Small plants may hold big answers (3/2/2008)

Specialist equipment experiments on the seabed supplied by Partrac Ltd

Some of the smallest plants on the planet may play a vital role in some of the largest questions facing mankind today, according to marine scientists at the University of Portsmouth and the National Oceanography Centre, Southampton (NOCS).

Scientists have won a grant worth £700K to examine how the lifecycle of sea algae affects the ocean's fragile ecosystem. Algae are floating microscopic plants, also known as phytoplankton, which absorb carbon dioxide from the atmosphere, helping to regulate atmospheric concentrations of carbon dioxide and other greenhouse gases.

The money will be used to examine whether disturbing sediment on the seabed stimulates the growth of algae by releasing nutrients. The work will focus in the North Sea where natural and man-made sediment disturbance is a major feature of the environment.

Dr Gary Fones from the University of Portsmouth said: "Coastal seas like the North Sea are crucial in controlling the cycling of nutrient elements which are essential to life on earth, particularly as nearly a third of the world's algae is produced in these regions."

Algae rely on nitrogen, phosphorus and silicon in the water for growth and scientists used to believe that the North Sea receives enough nutrients from rivers to maintain the growth cycle. But recently they discovered that the actual amount coming in from rivers and surrounding seas is less than that required to start the growth cycle.

Scientists now think that some nutrients are released from dead algae which have sunk to the seabed when it is churned up by strong winds, waves, tides and by trawling gear used in fishing. This study will look at the impact of disturbance of the seabed using specialist equipment to simulate the stirring of the sediment on the seabed in three areas of the North Sea and in the laboratory under more controlled conditions.

Dr Boris Kelly-Gerreyn from NOC said: "We know that sediment suspended in seawater plays a vital role in regulating phytoplankton, but new technology is facilitating greater research. This exciting new partnership brings together many skills including computer modelling, laboratory experiments and ship deployments to address a key gap in our understanding."

The project, which will run for 41 months, is funded by the Natural Environment Research Council (NERC) and the Centre for Environment Fisheries and Aquaculture (CEFAS).

Dr Fones said: "The study will provide evidence to further our understanding for assessing the influence of environmental change and human impact and will help in the sustainable management of the sea as one of the planet's most valuable resources."

Note: This story has been adapted from a news release issued by the University of Portsmouth

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