You may recall that earlier this month I gave you a fair taste of what fisheries expert Tony Andrews had to say in an extremely insightful discussion paper on the problems facing wild Atlantic salmon.
In the sure and certain knowledge that something similar has to be done to save what remains of our indigenous flora and fauna from the callous wreckers dressed in the cloak of righteousness, I include in today’s column the remainder of Tony’s dissertation.
Tony Andrews said: “Research over the past decade has given us insights into migration and distribution of wild salmon at sea. The aim of the SALSEA project was “to increase understanding of how salmon use the ocean, where they go, how they utilise currents and the ocean’s food resources and what factors influence their migration and distribution at sea”, and that is precisely what the project achieved.
“Migration models have provided us with detailed information on migration routes of post-smolts from southern Europe, as they move northwards along the shelf edge. Genetic markers for regional salmon stocks and in some cases for individual rivers are becoming available.
“These new data allow us to map salmon ‘migration corridors’ in the ocean, ultimately to ensure that these receive the level of protection currently afforded to other marine based Special Areas of Conservation (SACs). It is now recognised that salmon rivers with SAC status should include estuarial and marine areas used by the salmon during their migrations. Most fishery managers acknowledge that management responsibility for post-smolts does not end at the interface of fresh and salt water. They accept that ways must be found to ‘shepherd’ and protect salmon stocks at sea, particularly vulnerable post-smolts. In the future, for example, we are advocating that designation of Marine Protected Areas for salmon should go hand in hand with increasing knowledge of their migration corridors.
“Patterns are ever-changing and far from simple to interpret and fully understand. Dependence and independence: why is the distinction important? In general, as long as marine mortality is at ‘normal’ levels of between 70 per cent and 80 percent, most salmon rivers can produce sufficient smolts to provide the basis for a sustainable stock. While fishery managers should continue their essential monitoring of stocks and habitats, we should acknowledge that, individually and collectively, rivers are mostly doing their job of generating enough smolts – if it weren’t for the unpalatable fact that well over 90 percent of outgoing smolts fail to return. There are of course exceptions.
“The problem is that, while we know that as few as 5 per cent of post smolts survive to adulthood, we don’t know where the ‘cliff edges’ of marine mortality are taking place. It is obvious that coastal waters are dangerous for both post smolts and returning adults. Work is already taking place in most Atlantic salmon countries in tracking coastal migration routes, prioritising risks, and removing obstructions (e.g. coastal nets). In Canada, Ireland and Norway and, more recently in Scotland, there is action to identify bottlenecks or choke points along migration routes. Remedial actions, where feasible, follow swiftly.
“Ocean migration routes are more difficult (and expensive) to map and assess in terms of salmon survival, but already, as a follow-up to SALSEA, NASCO, with support from the Ocean Tracking Network, is addressing this issue.
“Biologists distinguish between ‘density dependent’ and ‘density independent’ mortality. A river catchment provides a density dependent environment for salmon, which limits the size of a fish population in terms of the number of individuals that can survive in that environment. No matter how many eggs are laid, how many alevins are recruited, how many fry are produced, or survive to become smolts, numbers will be limited by the carrying capacity of the available riparian habitats.
“Mortality of salmon at sea is density independent, because it is not linked to salmon numbers, constrained by carrying capacity as occurs in the fresh water environment. In other words, in the egg, alevin, fry and parr stages, numbers of salmon are density dependent, while at the smolt, post-smolt and adult stages they are density independent. Constraints on salmon abundance at sea arise, therefore, from other causes, which must now be prioritised in terms of risk and cost effectiveness.
“Other factors affecting mortality in the lower river, the estuary or at sea have a direct effect on the number of returning, adult spawners. There is little natural buffering to guard against unforeseen circumstances at this stage in the life history, as there would be if very significant mortality occurred at the ova or fry stages. It is vitally important to appreciate the disproportionate importance of smolt/post-smolt and adult salmon survival as opposed to repairable losses at earlier stages of the life cycle.”
In a letter, Seamus Connor DCAL Chief Fisheries Officer said: “As Chief Fisheries Officer I wish to correct some factual inaccuracies in a letter from Seamus McKillop which was printed in your column of October 24.
“It is simply not true to assert that DCAL is “presiding over the destruction of salmon and sea trout stocks”. In fact, the Department has been proactive in its management approach to protect both salmon and sea trout. Legislation passed in 2014 has made it illegal to take salmon or sea trout in the DCAL area except on rivers which have met their management targets and there is a surplus of fish to take.
“The Department also continues to monitor stocks annually in the major salmon rivers. Data from each river is assessed by an independent scientific group to help determine which rivers will remain as catch and release only and which rivers can be opened for anglers to take fish, with the results published on the DCAL website.
“This work has been carried on in the context of salmon stocks not only in the local rivers, but also throughout the North Atlantic, continuing to be affected by low survival rates at sea. This in turn results in a lower adult return from those smolts that leave our rivers.
“On the issue of fish health, the last “outbreak” of IPN in the salmon cages at Red Bay and Glenarm was in 2007. The DARD/AFBI annual testing regime for all land and marine based fish farms includes testing for IPN (among others) in all the salmonid stocks and all results have been negative since. DARD also checks the wild stocks as part of its annual electrofishing regime – again all checks have been negative since the sampling started (c.2007).
“The Red Bay and Glenarm sites are also visited by DARD Fish Health Inspectors on a monthly basis during harvesting, as part of the lice monitoring and fish health inspections. There are no issues of concern from a fish health aspect.
“It is clear that Government Departments are acting in the best interest of fish stocks and anglers alike and we will continue to do so.’’
Cushendall MLA Oliver McMullan said he had sent the contents of the letter which Mr Connor had submitted to the Council, to the Department to get its views, but had not, at the time of writing, received a reply. Oliver said he was very interested in the fact that the DoE had threatened to prosecute the salmon company for breaching the licensing conditions and would like to pursue this further.
The second Northern Ireland angling conference will take place on Saturday November 14 at Craigavon Civic and Conference Centre. The theme will be on “club and coach development”, focusing on the areas that are important to your angling club. Tickets cost £10.