Aquaculture is a major contributor to Canada’s food system, especially along the Atlantic coast, where salmon farming supports jobs and local economies. But ocean conditions are changing, and traditional open-water net-pen farming is increasingly at risk from warmer water, oxygen stress, and biological threats.

Why the Atlantic Ocean Is Getting Warmer

Climate science shows that ocean temperatures in the Northwest Atlantic, including off eastern Canada, are rising faster than the global average. High-resolution climate models indicate that this region may warm two to three times faster than the global ocean over the long term due to changes in ocean circulation patterns. (Source: gfdl.noaa.gov)

Warmer water reduces dissolved oxygen and increases stress on cold-water species like Atlantic salmon, which prefer cooler conditions. When the sea warms, salmon in open pens cannot escape, increasing the chance of stress, disease, or mortality.

From Net Pens to RAS: Decoupling from the Open Ocean

The core vulnerability of traditional net-pen farming is that it is coupled directly to ocean conditions: ambient temperature, oxygen levels, currents, and biological threats such as parasites or harmful algal blooms. Closed-containment systems (land-based or near-shore) like Recirculating Aquaculture Systems (RAS) instead create a fully controlled environment where water quality, temperature, and oxygen are regulated independently from the ocean.

Key benefits of RAS include:

• Controlled Environment: RAS allows operators to maintain optimal temperatures and oxygen levels year-round, regardless of ocean heat fluctuations.Biosecurity: Closed systems reduce exposure to ocean-borne pathogens, parasites, and contaminants.
• Sustainable Resource Use: RAS reuses and recycles most of its water, lowering environmental discharge and the risk of escapes.

Although RAS requires larger capital investment and technical expertise, its climate resilience and sustainability features make it highly attractive for future-proof aquaculture in a warming world.

Climate Risks and Industry Resilience

The ocean’s warming trends are a global and regional reality, and climate change is influencing fish biology, ecosystem structure, and aquaculture operations. For Atlantic salmon and other cold-water species, even modest increases in temperature can negatively affect growth, metabolic rates, and survival.

The marine environment around Atlantic Canada is experiencing temperature increases, and shifts in ecological dynamics are documented in scientific studies and government reports.

By moving production into controlled systems like RAS, farmers can decouple harvest outcomes from directly fluctuating ocean conditions, making production more predictable and less vulnerable to climate disruption.

A More Resilient Path for Canada’s Aquaculture

Canada’s seafood sector is already central to coastal communities and food security. Maintaining that role requires innovation alongside sustainable practices. While ocean-based aquaculture continues to improve sustainability outcomes, controlled systems can add climate resilience and consistency to production.

By adopting RAS technology and other adaptive approaches, Canada’s aquaculture industry can better withstand ocean warming, protect fish welfare, and support long-term economic stability.