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| ecosystems | rocky | sandy | seagrass | coral rubble | coral reef |
| Rocky
shore ecosystem updated Sep 09
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. While the rocks may appear barren, they are usually full of life! Take a closer look! Home on the Rock: Rocks provide a firm surface for lots of animals. 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. Where are the animals? At low tide during daylight, most rock dwellers are inactive and hide in crevices where it is cool and wet. 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. Tiny animals graze on this miniature meadow. 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 be found. Many rock-dwellers are well camouflaged. Onch slugs often perfectly match the rock surface. Don't step on them! Tiny banded bead anemones may coat the rock surface or the sand at the base of a boulder. Immobile animals such as barnacles, oysters and ascidians may be found in some areas of a rock, sometimes in large numbers. Drills may form large groups to lay their eggs on a shady part of a boulder. Zonation is particularly obvious on large boulders and on the rocky shore near the high water mark. Here bands of different animals and plants form, corresponding to the tide heights. 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. 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. The rocks may appear bare but they are usually coated in a layer of plants, especially parts of the rock which are submerged for some time of the day. Besiders larger seaweeds, microscopic algae may form a thin layer over the rocks. Tiny animals graze on these and they are preyed upon by small predators. These are in turn eaten by larger animals. Larger animals such as onch slugs, limpets, periwinkles and other snails may graze on the growths on rocks. Don't climb rocks! The rocks are slippery with algae and covered with razor sharp barnacles that can give a nasty cut. 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 flats. 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. |
 Natural rocky shore of Labrador 
Although tiny, periwinkle
snails are toughand can survive on parts of a rock that other animals can't. Don't pick them off the rocks! 
Onch slugs
are commonly seen on our rocky shores but are very well camouflaged. Watch your step!  Barnacles are stuck permanently on a hard surface and don't move once they settle down.  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. |
The rocks are alive! Take a closer look, watch your step.
Links
References
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Second edition. Prentice Hall. 271 pp.|
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