Graphic by Annabel Driussi for Our Daily Planet

by Amy Lupica, ODP Contributing Writer 

According to a 2020 U.N. environmental report, seagrass “prairies” play a massive role in the health of the world’s oceans and if nothing is done to stop their decline, the world will face serious consequences. 

Seagrasses support rich biodiversity that sustains a whopping 20% of the world’s fisheries, and protects shallow-water sea beds from erosion, protecting coastlines from storm damage. Experts say this long-overlooked ecological powerhouse can help us solve our biggest environmental challenges.

Why This Matters: Oceans serve as the world’s largest carbon sinks, but due to rising temperatures, they are losing their ability to remove carbon from the atmosphere. We rely on oceans to absorb over 30% of the carbon in the atmosphere each year. Other major carbon sinks around the world are also at risk, most notably perhaps the Amazon rainforest, which has suffered unprecedented forest fires and unceasing development in recent years. Without these crucial carbon sinks, atmospheric CO2 levels will accelerate further. 

Seagrass plays a massive role in the carbon lifecycle of oceans, and it is declining due to a variety of ecological stressors, primarily caused by human activity. The report cites “urban, industrial and agricultural run-off, coastal development, dredging, unregulated fishing and boating activities, and climate change” as primary threats to the world’s 72 seagrass species, 22 of which are in decline. Almost 30% of global seagrass area has been lost in the last since the late 1800s. Experts estimate that the loss of seagrass releases 299 Tg (over 659 billion pounds) of carbon to the atmosphere per year.

Deep-Sea Frontiers: Seagrass is one of the most widespread coastal habitats on the planet, existing in 159 countries and 6 continents, ranging from subarctic to tropical latitudes. 

• Around 300,000 square kilometers of seagrass has been mapped worldwide and experts expect there is much more to be discovered. 
• The U.N. Environmental Programme reports that seagrass plays a crucial role in “supporting food security, mitigating climate change, enriching biodiversity, purifying water, protecting coastlines and controlling diseases.” 

Experts worry that seagrass has been overshadowed by other marine ecosystems, which are also in severe decline, despite how connected they are to seagrass. Seagrasses are among the least protected coastal ecosystems in the world. Ronald Jumeau, a United Nations representative from the Republic of Seychelles calls them “the forgotten ecosystem.” “Swaying gently beneath the surface of the ocean, seagrasses are too often out of sight and out of mind, overshadowed by colorful coral reefs and mighty mangroves,” he said.

The report calls for urgent action to preserve and manage seagrass. Conservationists call for a top-down approach, asserting international programs like the Paris Agreement as well as local, collaborative community programs are essential to the future of seagrass. The report asks that countries invest in scientific and policy research into seagrasses, make concrete plans for the protection of seagrasses, and boost public awareness of these at-risk ecosystems.