Salmon can now be grown from egg to full-size on land-based fish farms, but a new report for the Irish aquaculture industry says capital costs are too high to attempt it here.
A land-based project similar in size to that formerly planned for Galway Bay could cost €100 million, the study for the Irish Salmon Growers' Association estimates.
The study by Danish-born fish farming pioneer Ivar Warrer-Hansen calculates capital costs would be €33 million for a 5,000-tonne a year farm on land. Farmed salmon begin their lives on land in hatcheries, but are conventionally farmed to adult size in marine sites. World production is now about 2 million tonnes a year.
Spearheaded by the ESB, through its river salmon management programme, fish farming here reached about 25,000 tonnes in the 1990s, but has dropped to about 10,000 tonnes.
A combination of issues, including designation of sensitive marine habitats and concerns about environmental impact, has stymied projected growth. There are some 600 finfish and shellfish licence applications applications awaiting approval.
As the author explains, rearing salmon in closed containment is perceived as being more attractive than at sea, due to reduced interaction with native or wild stocks and greater control over the immediate production environment, including disease risks and protection from coastal storms.
Land-based farming of finfish species such as eel, tilapia and catfish has developed internationally, while there has also been some success with sea bass, turbot and perch.
Water quality
However, water quality standards have to be higher for salmon than for other species and there are “biological” issues with males tending to mature earlier in re-circulating aquaculture systems.
Pilot-scale projects in Canada and in the US have proved it is possible to rear salmon to “market quality” in these systems. Mr Warrer-Hansen says two pilot-scale and one commercial unit have sold about 1,000 tonnes of fish on the markets over the last few years, but this could increase as more small units are brought into production in various countries.
His study notes that only seven or eight land sites would be needed here to reach the Government’s target of farming 38,000 tonnes of fish. He says capital costs make it “difficult to be competitive, especially during those regular periods where production costs rise above market prices”.
