Aquaculture and the Environment

Aquaculture and the Environment: The South West of England’s Contribution to Sustainable Practices

The South West of England, with its pristine waters and diverse ecosystems, is not only a hub for aquaculture but also a leader in environmentally sustainable practices. The region demonstrates how aquaculture can coexist with and even enhance marine and coastal ecosystems, aligning with global goals for sustainability and biodiversity.

Whilst we recognise the room for improvement and continue to apply pressure to private industries which harm our shared water resources such as local water utilities, which limit further development of products for human consumption in some areas, our aqauculturists have carefully and expertly chosen sites which utilise the best of south wests waters.

Shellfish Farming: Natural Cleaners of the Ocean

Shellfish farming in the South West, particularly in the Fal Estuary, Poole Harbour, and River Exe, plays a significant role in environmental stewardship. Species such as mussels and oysters are natural filter feeders, improving water quality by removing excess nutrients like nitrogen and phosphorus.

• Ecosystem Benefits:

• Enhanced water clarity promotes seagrass growth, a vital carbon sink.

• Reduced risk of algal blooms supports overall ecosystem health.

This low-impact form of aquaculture requires no feed inputs, making it one of the most sustainable methods of seafood production.

Seaweed Cultivation: A Climate Solution

Seaweed farming is an emerging sector in the South West with enormous environmental potential. Farms in Cornwall and Devon are cultivating species such as kelp and dulse, contributing to:

• Carbon Sequestration: Seaweed absorbs carbon dioxide during growth, mitigating the effects of climate change. Whilst kelp farms in the UK seem to offer some sequestration properties, there is ongoing research into how much can be attributed to farms where sequestration depends on material being moved to deep sea, and into the local food chain. further research is required to understand the complexities 0f these carbon cycle interactions and the material use cases.

• Biodiversity Enhancement: Seaweed farms provide habitat for juvenile fish and other marine organisms. a growing evidence body has been produced demonstrating the benefits of these artificial ecosystems can benefit the local ecosystem by providing refugee for species, across a range of taxonomic levels ranging from micro-organisms upto key local fish species. Whilst research also shows that these immediate benefits may once farmed species have been removed, restorative practices and nature inclusive designed infrastructure may provide ongoing habitat benefits.

• Sustainable Products: Seaweed is used in bio-packaging, organic fertilisers, and as an alternative to fishmeal in aquafeeds, reducing reliance on wild-caught fish, for not on ly other aquaculture industries such as salmon production but farm feeds at large. Some species of microalgea have even been shown to reduce the methane production of cows whilst providing highly nutritious feed for these farmed species.

Restorative Aquaculture

The South West is at the forefront of restorative aquaculture, which uses farming techniques to rehabilitate degraded marine habitats.

Native Oyster Restoration:

Projects in areas like Plymouth Sound are reintroducing native oyster reefs, which improve water quality, provide habitat for marine life, and boost biodiversity.

Seagrass Meadows:

Collaborations between aquaculture businesses and environmental groups are restoring seagrass habitats. These meadows act as nurseries for fish, store carbon, and stabilise sediment.

Innovation in Sustainable Practices

The region’s aquaculture industry is actively adopting innovative technologies to minimise environmental impacts.

Integrated Multitrophic Aquaculture (IMTA):

Farms in the South West are exploring IMTA, combining finfish, shellfish, and seaweed cultivation. This approach mimics natural ecosystems, with waste from finfish providing nutrients for shellfish and seaweed, reducing overall environmental impact.

Recirculating Aquaculture Systems (RAS):

Land-based systems for trout farming use closed-loop water recycling, drastically reducing water use and pollution.

Environmental Monitoring and Research

The South West benefits from world-class marine research institutions, including the University of Plymouth and Exeter Marine. These organisations provide critical insights into the environmental impacts of aquaculture and develop solutions to mitigate challenges like:

• Disease outbreaks in shellfish.

• Managing interactions with wild species.

• Enhancing the resilience of farmed species to climate change.

The integration of advanced monitoring technologies, such as AI and remote sensing, allows farms to track environmental conditions and adapt practices in real time, ensuring long-term sustainability.

Offshore Aquaculture: A New Frontier

With its strong maritime heritage and access to deeper waters, the South West is well-positioned to lead the UK in offshore aquaculture development. Offshore systems have the potential to:

• Reduce pressure on coastal ecosystems.

• Increase production capacity while maintaining environmental integrity.

• Operate in harmony with other marine activities like wind farming and wildlife conservation.

A Model for Sustainable Growth

The South West’s aquaculture sector exemplifies how food production can support, rather than exploit, the environment. Its focus on shellfish and seaweed farming, restorative aquaculture, and innovative practices makes it a model for sustainable growth, balancing economic benefits with ecological health.

As the UK strives to meet net-zero targets and enhance food security, the South West’s aquaculture industry offers a blueprint for how the sector can lead the way in environmental sustainability.