Displaying items by tag: Atlantic salmon
Research from Dr Katie Thomas of the Marine Institute has investigated the mechanisms for growth mark formation in scales of Atlantic salmon (Salmo salar Linnaeus) and the cause of variations in scale growth measurements.
Dr Thomas recently graduated with her PhD on her thesis, titled Scale Growth Analysis of Atlantic salmon (Salmo salar L) Unlocking Environmental Histories, from the Galway-Mayo Institute of Technology (GMIT) under the supervision of Dr Niall Ó Maoiléidigh, Marine Institute; Dr Deirdre Brophy, GMIT; and Tom Hansen, Institute of Marine Research Norway.
The PhD was funded by the Marine Institute, the Institute of Marine Research Norway and the Loughs Agency, Northern Ireland.
The Atlantic salmon is native to the temperate and sub-Arctic regions of the North Atlantic Ocean, utilising rivers for spawning and nursery and the marine environment for adult feeding, development and rapid growth.
Direct observation of the salmon’s life is challenging and costly, so scales are widely used to assess and monitor changes in growth.
“The entire life history of an individual fish is recorded on a scale which begins to form during the fry stage of the lifecycle,” Dr Thomas said.
“As the scale develops, it lays down concentric ridges or rings called circuli, which look similar to rings on a tree. The number of circuli on a scale and the distances between each circuli are measured to provide a history of individual and population growth histories.
“These changes over time can be used to infer the salmons use of the ecosystem, and indicate whether changes in growth are apparent over time and between populations.”
Scale measurements are taken from a specific body location as recommended by the International Council for Exploration of the Seas (ICES) to standardise scale analysis globally.
The first aim of Dr Thomas’ research was to compare wild Atlantic salmon growth measurements from different body areas and to establish a calculation or a conversion that could be applied to match the measurements from the standard sampling location.
“Because scales do not form at the same time, the size and shapes of scales can look very different to each other. The next part of my research was to take size and shape measurements from scales across the body and produce a calculation that determines where on the body a scale may have originated,” she added.
Overall salmon survival during the marine phase is strongly linked to the post-smolt growth period, which is the scale growth from when a young salmon migrates to sea up to the first winter at sea.
It is widely believed that circuli form on the scale every seven days during the summer and every 14 days during the winter and also the wider the distance between the circuli, the better overall growth is
As this had never been experimentally validated before, the next aim of the research was to undertake experiments in the Institute of Marine Research laboratory (Matre) in Norway.
Dr Thomas explained: “Results from the experiments showed that circuli formation rates are not constant but ranged between four to 18 days. In addition, the spacing between the circuli did not reflect growth rate suggesting that wide spacing between each circuli was not necessarily an indication of good growth.”
In the last stage of the research, scales from Atlantic salmon collected from three Irish rivers — Burrishoole, Moy and Shannon — between 1954 and 2008 were analysed to determine if marine growth had changed during that period.
The research showed that post-smolt scale growth declined over the decades corresponding to declines in return rates of Atlantic salmon, but the change in growth was not consistent between the different rivers.
This highlighted that the trends observed in one national index river may not be representative of change across all Irish populations, and that more than one index river should be used to investigate survival rates in our salmon populations.
The new knowledge generated from the PhD thesis supports more accurate interpretation of scale growth measurements, furthers our understanding of the factors affecting the survival of the wild Irish salmon and ultimately benefits the future management of this iconic species.
Dr Niall Ó Maoiléidigh of the Marine Institute said: “Dr Thomas’ research feeds directly into the institute’s long-term monitoring and stock assessment programme for Irish salmon stocks and the ongoing programme of research in the Burrishoole national index river initiated in the 1960s.
“These results are helping unravel the complicated links between climate change and factors which are causing persistent declines in salmon returns to rivers, not just in Ireland, but in countries on both sides of the Atlantic where salmon occur.”
Dr Thomas’ thesis is available on the Marine Institute’s Open Access Repository. A paper from this thesis titled ‘Experimental Investigation of the effects of temperature and feeding regime on scale growth in Atlantic salmon Salmo salar post-smolts’ was also recently published in the Journal of Fish Biology.
Dr Thomas’ current research is funded under Ireland’s DCF Pollack Programme, which is supported by the European Maritime and Fisheries Fund (EMFF).
This salmon comes from sustainably managed traditional net fisheries on estuaries and rivers around Ireland, where the number of returning salmon allows fish to be harvested while maintaining a healthy stock of spawning fish for future generations.
In total, the commercial quota for the wild Atlantic salmon harvest is just 11,131 from a total of 58,599 (angling and commercial combined), which makes it a premium and sought-after product.
Inland Fisheries Ireland (IFI) says wild Irish salmon can be regarded as truly organic, having lived its life in the wild, fed on wild fish and krill, and travelling thousands of miles on its long ocean migration, ensuring firm flesh and high levels of healthy Omega-3 oils.
Salmon conservation measures ensure that only appropriately tagged and recorded wild salmon, commercially caught within the state, may be sold.
As part of the wild salmon and sea trout tagging regulations, all legally caught wild salmon must have a valid gill tag (green in the case of draft net, white in the case of snap net fishing) or tail-tag, in the case of imported wild salmon, before processing, and only authorised dealers or commercial licensed salmon fishermen may sell them. It is not permitted to sell rod caught wild salmon within the state or sell wild salmon without a valid gill or tail tag attached.
Sean Kyne, Minister of State at the Department of Communications, Climate Action and Environment, said: “Wild Atlantic Salmon is a premium product. We all have a duty to ensure that conservation measures continue to be effective. Buying or selling illegally caught salmon jeopardises Ireland’s potential to have a sustainable salmon fishery into the future.”
Farmed salmon and organic farmed salmon is a very different product to wild salmon. Farmed salmon is widely available year round. If consumers have any doubts as to the origin of the salmon, please ask the supplier and help conserve Ireland's wonderful wild salmon resource. Farmed salmon being sold as wild should be reported to the Food Safety Authority. For more information visit www.fisheriesireland.ie.
#Angling - Inland Fisheries Ireland (IFI) recently welcomed a visit from Dr Jed Wright of the US Fish and Wildlife Service, who is an expert in habitat assessment, protection and restoration programmes for Atlantic salmon in the Gulf of Maine.
During this visit, Dr Wright spent a day viewing weirs on the Rivers Nore and Slaney and was impressed by the "innovative" fish passage techniques used to support fish migration efforts over a number of these structures.
Following this, Dr Wright gave two informal talks dealing with riverine habitat restoration and barriers assessment in Maine.
Dr Cathal Gallagher, head of research and development with Inland Fisheries Ireland, said IFI "welcomed this important opportunity to share expertise in riverine and habitat restoration techniques.
"It is important that Ireland shares expertise in dealing with complex and difficult issues associated with restoration of damaged rivers and habitat. This is of particular importance when addressing Ireland’s commitments under the Water Framework Directive.”
As BBC News reports, Minister for Culture, Arts and Leisure Carál Ní Chuilín said that the new rules are "the first step in a series of conservation measures aimed at protecting stocks of the iconic Atlantic salmon".
The rod and line catch sale ban is intended to encourage the practice of 'catch and release' which is set to become mandatory next year, and also brings NI legislation into line with the rest of Britain and the Republic of Ireland.
It comes months after the shocking news that just three out of every 100 wild salmon returned to Northern Ireland's rivers in 2011, prompting concerns that the species has declined to "Dodo levels".
Another threat to salmon numbers is the rise of invasive species in Northern Ireland's waterways, which as the News Letter reports have cost the economy more than £46 million a year, according to Environment Minister Alex Attwood.
Highlighting the risk to NI's marine wildlife and plantlife, as well as fisheries and agriculture, the minister said "increasing awareness of the threat of invasive species and the need to tackle them is key to achieving success".
A new strategy by the Legislative Assembly will involve partnerships between government, the community and environment groups "working in tandem" to deal with the problems caused by invasive species such as the Japanese sea squirt, detected in Strangford Lough last year.
#FishFarm - Inland Fisheries Ireland has welcomed "a clear acceptance of the impact of sea lice on juvenile salmon" following a recent Marine Institute publication that identifies the effect of sea lice emanating from aquaculture facilities on wild Atlantic salmon mortality.
According to IFI, the paper published in the Journal of Fish Diseases "concurs with previously published international research" that it says establishes an incontrovertible link between fish farm developments and negative effects on local wild salmon numbers, as previously reported on Afloat.ie.
It adds that "the debate can now progress to identify the best methodologies to reduce or eliminate this impact" as well as moves on "the issue of escaped farmed salmon".
In a statement on the new paper, IFI says the research "identified that just under 40% of released juvenile salmon showed a significant difference in return rate between sea lice ‘treated’ and ‘non-treated’ groups, indicating that mortality from sea lice is significant in 40% of the releases in the study. Unfortunately, there was a significant effect from sea lice in six different bays along the west coast over the study period.
"This recent study provides further evidence that salmon will be impacted by sea lice. The location of salmon farms in relation to salmon rivers and the control of sea lice prior to and during juveniles salmon migration to their high seas feeding ground is critical if wild salmon stocks are not to be impacted.
"The development of resistance to chemical treatment of sea lice and other fish husbandry problems, such as pancreas disease and amoebic gill disease, are likely to make effective sea lice control even more difficult in future years."
IFI also highlights the Norwegian government's concerns about the impact of sea lice and escaped farm salmon on wild salmon stocks.
The statutory body for the protection and conservation for Ireland's inland fisheries reiterated its support for "the development of a sustainable aquaculture industry" to "safeguard wild salmon and sea trout stocks into the future".
It adds that recommendations on the above issues have been made in its submission to the Department of the Marine on the Environmental Impact Statement regarding the proposed deep-sea organic salmon farm in Galway Bay, a scheme that has been the subject of controversy over recent months.
#INLAND FISHERIES - Minister of State Fergus O’Dowd was on hand to launch the Atlantic Aquatic Resource Conservation (AARC) conference in Limerick on Wednesday 28 November.
The conference, attended by delegates from five countries, is intended to showcase integrated collaborative water resource management projects across the European Atlantic Arc, comprising Portugal, Spain, France, Britain and Ireland.
The AARC project is the culmination of work undertaken by 13 international partnerships across these five countries, and the conference provides an opportunity to share the research, findings and recommendations to support the conservation of native fish species.
As the project nears conclusion next month, all AARC project requirements have been met and exceeded in a number of cases, according to Inland Fisheries Ireland (IFI).
In Ireland specifically, the project has made a valuable contribution to the Shannon Salmon Restoration Plan (SSRP) which looks at redressing the decline in Atlantic salmon populations throughout the Shannon river system.
Overall, says IFI, AARC has provided an important instrument to facilitate a pan-European approach to conserving our indigenous, migratory fish stocks.
Speaking at the launch of the conference, Minister O’Dowd highlighted the importance of EU research programmes like AARC in enhancing international research and collaboration.
“The strong inter-regional co-operation, under AARC, between regional authorities and research institutions has increased our knowledge of the conservation requirements of these important European fish species,” he said.
“AARC has ensured that we will play our part in utilising this new knowledge and co-operation for the enhancement of the conservation status of important EU species and habitats.”
AARC is a three-year project, launched in 2009, which focuses on migratory stocks of protected fish species: shad, Atlantic salmon, sea trout, sea lamprey, European eel and smelt. Across Europe these species have economic, cultural and environmental value but are in decline.
The issue of their decline is truly transnational, says IFI, and can only be addressed through long-term intensive transnational collaboration.
A major theme running through the AARC project was establishing the role of wider stakeholders in the management of our aquatic resources. Many of the AARC partners have worked to engage local stakeholders in protecting, conserving and managing these resources through the AARC project activities.
In Ireland, the project dealt with restorative initiatives for Atlantic salmon in the Shannon system. This included determining the genetic composition of contemporary and historical populations of salmon in the Shannon and comparing the relative performance in the wild of the progeny Feale, Mulkear and Shannon wild and hatchery salmon populations.
IFI was joined in the project by fellow partners ESB Fisheries Conservation, University College Cork and the Marine Institute. Of the total project budget of €3.87m, Irish partners received €754,242 over the three years.
The Shannon AARC project will address issues pertaining to fish passage, water quality, habitat and hatchery programmes in addition to the construction of a project specific geograpgic information systems (GIS), co-ordination of stock assessment surveys and the promotion of catchment management.
Ultimately it will help identify important factors in the conservation of Atlantic salmon in the Shannon, and will provide a set of useful maps and a spatial visualisation tool for improved planning and development throughout the Shannon catchment.
Results will help inform fisheries staff of the current status of Atlantic salmon populations in the Shannon as well as provide a useful inventory or potential and/or historical salmon locations in the Shannon.
The project will also benefit inter-agency co-operation, particularly in relation to River Shannon fisheries management, and will strengthen the links with relevant research institutions and international fisheries experts.
#GALWAY FISH FARM - The board of Inland Fisheries Ireland (IFI) has issued a statement on the proposed Aran Islands deep sea salmon farm in Galway Bay, which has been the source of some controversy in recent weeks.
The board said it agrees with the recent statement by Minister Fergus O’Dowd on offshore salmon farming, and that it welcomes the development of Ireland’s aquaculture sector "once any development complies with Ireland’s obligations under relevant EU environmental legislation, particularly the Habitats Directive, and does not adversely affect salmon and sea trout stocks."
In addition, the IFI board said it has made a submission on the Environmental Impact Statement (EIS) prepared by Bord Iascaigh Mhara (BIM) for the proposed offshore salmon farm as part of the public consultation process, which is available on the IFI website.
As previously reported on Afloat.ie, the public consultation period began last month for the 500-hectare organic fish farm to be located off Inis Oirr. BIM has applied for a deep sea salmon farming licence at the site, which would be one of the largest of its kind in Europe. If approved, the operation could more than double Ireland's current farmed salmon production rate.
The IFI board's statement notes: "In the submission, concerns were raised in relation to the location and scale of the proposed salmon farm and how its development and operation could impact on wild salmon and sea trout stocks and their habitat.
"These concerns are based on scientific reports by respected authors and knowledge of the impact of existing fish farms on salmon and sea trout populations off the west coast of Ireland."
The submission also highlights "recent peer reviewed international scientific literature on the impacts of sea lice on salmonids" which poses a significant threat to wild salmon in Irish waters, as reported on Afloat.ie.
The board said it does not believe "that the corpus of peer reviewed international scientific literature which recognises the negative impacts of sea lice on salmonids have been adequately dealt with in the EIS".
While welcoming "any sustainable initiative which will provide jobs in rural coastal communities", the IFI board said it questions the figure of 500 jobs it's been reported the 15,000-tonne fish farm project would create, making comparison to a new 2,000-tonne aquaculture scheme in Scotland that's expected to create just four full-time positions.
The board members say they "have serious concerns that whatever the number of jobs created by the current proposal, they will be more than offset by the associated loss of jobs in the recreational angling and tourism sectors" if the scheme results in any negative effects on those areas.
"Ireland's reputation as a pristine wild fishery destination must be safeguarded," they added, noting that proposals for two further offshore salmon farms in Mayo and Donegal "are premature given that significant issues over the current proposal have not yet been resolved.
"No further applications should be progressed until all stakeholders are satisfied that the current proposal is sustainable and has no adverse impact on wild salmon and sea trout stocks."
Inland Fisheries Ireland is the State agency charged with the conservation, protection, development management and promotion of Ireland's inland fisheries and sea angling resource.
As previously reported on Afloat.ie at the end of June, Ireland's fisheries board had announced a "significant delay" of four to six weeks before publishing the licence application.
But in a recent statement, BIM announced that it received permission some weeks ago from the Department of Agriculture, Food and the marine to begin the statutory consultation process, in which it is sharing the licence application and Environmental Impact Statement "with a list of State bodies for their appraisal and feedback".
The statutory consultation will continue till Tuesday 2 October 2012, and BIM promises that all feedback will be made available to the public via the BIM website "to further assist them in their assessment of the Environmental Impact Statement when it goes to full public consultation".
The 15,000-tonne organic salmon farm would be located off Inis Oírr in the Aran Islands on a 500-hectare site, and would be one of the largest of its kind in Europe, projected to be worth €103 million annually for the economy.
BIM intends to franchise the licence, should it be approved, to a third party "who agrees to a legally binding contract to farm the Atlantic salmon to the highest organic and environmental standards". Approval of the project could also see the creation of as many as 500 jobs, some 20% more than previously estimated.
The news comes after the ministerial apprival of salmon farm licence assignments from five separate operators in nearby Connemara, designed to "consolidate and revitalise" aquaculture in the region.
Explaining BIM's plans for the consultation process, the statement added: "Previously, both statutory and public consultation would have been carried out in parallel. However, Ireland has recently (June 2012) ratified the Aarhus Convention. The convention lays down rules to promote citizens involvement and to improve public consultation in the making of decisions with potential environmental impact by the state.
"Given the recent ratification of the Convention and for a number of other legal and technical reasons, the Minister for Agriculture, Food and the Marine, Simon Coveney TD, has signed a new Statutory Instrument (SI No 301 of 2012), bringing into law new periods of public consultation for fish farm licence applications. In this instance the Department of Agriculture, Food and the Marine have instructed BIM to carry out statutory consultation in full before proceeding with public consultation.
"BIM believes that this approach will help to further inform the public during their period of consultation."
#ANGLING - Climate change in the Atlantic may be a significant factor in the decline of wild salmon returning to their native rivers in Ireland - especially with the news that a section of ice twice the size of Manhattan has calved from a glacier in Greenland.
Angling correspondent Derek Evans writes in The Irish Times about the major ice sheet separation along the north-west coast of Greenland, which experts have attributed to warming ocean temperatures.
It is the second such indident to occur in the past three years, after the Petermann glacier lost some 97 square miles of ice in August of 2010.
As reported on Afloat.ie last year, the effects of climate change on the world's oceans are forcing species such as wild salmon to adapt by feeding in colder waters.
The Irish Times has more on the story HERE.
#ANGLING - Northern Ireland's taxpayers could be left with a bill for millions in EU fines if action isn't taken to reverse the decline of salmon stocks, the News Letter reports.
Ulster Unionist MLA Robin Swann said he believes that voluntary measures to help protect the North's Altantic salmon will not remove the threat of "fines which would likely run into millions which [the people of NI] will end up paying".
Annual monitoring of the North's salmon rivers has shown a failure to reach targets most years since 2002, with the survival rate of salmon in the marine phases in some cases dropping to as little as 5%.
Coastal drift nets and bag nets off the north Antrim coast - which contravene EU directives - have been blamed for intercepting salmon stocks before they reach the rivers, and anglers and conservation groups have already called for a ban.
But Swann says that Department of Culture, Arts and Leisure (DCAL) does not yet have the legislative power to stop them.
The News Letter has more on the story HERE.