Inland Fisheries Ireland PR: Wild Salmon Survival in the Balance – 1% may be the Crucial Tipping Point.

Press Release 05/02/2013

Wild Salmon Survival in the Balance – 1% may be the Crucial Tipping  Point

Inland Fisheries Ireland (IFI) notes the recent Marine Institute (MI)  publication which identifies that sea lice emanating from aquaculture  facilities can cause mortality to wild Atlantic salmon.  In this regard,  the recent publication (Jackson et al, 2012) concurs with previously  published international research (Krkosek et al, 2012 & Gargan et  al, 2012). IFI welcomes the fact that there is now a clear acceptance of  the negative impact of sea lice on juvenile salmon and the debate can now  progress to identify the best methodologies to reduce or eliminate this impact.  IFI would also like to see similar progress in relation to the issue of escaped  farmed salmon.

In recent years approximately 5% of all juvenile salmon going to sea return  back to their native rivers as adults to spawn.  Precisely because natural  mortality rates of salmon are high, even a proportionally small additional  mortality from sea lice can amount to a large loss in salmon returning.   To put this average 1% reduction in return rates, as reported by the MI, in  context, if 3,000 salmon return to a river, and this represents a 5% return  rate, a reduction in the return rate to 4% translates into a reduction of 1/5  (20%) of the adult salmon or 600 fewer fish returning. The Board of IFI is  concerned that this level of additional mortality has the potential to curtail  commercial or recreational salmon fisheries and impact on individual river  salmon conservation limits and may be the tipping point between having an open  or closed fishery.

The paper 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.

Norway, one of the world’s biggest producers of farmed salmon are also  seriously concerned about the impact of sea lice emanating from aquaculture  facilities on wild salmon stocks and the issue of escaped farmed salmon. In  their Strategy for an ‘Environmentally Sustainable Norwegian Aquaculture  Industry’ produced by the Norwegian Ministry of Fisheries and Coastal Affairs  they state:

Even though salmon lice occurs in wild salmon and sea trout, it is an  example of a parasitic disease which has been intensified by the multitude of  hosts in aquaculture facilities. In addition to being passed from fish to fish,  it can also be spread over long distances by currents

They further state;

If delousing in fish farming fails to yield the desired effect on lice  figures for wild fish, it may be necessary to consider a reduction in the  biomass of the farming facilities (reduce the number of hosts) in the  worst-affected areas.”

On the matter of escaped farm salmon, the Norwegian authorities have stated  that “scientific comparisons of wild and farmed salmon, and their  cross-breeds, has shown that gene transfer from farmed to wild salmon can  reduce the latter’s ability to survive. This is why such gene transfer is one  of the main problems with escapes”. IFI would like to see similar progress  made on the issue of escaped farmed salmon as has been made on the sea lice  issue.

IFI are supportive of the development of a sustainable aquaculture industry  and welcome all advances in research that will underpin the sustainability of  this industry and safeguard wild salmon and sea trout stocks into the future.  Recommendations to address the issues of sea lice, escapes, location and scale  have been made in IFIs submission to the Department of Agriculture, Food and  the Marine on the Environmental Impact Statement regarding the Galway Bay fish  farm development.


Media enquiries

Suzanne Campion Head of Business  Development, Inland Fisheries Ireland, Anglesea Street, Clonmel, Co. Tipperary. Tel: 052 6180055 Fax: 052 6123971 Email:
This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Notes to the Editor

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 promotes, supports, facilitates and advises the  Minister on, the conservation, protection, management, development and  improvement of inland fisheries, including sea angling. It also develops and  advises the Minister on policy and national strategies relating to inland  fisheries and sea angling.

BIM and the Marine Institute operate under the aegis of the Department of Agriculture, Food and the Marine. Strategy for an Environmentally Sustainable Norwegian Aquaculture  Industry.

Speeches from Ms. Kristine Gramstad state secretary to Minister of  Fisheries and Coastal Affairs Norway:–a-prerequi.html?id=652555

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s