SS4.07 Lipids/Fatty Acids in Ecological Research
Date: Tuesday, June 11, 2002
Time: 3:00:00 PM
Location: Saanich
 
AhlgrenG, Uppsala University, Department of Limnology, Uppsala, Sweden, gunnel.ahlgren@ebc.uu.se
Snoeijs, P, , Uppsala University, Department of Plant Ecology, Uppsala, Sweden, pauli.snoeijs@ebc.uu.se
Pedersen, M, , Stockholm University, Plant Physiology, Stockholm, Sweden, marianne.pedersen@botan.su.se
 
IMBALANCE OF FATTY ACIDS IN THE LOWER PART OF THE BALTIC FOOD WEB - A REASON FOR OXIDATIVE STRESS IN FISH?
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A reproductive disturbance in the Baltic salmon, the M74 syndrome, has been reported since the beginning of the 70s. This disturbance can, in certain years, cause up to 90% mortality of newborn fry. Previous research has revealed that it may be caused by oxidative stress. In an investigation on astaxanthin and thiamine dynamics in the lower trophic levels of the Baltic salmon food web, it was found that oxidative stress may be related to reduced levels of the carotenoid astaxanthin and the vitamine thiamine. Another sign of stress is abnormal high levels of the docosahexaenoic acid (DHA) in the phospholipids of defective fish eggs compared to healthy eggs. High levels of DHA with 6 double-bonds can be harmful, leading to increased levels of free radicals that together with decreased levels of antioxidants increase the risk for injuries. We compared the fatty acid levels in phytoplankton and copepods from areas in the Baltic Sea, where the M74 syndrome is common, with plankton from an area on the Atlantic coast of Norway where the syndrome has not been found.