Unit 6 Industries of the Intertidal Zone – An Exploration

Author：Wen-Chien Cheng(鄭文健)  Translator:Gloria Fung

Learning about the Intertidal Ecosystem

Penghu is an island county surrounded by the sea. The sea is an important part of the daily life of Penghu people. Have you ever taken a walk or strolled by the shore? The sea breeze, the beaches, the waves … what lovely scenes! Have you noticed that when you walk out further from the shoreline, there is a stretch of ground that we can only reach in low tide where we can find all kinds of creatures, rocks and coral? This area that emerges from the water in low tide is called the "intertidal zone."

Different kinds of intertidal creatures live in slightly different habitats: the wharf roach (海蟑螂), blue-green algae (藍綠藻) live in the spray zone which is dry much of the time but is sprayed with salt water during high tides. A variety of whelks, barnacles and oysters live on rocks. In the tidal pools in the low tide zone are all kinds of small fish, sea cucumbers, and sea urchins. Clams and shrimps prefer to live in the sand. The coral reefs which are above water are the busiest -- crabs, mantis shrimps (蝦蛄), honeycomb moray eel (錢鰻), and octopus … they are an interesting sight. The intertidal zone is a colorful and busy place. If you observe it carefully, you are likely to see many kinds of sea creatures flit by.

Learning about the Industries of the Intertidal Area

Because the intertidal area is rich in marine resources; Penghu residents, who depend on the sea for their living, have developed a number of industrial activities that make use of marine resources.

Whatever the season, whatever you are planning – be it cooking a special dinner or making some extra money, going to the intertidal zone for whelks or clams is a sure way of achieving your goal, as long as you are quick on your feet. The intertidal zone provides the best baits for the fisherman – bloodworms (赤蟲), snapping shrimp (槍蝦), and wharf roaches. If you prefer to use fishing nets, our forefathers designed many different kinds of nets; some nets stand on poles in the intertidal zone and form a barrier that stop fish from escaping; others are tossed out when the fisherman sees fish. The most efficient way is to row out to sea trawl for fish, shrimp and crabs. Trawling is an activity where everyone is needed to help to bring the net ashore. It is also possible to fish without using nets. Building weirs with rocks is a way of trapping fish just when they think they have found a home.

Although the powerful northeast monsoon makes winter really cold, it is the season when seaweeds and the red seaweeds are at their best. During the season, many fishermen work hard to harvest the green and black "gold." From the middle of the first lunar month, octopuses begin to make their appearance in the intertidal zone. Because they are seafood that brings in a lot of money on the market, many fishermen go to sea at night with lanterns to look for octopuses. Baby eels, the slow-moving smooth spooner (Etisus laevimanus 「大狗仔」) and the scary-looking honeycomb moray eel are all valuable resources for the fishermen whose livelihood depends on these intertidal creatures.

Are you feeling a bit overwhelmed by the variety of intertidal industries? Is there much you have never heard of or seen? It is because even though the intertidal zone has so much to offer, we have not treated it with respect. Sometimes we have even dealt with it very roughly -- like poisoning the fish, vandalizing the coral reefs and over-fishing -- with the result that these resources are rapidly disappearing and some are even on the verge of becoming extinct. Because the yield is low in some of the industries, only a small number of people have continued with them. In some cases, the government has imposed bans on the predatory activities in order to ensure the continued existence of the marine resources.

Just imagine, if we don’t protect the intertidal zone, there will come a time when our children will walk to the seashore and not be able to see the whelks among the rocks, or the shrimp and fish swimming in the water. They will be faced with a "dead" ocean where there is no life. Won’t that be really sad? This is the reason why you and I have to start protecting the resources in the intertidal zone starting this very minute.

A Taste of the Industrial Activities

You can have a taste of some of these intertidal industrial activities. However, you need to be equipped for your experience – a sun hat, protective gloves, slip-proof rubber shoes, a bamboo basket and tools are must-haves. Also, don’t forget to bring plenty of water. Now, don’t you think you look like a young fisherman?

The most easily accessible intertidal industry is whelk-picking. You just have to go to the rocks in low tide and you will find a lot of slow-creeping whelks. You have seen or eaten many of them, haven’t you? Do you know their names? Remember to write down these names after you have checked with your teacher; then, the next time you see them again, you will be able to call them by their proper names.

Digging for clams is another interesting activity. When you dig out the beautifully patterned clams from under the sand, you will feel like you have just found buried treasure. If you feel that it is too tiring to do a carpet search, you have the choice of using the long poke. If you keep at it, you will soon become an expert who is able to tell by sight where the clams are hiding.

You probably have seen pictures of stone weirs on television or in books. Have you ever visited a weir? There are several hundred stone weirs in Penghu, all of them the brainchild of our fishing forefathers. When you are at the weir, you will discover that much thought has gone into the materials used, the structure and the design. Make sure you listen carefully to your teacher’s explanation on your visit. You can also try looking up the information before your visit.

Dredging for seaweeds is the main winter industry in Penghu. To go picking seaweeds in the windy and cold weather is very hard work for fishermen. If you have the chance to observe them dredging for seaweed in the intertidal zone, you may want to watch them closely and take note of what they do. You will realize that the tasty seaweed soup you get for dinner took a lot of hard work from many people to get to your dinner-table.