Seagrass meadows could be good for your health – yet they’re disappearing fast
The wellbeing benefits of nature are often linked to forests or habitats that support diverse pollinators. Spending time in green spaces reduces stress and anxiety, for example.
By contrast, the benefits of the ocean are more commonly associated with fishing, exciting creatures such as whales and dolphins, or adventure watersports, rather than as a living system that directly supports human wellbeing. Yet growing scientific evidence shows that marine biodiversity is fundamental to the health of people, animals and the planet.
The “one health” concept (a term now widely used by the World Health Organization) captures this connection by recognising that human health, animal health and environmental health are inseparable. Our new paper in the journal BioScience applies this idea to seagrass meadows for the first time. We argue that healthy coastal ecosystems such as seagrass meadows are not optional extras, but essential infrastructure for resilient societies.
Coastal seas host some of the most biologically rich ecosystems on Earth. Kelp forests, oyster reefs, saltmarshes and seagrass meadows form the foundation of complex food webs that support fisheries, regulate water quality and protect shorelines. These habitats influence everything from food security and livelihoods to exposure to pollution and disease.
Read more: From fish to clean water, the ocean matters and here’s how to quantify the benefits
Take seagrass meadows as one example. These underwater flowering plants stabilise sediments, reduce wave energy and filter nutrients from coastal waters. The benefits ultimately reduce coastal flooding and make the environment cleaner. They also support young fish and invertebrates that later populate offshore fisheries.
Seagrass and water quality exist in a delicate balance. When the quality becomes too poor the seagrass becomes less abundant, and it’s then less able to act as a filter. This further exacerbates the water quality problems with implications for fish and other wildife.
Similar patterns are seen when kelp forests collapse or shellfish reefs are lost. This is why we need better recognition for the important roles these habitats play.
Marine biodiversity also helps regulate the Earth’s climate. Coastal habitats such as seagrass capture and store carbon and can reduce the negative effects of storms and flooding.
While saving these ecosystems can’t replace the need to cut greenhouse gas emissions, their loss can accelerate climate impacts at local and regional scales increasing risks to coastal communities.
Despite their importance, many marine ecosystems have been severely degraded. Pollution, overfishing, coastal development and warming seas have reduced biodiversity along coastlines around the globe.
These losses are rarely visible to the public as they’re hard to see. This is because these losses occur underwater and gradually. Yet their consequences are increasingly felt through declining fisheries, poorer water quality and greater vulnerability to extreme weather. These factors all ultimately affect our health and wellbeing.
Our new paper argues that restoring marine biodiversity requires a shift in how success is measured. Conservation and restoration efforts are often judged by the amount of hectares of habitat planting planted or short-term project outcomes. While these metrics are easy to calculate, they can obscure the real goal: the recovery of ecological function and long-term resilience.
A collaborative approach
This is where the one health perspective becomes particularly valuable. By linking environmental condition to human and animal health, it encourages collaboration across disciplines that rarely interact. Coastal management, public health, fisheries policy and climate adaptation are often treated separately yet they all depend on the same underlying ecosystems.
Examples from around the world show that biodiversity can do miraculous things, such as seagrass meadows trapping pathogens, reducing harmful bacteria in coastal waters that kills corals and contaminates seafood. That’s nature directly buffering human and animal health.
We also know that when habitat is degraded and lost, it displaces associated wildife. This can lead to greater interactions between wild and farmed animals. In the case of seagrass loss, typically we know that geese become displaced to farmland to graze. This has the potential to increase interactions with farmed animals and could enhance spread of diseases such as bird flu.
Recovery of our ocean habitats and the wildlife, plants and microbes that live there is possible. Where water quality improves and physical disturbance is reduced, marine habitats can rebound, bringing measurable benefits for biodiversity fisheries and coastal protection.
Importantly, the benefits then extend to people – cleaner water, a more affable environment and better, more abundant food. However restoration of these habitats alone cannot compensate for ongoing damage. Protecting what remains is consistently more effective and less costly than rebuilding ecosystems after they collapse.
Marine biodiversity may feel distant from everyday life but it quietly supports many of the systems that societies depend on. Recognising oceans and coasts as part of our shared health system rather than as separate from it could transform how we manage and value the marine environment. In a changing climate, this shift may prove essential not only for nature but for our own resilience.
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The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.