irradiance, air temperature, humidity and atmospheric pressure) and by remote sensing of sea surface temperature and ocean colour.
MarProd is the UK main contribution to the Global Ocean Ecosystem Dynamics project (GLOBEC), a core project from the International Geosphere-Biosphere Programme (IGBP) responsible for understanding how global change will affect the abundance, diversity and productivity of marine populations.