Mighty Posidonia…

Seagrass meadows may not be the most striking of marine habitats at first glance, but they are one of the most productive ecosystems on Earth.

These underwater meadows provide food and shelter to hundreds of species, including all-time favourite marine conservation icons like sea horses. Commercially important species also call seagrass meadows home – blue swimmer crabs can be found hiding amongst their leaves, and snapper and luderick can often be seen swimming above meadows.

Seagrasses act as a ‘nursery’ grounds for fish and other critters like prawns. Without the dense canopy that the seagrass provides, predators may eat these critters before they make it into adulthood.

Seagrass meadows are extremely effective at capturing carbon and can slow down climate change by storing carbon up to 4 times faster than terrestrial forests.

The benefits of seagrasses can also be felt on land, as these plants stabilise sediments and protect our shorelines from erosion. Because seagrasses remove dissolved nutrients and sediments from the water column, they also contribute to water clarity.

Finally, seagrasses are also truly remarkable in evolutionary terms. One may think of them as the ‘dolphins’ or marine mammals of the marine plant world: seagrasses are flowering plants with terrestrial ancestors that returned to the sea and re-adapted to the aquatic environment, just like dolphins and whales evolved from four-legged land mammals that returned to the ocean.