Over 200 scientific studies have found that seagrasses have been disappearing at a rate of 110 km2 per year since 1980
It's not rainforests, mangroves, or even disappearing coral reefs, but rather seagrass beds that have recently caught the attention of hundreds of scientists as the effects of pollution and development continue to take their toll on this little-known ecosystem.
A flowering plant, seagrass shouldn't be confused with seaweed - it's thought there are in fact some 60 different species of seagrass which make up large ‘meadows' underwater. There they pollinate and live out their lifecycles all beneath the surface. Seagrass ‘meadows' can be made up of one single species, or a mixture of many different varieties, but all offer important habitats for marine life.
Seagrass beds harbour thousands of fish, bird, and invertebrate species; and provide a major food source for endangered species across the planet such as dugong, manatee, green turtle, and seahorses.
But with no specific protection for these habitats, more than 100 scientists have now called on global governments to back the protection of seagrasses. The good news is that these experts remain optimistic that seagrass beds can thrive well into the future but only if the scientific community becomes more unified and joins forces to support a singular approach to tackle the ongoing environmental threats to these underwater grasses.
Seagrass is important for many forms of life, and has an ability to modify its physical environment, so it can trap and bind nutrient-enriched sediment, encouraging the deposit and suspension-feeding invertebrates.
The leaves of seagrasses provide shelter for bacteria, algae, protozoans, coelenterates, molluscs, bryozoans, and echinoderms, yet they are threatened by coastal development including tourism, aquaculture, energy projects, and from environmental changes and sea levels rising.
In a report by the Proceedings of the National Academy of Sciences of the United States of America (PNAS) entitled Accelerating loss of seagrasses across the globe threatens coastal ecosystems, a global assessment of 215 studies found that seagrasses have been disappearing at a rate of 110 km2 per year since 1980 and that 29% of the known areal extent has disappeared since seagrass areas were initially recorded in 1879.
Dr Richard Unsworth, fisheries ecologist based at Swansea University, specialises in researching seagrass ecosystems and is also the founding director of marine conservation charity Project Seagrass, and president of the World Seagrass Association. A statement from the World Seagrass Association calling for action to secure the future of seagrass has been backed by 122 scientists across 28 countries.
Dr Unsworth says there is clear global evidence of a widespread trajectory of seagrass loss in all areas of the world, driven mostly by poor water quality and coastal development. And having just led a widespread analysis of evidence (using expert witnesses and scientists) of seagrass loss at the heart of the Coral triangle in Indonesia, he has discovered that extensive seagrass loss has occurred at almost all the locations he investigated. This places the livelihoods of hundreds of thousands of people in jeopardy.
In the UK, Dr Unsworth suggests that at least six hectacres of seagrass in the UK has been lost due to static boat moorings, however he stresses the need to to remain optimistic: "At our recent conference in North Wales, I ran a workshop with Profuessor Carlos Duarte (KAUST) entitled ‘finding #oceanoptimism for seagrass'. This workshop was aimed at finding those poorly reported examples of where seagrass conservation is working. All too easily we report the stories of conservation doom and gloom rather than stories of hope - as conservationists we need to inspire people to change things and take real actions to save our natural environment.
"That workshop presented examples of how communities, government and NGOs are making those changes around the world and showed that although we still have many problems there is light beginning to glimmer at the end of the tunnel."
The EU Water Framework Directive has established the first EU-wide monitoring of seagrasses as ‘canaries of the sea'. This is leading to both governments and regulators responding to the condition and plight of seagrass ecosystems. Dr Unsworth says although it has its flaws, the very creation of this programme means things can improve, telling the Ecologist: "We see this as a very progressive step."
There is also increasing knowledge of how to successfully restore seagrass meadows around the world and, according to Dr Unsworth, decades of work carried out in Denmark to improve coastal water quality (namely to reduce nitrates) has led to a significant and widespread expansion of seagrasses around that country.
Dr Unsworth adds: "Protection of seagrasses requires that people develop a better understanding of what it is and why it's so important so that the necessary measures can then be taken with support of the general public.
"This means better management of our riverine catchments, more effective and targeted Marine Protected Areas (MPAs), and better consideration of seagrass during coastal development planning.
"To help improve people's understanding of the issues, we've set up Project Seagrass (www.projectseagrass.org) and developed a web portal and phone app (www.seagrassspotter.org) designed to get communities learning more about seagrasses and helping scientists to collect much-needed further data on where these habitats are."
Laura Briggs is the Ecologist's UK news reporter.
Follow her here @WordsbyBriggs