Restoration of Salmon and Sea Trout in the Applecross River

In keeping with most rivers in the North West Highlands, the numbers of adult salmon and sea trout returning to the Applecross River dropped dramatically during the 1990’s to near extinction levels. Several factors are likely to have contributed to the decline including climate change, affecting both the marine and freshwater environments, over exploitation particularly when migrating smolts are caught as part of a by-catch, increasing predator numbers, food supply and sea lice infestations on smolts. The net effect was that, with so few adult fish spawning successfully in the river, the production of juveniles and subsequently the numbers of smolts leaving the river was severely depleted.

To increase the numbers of migrating smolts and thereby have a chance of restoring runs of adult salmon and sea trout to the river within a reasonable time-scale, it was obviously necessary to replace the lost juveniles in the river. With the co-operation of the Applecross Trust, the Seafield Centre at Kishorn devised and implemented a restoration programme for the river involving stocking with significant numbers of young fish. While many rivers use captured wild fish as broodstock for stocking programmes, this was not an option for the Applecross River since only a few adults were returning to the river. Therefore, to generate the numbers of juveniles required to make a difference, a captive broodstock for both sea trout and salmon had to be established. This was instigated in 1995 and 1996 respectively, by retaining some of the eggs stripped from the few wild fish and rearing them through to maturity in captivity. This eventually resulted in large numbers of eggs being produced from humble beginnings.

With eggs from the captive broodstocks coming on-stream towards the end of the 90’s, significant numbers of both salmon and sea trout have been introduced to the river each year. The young fish are stocked out throughout the river at various stages and at different times of the year. Early fry go out in June, larger fry and parr in late summer and some are taken through to the smolt stage before being released from a specially constructed release pond towards the lower end of the river. These smolts are held in the pond for only 3 weeks (for imprinting) before being released after which they migrate to the sea almost immediately.

The effect of the restoration programme has been two-fold. The primary objective was to increase the number of returning adults. This has been achieved to some extent with rod catches showing a significant increase in recent years. This has made it possible to catch up a number of hens and cocks at the end of each season to bring in “new blood” to the Broodstock. The second effect is on the biodiversity of the Applecross catchment. The health of a river is largely judged by the level of young stock within it and many species, including saw-billed ducks and otters, require good fish numbers for their survival. In this respect, the stocking programme has benefited more than just the anglers.