Mount Fuji

Tropical Tokyo and the green clams 

Remember the Blue Oyster Cult? They were a forgettable rock band in the '70s. Their big hit was ... was ... heck, forget about it. Now for an encore: the Tokyo green clam clusters.

Tokyo is rapidly getting more tropical. It has always been right on the cusp of perennial and semi-tropical. Palm trees grow next to firs, and monkey-wood trees are mixed in with pines in Tokyo parks. The doctor or retired thug who is building his hulking new house across the street from your reporter had the landscapers plunk down a small forest of fully grown palm trees yesterday, with their roots still wrapped in earth balls. Voila, instant tropical garden in the middle of November. Your reporter is hoping next for toucans and parrots to drive out the Volkswagen-sized crows that infest the neighborhood. Tropical rain bursts are getting more and more frequent as the heat reflected off Tokyo buildings causes highly localized and sometimes destructive rainstorms. Winter every year seems to be getting warmer. Though we are already in the middle of November, overcoats are not out and the heat has not been turned on yet.

No need, however, to point a finger at global warming or even at the Little Climatic as the culprits for Tokyo's tropicalization. The guilty parties are closer at hand. One has only to look at Tokyo Bay to see that this is an entirely man-made catastrophe.

Tokyo Bay is a finger that sticks into the island of Honshu, Japan's main isle. Tokyo and Yokohama sit on it, with a score of lesser cities. Perry's threat to sail up Tokyo Bay within sight (and cannon shot) of the Imperial castle in Tokyo forced Japan to open to the world in the early 1850s. Today, it's easy enough to forget that Tokyo is a harbor city; it seems to have turned its back on the ocean. Still, many names in the city remind you of the ocean: the most fashionable section of the city, for instance, Minato-ku, is "harbor borough" in English.

The rivers that flow into Tokyo Bay form a highly fertile delta that Tokyo sits upon. Before Tokyo plopped itself down here in about 1640 — it is younger than such cities as Boston, New York or Philadelphia — a few tiny fishing villages sat lost in a wasteland of reeds and marshes. Snowy white egrets flapped overhead searching for fish among the winding streams, and fishermen cultivated long racks of edible seaweed in the shallow waters offshore. To imagine Tokyo Bay in its pristine state, try to imagine the Danube Delta where it flows into the Black Sea. Poverty has stunted and stopped any development except for a few decaying monoliths from the communist era, crumbling in the salt air. Egrets rise into the same air, and fishermen in small boats pole their way among the towering reeds to nets and weirs set among the marshes.

The rivers that flow into Tokyo Bay, such as the Sumida, have been so restrained and corseted by the dykes and riverworks that the Japanese are still not finished with building that they seem to have faded to insignificance. A professor at the University of California has calculated that in the last 50 years Japan, which is 1/26th the size of America, has poured seven times as much concrete on public works as the U.S. has. Victor Schauberger, the theorist of living water, would have wept to see what the Japanese have done to their rivers.

Perhaps the combination of unfettered rivers, an extensive, indeed bay-wide, marsh system and tidal action at one time sufficiently flushed Tokyo Bay on a daily basis and supplied a comfortable environment for the Northern Pacific marine life that lived there. But the marshes are now entirely gone. Over half of Tokyo sits on landfill, the seaweed-gathering sites long-since filled in at the beginning of the 20th century. With the rivers as concrete-jacketed as they are, and the marshes gone, the tides are no longer sufficient to do more than push the water around the bay and occasionally move it in and out in a sluggish fashion, but not really to flush the bay. In effect, Tokyo Bay has been cut off from the North Pacific ecosystem.

A short boat ride out into the bay brings you to the Tokyo Bay lighthouse, which is actually a small offshore platform in the relatively shallow waters in the middle of Tokyo Bay. There is a lighthouse on the platform and also what looks like a small hotel, but that is a mystery for another day. The Japanese Coast Guard doesn't like you diving near there because it is too close to shipping lanes. So, naturally, this is where everyone dives. It's becoming more and more popular as a diving destination because of the acre after acre (hectare) of green clams that spread out a short swim away from it.

Tokyo Bay, cut off from the ecosystem of the North Pacific, is now becoming part of the Indian Ocean ecosystem. It has, in effect, become part of the tropical marine ecosystem.

Clams, in case you haven't noticed, are supposed to be dull gray. The bright green, almost fluorescent green clams on the bottom of Tokyo Bay, which look like some strange, unripe fruit waiting to be plucked, are called Muhl clams. They cluster in long banks, and have changed large parts of the bottom of Tokyo Bay to a bright green color. The nearest to Tokyo Bay these clams are otherwise found is the Indian Ocean. They are native to the coasts of India and Africa, but are now also beginning to be found off the coasts of South America too. They don't grow in water colder than 10 degrees centigrade (52 degrees Fahrenheit).

But even more amazing than the green clams are the groups of angel fish, straight out of 20,000 Leagues Under the Sea, striped in bright patterns, like glittering shards of glass. The angel fish, swimming in nervous clusters, are ready to flee at a moment's notice to the Indicus seaweed, their usual home, which as the name implies, is from the Indian Ocean. It has also found a home on the bottom of Tokyo Bay. Striped shrimp — striped red and white and longer and thinner than scampi — natives of Thailand and dwellers in comparatively warm waters, also live among the Indicus at the bottom of Tokyo Bay.

The route all the tropical fish and vegetation that have arrived in Tokyo Bay have taken is not hard to discover: they rode in the ballast water of merchant ships. Generally, coming into Tokyo Bay, the ships dump their ballast water to navigate the shallower parts of the bay. The water may well have been carried as ballast all the way from India, and it contains countless eggs, cells and even some exceptionally hardy small marine life. They all find a welcome home and start to grow and thrive in Tokyo Bay.

How does this tropical vegetation survive in Tokyo Bay? True, the entire Tokyo area is warming, but this should not be enough to affect the oceans. A man-made change is taking place: circling Tokyo Bay to serve the metropolis greedy for electrical power are countless electrical generating plants, pearls on an endless string, which must suck in vast amounts of bay water to cool their generators and then pump it out again as hot water. So much hot water is being pumped into Tokyo Bay that more and more tropical species are taking hold each year. The temperature, even in winter months, is above 10 degrees centigrade (52 degrees Fahrenheit) although icebergs can occasionally be spotted offshore floating down from the north.

This is an ecological catastrophe in the making. Increasingly intrusive foreign species are driving out native Japanese species as their environment is destroyed by man. Lunkers (big American bass) have repopulated large areas of Lake Biwa in the center of Japan where native fish have died out due to ill-thought-out reclamation or water supply projects. The problem is that the lunkers are now increasingly colonizing the areas where native fish live. Attempts, none too successful, are also being made to clear non-native species out of the moat of the Imperial Palace in Tokyo. Raccoons, recently brought from North America, are beginning to compete with the native takuni on the outskirts of cities.

Japan is not alone in this problem. Intrusive species like the American gray squirrel are driving European red squirrels out of their accustomed feeding grounds and newly introduced plants and birds are becoming worldwide pests. In California, parrots released during a pet shop fire years ago have established hardy breeding populations, driving out native species. With this, certain types of insects, that were held in check by the native bird population are beginning now to increase, along with the need for pesticides to keep them down.

But there is nothing quite on the scale of Tokyo Bay, where an entire tropical ecosystem is being transported almost to the coasts of Siberia. It is difficult to understand the complacency of the Japanese, but there seems to be no sense of alarm, rather one of wonder at the green clams and the beauty of the angel fish.

Tokyo Bay may well be approaching the Aral Sea as one of the two greatest ecological disasters in the world today. The causes of both these disasters are exactly the same. They are both entirely man-made. In the case of the Aral sea, it was a desire by muddled Russian planners to use the waters to feed the Uzbekistan cotton crops, that thirstiest of all crops. No thought was given to the possible effect on the environment.

Japanese cluck their tongues in disbelief when they see on their TVs pictures of huge fishing boats propped up on logs in the middle of a desert that was once the Aral Sea. The sea has receded miles and miles (kilometers) until the Aral Sea is now only a third of its former size, and the ecology and economy of the region has been entirely destroyed. Will Tokyo Bay be next?

Yet, the situation in Tokyo Bay is not far removed. The conservation movement — the Japanese government hates any citizen opposition with a steady, beaming, unrelenting hatred — is only just starting to awaken in Japan. Vital decisions about nuclear energy are still being taken behind closed doors. Great progress has been made in cleaning up rivers and the air, it is true, but Tokyo Bay is a problem that has not yet won recognition. The conservation movement is still testing its limited strength against the government, in battles over dams that will do far more visible damage, and has not been able to turn its attention to the more invisible and silent world just a short way from the glitter of Roppongi and the classy Asakusa night districts.

But when the last customer has left, the sign is finally turned off and the last debris has been swept away, it is only a 10-or-so-minute walk to the bay. It is a walk few choose to make. The city reflects on the water and on a clear night it seems the whole bay is circled by light as far as the eye can see. How much longer Tokyo Bay can yet remain alive is anyone’s guess.

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Editor's note: Bill Stonehill hails from Chicago, Illinois. Trained as an engineer and China specialist, he has now been living in Tokyo for well over 20 years. He imports Swiss watches, is expert at taking them apart, and if anyone knows what makes Japan tick too then he does. From 1999 until 2001 he wrote a regular Japan column for the Morrock News Service (sadly discontinued), which was enjoyed by Web-surfers around the world. We greatly appreciate the author's allowing us to republish some of his very best articles here in Japan Perspectives.