The dangers of mangroves
Driving farther south, you hit the Fangyuan coast. It's an area of broad tidal flats, where you can look out across seemingly endless expanses of sand and mud. From the coastal dikes to the water at low tide, it's six kilometers. Various kinds of shrimp, crab and shellfish live here, including many unusual species such as mud shrimp that build their nests on shore. There are also mactra and other wild clams. The rich biodiversity attracts nearly 200 species of birds each year to forage. In fact, there used to be broad tidal flats along the entire Taichung and Changhua coast. Sadly, the mudflats of Taichung were destroyed in the 1980s when they built coastal industrial parks and coal-fired power plants. Now all that's left is this area in Changhua. Ecologists see it as a great treasure.
Tsai Chia-yang explains that the tide range here along the central coast is the greatest anywhere in Taiwan, because it's where the Philippine current from the south meets the ocean current from the north. They bring in a lot of seawater, and as both tides roll out, they also pull a lot of water with them. There's a five-meter difference between high and low tide. The farther you go north and south from here, the smaller that difference becomes. At Kaohsiung and Keelung, there is only a one-meter difference. The large tidal range coupled with the flat coastal topography creates tidal flats that are more expansive than in any other area of Taiwan.
What's more, because the tidal flats of Changhua are mudflats, they are naturally used to being washed over by seawater. "There's no need for mangrove forests or breakwaters with armor blocks," says Tsai Chia-yang. He points to the large planted mangrove forests of Fangyuan with some regret. He notes that the mouth of the Tanshui River up north is sandy. It has loose soil that erodes easily, so that mangroves serve a stabilizing function there. For that sort of coast, it is an excellent tree. Yet mangroves have an altogether different effect on the mudflats here.
Mangroves moderate the tidal flow and speed the accretion of mud, so that some species of wildlife that are ill suited to this transitional mudflat ecology, such as the fiddler crabs Uca formosensis and Uca lactea, give way to other species, such as Uca arcuata. Thus, the animals and plants change, and over time the beach turns into land, and the mudflats and their special ecology are gradually eliminated.
Mangroves grow extraordinarily fast, their shoots spreading out toward the sea with the tide. Consequently, during Arbor Day last year, Chia organized local school kids to go to the shore and pull out mangroves, and he is calling for a stop to the mistaken policy of planting them here.
Tacheng Township is located at the extreme south of Changhua County. In recent years the county government pushed to get rid of its coastal conservation area designation, hoping to build a Tacheng Industrial Park that would relieve hard economic times for local residents.
The industrial park "would deal a mortal blow to the Changhua coast," says Tsai. From Fangyuan to Tacheng is the largest pristine stretch of shoreline in Changhua. Because the coast from Fangyuan northward has all been reclaimed from the sea, this original pristine beach and its ecological systems are particularly precious. Even more frighteningly, the Tacheng Industrial Park is slated to include high polluters such as petrochemical and steel plants. "As soon as Yunlin refused Kuo Kuang Petrochemical, the company turned its attention to Tacheng. If the industrial park is allowed, it will wreak havoc on the Changhua coast and the Choshui River estuary."
Having seen the Changhua coast transformed, Tsai Chia-yang has been actively working to rally related organizations around this cause, calling for everyone to make a last stand for the Changhua coast. "We respect people's right to development, but human benefit cannot trump benefit to the whole coastal ecosystem," he says.
On the way back to Taipei from Tacheng, the vast mudflats, the rows of oyster racks, and the men and women carrying them offer the very picture of a tranquil fishing life. Not far away trucks rumble on the elevated highway, bearing witness to the profit-oriented mindset of industrial civilization. How will people choose? When will they finally learn to live in harmony with nature?
The Changhua Coastal Industrial Park at more than 3600 hectares is split into three separate areas: Hsienhsi, Lunwei and Lukang. Construction began in 1979 but was stopped amid a worldwide recession. Then, after construction had restarted, manufacturers began to pull up their stakes to head abroad in the 1990s. Currently, only the Lukang area has a relatively high occupancy rate. Here it is seen during morning rush hour.
A long birdwatchers' screen that was high as a man has now been almost entirely buried by sand. The unusual landscape attracts photographers and sightseers.
The vast mudflats of the Changhua coast are a paradise for many species of foraging water birds and benthic organisms. The photos show, from left to right, Eurasian curlews, a dunlin, a mud shrimp (Upogebia sp.), and a fiddler crab (Uca formosensis).
Oystermen work the coastal mudflats as they have for centuries, the very picture of tranquil fishing life. Whether they can continue to do so is a question that mankind will have to answer.