Exploring on the rocky seashore

Forest and Bird, Volume 14, Issue 3, 1 August 1982, Page 46

Exploring on the rocky seashore

By

David Gregorie

WHEN YOU PICK your way along a rocky shore you will probably have your head down, watching where you put your feet. You may see very few living things except some battered-looking shrubs and some gulls screaming their silly heads off.

HOW "DULE, "you "think, nothing much lives here. Look more closely: from the tops of the cliffs to as deep as you could dive there are dozens of different kinds of plants and hundreds of different kinds of animals. Even the sea is a sort of living soup; if you scoop up a jar of sea water and hold it up to the light, you will see hundreds of tiny living things moving around. These are plankton. They are not just one kind of animal, but hundreds of different kinds of tiny animals and hundreds more of baby animals that will one day grow much bigger, unless they get eaten of course! They are the beginning of the great ‘‘food chain’’ of the ocean. Lots of creatures feed on them directly, from the pipi hiding under the sand and sucking cold plankton soup in through its siphon tube to the tens of thousands of small fish swimming through the clouds The four zones of life along thé rocky shore, from the shore zone on the left, through the splash zone and the tidal zone, to the light zone.

of plankton and snapping it up as they go. Bigger fish eat the little fish, and large fish eat the bigger fish; all of them, right up to the sharks and the swordfish, depend on the plankton. If some dreadful pollution killed all the plankton in the sea, you would never again have fish and chips! Well, you could have the chips. Four layers Life along a rocky seashore is something like a club sandwich, each layer containing something different. We call the layers ‘‘zones’’ and there are four of them, from the tops of the coastal cliffs to the cold, dark deep of the ocean. We call the top layer the shore zone. This is anywhere along the coast where the sea breezes blow, but out of the reach of the waves and spray. This is where the sea birds have their nests, where the hardy shore plants grow, and where hundreds of insects, spiders, lizards, and _ other creatures scuttle and hide. The next layer we call the splash zone. This is a tough place to live. It is above the high-tide zone, but often gets

drenched with spray and is occasionally drenched with a storm-tossed wave. Not many plants live here except lichen and algae, which do not need soil to live in. A few iceplants and the tough taupata shrubs may survive in sheltered spots on little patches of soil. Grass grows where it can. Only a few hardy animals can stand these awful conditions. Barnacles, sand lice, shore crabs, and a few more. We will meet them again in the next issue of Forest and Bird. The tidal zone is the next layer and it is so interesting that I will spend the whole of my next article writing about it. The tidal zone is all along the coastline between the hightide mark and the low-tide mark. Most of the zone is under water twice a day and out in the wind and sun twice a day. This is where you will find rock pools-large and small pools of sea water left behind by the falling tide. Cracks between the _ rocks shelter crabs, barnacles, limpets, starfish, mussels, and lots Of- Olmer . interesting creatures. The» rock pools themselves are full of life — from tiny shrimps to octopuses. But more about them in the next issue. The last layer that we can get into is called the light zone. This is all the sea around the coast from the low-tide mark to as deep as light can pene-trate-about 20 m. Many of the creatures that live in the tidal zone can be found here, but the species change as the water gets deeper. You can’t explore this zone without a face-mask, snorkel, and flippers. But we can explore the other three zones with a sensible friend. An interested adult is handy to have around on a shore trek, provided that it knows how to keep quiet, can keep its eyes open, and doesn’t

mind getting wet. Because, make no mistake about it, you will get wet! You could go with your mother or father, aunt or uncle, or an adult friend. But don’t go alone. The photos reproduced on this page show how dangerous a rocky shore can be. Preparations Now, what about preparations? You can’t just wander down to the rock pools any old time in your T-shirt, jeans, and jandals. A T-shirt is a good idea; it stops you from getting sunburnt as you bend over looking into the rock pools, but the other items need more thought. Time is important. Low tide

is the time for exploring rock pools, but low tide is at a different time every day. You can find out when low tide is by ringing the harbour board or lighthouse keeper, asking some professional fishermen, or asking your local bookshop to order a copy of the New Zealand Nautical Almanac and Tide Tables from the Government Printer. Clothing is important. Jeans are dangerous. When they are wet they are heavy, and the weight could drag you under if you fell in. Wear shorts or togs, then it won’t much matter if you do get wet. Jandals can be dangerous too; it is very easy to lose your footing and hurt yourself on the rocks.

The best footwear is tennis shoes that fit your feet tightly. You may like to wear a hat too. You won’t need much in the way of equipment unless you

want to take some of the creatures out of the water to have a good look at them before you put them back. You could take a kitchen sieve and a plastic container of some sort. And your lunch.

My next article will tell you about the plants and animals you will find-from sea lettuce to seagulls, from cat’s eyes to crayfish. And many types of animals you have never even heard of before. ©