River Carron Fishing

Attadale owns the fishing on the River Carron from the road bridge at Strathcarron to the river mouth. Day tickets are available from Roddy MacLennan on 07818 032368.

Please view the River Carron Restoration website here

Salmon and sea trout stock collapse

Stocks of both salmon and sea trout in the River Carron collapsed in the latter half of the 1990’s as evidenced by rod catches dropping to single figures per season. The most likely main cause for the collapse was big winter spates moving gravel and washing out eggs.

Dr James Butler, biologist for the Wester Ross Fisheries Trust at the time, was interested in the possibility that redd washout was a problem for rivers in the Wester Ross area. He had evidence from the River Broom of a significant correlation between total winter runoff and the abundance of fry the following summer. He devised a set of field work trials taking in 18 of the main rivers in Wester Ross, including the Carron, to investigate the possibility. Sites were chosen on each river where gravel movements could be monitored through the winter. 

In the first of these winters, the spate was of such a size that the river at Arineckaig changed course moving approximately 100 metres to the north. In the process, thousands of tonnes of gravel went down the river with the inevitable serious consequences for stock. It is highly likely that the spates in these years were responsible for the collapse of the stocks in the late 1990’s. Since damaging winter spates are an almost annual occurrence, it is inevitable that much of the natural spawning will be unsuccessful with only those fish spawning in more stable areas being able to contribute to the stock.

Initial recovery of salmon stocks

During the second half of the 1990s a stocking programme was instigated by taking wild fish from the river to use as broodstock. Despite much effort, very few fish could be caught resulting in relatively low numbers of fry available for stocking. These were stocked out as fed-fry in mid-summer with the most in any one year being 9,000. Smolt production from this number would have been relatively low resulting in no noticeable increase in adult fish returning to the river. Stocking is a numbers game, so, with so few fish available in the river, the only way of “upping the ante” was to create a captive broodstock from eggs taken from the wild hens that could be caught. These fish were brought through to maturity entirely in freshwater at facilities at Attadale established specifically for the purpose.

The first fry from the captive broodstock were produced in 2001 allowing 150,000 to be stocked out from early fed-fry through to autumn fry. Electrofishing surveys carried out through the 1990’s revealed low numbers of juveniles throughout the catchment justifying stocking activity to take place over the whole of the river system. Since the first major stocking in 2001, the same stocking strategy has been used each year ensuring that as much of the suitable habitat as possible is utilised. The level of stocking each year has varied depending on the number of eggs available from a combination of captive broodstock and wild broodstock caught by rod and line from the river. 

The first major question is whether the stocking programme was responsible for the initial dramatic increase in rod catches and therefore the number of salmon and grilse returning to the river or could it have been a natural recovery. 

The most likely scenario is that the initial recovery of stocks in the river, as reflected by the rod catch, was from the stocking, with a modest number coming from natural spawning. From 2008 onwards, returning adults would have come from a combination of natural spawning and stocking.

Relative contribution of stocked and wild salmon

The Carron has been restored to become a viable salmon fishery once again. In fact, numbers of returning adults, based on rod catches, are at historically high levels going back to 1952 when national recording began. The current 10-year average for salmon and grilse is 246 compared to the best average prior to the stocking programme of 150. Comparisons between the 10-year average immediately prior to stocking is even more dramatic with 16.8 for salmon and 6.5 for grilse  with the current figures of 98.4 and 147.8 respectively. The success of the river comes at a time when many Scottish rivers are struggling and salmon are described as being in crisis. The question is whether the wild native Carron stock is now maintaining the fishery or is its current high level of success largely due to the fact that stocking is carried out each year. It is also possible that a healthy contribution is made by both.

The suggestion that fry reared in tanks through the summer become domesticated and are therefore incapable of coping once released into the river certainly did not hold true for this batch of fish.

Information for all stages is of great importance for the future management of the Carron but even more important for the wider salmon management community that is facing declining stocks in many of Scotland’s rivers. To provide useful information requires that the evidence is accepted by the scientists who ultimately make the decisions on how salmon stocks and fisheries are managed. 

The next phase of the Carron project should provide unique evidence robust enough to properly consider the merits or otherwise of stocking.

Sampling for DNA

Over the period of the stocking programme, although the preferred stage at release has been autumn fry, because there is evidence that this stage has given good results, other stages have also been used with unknown results. From the time that tissue samples were kept from each pair of broodstock, all stocking has involved batches for which the DNA can be determined for all the brood fish contributing to each batch. By identifying stocked fish from their DNA, it will also be possible to determine which batch they came from and where in the river they were stocked.

Given the perilous state of many salmon stocks in Scotland at the moment, effective management is crucial. Over 20 years of stocking on the Carron provides a unique opportunity to fully assess the benefits or otherwise of a well-documented programme. 

To achieve this, it is essential that the large number of tissue samples collected are genotyped and analysed to ensure that the regulatory authority do not ignore the potential benefits of stocking programmes that are appropriately designed and implemented. If stocking as a tool in the tool box of salmon management is effectively removed, then any river facing a similar situation as was the case for the Carron in the late 1990s may find that its native stock disappears completely. It would be criminal to allow this to happen simply because an opportunity is missed.