Marine Aquaculture: A tool for diversification strategies to combat climate change

By Kim Thompson, Director of the Aquarium of the Pacific’s Seafood for the Future Program

Climate change is accelerating and disruption in the form of droughts, wildfires, heat waves, ocean acidification, severe storms, and flooding is on the rise. Headlines emphasize the ocean as a victim of climate change – it is time to also realize the ocean can be part of the solution to climate change. The ocean can contribute to a diverse portfolio of solutions that provides resilience to climate shocks.  A key element of this portfolio is marine aquaculture.

Marine aquaculture can provide food, carbon sequestration, and reduced emissions. Some forms of marine aquaculture may even lessen the impact of storm surges and sea level rise on coastal ecosystems and communities. These direct benefits are all important.  But some of the most important benefits marine aquaculture offers is contribution to the diversity of responses to the climate crisis. One of the most robust empirical and theoretical conclusions of resilience science is the importance of diversity and diversification.

Economic diversification

Marine aquaculture can support new jobs and sustain working waterfronts. It can also help fishers diversify their livelihoods, so they have a more stable and predictable source of income as climate change increases the unpredictability of wild fisheries.  

Energy diversification

Much of the focus for climate change solutions is on energy, and rightfully so! Energy production is by far the largest source of greenhouse gas emissions that cause climate change. Seaweed is being explored by the Department of Energy to support the growing portfolio of sustainable clean energy sources. Using seaweed for this purpose will require farming, as wild harvests cannot sustain the scale needed to produce a meaningful supply.

Food diversification

Second to energy in terms of climate change-causing greenhouse gas emissions is food production. Research shows that diversifying our food production is one of the most promising solutions to create a more sustainable and resilient food supply in the changing climate. Producing more food in the ocean can provide insurance when land-based systems are impacted by climate change-related shocks (e.g. drought, fires, and flooding). A recent study found that well-managed wild fisheries and sustainable ocean farming can sustainably increase the ocean’s contribution to the food supply by 36 to 74 percent compared to current yields.

Climate mitigation diversification

Marine aquaculture can play a role in reducing emissions. Protein produced by marine aquaculture generates far less greenhouse gas than livestock.  Moreover, some species of red algae have been shown to cut by 90 percent the methane “burped” by cows when those algae are added as a supplement to their feed.  Given the fact there are 1.5 billion cows in the world, this red algae could play an astonishing role in our fight against global warming -- but only if production could be scaled up via marine aquaculture.

Marine aquaculture as a tool for diversification

Responsibly farming the ocean is not the ‘silver bullet’ solution to climate change. Resilience science tells us silver bullets are fantasy.  But a portfolio of many different solutions played out simultaneously is the answer. Marine aquaculture can be a powerful tool to support diversification in multiple problem areas: economic growth, zero-carbon energy, food production, and climate mitigation. The U.S. has the capacity to responsibly grow marine aquaculture to support these diversification efforts.