krill. (Photo Credit: MAR-ECO/Oystein Paulsen/CC BY-SA 3.0)
UNITED KINGDOM
Thursday, August 07, 2014, 03:00 (GMT + 9)
In response to concerns expressed in a British newspaper as to the future of salmon stocks, an important international organization addressed certain issues considered the most likely cause of the decrease in size and weight of the returning salmon to British waters.
According to an article published in The Telepgraph newspaper, overfishing sandeels and krill might be the cause for the salmon not to have sufficient food at sea but The Marine Ingredients Organisation (IFFO) does not agree on this conclusion.
“The only significant fishing for krill is conducted in the Southern Hemisphere (Antarctica) far away from the feeding grounds for the Atlantic salmon. Secondly, the fishing for sandeels (which are only found in the North Sea) is carefully monitored by the International Council for the Exploration of the Sea (ICES),” explains Andrew Jackson, IFFO Technical Director, in a letter sent to the editor of the British newspaper.
Another issue he clarifies is the fact that the article suggests that sandeels are being caught for the production of fertilizers but Jackson stresses it is “totally erroneous,” since these species are intended for the production of marine ingredients for human and animal nutrition.
IFFO supports the research conducted by Professor Chris Todd of St Andrew’s University, concluding that the primary cause of the low weight of returning salmon to Scotland is due to the warming of the seas in the North Atlantic.
“My research, in collaboration with Marine Scotland Science, has focused not on mortality rates and population decline, but on the changes in size and quality of salmon returning to Scottish rivers over the past 50 years. This variation seems to stem from the effects of climate change on the ocean, and the anomalously high temperatures salmon find in the North Atlantic,” Todd points out.
This research has been developed with funding from the European Commission, the Atlantic Salmon Trust (AST), the Association of Salmon Fishery Boards for Scotland (ASFB), and the Fishmongers Company.
The researcher explains that a returning salmon, known as a grilse, will have grown 100-fold in size from the rich feeding to be found at sea but between 80-90 per cent of grilse, and fewer still multi-winter fish, will not survive their journey due to the risks experienced.
Todd states that over millions of years salmon have survived ice ages and eras of global warming and that helping salmon populations recover naturally is clearly a better strategy than rearing them artificially.