Seagrasses are found in shallow marine waters. They are fully submerged and are attached to the ocean floor by thick roots and rhizomes. They typically form dense beds in shallow, sandy bottom environments.

On St. Maarten, seagrasses can be found at Simpson Bay, Great Bay, Little Bay and Simpson Bay Lagoon. There are seven types of seagrasses, three of which are found locally: Paddle Grass (Halophila decipiens), Manatee Grass (Syringodium filiforme) and the most common, Turtle Grass (Thalassia testudinum) so called because it is the staple diet of the Green Turtle (Chelonia mydas).

The seagrass beds of St. Maarten are a critical component of the island’s ecology. They play a vital role in water quality by trapping and filtering large amounts of fine sediment, binding it with their interwoven stems and roots. This helps prevent terrestrial sediments from reaching the reef and smothering and killing coral reef organisms. Seagrass beds also help stabilize the ocean bottom and prevent shoreline erosion by slowing down wave action.

Seagrasses serve as a very important habitat and shelter for the young of many species of reef animals such as fish, lobsters and globally threatened Queen Conch (Strombus gigas). Other common inhabitants are cushion stars, urchins and sea cucumbers. Adult reef fish and sea turtles also migrate to seagrass beds to fee

Most of St. Maarten’s seagrass beds were destroyed by hurricanes Luis and Marilyn in September 1995. Many have since recovered but are under pressure from threats such as dredging for land reclamation, anchoring, nutrient and sediment load and other forms of pollution.