(Brest) Shellfish farming does not contribute to the fight against global warming: on the contrary, it is an activity that emits CO2, underlines a study going against a widespread untruth in the scientific literature.
Mr. Pernet became interested in the issue during his interactions with the shellfish industry. “I had a lot of questions about granting carbon credits to shellfish farming” for its supposed role in CO2 sequestration, “and I didn’t understand why people were asking me the question,” he explains. “I always learned at school that the only living CO2 sinks were plants.”
The Myth of CO2 Sequestration by Shellfish
The idea has spread that shellfish sequester CO2, akin to the wood of trees, due to their shells being composed of carbon. This notion is further exacerbated by recommendations from the Aquaculture Advisory Council in April 2022, which suggested that the European Commission explore carbon credits for CO2 sequestration via shells.
Dispelling the Myths
“This is completely false; it is absolutely not CO2 that is used” to create the shells, but rather bicarbonate derived from rock erosion,” emphasizes the researcher. This critical distinction highlights the fact that calcification related to shell formation does not sequester carbon; instead, it releases CO2 back into the water. This process significantly diminishes the ocean’s capacity to absorb atmospheric CO2.
Ecological Benefits of Shellfish Farming
Despite its drawbacks in terms of carbon emissions, shellfish farming does provide numerous ecological benefits. These include:
- Clarification of seawater
- Regulation of nitrogen levels
- Regulation of phosphorus levels
- Support of complex marine ecosystems
Mr. Pernet notes that shellfish farming remains “the least carbon-intensive way of producing animal proteins.” However, he advocates for caution in how public funds are allocated to projects misrepresented as environmentally beneficial.
Recommendations for Sustainable Shellfish Farming
To mitigate CO2 emissions associated with shellfish farming, experts recommend implementing the following practices:
- Recycling Shell Waste: Returning consumed shell waste back into the ocean allows it to dissolve and trap CO2.
- Algal Cultivation: Growing algae alongside shellfish can improve ecosystem health and further reduce carbon footprints.
Impact on Climate Policy
The findings of this study bear significant consequences for climate policies surrounding aquaculture and carbon credits. Addressing misconceptions about the role of shellfish farming in carbon cycles is crucial, especially for policymakers considering incentives based on flawed assumptions.
Case Studies: Exploring Shellfish Farming Practices
Various regions have implemented innovative practices that enhance sustainability in shellfish farming:
| Region | Practice | Outcome |
|---|---|---|
| Pacific Northwest, USA | Integration of shellfish farming with seaweed cultivation | Increased biodiversity and reduced nutrient pollution |
| Southern France | Use of biodegradable nets for oyster farming | Reduction in plastic waste and improved ocean health |
| Eastern Canada | Community-led shell recycling programs | Enhanced local engagement and reduced CO2 release |
Practical Tips for Sustainable Shellfish Farming
For practitioners in the shellfish farming industry, here are practical tips to reduce environmental impact:
- Regularly assess shellfish health and water quality.
- Implement sustainable feed practices to minimize waste.
- Engage with local conservation efforts to enhance ecosystem services.
- Educate consumers about the benefits of sustainable shellfish consumption.
Personal Experiences in Shellfish Farming
Local shellfish farmer and advocate, Mary Ellen, shares her journey: “I started farming oysters originally thinking I was contributing to climate solutions. After learning the facts, I shifted my focus to improving practices and community education about the real environmental impact of our activities.”
Her efforts demonstrate the importance of adaptable practices in resisting pressures of misrepresented environmental claims in aquaculture.
