Effective conservation will rely on stopping the loss of existing ecosystems and re-establishing ecosystems in places where they have already been lost or degraded, the study suggests.
“Pairing global observations of mangrove and seagrass coverage change through time with modelled changes, we demonstrated that only protection and restoration combined can support substantial gains in coverage of these ecosystems into the future,” says Professor Rod Connolly, director of the Coastal and Marine Research Centre and The Global Wetlands Project based at Griffith University.
According to the Marine Education Society of Australasia, Australia has the world’s third-largest area of mangroves and is home to approximately half the planet’s mangrove species.
While they cover only a relatively small area of the country, mangroves provide crucial services, hosting diverse animal species and protecting coastlines against storms and erosion. They are also of cultural importance to many coastal Indigenous communities.
The new paper modelled several different scenarios for conservation of global mangrove and seagrass ecosystems, projected ahead to 2030, 2050 and 2070.
The paper suggests that a baseline of no additional conservation effort would see the loss of more than 1000 square kilometres of mangroves and 55 square kilometres of seagrasses by 2070. Protection efforts alone would not be able to make up for global mangrove loss, but they might be able to maintain seagrass ecosystems.
However, with restoration, or protection plus restoration, the models projected “considerable” net gains in the size of both ecosystems.
“Our research suggests that if ambitious action is taken to both protect and restore, gains of up to 5% for mangroves and 35% for seagrasses could be achieved by 2050,” says research fellow Christina Buelow, the first author of the paper.
“There is an urgent need to halt and reverse loss of mangroves and seagrass to continue to benefit from the services these ecosystems provide to coastal communities, such as enhancing coastal resilience and contributing to climate stability.”
The study aims to add certainty and direction to global mangrove and seagrass conservation strategy.
“Our research can be used to set global conservation targets for coastal ecosystem recovery that are not only scientifically sound but also have the necessary ambition required to inspire coordinated international action,” says Connolly.
Chris Brown, a co-author on the study and associate professor at the Coastal and Marine Research Centre and the Global Wetlands Project, reiterates that ambition is key to preserving the future of these ecosystems.
“Imagine if we put the kind of effort we are putting into space programs into protecting the Earth’s ecosystems,” he says.