The United Nations wants you to know and honor grass.
The wish of this organization’s general assembly is not for a celebration of lawns or marijuana, but rather a day honoring seagrass. In May, 2022, Resolution A/RES/76/265, was passed which “highlights the urgent need to raise awareness at all levels and to promote and facilitate actions for the conservation of seagrasses,” March 1st was designated World Seagrass Day.
In case you missed the merriment, don’t despair as I believe that this party should continue through the week and even through the year. Seagrass should never be far from our minds once we know about its value in our life and on our planet.
Seagrass describes marine flowering plants that are found in shallow, coastal areas. Seagrasses are plants, underwater flora that are distinctly different from seaweeds or algae, which are not considered true plants. Plants have roots, stems and leaves, while seaweeds do not have a true vascular system, instead having holdfasts instead of roots and stipes rather than stems.
In 159 countries on six continents, covering more than 74 million acres, seagrass is one of the most widespread coastal habitats on earth. Two predominant species, eelgrass and widgeon grass, are the seagrass superheroes on the Island and can be found in our ponds and marine environments.
These aggregations of greenery provide many benefits to people and wildlife. Underwater meadows of seagrass sustain fisheries and wildlife, help improve water quality though the uptake and recycling of nutrients, buffer ocean acidification, protect shorelines by reducing wave energy, and store immense amounts of carbon. They are literally the lungs of the sea, producing oxygen at a rate of ten liters per square meter of seagrass.
The carbon sequestered by coastal marine systems is called blue carbon and seagrasses are one of the champions of this effort. Only 0.1 per cent of the ocean floor is covered with seagrasses, but they pack a wallop when it comes to carbon sequestration. These great grasses hold up to 18 per cent of the world’s oceanic carbon. According to the Marine Conservation Society, “seagrass captures 35 times more carbon than tropical rainforests and is home to 40 times more marine life than bare seabeds.”
But all is not good with the grasses. Twenty-two of 72 individual seagrass species worldwide are in decline. Since the late 19th century, more than 30 per cent of seagrass habitats have been lost and continue to disappear at an annual rate of 7 per cent. That translates to a football field of seagrasses lost every half-hour.
The decline hasn’t come out of the blue and hasn’t been all human-induced. How can we stem the tide of destruction? Education, protection, responsible fisheries, reducing water pollution and runoff, restoration and research are good places to start.
Beyond the science is seagrass’s artistry. These carbon-collecting, swaying spears of seagrass have us rooting for its (and our) resilience, and those of us that appreciate it go deep in its praise. University of Washington professor of biology and seagrass enthusiast Jennifer Ruesink might be the best spokesperson for these magnificent meadows, effusing that this particular plant is “wonderful in the truest sense of that word — the way it grows, moves, and shapes the environment provides a continual source of wonder.”
Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown, and author of Martha’s Vineyard: A Field Guide to Island Nature and The Nature of Martha’s Vineyard.
This article appears in March 6, 2026.