Seagrass Habitat

The beauty and diversity of Bermuda’s marine environment is enhanced by its extensive seagrass meadows. These seagrass communities are important habitats, serving as both nursery and grazing areas for other marine inhabitants. Besides contributing essential oxygen, through photosynthesis, seagrasses also enhance Bermuda’s water quality and clarity by trapping marine sediments suspended within the water column, and stabilizing benthic sediment, minimizing the effect of erosion.

Take a virtual swim through a Bermuda seagrass bed

What is Seagrass?

Seagrass is a true plant that produces flowers. Unlike flowering plants on land, all seagrasses grow and reproduce fully submerged underwater. For this reason, seagrasses have specialized methods for the pollination of their flowers and for the dispersal of their seeds. The ability of seagrasses to form extensive meadows is aided by their well-developed underground horizontal stem and root systems. Seagrass roots extend deeply into sand and mud bottoms to anchor and support them.

Why is Seagrass Important?

Seagrasses and the communities they foster are important both economically and ecologically. The services provided by seagrass communities have high value.

Economic Value of Seagrass

Bermuda has approximately 1600 hectares of seagrass that is valued at $81,048,000 per year.*

 * value based on $50,655 per hectare per year for the Florida Keys National Marine Sanctuary.

Ecologic Value of Seagrass

Seagrasses:

  • provide essential food for marine animals (green turtles, some young or small fish, small snails, and crustaceans (sea lice and shrimp).
  • offer a sheltered home to hundreds of other marine plants and animals.
  • are an important initial link in the food chain that extends to include larger fish of Bermuda’s sport and commercial fishery.
  • remove carbon dioxide from the marine environment, that they convert to oxygen, through the process of photosynthesis.
  • have extensive root systems that hold sediments in place and reduce erosion of our coastlines during rough weather.

Bermuda Seagrass Species

Five different species of seagrass are known to occur in Bermuda. Four of these are open-water species that are found in bays and across the east and north lagoons toward the rim reef: Thalassia testudinum (turtle grass), Syringodium filiforme (manatee grass), Halodule sp (shoal grass), and Halophila decipiens (paddle grass). One species, Ruppia maritima (widgeon grass) is found in the majority of Bermuda ponds.

Turtle Grass - Thalassia testudinum

Turtle Grass – Thalassia testudinum

Turtle grass can be recognized by its wide, flat, ribbon-like leaves. Of the four open-water seagrass species found in Bermuda the leaves or blades of turtle grass are the largest and most robust. An extensive root system of well-anchored runners help this species to form large, thick meadows. Depth 1 to 10 m.

 

Manatee Grass - Syringodium filiforme

Manatee Grass – Syringodium filiforme

In Bermuda, Manatee grass is the most common seagrass. Manatee grass is unique in that it has cylindrical rather than flattened leaves. This seagrass is commonly mixed with other seagrass species, but may also be found in solitary patches or large meadows. Depth 1 to 15 m.

Shoal Grass - Halodule sp.

 

Shoal Grass – Halodule sp.

Shoal grass has slender flat leaves or blades much narrower that turtle grass blades. The blades are distinctive in having three teeth on the tip of each blade. Shoal grass occurs mixed with other seagrasses or on its own. There is currently some debate about the species of Halodule found in Bermuda. Depth 1 to 12 m.

 

Paddle Grass - Halophila decipiens

Paddle Grass – Halophila decipiens

This small plant has paired oval leaves and grows in deeper or murkier water. It is widespread around Bermuda. The seasonal occurrence of paddle grass is more prevalent in the summer months. Because paddle grass does not have deep roots, it is easily torn out of the soft mud in which it grows. Depth 2 to 20 m.

Widgeon Grass - Ruppia maritima

Widgeon Grass - Ruppia maritima

Widgeon grass (sometimes called eelgrass in Bermuda) is found in most of the ponds of Bermuda, including freshwater, slightly salty and tidal seawater ponds. Unlike other seagrasses, widgeon grass can only flower at the water surface, hence its occurrence in shallower pond areas.

 

 

A substantial loss of Bermuda’s seagrass population between the years of 1997 and 2004 prompted the Bermuda Government Department of Conservation Services to implement a benthic mapping, monitoring and assessment program (BBMAP). A primary goal of the program is to acquire data that allows recognition and possible causal association of any future changes in Bermuda’s benthic environment.  

Some animals and plants found in seagrass beds in Bermuda include:

  • Bucktooth Parrotfish (Sparisoma radians)  Sparisoma sp.
  • Green Turtle (Chelonia mydas)
  • Seahorses (Hippocampus spp.)
  • Queen Conch (Strombus gigas)
  • Harbour Conch (Strombus costatus)
  • Bermuda Bream (Diplodus bermudensis)
  • Grey Snapper (Lutjanus griseus)
  • Spotted Goatfish (Pseudupeneus maculatus)
  • Grunts (Haemulon spp.)
  • Spotted Eagle Ray (Aetobatus narinari)

Learn More About Seagrass:

Related Research: