Fishermen play crucial role in five-year herring stock survey off Western Scotland

The importance of scientific sampling to assess the composition of fish stocks and their status has been underlined by the results of an international five-year study on Western herring, in which Scottish fishermen played a key role.

One of the aims of the sampling surveys carried out by Scottish and other nationality fishing vessels working in partnership with government marine science institutes, was to determine whether the herring stock off the west coast of Scotland comprised of one stock, or different stocks split between the north and south.

The study on the genetic make-up of herring revealed that there are indeed different stocks, with those spawning in the northern sector off Cape Wrath and adjacent areas being genetically identical to North Sea herring, while those spawning further south around Ireland are a discrete, separate stock. Dr Steven Mackinson, Chief Scientific Officer of the Scottish Pelagic Fishermen’s Association (SPFA), said that such knowledge is important because it greatly aids decision-making in fisheries management to ensure stocks are harvested sustainably.

For the last few years, no commercial fishing has been permitted for Western herring because, for undetermined reasons, levels of the various stock components are low.

Later this year, the results from this new five-year data set will be considered for the first time by the International Council for the Exploration of the Sea (ICES) to assist in a full “stock-take” of the information available to assess the status of Western herring, which the SPFA said will aid in the development of an effective rebuilding plan.

Dr Mackinson said the development will show how fishermen working collaboratively with scientists can play a crucial role in survey work, which can then be fed into the official assessment process, thus helping ensure that the best available information is applied to addressing issues of shared concern. Industry’s support for scientific data collection means that there has been a higher intensity of monitoring than would otherwise have been possible, which is providing information to help make the stock assessment more robust.

Due to constraints on financial resources, there is often a shortfall in information from marine scientific surveys carried out by national governments. Dr Mackinson has stated that the scope of the activities of fishing boats, and the wide sea area they cover, offers the ideal platform for collecting relevant marine data to somehow alleviate the shortfall.