In the Atlantic Ocean, there are paths which fish take. People can't see them, but they are there. Salmon follow these paths back to the rivers and return each year to the place where they were born. In 1953, the salmon of the Miramichi River on the coast of New Brunswick returned there and deposited their eggs. The Miramichi was one of the finest salmon streams of North America. The eggs lay there in the fall and winter and developed slowly. The young hatched in spring and fed off the yolk sac before they began to eat insects. Along with these newly born salmon, there were also young salmon of a year or two old. These young ate insects in the stream.
The watershed of the Northwest Miramichi was included in a huge spraying campaign by the Canadian government, intended to kill off the spruce budworm. The budworm, they thought, was killing off the forest. In eastern Canada, the spruce budworm becomes extremely populous every 35 years. The Canadians sprayed DDT over millions of acres of forests. The spraying included the river. As soon as it was over, it was clear that the forest life was dying. People found many dead and dying fish. In fact, all the life of the river was severely damaged from insects to fish. The salmon that lived had nothing to eat. None of the newly spawned salmon survived. The older young salmon died in numbers of five dead to one surviving.
Surveys of the river population showed not only a loss of the young fish, but serious changes in the river itself. The whole river environment was damaged. The insects which the salmon feed on were wiped out. Smaller insects re-established themselves fairly quickly, but the larger ones took much longer. Canadians attempted to transplant some of the larger insects, but they died with each re-spraying.
All the spraying was for nothing, because the budworms increased. Still, the Canadians continued spraying. They only reduced the level of DDT being sprayed. After several years of the same policy, the Canadians found very little to substantiate the claim that spraying is effective.
A set of circumstances, however, saved the Northwest Miramichi from total destruction. In 1954 the watershed of the river was sprayed. Thereafter, only a narrow band was sprayed in 1956. In the fall of 1954 a tropical storm brought heavy rainfall resulting in freshets that carried much fresh water out to the sea and drew in large numbers of salmon. The gravel beds of the streams, then, received an unusual amount of eggs that year. In the spring of 1955, the newly spawned salmon found ideal conditions for survival, because the smallest insects, the ones they feed on, were abundant. They also had few competitors for all this insect food. They survived in large numbers, went back out to sea, and many returned in 1959 to add more life to the stream.
The Northwest Miramichi survived only because the massive spraying was done only once. In other streams which are sprayed repeatedly, the results are shocking and saddening. In all sprayed streams, young salmon are almost nonexistent. In the Southwest Miramichi, which was sprayed twice, the catch of salmon that year was at a record low. Fishermen noted a lack of grilse, the youngest group of the returning salmon. If the fishing industry is to survive, the Canadian government has to find another solution to their problem than the use of insecticides.
The Canadian example is not an unusual one. In Main, only a remnant of the huge salmon runs of previous years can be seen. Streams are polluted by industry and choked with logs. Biologists and conservationists have to fight long and hard to win anything for the river. When they sprayed for budworms in Maine, the Maine Department of Inland Fisheries and Game reported large numbers of fish with DDT poisoning. The symptoms include blindness, erratic swimming patterns, spasms and tremors.
In all the places where there are large forests, the dangers of spraying threaten fish populations. In the Yellowstone Park, a spraying campaign affected ninety miles of the river and a 300-yard length of the shoreline. Huge numbers of fish were found dead. The Forest Service said it had acted on the guidelines that one pound of DDT per acre was safe. A study was conducted involving several agencies in cooperation. They found a clear pattern in every instance of spraying. The smell of DDT is unmistakable over the forest, an oily film covers water. Dead fish line the shore. All the fish which were tested were found to contain DDT in their tissues. The most damaging result of spraying was the severe reduction of food organisms. Insect populations take a long time to rebuild after they're destroyed. Even after two years, the insect population remained quite low. The fish often don't die immediately. Therefore, the numbers of dead fish far exceeds the census figures. In times of severe stress, any organism draws on fat reserves. In this case, fat reserves contain the poison DDT. Not only had the DDT proved extremely harmful to the river, the budworm population hadn't been decreased. The Montana Fish and Game Department, one of the members of the study team, expressed strong opposition to the continued spraying of DDT or like poisons.
In British Columbia, there was an outbreak of the black-headed budworm. In 1957, the forestry officials decided to carry out control operations. They consulted the Game Department and agreed to take many precautions so as not to hurt the salmon runs. Despite their precautions, 100 percent of salmon were killed in at least four major streams. Since salmon have a homing instinct, they return to their native streams every year. This means the there will be no re-population of these streams from salmon of other streams. The officials will have to bring in salmon artificially.
Spraying is not the only solution to the problems of forest insects that become overpopulated. Natural parasitism can be used, a method of finding the insect that is the enemy of the targeted insect and introducing them into the forest. Microorganisms can be introduced which will serve as diseases to the targeted insects and thus kill them off naturally.
The pesticide threat to fish can be divided into three parts. The first involves the fish of the running streams of the northern forests and the single problem of forest spraying. The second involves many different kinds of fish that inhabit both flowing and still waters all over the country. It also involves the wide use of insecticides for many agricultural uses. The third problem involves what is to be expected in the future. This problem involves the fish of the salt marshes, the bays, and the estuaries.
The use of the new organic pesticides guarantees the death of fish. Fish are "fantastically sensitive to the chlorinated hydrocarbons that make up the bulk of modern insecticides." Reports of massive fish kills have become common. 25 million Americans are involved in the fishing industry. 15 million Americans are casual anglers.
The mass destruction of fish resulting in agricultural spraying is visible everywhere. In California, 60,000 game fish were killed following a control operation. In Louisiana, more than thirty instances of heavy fish kill were reported in one year. In Pennsylvania, fish have been killed in large numbers. In the Southern U.S. the control operations against the fire ant have used Dieldrin, a chemical with a well-documented history of extreme hazard to water life. Heptachlor is also widely used against fire ants. Fish have been found with Heptachlor in their tissues. The destruction of fish, frogs and other life was so great that the American Society of Ichthyologists and Herpetologists called on the Department of Agriculture to stop spraying Heptachlor, Dieldrin, and other poisons. The campaign to save cotton crops from insects has also caused a great deal of destruction. In 1950, 80-95 percent of farmers were urged by the government to use insecticides, especially one called Toxaphene, a chemical extremely dangerous to fish. That summer saw heavy rains. The poison washed into the waterways and killed huge amounts of water life.
Farm ponds become death traps when farmers are encouraged to apply heavy doses of insecticides to their land. the poison is carried in by rains and run-off. Crop-dusting pilots don't turn off the sprayers when they fly over bodies of water. Even if farmers applied much less insecticides, the problem would remain. The problem with farm ponds and lakes is that farmers typically repeat spraying every year. The chemicals build up; they don't go away.
In many parts f the world, ponds are used to grow fish that are indispensable as a food source. In Rhodesia, even small doses of DDT and other insecticides have proven to kill all the life of fishponds. In the Philippines, China, Vietnam, Thailand, Indonesia, and India, the problem of insecticide poisoning of fishponds causes immediate and severe reductions of the food supplies. No method has proven effective in purifying a pond after it's been exposed to insecticides.
One of the worst fish kills occurred in the Colorado River below Austin, Texas. In 1961, dead fish appeared in Town Lake in the center of Austin. Then there were reports of dead fish fifty miles downstream. A wave of poison was moving downstream. A month later, dead fish were reported 100 miles downstream in La Grange, Texas. A week later, dead fish were reported 200 miles south. Officials closed the locks on the Intracoastal Waterway in order to keep toxins from flowing into the Matagorda Bay and divert them into the Gulf of Mexico.
Officials in Austin found a plant that was leaking chemicals. It had been producing DDT, Benzene Hexachloride, Chlordane, and Toxaphene, among other chemicals. The plant manger admitted that the insecticide had been washed into the storm sewer recently. He also admitted that the plant had been dumping insecticide spillage for the past ten years. Fishery officers found other plants like this one. The Game and Fish Commission predicted that even if there were no further pollution, the pattern of fish population of the river would be impeded for years to come. No one knows what will happen to the Gulf of Mexico which received all those toxins.
No one knows the long-term effect of insecticide poisoning of estuaries, salt marshes, bays and other coastal waters. On the eastern coast of Florida, in the Indian River country, 2,000 acres of salt marsh were treated with Dieldrin to kill the larvae of the sandfly. The campaign resulted in disaster. The State Board of Health reported the results. Dead fish were everywhere. In the water, sharks could be seen eating the masses of dead fish. All species living in the area were severely damaged. Another case of insecticide poisoning occurred on the opposite coast of Florida where the National Audubon Society operates a sanctuary for sea birds. A campaign to kill the source of mosquitoes ended up killing huge numbers of fish and crabs. The fiddler crab was especially affected. The fiddler crab is an important food source for many animals, from raccoons to birds.
Inshore waters have an extremely important place in the overall ecology. Fish use these waters as safe places for breeding and spawning. Shrimp also use these areas for their young. Shrimp are extraordinarily sensitive to insecticides. The threat to oysters and clams is even greater. They live on the bottoms of bays and sounds and tidal rivers. Pesticides kill the plankton that they feed on.
There is much ignorance in regards to chemical poisoning of waterways. It's unknown how many chemicals are poisoning bodies of water and waterways or what their combinations will produce. We don't know what kinds of changes these chemicals undergo in their long transit from the land to the ground water to the waterways to the oceans. The fisheries of the fresh and salt water are invaluable resources. We should divert some of the money from the development of ever more toxic compounds to the study of the effects of these chemicals and to the study of natural and non-toxic solutions to the problems we face.
The urgency of Carson's appeal is further established in this chapter on the waters of the world. The dominant note of the chapter is voiced at its end. Scientists don't know what the affects of all this poison will be in the future. They don't have any way to measure what the chemicals are when they've passed through their primary use and have traveled through the water, mixing with other chemicals, to reach the ocean. They are seriously under funded in their efforts to find out and at the same time, chemical research money goes to the development of more and more toxic chemicals.
Clapsaddle, Diane. "TheBestNotes on A Long Way Gone".
TheBestNotes.com.
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