Friday, March 13, 2009

Aliens on the agenda in Oban?

It is interesting to note that the Scottish Environmental Protection Agency (SEPA) met at the Scottish Association for Marine Science yesterday to discuss local aspects of the European Water Framework Directive (WFD). The Argyll and Lochaber Draft Area Management Plan is one of eight branches of the Draft River Basin Management Plan for the Scottish River Basin District (RBD). The purpose of these directives is aimed at protecting and improving Scottish water, whether freshwater or marine.

In 2006 SEPA brought together various stakeholders from across Scotland to provide help and advice during the creation of the drafts. Organisations with interest in land, sea, forestry, farming, conservation, industry, tourism and rural business have come together to help shape the strategy and resolve issues through collaboration and discussion.

One particular topic of discussion raise yesterday afternoon was centred on the risks posed by invasive non-native and alien species of flora and fauna that have taken up residence in Argyll and Lochaber.

There have been close to 1000 invasive non-native species indentified in Scotland so far, and approximately 65 of these are from the marine environment. SEPA and the stakeholders involved are particularly interested in some of the risks associated with these plants and organisms. Japanese knotweed (Fallopia japonica) and Wireweed (Sargassum muticum) are amongst the most notorious aliens present in Scotland. However I am keen to explore the issues surrounding a marine alien whose presence may be considered more beneficial than threatening and why this can cause an additional dilemma.

The Pacific Oyster (Crassostrea gigas) has now been named as an invasive, non-native species and a curse to those eager to extol the virtues of the Native Oyster (Ostrea edulis). This is causing friction between conservationists and shellfish farmers. The Pacific Oyster is a vital element of oyster production in Scotland and the growth rate of the native species cannot compete with that of the pacific variety. Evidence from the Fisheries research services suggests that the Pacific Oyster will in fact not be able to acclimatise and establish itself in Scottish water. This is due to a temperature deficit between the species warmer native Asian waters and the cooler Scottish seas. This species is also of economic and social importance as is maintains populations in remote regions of the country and provided employment and wealth.

1 comment:

  1. Could you tell me which source of information you are quoting when you say that the Pacific Oyster will not be able to reproduce in Scottish waters? It is now breeding and establishing reefs outside culture sites on the south coast of England, Belgium and in the Wadden Sea, Germany. OK, these sites typically have higher summer seawater temperatures at present, but with seawater temperatures predicted to increase over the next few years is it not likely that Scottish populations may also start to breed?