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Wednesday, Sept. 15, 2021 (Halifax, NS) – A landmark study has shown what kind of toll the production of a variety of aquatic or ‘blue foods’ has on the environment, while highlighting the significant unfulfilled potential for aquaculture to become more sustainable.

The research, titled the “Environmental performance of blue foods,” was one of five initial scientific papers published today as part of the Blue Food Assessment (BFA).

The authors, from Dalhousie University and several other international institutes, produced the most standardized assessment of the environmental pressures stemming from ‘blue food’ production to date. It covers nearly three quarters of global production and draws on studies reporting data from more than 1,690 fish farms and 1,000 unique fishery records worldwide.

The paper finds that seaweeds and farmed bivalves, such as mussels and oysters, generate the fewest greenhouse gas and nutrient emissions, like phosphorous and nitrogen, and use the least land and water. Capture fisheries also result in few nutrient emissions and use limited land and water. Compared to farmed fish, however, the researchers found greenhouse gas emissions range from relatively low, for such species as sardines and cod, to relatively high for flatfish and lobsters.

“Our results highlight not only the large differences in environmental impacts between and within major sources of blue foods across these environmental stressors, but confirm the important role that many blue foods can play in reducing the impacts of human diets,” says Peter Tyedmers, a co-author and professor in Dalhousie’s School for Resource and Environmental Studies.

Commonly eaten farmed finfish, such as salmon and carp, outperform other farmed blue foods on several environmental indicators, while most blue foods outperform chicken, which generates similar environmental pressures as tilapia, one of the more impactful blue foods assessed.

This new set of standardized metrics can be used to benchmark the environmental impacts of blue foods to steer future production toward lower emissions and resource use -- a key part of the UN Sustainable Development Goals and ocean health.

“With demand for blue foods rising around the world, we need a better understanding of how the environmental pressures compare across this diverse group of foods so we can ensure we are eating not just nutritiously, but also sustainably,” said Jessica A. Gephart, lead author and researcher at American University.

The paper also highlighted the potential of many subsectors, such as carp and milkfish, to improve their environmental performance through better farm management, efforts that reduce feed inputs and innovative technological interventions. Capture fisheries also have potential to reduce greenhouse gas emissions through improved management and optimizing gear types.

This research fills gaps in previous studies on the environmental stresses associated with food production, which often exclude blue foods. When blue foods are included, they are often lumped together, overlooking the vast range of species in the sector.

The study will ultimately allow businesses, certifiers, NGOs, consumers and other interested parties to make more informed decisions about how to support sustainable blue foods, while also highlighting the rich diversity and variety of the blue food market.

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Notes for editors:

The full list of research papers produced as part of the Blue Food Assessment is available online. A list of the BFA leadership team is also available here.

For more information or to arrange interviews, contact c/o Marchmont Communications:

Donna Bowater
Marchmont Communications
donna@marchmontcomms.com
+61 434 635 099
+44 7929 212 534

Alison Auld
Senior Research Reporter
Dalhousie University
Alison.auld@dal.ca
+902-220-0491