Salmon fishery statistics - 2012 season

Interpretation

Recent events

The reported rod catch in 2012 was very similar to that in 2011 and was 95% of the previous 5-year average.

It should be noted, however, that annual changes in catch are not a simple reflection of changes in the underlying numbers of fish returning to Scottish waters. Both catch size and the allocation of catch among fishing methods may be influenced by many factors, particularly fishing effort and river flows. Thus, when inferring the status of stocks from catch data, it is important to consider trends over a number of years as well as focussing on catch levels for the most recent year.

The decline in net fisheries and in the numbers of salmon returning to home waters

Both fixed engine and net & coble fisheries have experienced considerable decline over the period since 1952 and catch and effort in both fisheries remain at historically low levels.

Marine survival of salmon has declined substantially over the period covered by the catch statistics. This phenomenon is not unique to Scotland and similar declines have been detected in a number of monitored sites on both sides of the North Atlantic.

The numbers of salmon entering rivers appear to have increased

In contrast to the net fisheries, the rod and line catch has increased since 1952, when records began. Assuming no trends in exploitation rates (the percentage of available fish capture) over time, the catches provide insights into the status of salmon stocks.

Declines in the marine survival of salmon have led to lower numbers returning to the Scottish coast over much of the time series. Reductions in the netting industry over this period allowed a greater proportion of these fish to enter rivers, however, resulting in an increase in the numbers of fish available to the rod fisheries and escaping to spawn. The decline in the netting industry thus acted as a buffer for the rod fishery as marine survival declined.

Net catches are now around 5% or less of those taken in the past and have remained at this level for the last decade while annual rod catches have continued to increase. In small part, an increase in rod catch would be expected as catch-and-release has increased. However, observations of salmon numbers at Marine Scotland monitoring sites suggest that overall marine survival of Scottish salmon has now stabilised or is increasing.

The number of salmon escaping to spawn is an important factor in determining whether sufficient eggs have been deposited to use the rearing habitat fully and hence maximise subsequent smolt production. However, it is not just the number but also the size and condition of salmon that determines the total numbers and also, perhaps, quality of eggs deposited. Monitoring work indicates a decline in both the size and condition of salmon returning to Scottish waters which may act to reduce the average numbers of eggs carried by individuals.

Trends in abundance vary among stock components

There are clear differences in trends of catches of individual stock components over the time period that these stocks have been monitored. Thus, although rod catch as a whole has increased over the time series, the numbers of spring salmon in the catch have generally declined since the 1950s, and although spring salmon catch has stabilised in recent years, it remains at a historically low level.

Thus interpretation of catch information at finer geographic scales ( e.g. particular components of the returning stock) may lead to interpretations of stock status which differ from an assessment based on total annual catch.

Downloads

Topic sheet no. 67 explains how we collect the catch statistics and is available for download at http://www.scotland.gov.uk/Topics/marine/science/Publications/TopicSheets/tslist

Summary data for the 2012 fishing season are available for download at http://www.scotland.gov.uk/Topics/marine/science/Publications/stats/SalmonSeaTroutCatches

The data provided for download are the best available at the time of publication. Our records are amended when further information is provided and the most accurate historical data may be obtained directly from us.

Contact

If you have a specific request for Scottish salmon and sea trout fishery information, please contact us directly at ms.catchform@scotland.gsi.gov.uk