If Atlantic Canada wants to have a strong aquaculture industry, then they must not put "all [their] eggs into one salmon basket". This was the key message from Professor Thierry Chopin, University of New Brunswick, when he presented at the Aquaculture Canada and Coldwater Harvest 2016 Conference held in St Johns, Newfoundland, this month.

Presenting 30 years of aquaculture and fishery data from across Atlantic Canada, Professor Chopin demonstrated that the production and value of finfish aquaculture, which is dominated by Atlantic salmon, peaked in 2012, but has since declined to the same levels as seen in 1999. Shellfish aquaculture value has shown some increase (in line with increasing production), though it remains at lower levels than for finfish. The picture is rather different for the lobster fishery, which has seen increases in its production and value.

These findings are in stark contrast to a popular belief that aquaculture – and in particular salmon aquaculture – is still on the increase in the region. Moreover, although the Food and Agriculture Organization (FAO) of the United Nations reports that we have reached, or are about to reach, the 50/50 capture fisheries/aquaculture seafood supply threshold worldwide, this is not the case in this region.

With talks about developing aquaculture across the region, and particularly focusing on increasing the production of Atlantic salmon, Professor Chopin’s perspective is timely.  Relying on a near-mono-culture system of salmon aquaculture could leave the industry vulnerable to issues such as an outbreak of disease, or a widespread and unexpected change in environmental factors that reduce the fitness of farmed salmon across the region.  He also noted that climate change could impact aquaculture production – making some species more, and some species less feasible to farm in the region.   

With growing markets, Professor Chopin pointed towards invertebrate and seaweed farming as having strong potential for Atlantic Canada aquaculture diversification.  In addition, these species could have local environmental benefits.  For example, bivalves, such as mussels and oysters, may act as natural bio-filters for small organic particles; sea urchins and sea cucumbers may reprocess large organic particles; and seaweeds reduce the dissolved inorganic nutrient loads. Seaweeds could also help to reduce local ocean acidification levels by sequestering carbon dioxide. 

Professor Chopin, who is also the scientific director of the Canadian Integrated Multi-Trophic Aquaculture Network (CIMTAN), advocated for diversification through Integrated Multi-Trophic Aquaculture (IMTA) systems within an integrated coastal area management strategy.  These systems take advantage of the complementary functional roles of the different cultivated species and of the ecosystem services they provide.  Markets for salmon and mussels for human consumption have already been tapped into.  Markets for seaweeds and other invertebrates remain to be developed, not only as food but also for many other applications, focusing on North America and Europe, instead of on saturated Asian markets. 

This story appeared in The Fish Site.