The CSTP Technical Report presents extensive chapters on sea trout fisheries inventory, stock identification (using genetics and microchemistry), freshwater production, life histories and marine ecology across its distribution around the Irish Sea.
Available at link http://celticseatrout.com/downloads/technical-report/
The final closure event was held in Wales (Bangor, Gwynedd at Plas Menai) on 8th January and was well attended by 105 people including anglers and local fishery managers. This was the last in a series of such meetings, with previous ones having been held in Scotland (Dumfries) and Ireland (Drogheda). Updates on the outcomes of all Workpackages were presented.
The formal Report for Interreg is nearing completion
Related events
ICES sea trout workshop, WKTRUTTA, Copenhagen 12-14th November 2013. This meeting was commissioned by the International Council for the Exploration of the Sea (ICES), the body responsible for marine fisheries Assessment in European and Scandinavian countries. Bringing together sea trout specialists from many countries, it included representatives from the CSTP and CSTP results fed into this review. It is the first such review within ICES for 20 years, demonstrating an increasing interest in sea trout fisheries.
An International Sea Trout symposium, similar to the last Symposium in Cardiff, 2004, is being planned for 2015 by various CSTP partners and others from British Isles, Europe and Scandinavia. It is in an early planning stage, but results from the CSTP, other Interreg-funded projects and many more programmes will be presented. The focus will be on the practical management applications of the emerging scientific results.
The Atlantic Salmon Trust has awarded a grant of £10,000 to Dr Carys Davies, Bangor University, to carry out a preliminary assessment of the lipid status of sea trout tissues sampled during the CSTP from the Irish Sea. This is a first ever study on this topic and will inform on the condition and maturation status of adult fish which is believed to be important in determining their age and season of return to rivers.
The CSTP was an Interreg IVA funded project, running from 2009 to April 2013, intended to improve the management and long term future of sea trout in the Celtic seas by providing information and management advice, and by establishing a wider awareness and long term network of people working to secure the future of sea trout.
The project was delivered through the Ireland-Wales Cross-Border partnership; but because of the wide-ranging distribution of sea trout, work was carried around the Irish Sea in a multi-partner collaboration. Participants were Bangor University, Inland Fisheries Ireland, University College Cork, The Environment Agency Wales and the EA England, Isle of Man Government, Nith District Salmon Fisheries Board, Galloway Fisheries Trust, Annan District Salmon Fisheries Board and Buccleuth Estate (Border Esk). Subcontractors included APEM Ltd, Cefas and Fishskill Many other groups gave support and major feature of the programme was sampling of sea trout by anglers throughout the participating countries.
The work was split into 7 tasks:
Five key questions to answer, some addressed by multiple tasks, were:
The CSTP has made progress against all these questions and an outline of the results is given below. An Interreg Report has been completed and submitted to the EU and work is continuing to complete a Technical Report by October 2013. The huge amount of information gathered offers scope for even further work in the future. This note is an interim outline for information, pending the final full report.
Genetics was used to establish a genetic baseline of sea trout in 99 rivers by sampling juvenile trout in nursery streams. Sea trout sampled in different parts of the Irish Sea could then be genetically profiled and assigned back to their region/river of origin. By this means it was possible to get a picture of where fish caught at the sea originated from and where they would, probably, have returned to spawn (we know from other work that sea trout home tightly to their natal river). There are many caveats and sources of uncertainty in this work, but in essence there were found to be nine principal regional groups within the data set and clear differences in the areas that these groups occupied during their feeding migration, although there were also examples of substantial exchange rates between them. The micro-chemistry data (based on the chemical composition of scales which take on the fingerprint of the environment that fish live in) broadly supported this spatial structuring.
This work was based on the long term variation in rod catch data. The quality and detail of catch recording varies greatly around the area which limited this analysis, and fishing effort data, which is an important influence on catches, was often missing. However even with these constraints is was apparent that sea trout abundance tracked closely amongst regions and countries (eastern Ireland, Wales, southwest Scotland and northwest England). While there were some significant river specific variations, this pointed to some common factors acting on catches and possibly stocks. Between-river variations in abundance were huge, as is well known. Clearly, river size and associated fishing effort are dominant factors controlling catch; but there are other factors some of which were explored through task 6. Particularly, chemical productivity of the water and land cover type seemed to influence sea trout fishery status, rivers with low alkalinity with higher cover of forest and less intensive land use types tending to be the better sea trout rivers
This information came from an extensive scale reading programme coupled with measurements of fish size. Scale reading can reveal the age of a fish at capture and at smolting, its growth rate in different years and its previous breeding schedule. These are essential pieces of information in building models of how population size varies which are indispensible for good management. In addition, scale sample size and quality are important to produce acceptable unbiased information on the composition of each river stock. It proved extremely hard to get consistent scale reading across the participating teams, given the wide variety of prevalent life histories seen in the area. Not all rivers gave sufficient samples, but adequate data came from around 20 rivers. A number of improvements in methods were developed, and the data sets are still being subject to quality checking; but again a broad pattern is already evident. This was of faster growth and higher survival (more multiple spawners) in southern Wales rivers; high survival, but somewhat slower growth in the northwest England and southwest Scotland (Cumbria and Galloway) rivers and lower survival off the Irish coast, where finnock (fish returning in the same year that they smolted) dominated the runs in most rivers. The Currane in southwest Ireland, was a notable exception with a high proportion of long-lived adult sea trout. An unexpected result was the high degree to which sea trout continue to feed and grow during winter months at sea. Growth analysis is still continuing, but the strong influence of water temperature is evident with faster growers in the warmer areas. However, this is a complex pattern, and hydrodynamic modelling (computer projections of likely positions of migrating fish, based on tides and current patterns in the Irish Sea) coupled with the genetic data is being used to piece together the growth of the fish moving between areas of different temperature.
Sea trout go to sea to put on rapid growth, which they achieve through a high fat content fish diet. Sandeels and sprat are by far the dominant prey items, with a much smaller proportion of other fish species and crustaceans. There appear to be differences in diet composition between different regions of the Irish Sea which will also affect the growth opportunities for different stocks. Because of its link with growth, prey abundance might be expected to affect the abundance of sea trout as well as many other creatures such as birds, which depend on this crucial link in the food chain. However, the important question about how prey abundance itself varies over time cannot be answered because there is limited monitoring of sandeel, sprat or other small prey fish species in the Irish Sea; this is clearly an aspect to be looked into.
Mathematical models are routinely used to project forward, or to hindcast, the composition and abundance of marine fish stocks and salmon. With such models, when adequately set up, one can estimate how stocks might respond to altered fishing regulations and potentially to environmental factors such as changing temperature or food availability. These models must also consider the uncertainties which stem from the quality of the source data and in the level of understanding of the specific processes governing each part of the life cycle. Such modelling is the last stage in the CSTP and depends upon the results of the other activities. Doing this for sea trout is a tall order, because of the particularly variable life history of the species (far more variable than Atlantic salmon). Nevertheless some significant advances are anticipated in this and will be reported in due course and made available for practical application by fishery managers. Simply assembling better descriptions of growth, age and size structure and fecundity is a major step forward and this is already available.
The CSTP has produced new and valuable information, as well as a stored permanent archive including data, a scale collection and other samples that will be available for future studies. Its primary purpose of improving understanding of sea trout stocks in order to support better management has been achieved. Many questions remain and some new ones have emerged, but the base that the CSTP has established will greatly assist in addressing these as resources become available in the future. The project did not aim to manage individual stocks, which would be impossible on such a scale and impracticably due to contrasting regulatory infrastructure and legislation across the countries. That important work remains the responsibility of the competent local agencies and groups. Rather, the CSTP focus has been on applied science and its application in management and on developing knowledge that has wide, generic application around the Irish Sea. Such a wide-scale comprehensive, cross-disciplinary project has not been carried out before on sea trout in the British Isles. Consequently, there have been some important scientific developments in studies of sea trout genetics, microchemistry and population dynamics which will lead to further advances, as resources allow. Recommendations will be made on these and also on several practical aspects of sea trout monitoring and assessment where lessons have been learnt from this project.
Finally, the project team would like to extend sincere thanks to the hundreds of anglers, netsmen and other interested people who contributed through providing fish samples, or in other ways.
Sea trout were top of the agenda at a recent meeting between Minister Alun Davies from Wales and Minister Fergus O’Dowd held in Dail Eireann, Dublin. Both ministers were briefed about progress with the INTERREG IVa Ireland-Wales funded Celtic Sea Trout Project which finishes in 2013.
Sea trout are present in most coastal rivers discharging into the Irish Sea and their status in freshwater and in the marine environment in the Irish Sea is central to the project. By providing detailed information about the status of sea trout stocks, their genetics and their varied life histories the project aims to enhance the fisheries for the benefit of all stakeholders. Strengthening the contribution of sea trout to rural economies, to general quality of life and well-being, to national biodiversity are also important project aims. Sea trout life history variation may also contribute to understanding the effects of climate change.
For sustainable management the Celtic Sea Trout Project team is working on developing a number of management tools which will assist fisheries managers to assess fishery performance and better manage this valuable species. The requirement to manage sea trout sustainably across the Ireland-Wales interface (i.e. the Irish Sea) was strongly emphasised to both Ministers.
Both Ministers heard that angler engagement across the project has been important to provide sea trout scale samples and that the project has served to increase awareness of the value of this excellent angling species.
Minister Davies, who is Deputy Minister for Agriculture, Food, Fisheries and European Programmes, was also briefed about the role and broad responsibilities of Inland Fisheries Ireland.
…ENDS…
Suzanne Campion,
Head of Business Development, Inland Fisheries Ireland
Anglesea Street,Clonmel, Co. Tipperary.
Tel: 052 6180055 Fax: 052 6123971;
Email: suzanne.campion@fisheriesireland.ie Website: www.fisheriesireland.ie
Ireland is well endowed with sea trout fisheries. On the east and south coast large systems like the Boyne, Slaney, Ilen, Argideen and Currane are well known high quality sea trout fisheries. But other angling treasures are coming to light through the project – systems like the Castletown in Dundalk and the Colligan in Waterford are potentially excellent fisheries which we have to understand better and conserve. Individually, these sea trout fisheries on our smaller rivers have the potential to generate small but important social and economic benefits within local communities. Collectively, their importance and value at a regional and national level may be far greater than generally realised.
Inland Fisheries Ireland is a statutory body operating under the aegis of the Department of Communications, Energy and Natural Resources and was established under the Fisheries Act on 1st July 2010. Its principal function is the protection and conservation of the inland fisheries resource. IFI will promote, support, facilitate and advise the Minister on the conservation, protection, management, development and improvement of inland fisheries, including sea angling and develop and advise the Minister on policy and national strategies relating to inland fisheries and sea angling.
