Seagrasses are marine flowering plants that are found in shallow waters from the tropics to the Arctic Circle, covering over 300,000 square kilometres of the ocean floor.
Although not as colourful as coral reefs, or mysterious as mangrove forests, they provide a wealth of benefits to humans and marine life.
‘Blue forest’ benefits
Seagrass meadows – often referred to as a type of “blue forest” – supply food and shelter to thousands of species of fish, seahorses, turtles, and other marine animals, and sustain some of the world’s largest fisheries.
Non-marine species, including some geese and ducks, rely on them too, as they graze on seagrasses during their autumn migration.
Seagrasses improve water quality by filtering, cycling and storing nutrients and pollutants, thus reducing contamination in seafood. As part of the marine ecosystem, they store up to 18 per cent of the world’s oceanic carbon.
Nature in harmony
They also reduce wave energy, serving as the first line of defense along coasts, protecting communities from the increasing risk of floods and storms.
“The seagrass ecosystem is a perfect example of nature in action, where habitats and the delicate web of life are intertwined in perfect harmony,” said Leticia Carvalho, Head of the Marine and Freshwater Branch of UN Environment Programme (UNEP).
Disappearing fast
Despite their importance, including in climate mitigation, seagrass meadows are in danger.
A football field worth of seagrass disappears every 30 minutes, with an estimated seven per cent of meadows being lost worldwide each year, according to UNEP. Key drivers are ocean acidification, coastal development and rising ocean temperatures due to climate change.
SDGs and climate connection
World Seagrass Day aims to raise awareness about the threats to these ecosystems, and promote their conservation, which is critical for the achievement of the Sustainable Development Goals (SDGs) and the Paris Agreement on climate change.
It was established by the UN General Assembly in a resolution adopted in May 2022.
Ms. Carvalho said the world must prioritize timely, ambitious and coordinated actions that conserve, restore and sustainably manage seagrasses.
As that happens, countries will need to ensure that local communities, who have been living in harmony with nature for thousands of years, also benefit, she added.