updated Dec 2019
learn only 3 things about the ecosystem...
| The rocks are alive! Take a closer look, watch your step.
Don't take snails off the rocks! They will wash away with
the tide and may die.
looking under a stone, turn it back gently the way you
first found it.
A shore with lots
of boulders, rocks and stones is called a rocky shore (surprise!).
Such shores are often found at the base of natural cliffs which are
cloaked in a coastal
forest. The rocky shore is a result of the natural, gradual erosion
of such cliffs. At the low water mark, a rocky shore may gradually
merge with a coral rubble area. Even artificial
surfaces such as seawalls, jetty legs and large trash on the shore
provide hard surfaces for dwellers adapted to a rocky shore. While
the rocks may appear barren, they are usually full of life! Take a
Home on the Rock: Rocks provide
a firm surface, a scarce commodity in the sea. Coastal forests and
other landward ecosystems produce nutrients that flow onto the rocky
shore. But rock dwellers, especially those living at or near the high
water mark, have to cope with being baked in the sun at low tide,
while waves may pound on them at high tide. When it rains, they have
to cope with sudden changes in salinity.
Where are the animals? At low
tide during daylight, most rock dwellers are inactive. Some seal themselves
up in their shells. Others hide in cool wet crevices, under stones
or are buried in the sand nearby. At night or on a cool, overcast
day, you might see some of the more active snails, slugs, crabs and
sea slaters out and about. But they are often well camouflaged.
Although a rock may appear to be barren, often it is coated in a thin
layer of tiny seaweeds or a film of microscopic plants. Grazing on
this meadow are tiny animals, as well as large ones such as onch
slugs, limpets, periwinkles.These
are preyed upon by small predators.
Closer to the low water mark where it is wetter, large seaweeds can
grow more abundantly, on stones and rocks which provide good hard
surfaces to cling to. Here, larger grazers and their predators may
Various animals settle on large boulders at Punggol Beach.
|Zones of life: Zonation is particularly obvious on large boulders and on the rocky shore near
the high water mark. As each kind of plant or animal settles and thrives
in a spot it is best adapted to, distinct zones on a rock often develop
in response to tidal and other influences.
Watch your step! Many rock-dwellers
are well camouflaged. Onch
slugs often perfectly match the rock surface. Tiny banded
bead anemones may coat the rock surface or the sand at the base
of a boulder.
Don't pick snails off the rock!Many
snails glue their shells to the rock then retract completely into
their shells at low tide. If you pick off the snail from the rock,
you can't 'stick' them back onto the rock. When the tide comes in,
the snails may be washed away and die.
Pool party: Sometimes, a pool
of water may be trapped in a large boulder or arrangement of rocks.
Such a rock pool is precious shelter for a wider range of animals
during low tide.
| Onch slugs are commonly seen
on our rocky shores but are
very well camouflaged. Watch your step!
Various periwinkles can be seen on rocks. Do not pick them off!
The underside of a stone may be full of life! Be sure to turn the stone gently back
after having a look at the underside.
| Life on the Dark Side: Under a
stone it is safe, cool and wet. Here you might find encrusting animals
stuck to the stone. Such as sponges and keelworms. As
well as more mobile animals such as snails and porcelain
crabs. Larger crabs, shrimps and even some fishes may hide under
stones. On the upper side, large seaweeds and immobile lifeforms that
need sunlight may grow.
Please be gentle when looking
under a stone. Be sure to put it back exactly the way you found it
so that animals and plants are not harmed. Don't crush animals as
you turn the stone over.
Rocky nursery: Hard surfaces are
a great place to lay eggs on! The distinctive egg capsules of snails
such as the Spiral
melongena, Drills and Nerites are commonly seen.
Please don't pry open oysters
or barnacles. You will hurt and kill them.
Don't climb rocks! The rocks are
slippery with algae and covered with razor sharp barnacles that can
give a nasty cut.
are sometimes seen in fast-moving swarms on the rocky shore.
The rare Nyireh
is generally only found on
our natural rocky shores.
|Where can we explore rocky shores in Singapore? Labrador has the last large mainland rocky shore. There are also narrow and
patchy rocky shores at Changi. Among our northern islands, there are
rocky shores on Pulau
Ubin, the most famous being the one at Chek
Jawa. While on our Southern islands, there are rocky shores at Sentosa, St. John's Island, Sisters
Islands. Smaller patches of rocky shores are also found at Pulau
Semakau which is better known for its seagrass meadows and reef
Are artificial granite sea walls rocky shores? While some rocky shore animals can live on artificial sea walls, there
is a greater diversity of plants and animals on a natural rocky shore.
In some sandy areas, a hard surface may become
a miniature rocky shore. These include jetty pilings, abandoned tyres
and oil drums and scattered rocks or stones.
of rocky shores on Singapore shores