From Greenland to green lakes: cultural eutrophication and the loss of benthic pathways in

• Main Authors: Yvonne Vadeboncoeur, M. Jake, Vander Zanden, Hans-henrik Schierup, Kirsten Christoffersen, David M. Lodge
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2003
• Subjects: Greenland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.523.7097; http://limnology.wisc.edu/personnel/jakevz/pdf/2003_L%26O_VDBetal.pdf

Benthic community responses to lake eutrophication are poorly understood relative to pelagic responses. We compared phytoplankton and periphyton productivity along a eutrophication gradient in Greenland, U.S., and Danish lakes. Phytoplankton productivity increased along the phosphorus gradient (total phosphorus [TP] 5 2–430 mg m23), but whole-lake benthic algal productivity decreased, substantially depressing increases in primary productivity at the whole-lake scale. In shallow, oligotrophic Greenland lakes, periphyton was responsible for 80–98 % of primary production, whereas in Danish lakes with TP. 100 mg m23, phytoplankton were responsible for nearly 100 % of primary production. Benthic contributions ranged from 5 to 80 % depending on morphometry and littoral habitat composition in lakes with intermediate phosphorus concentrations. Thus, eutrophication was characterized by a switch from benthic to pelagic dominance of primary productivity. Carbon stable isotope analysis showed that the redistribution of primary production entailed a similar shift from periphyton to phytoplankton in the diets of zooben-thos. Benthic and pelagic habitats were energetically linked through food web interactions, but eutrophication eroded the benthic primary production pathway. Eutrophication is one of the most common water quality problems in lakes worldwide. Phosphorus storage in sedi-