Glacial Nutrients Contribute to Oceanic Food Chain
28.12.2009 - Water & Oceans, Ice & Snow, Flora & Fauna, Arctic
A study recently published in the journal Nature shows that the disappearance of glacial ice might lead to the disappearance of the production and export of high-quality food from glacial watersheds to marine ecosystems, which could have a significant impact on marine food webs. Researchers from four universities and the USDA Forest Service examined 11 coastal watersheds around the Gulf of Alaska, which is home to some of the most productive salmon fisheries in the world.
The research produced an interesting paradox, however. It is believed that the nutritional value of organic matter diminishes over time. Yet the results of the study show that watersheds fed by glaciers release organic matter that is much more biologically active than organic matter found in watersheds not fed by glaciers, and more than two-thirds of this organic matter was rapidly metabolized by marine microbes, going directly towards supporting marine food webs.
In short, the more glaciers contribute to a watershed, the older the dissolved organic material is and the more available it is to marine organisms. However as the glacier thin and retreat this source of nutients will eventually diminish over time.
Researchers such as Rick Edwards, who coauthored the study, believes it is essential to gain a better understanding of the watersheds and adjacent marine ecosystems and how they are being affected by climate change and management schemes. More research is needed to better understand the mechanisms at work.
Researchers from the University of Alaska Southeast, the University of Alaska Fairbanks, the University of California Davis, the Pacific Northwest Research Station under the USDA Forest Service and Virginia Tech participated in this research project.
