Atlantic salmon: what is happening to our salmon?
May 28, 2015
As the Atlantic Salmon Trust heads towards its 50th year, Robbie Douglas Miller explains what it is doing to answer this
The Atlantic Salmon trust are heading towards their 50th year. Robbie Douglas Miller takes the opportunity to reflect on what is happening to our salmon, and where the future lies in a competitive fishery management world.
Atlantic salmon is not only a valuable international resource, it has been at the heart of national cultures of countries in the North Atlantic region for at least 20,000 years. As has catching this most challenging, and often elusive creature. Use the classic salmon fly, after reading about a good number of the best vintage fly tying books. Or watch our video on how to catch a salmon for the best top tips.
In 1967, concerns over the unsustainable exploitation of salmon combined with the devastating impact of UDN disease led to the formation of the Atlantic Salmon Trust (AST). As the Trust heads towards its 50th year, it is a perfect time to reflect on where the future lies in a competitive fishery management world.
ASF's Jonathan Carr surgically implants sonic transmitter in kelt, along the Miramichi. Photo ASF
Perhaps surprisingly, there is no other organisation that purely and unequivocally represents salmon and sea-trout. AST’s vision is for the fish to return and breed from their rivers of origin in sufficient quantity to ensure that stocks are held at sustainable levels. It has spent 49 years initiating research and management solutions to this effect and whilst cognisant of other interests it represents only one: salmon and sea-trout. This gives the AST a clear perspective when it comes to deciding who or what comes first when prioritising activities and spending precious resources.
The world in which we now operate is a far cry from that which existed in 1967. With 41 District Fishery Boards and 26 River Trusts in Scotland, 55 River Trusts in England, Wales and Northern Ireland, The Angling Trust, Salmon & Trout Conservation UK, North Atlantic Salmon Conservation Organization (NASCO) and many more focusing on either a broader remit or working in local catchments, understanding what is in the salmon’s best interests is not as simple as you might imagine.
There have recently been some major changes to the AST structure. By far the most significant Board appointment is our new CEO, Sarah Bayley Slater. Well known in the fisheries world, she brings a proven track record of project management, fund-raising skills and a focus on delivering results.
ATLANTIC SALMON: SMOLTS IN THE COASTAL ZONE
To help with the “blue sky” thinking and strategic direction, eight new trustees and two new vice presidents have joined the AST Board to bring a fresh and clear perspective. Our three-pillars strategy represents the three principal habitats used by wild salmon and sea-trout – the ocean; the coastal zone; and the freshwater environment – and reflects the AST’s focus on the whole lives of the fish. The Board has set about identifying what we can achieve to understand better the causes of salmon mortality. Asking the question, “What is happening to our salmon?” in conjunction with looking at the three pillars, two main themes have emerged.
Smolt for release into the North Tyne.
The first, is: “Do our smolts die in large quantities in the coastal zone and, if so, why?” To get a clear understanding of this our team has been looking at how acoustic telemetry (tagging smolts and then monitoring their progress in stages towards the open ocean) might help on a large scale. We spoke to Jon Carr of the Atlantic Salmon Federation (ASF) in America, who has been using acoustic telemetry (AT) for more than 10 years to understand mortality impacts on rivers. Subsequently, we invited him over earlier this year to attend an AT conference that we organised jointly with the River Dee Trust.
ATLANTIC SALMON TRUST: NO CENTRAL CO-ORDINATION
In addition to imparting advice and experience, the overwhelming message was that there is no central co-ordination of this valuable work. Currently there are more than eight AT projects running across the UK independently, thereby missing an opportunity to share information, knowledge, equipment and cost. Without impacting on local projects, AST is looking to position itself as the central co-ordinator of the UK-wide AT effort, maximising the scope of the individual projects and collecting and imparting information on a national scale.
If financially possible, we would like to help build up a network of coastal arrays around the UK that would read AT tags used by all rivers systems, thereby reducing the costs and encouraging more groups to participate. This would help to build up a clear picture of the extent to which our smolts survive the first part of their sea journey; in essence, to develop an inshore tracking network for salmon and sea-trout in the UK.
It will then be possible to identify more clearly the causes of mortality in each section – lower river, estuaries and near shore – and look for local or national solutions. This project will tie in with a broader, ocean-wide AT work stream, the SALSEA-Track initiative, currently being initiated by NASCO.
ATLANTIC SALMON: UNDERSTANDING PELAGIC BY-CATCH
The second theme that has emerged during our research is the need to understand pelagic by-catch and look for ways to mitigate it. There is concern about the level of accidental killing of salmon by pelagic vessels at sea. Research has shown that salmon are caught as a by-catch while the SALSEA programme showed that feeding salmon are frequently found adjacent to shoals of other pelagic marine species and may well be impacted by major fisheries on these stocks. The extent of such catches is not known but it is certain that accidental by-catch does happen at certain times and in certain places.
At present, there is a major issue regarding the poor survival of salmon at sea, with as few as 5% of smolts returning as grilse to our shores. The loss of 95% of our smolts at sea is unprecedented. Perhaps the most practical action we can take to protect migrating post-smolts and young adult salmon is to quantify and manage the level of by-catch from the large pelagic fisheries in the open sea.
Pelagic fisheries are operated by fleets from the EU, Norway, Russia, Iceland and the Faroe Islands. They account for the harvest of millions of tonnes of fish a year. The fisheries use a range of gear, including surface trawls, pair trawls and gigantic purse seines. The quantities of fish taken in each sweep of these gargantuan nets are massive. Locating individual post-smolts, between 12cm and 20cm long, often squashed and descaled, amongst these vast quantities of fish is virtually impossible.
ATLANTIC SALMON: PRESENCE OF SALMON DNA
Recognising that manual surveys of catches on deck would be expensive and time consuming, AST and our colleagues at University College Dublin piloted the development of a novel technique to assess the presence of salmon DNA onboard ships – environmental or eDNA. The method involves the analysis of fish slime from the nets or onboard water samples for portions of salmon DNA shed from the fish through scale loss or slime/bodily fluids. The DNA collected may also provide valuable information on the origins of the salmon sampled, which will greatly add to our knowledge of salmon migration and distribution patterns in the ocean.
AST is confident that the development of eDNA-based forensic techniques offers a real possibility of practical, large-scale and cost-effective monitoring of pelagic by-catch. The priority is to deploy the eDNA technique to establish the presence of salmon. The proven presence of salmon will enable assessments of abundance to be carried out manually on individual vessels and greatly reduce the logistics involved in sub-sampling the fleet.
ATLANTIC SALMON: MOVING FORWARDS
Over the past six months, scientists at University College Dublin have been engaged in the first phase of the programme: development and testing of an Atlantic salmon specific eDNA probe. There is no doubt that the pelagic fleets will continue to seek new grounds or that the efficiency of fishing vessels will increase. As this happens, further efforts will be required to quantify the extent of by-catch of salmon in these fisheries and to introduce mitigation measures, such as altering the equipment used or restricting access to smolt-migration routes at certain times. Understanding and seeking to manage the by-catch issue is one of the few practical steps we can take to tackle marine mortality of salmon.
Given the reducing percentage of our smolts that survive the period of time that they are not in our rivers systems, these projects look to be the most valuable use of our time and resources. If we can help answer the “marine mortality” question and look at ways to improve the pitiful 5% return rate of our smolts, then we will be doing our bit to fill in the gaps and fulfil our brief as the charity that looks after salmon. During 2016, the AST team will be initiating these two work streams.
ATLANTIC SALMON: HOW YOU CAN HELP
The AST is not a membership organisation, relying on charitable and private donations. This new work is going to be expensive and time consuming. If you are interested in doing something for the future of this wonderful fish, you can support the work of the AST by becoming a friend or making a donation at www.atlanticsalmontrust.org. Alternatively, if your business owns, buys or sells fishing, makes rods, flies or sells fishing equipment, we would welcome you as a corporate friend while your customers would welcome your contribution to the bigger picture.
Robbie Douglas Miller is the chairman of the AST.