Sea Grass Meadows

Beautiful light on the seagrass beds of Cabilao, Philippines.

When most people think about going diving, normally their minds will wander to beautiful coral reefs with fish of all colors of the rainbow, or a deep dark haunting shipwreck, or maybe even jumping into a cage with some of this planets most ferocious predators. But there is something that most people would not think of as an exciting place to go diving, a sea grass meadow.

When you first go diving on a Sea Grass meadow it may seem boring and lifeless, however when you spend a bit of time on them you will realize this is not the case. Many fish choose it as a place to feed, and raise their young in the shelter of the leaves. You will find many mollusc, crabs, urchins and star fish on the meadows. And you also get the big things living there too, in many parts of the world they are the best place to see the Manatee and the Dugong.

Sea grass is not actually a type to grass, but it gets its name from the plants leaves, as they are long and narrow just like blades of grass, and also when growing in abundance they also look like large meadows. There are 12 genera with 58 species of Sea Grass known currently. Just like terrestrial plants, and most other plant species that is, sea grass needs to photosynthesize to get energy. This means that they are limited with where they can grow. You will only find them in shallow sheltered coastal water, usually growing on mud or sandy bottoms fixed in with a very strong root system. Most of the sea grass species will pollinate underwater, and complete their entire life cycle underwater.

Sea grasses also offer some amazing services to the planet. They are often labelled as ecosystem engineers, because they alter the habitat to suit their needs. For instance they have a very strong rhizome (stem, think ginger plant) under the sea bed, and attached to that are some very strong roots, which have all inter locked with other plants nearby creating a huge (square kilometers huge) anchor which not only firmly holds them down, but also stabilizing the sea bed. Their leaves also aid in slowing the currents, making it a most welcoming place for many fish species, especially juvenile.

Sea Grass Meadows also offer vital services to the coastal areas which they inhabit. They produce huge amounts of Oxygen, you can even see it when swimming along, in the form of little bubbles being released and floating up towards the surface. When you are diving or snorkeling over these meadows once your eyes have adjusted to the environment you will see these tiny bubbles of Oxygen everywhere.

Unfortunately sea grasses are generally in worldwide decline. The main reason for this is because of human disturbance. Destruction of habit, overfishing, and dumping toxic chemicals into the oceans are the main culprits. Especially bad is excessive input of nutrients (such as phosphorus, nitrogen and other chemical nutrients used in farming) which regularly find their ways into the oceans as it runs due to rain fall. When we drive motor boats over shallow sea grass meadows the propellers can cut it or tear the root systems. There are efforts however to restore and protect sea grass, this includes the addition of Marine Protected Areas (MPA’s), nutrient and pollution reductions and restoration projects using Sea Grass transplantation.

There are Sea Grasses found almost anywhere there is coral reef, but more commonly where there is a fringing reef (where the reef grows alongside the coastline as the seabed gets shallower), or between barrier reefs and the coast. The Caribbean Sea has some beautiful Sea Grass Meadows, making it one of the best places in the world to go SCUBA Diving, or Snorkeling with Manatees!

‘Sea Grass Meadows’ was written by Mike

Photo Credit – Steve De Neef