Is it good practice to have wrasses as a natural weapon against sea lice in farmed salmon?

Wrasses are becoming popular biological control agents for sea lice in farmed salmon. However, whenever introducing another animal into the mix, there is always cause for concern that they could themselves carry diseases or be vectors for transfer of diseases to the primary cultured fish. This is a great article that analyses the various aspects of wrasse health and the potential impact they could have on farmed salmon.

Journal of Fish Diseases
Volume 35, Number 8 (August 2012)
Diseases of north European wrasse (Labridae) and possible interactions with cohabited farmed salmon, Salmo salarL.
Authors: J W Treasurer 1
Author Affiliations:
1: Ardtoe Marine Laboratory, Acharacle, Argyll, UK
Source: Journal of Fish Diseases, Volume 35, Number 8 (August 2012)
Page Numbers: 555 – 562
Available Full Text:
Full Text: Subscription Required to view full text
Format: PDF
Size: unknown
Location: Publisher’s Site
Authentication: EBSCOhost EJS
Abstract: There have been several reported studies of wrasse health but none of these has shown transmission of wrasse diseases when stocked with farmed Atlantic salmon. Most of the studies have focussed on bacterial and parasite issues, including treatment of bacterial diseases with antibiotics and vaccination of wrasse. Classical and atypical furunculosis have been reported in wrasse following stress, and wrasse have been susceptible to vibrio infection. Further study is required on the vaccination of wrasse for furunculosis with latent carrier status to maximize survival. There are studies on viral diseases such as infectious pancreatic necrosis, infectious salmon anaemia and pancreas disease and although these did not give any undue concern for salmon health, there is also scope for further study in this area. Resident parasite communities of wrasse are largely host-specific and do not appear to be a threat to salmon. Given that wrasse have not, to date, been a vector of disease in salmon, attention should be placed on maintaining best practice in cohabiting wrasse with salmon. Other issues that should be addressed are good welfare of wrasse in pens and identifying measures of this, the identification of losses of wrasse in pens, being alert to potential emerging diseases through health screening of mortalities and assessing the risks associated with carrying forward wrasse from one salmon production cycle to the next. Issues of exploitation by fishing on wild wrasse stocks and improved biosecurity may be addressed by the increased movement by the industry to the stocking of farmed wrasse.
Citation: J W Treasurer . Diseases of north European wrasse (Labridae) and possible interactions with cohabited farmed salmon, Salmo salarL.. Journal of Fish Diseases, Volume 35, Number 8 (August 2012), pp. 555-562, <;

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