In Trinidad and Tobago, when we come across the word 'wetlands' we think of mangrove swamps and marshes. We envisage Scarlet Ibis in Caroni Swamp and manatees in Nariva... Who can blame us? The term 'wetland', however, has a much broader meaning, encompassing more than just mangroves and marshes.

According to the Convention on Wetlands of International Importance especially as Waterfowl habitat - also known as the 'Ramsar Convention' - wetlands are defined as:

Additionally, the convention states that wetlands "may incorporate riparian (riversides) and coastal zones adjacent to the wetlands, and islands or bodies of marine water deeper than six meters at low tide lying within the wetlands." The Convention therefore covers a wide variety of habitat types including rivers, seagrass beds and coral reefs.

While most of us know something about rivers and coral reefs, we know little about seagrass beds although we may have encountered them at one time or another without realizing it. If you have ever gone for a sea bath at Williams Bay in Carenage or Pigeon point in Tobago, you have probably walked over seagrasses. Some of us may consider them a nuisance, not knowing how important they are to our marine environment.

Seagrasses are submerged flowering plants (angiosperms) that have adapted to life in the sea. They differ from what we refer to as 'seaweed', in that they are plants with vessels and well-defined root and shoot systems. Seagrasses have been able to successfully colonize the marine environment because of five properties:

1. the ability to live in a salty environment;
2. the ability to function normally when fully submerged;
3. a well developed anchoring system;
4. the ability to complete their reproductive cycle while fully submerged;
5. the ability to compete with other organisms under the more or less stable conditions of the marine environment.

There are six species of seagrasses in the Caribbean, but it is not certain that all six exist in Trinidad and Tobago.

Species recorded in our country include turtle grass (Thalassia testudinum), shoal grass (Halodule wrightii), Halophila decipiens and Halophila baillonis. The presence of manatee grass (Syringodium filiforme) has not been confirmed.

In Trinidad, extensive seagrass beds are found on the west coast, at Williams Bay extending straight down to St. Peter's Bay and near to the Point Cumana River. Smaller communities are found near the Trinidad and Tobago Yacht Club and near the Pointe-a-Pierre Yacht Club. Only recently, seagrass was found in the North Claxton Bay area. The beds in Williams Bay and environs are mixed beds dominated by turtle grass while the beds in Pointe-a-Pierre and North Claxton Bay are dominated by Halophila decipiens. On the east coast, seagrass beds can be found in Salybia closely associated with the reef and also in the northeastern section of Guayaguayare bay.

In Tobago, the Bon Accord Lagoon has a well-developed seagrass community, which is part of the Buccoo Reef complex. Seagrass beds are also found in La Guira Bay, near Kilwgyn, and in Petit Trou Bay.

How important are seagrass communities to our environment? They have a number of critical functions. They are habitats and nursery grounds for recreationally and commercially important finfish and shellfish. Juvenile finfish found in seagrass beds in Trinidad and Tobago include snappers, croakers, grunts, groupers, seabreams and many others. Other commercial species found in these beds are queen conchs, serrete crabs, lobsters and shrimps.

Some animal species which are not of commercial importance are also found in seagrass beds. These include sea urchins (commonly referred to as sea eggs), sea cucumbers, starfishes, brittle stars, snails such as Murex, cones and olives, anemones, and sponges. Even a sea horse has been found in the Bon Accord Lagoon! Seagrass beds are also grazing grounds for turtles, hence the name 'turtle grass'. The diversity and abundance of organisms in these beds are quite high.

Seagrass beds are also:

• Major primary producers (food manufacturers) in the coastal environment. Their high primary productivity rates are linked tot he high production rates of associated fisheries;

• Stabilizers of bottom sediments; they provide protection against erosion along the coastline;

• Important nutrient sinks and sources i.e. they help in the recycling of nutrients.

In spite of the great importance of these systems, they are disappearing. Seagrass beds, once found in Scotland Bay, Grand Fond Bay (Monos Island), Five Islands, Cocorite (near the mouth of the Diego Martin River) and Speyside in Tobago, have already disappeared. The exact cause of their disappearance is still uncertain. Those seagrass communities that still exist are impacted by human activities. Human impacts include physical disturbance by anchoring of boats and by propellers, complete destruction by dredging and sand mining for coastal construction, heat and oil pollution, and the release of excessive organic materials such as sewage.

The Institute of marine Affairs, realizing how important these ecosystems are, especially in light of our declining fisheries, has initiated a sub-project as part of its coastal monitoring programme to acquire data on these communities and to continue monitoring them so as to facilitate their management.

Yesterday - February 2^nd - was designated World Wetlands Day, in commemoration of the signing of the Ramsar Convention in Iran, in 1971. As we think about preserving national assets such as the Nariva and Caroni Swamps and other wetland areas, let us remember that seagrass communities are also wetlands with many important functions. Let us try to protect ad preserve these systems also.

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