Wednesday, May 9, 2007

Seagrasses: Meadows in the Sea

Three NAKED facts

NF#1: Seagrasses are homes to many small animals. Like a meadow or miniature forest, seagrasses provide hiding places for small or slow-moving animals, places for animals to lay their eggs. Baby fishes also shelter here before moving to deeper waters when they grow up.

Interactive activity: Let's see what animals we can see on the seagrass?

Helpful Hints for Hermits
Tape seagrass is longer and has more to look at.

Things commonly seen...
Pinkish or pale stuff growing on the leaves. Could be algae or encrusting animals.
Small snails, tiny hermit crabs.
Tiny crabs.
Eggs (small dots, spirals)
Sometimes, bigger fishes hide among the leaves, e.g., filefishes, eel-tail catfishes.

NF#2: Seagrass roots form a mat on the ground that keeps the sediments down and the water clear. With stable ground, burrowing animals can safely make their tunnels.

We should try not to step on the grass too much. It breaks up the grass and hurts animals living among them.

Corny joke: It's like a grassy field at school. If we play soccer on it every day, some parts will become botak! (bald)

NF#3: Seagrass meadows are an important part of the food chain. Not many animals can eat seagrasses because they are quite tough to chew and digest. But lots of animals graze on the algae growing on seagrasses. As well as hunt and eat the small animals that live there. When seagrasses die and decay, lots of animals eat up the bits that float around.

Thoughtful question:
Can you guess what big animal eats seagrasses? (Lead them along) What eats land grasses? (Eventually someone will guess 'cow').

Sea turtles also eat seagrasses.

Too much Information
For visitors who Really Want To Know...

Seagrasses are the only flowering plants that can live in the sea. Like land plants, they have fruits and flowers. (If you want to compare with seaweeds: "seaweeds reproduce in another way, without flowers and fruits").

Some seagrasses you will see on Sentosa

Tape seagrass (Enhalus acoroides) is the longest seagrass found on our shores. Male flowers of the Tape seagrass are tiny (see the small white bits?). They form inside a bract that grows at the base of the plant. During a bloom of Tape seagrass, male flower float everywhere on the water. They look like bits of styrofoam! Sometimes, the male flowers join up to form 'rafts'.Female flowers are large and emerge on long coiled stalks. The pale yellowish petals last only for a day or so. Often, all that is seen are the V-shaped bracts. Soon, the large fruit develops. It is a hairy capsule that holds several seeds. The seeds are said to be edible and are eaten by some coastal dwellers. The raw seeds are said to taste like chestnuts.Spoon seagrass (Halophila ovalis) is commonly seen on many of our shores. Their flowers are tiny and they probably bloom rarely.More about seagrasses on the teamseagrass blog

No comments: