New insights relevant to the greenhouse effect are published today (Thursday 3 May) in Nature magazine in a paper co-authored by a leading Scottish life scientist.
Professor John Raven FRS of the University of Dundee's School of Life Sciences, worked with nine US-based scientists to examine photosynthesis in marine algae - "the grass of the sea" - on which other life in the sea, including fish, ultimately depends. The algae also play a key role in determining the level of carbon dioxide in the global atmosphere.
Through detailed study on a research voyage in the subtropical North Atlantic, the team identified a key factor in the growth of a blue green alga Trichodesmium which has implications for understanding how global temperatures are controlled. Their work suggested that it is phosphorus rather than iron - as was previously thought - that is the major factor controlling the alga's growth in that part of the ocean.
Said Professor Raven: " This alga is of particular importance because it is the main organism which fixes nitrogen in the way that plants such as peas and beans do on land. The rate at which microalgae in the oceans photosynthesise is important for marine food chains including those ending in fish eaten by humans. The importance of this work is that it adds to our understanding of what restricts the growth of photosynthetic organisms in the sea. This and other work shows that phosphorus can limit growth of photosynthetic organisms in some parts of the sea, while iron is the limiting nutrient in other areas and nitrogen limits in other large areas of the world ocean.
"Knowledge of what nutrients limit photosynthesis in different parts of the ocean contributes to our understanding of the marine food chains that end in fish, whales and seabirds. Such knowledge is also important in understanding the global carbon cycle and hence the processes controlling global temperatures."/ends
Notes
Professor Raven holds the University's Chair of Biology and is a world
authority on plants and photosynthesis.
The School of Life Sciences at the University of Dundee is the centre of 70 research groups and some 600 scientists.
Contact
Professor John Raven 01382 344281
Website: www.dundee.ac.uk/lifesciences/