Fatty acid composition of herring ( Clupea harengus L.): influence of time and place of catch on n-3 PUFA content

The fatty acid composition (FAC) was determined in muscle samples from 963 herring (Clupea harengus L.) caught during 2001–2003 in waters around Denmark. The overall variation in FAC was mainly related to seasonal (summer or winter) and annual (2001, 2002 or 2003) variation. No clear variation due to place of catch (Baltic Sea, Skagerrak, Kattegat or the northern, western or eastern part of the North Sea) was found.

Of the nutritionally important n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), EPA seemed to show a seasonal variation, with the highest amount during summer, whereas no periodic variation was observed for DHA. Herring from one catch, however, were found to have an extraordinarily high amount of EPA (11%) compared with all other catches (amounts of EPA ranging from 4 to 8%).

This high EPA content found only in herring caught in May 2003 in the northern North Sea (NSN) was in large contrast to the herring caught in the same place 3 months earlier, which had the lowest EPA content overall. The abrupt increase in EPA level from February to May was not correlated with biological parameters such as spawning type, maturity status, age, sex and size, but it might be related to variation in the FAC of the calanoid copepods on which the herring feed.

Considering the nutritional aspects, the high-EPA herring from the NSN catch in May 2003 had a relatively low lipid content (7%), making them highly suitable for human consumption. Copyright © 2007 Society of Chemical Industry