Biochemistry is the study of all chemical processes associated with living organisms. In the sea, chemical signals are transmitted within organisms, between organisms and through the water column across a range of distances. Interactions between organisms can be particularly important in close associations, for example, in the symbiotic interactions of microalgae with corals and giant clams, bacteria and microalgae with sponges, and clown fish with sea anemones.
An important area is investigation of biosynthetic pathways, which are the chemical pathways for manufacturing all substances and compounds that organisms produce and are made of. Understanding biosynthetic pathways is fundamental to understanding life itself. Marine biochemistry is not confined to organic chemistry but is also concerned with inorganic elements involved in life processes, which includes study of bioaccumulation of specific elements such as heavy metals and other pollutants.
Biochemists play an important role in the study of the greenhouse effect and global warming by examining the role of photosynthesis in marine plants, especially tiny phytoplankton, in removing carbon dioxide (CO2) from the atmosphere. They also examine the processes that release CO2 from the oceans back into the atmosphere.
The fate of substances produced by photosynthesis is also an important field of investigation. Although photosynthesis does not occur below depths of about 100 metres because of insufficient light, organic production is still considerable in deep water because of the utilisation of dissolved organic matter, mainly by bacteria. This dissolved organic material mostly derives from photosynthesis in surface waters but in special cases can also arise from deep-sea hydrothermal vents. Marine biochemists study the nature of all life process chemicals in the oceans.
Another important field is biogeochemistry. This includes study of the biological and chemical processes involved in the transport of material through the water column to the sediment, its long term storage and modification in the sediment, and whether and how it is subsequently released. Marine biochemists also study the effects of human activities, including increasing nutrient and sediment loadings in the oceans.
Marine biochemical research is mainly conducted in universities, federal government agencies such as CSIRO and the Australian Institute of Marine Science, and in some state and local government agencies. .
Photos: Researchers (top) examining cultures of microscopic algae in a biochemistry laboratory, and (bottom) studying the biochemistry of mangrove trees.