Silent Springs Rachel Carson

1. Silent SpringsRachel Carson Michael Crawley Anup Shah April Quijano

2. Chapter 9: Rivers of Death • The spraying of DDT and other insecticides in ecosystems has caused many disturbances and problems in organisms communities.

3. Rivers of DeathThe Salmon and the Spruce Budworm • In 1953, salmon returned to the Miramichi River located in New Brunswick, Canada, in order to deposit eggs. • Coniferous forests of spruce and balsam trees provide the kind of grounds needed for salmon to survive. • Along with the hatched salmon in the spring of 1954, salmon one or two years old swam in the Miramichi searching for various insects to feed on. In the summer, it was a struggle for these fish to find any source of food. • The watershed of the Northwest Miramichi was included in a vast spraying program designed to save the forests from the spruce budworm. • The budworm is a native insect that attacks many kinds of evergreen. It seems to be abundant every 35 years in Eastern Canada and there was an upsurge in budworm populations in the 1950’s.

4. Rivers of DeathThe Salmon and the Spruce Budworm (cont.) • Spraying with DDT had begun in order to combat the budworm. First the spraying began in a small way and then at an accelerated rate in 1953. • Millions of acres of forests were sprayed instead of thousands as before, in an effort to save the balsams which are the main producer for the paper industry. • In 1954, planes were sent to spray the Northwest Miramichi with one-half pound of DDT per acre. The pilots did not avoid the streams or turn of the spray nozzles while passing over the areas of water. • Within two days after the spraying, dead and dying fish, including many young salmon, were found along the banks of the stream. Brook trout also were found dead and birds were spotted dead on roads and in the woods. • Before the spraying the stream contained caddis fly larvae, stonefly nymphs, and blackfly larvae, which all are the diet of young salmon but all of these insects were killed due to the DDT spraying. Therefore, the salmon had no source of food after the spraying. • The salmon born in the spring were all killed due to the insecticides. For every six young of the 1953 hatch that had foraged in the stream, only one remained. The salmon of the 1952 hatch lost a third of their population as well. • At this time the salmon had a Type 3 survivalship curve. This meant that the salmon had very high death rates for the young and had only a few survive.(52.1) • The DDT acted as an abiotic factor that greatly effected the flow of a food chain which resulted in the death of the salmon. • The DDT spraying interrupted the repeated reproduction of salmon during salmon season. (52.2)

5. Rivers of DeathThe Salmon and the Spruce Budworm (cont.) • The Fisheries Research Board of Canada conducted a survey that showed more than a loss of fish; it revealed a serious change in the streams themselves. • The repeated sprayings completely altered the stream environment, and the aquatic insects that are the food of salmon and trout had been killed. • A lot of time is needed to for most of the insects to build up sufficient numbers to support a normal salmon population - time measured in years rather than months. • In order to supply natural food, Canadians tried to transplant caddis fly larvae, but these larvae would be destroyed if another spraying occurred. • The budworm populations did not decrease after the spraying and this led to sprayings from 1955 to 1957 in New Brunswick with some places being sprayed 3 times. By 1957, nearly 15 million acres had been sprayed. • In 1954, a tropical storm hit Canada and salmon were drawn in from the ocean. There was an abundance of eggs in 1955 due to the storm in 1954 and the young salmon were able to live because of the number of midgies and blackflies. Unfortunately, the older salmon got killed off by the spraying in 1954

6. Rivers of DeathThe Salmon and the Spruce Budworm (cont.) • In all sprayed streams, young salmon of every size are scarce. In the main Southwest Miramichi, which was sprayed in 1956 and 1957, the 1959 catch was the lowest in a decade. • In 1959, the whole Miramichi watershed produced only 600,000 smolt (young salmon descending to the sea). This was less than a third of the runs of the three preceding years.

7. Rivers of DeathSpraying in the United States • The spraying of DDT also took place in Maine in order to stop the spread of forest insects. The spraying did not display a major hurt to the salmon of Maine, but instead to other fish in 1958. • A study found that moribund suckers were showing signs of DDT poisoning; they swam erratically, gasped at the surface, and exhibited tremors and spasms. • In the first 5 days of spraying, 668 dead suckers were collected and minnows and trout were also killed. • In 1955, Yellowstone National Park was sprayed which greatly affected the fish population. About 90 miles of rivers were affected and in a 300 yard length, 600 dead fish were counted, including brown trout, whitefish, and suckers. • Even with these results, Forest Service officials stated that it was safe to spray one pound of DDT to the acre. • Montana Fish and Wildlife Service studied the death and discovered that the insecticide was very harmful to the fish and wildlife. • Control of the budworm had not even been achieved after all of this spraying. • Despite the precautions taken to try to help reduce risks of spraying, 100 percent of the salmon in four streams was killed.

8. Rivers of DeathAlternate Methods to Spraying • There are cases on record where natural parasitism has kept the budworm under control more efficiently than spraying. • There are possibilities of using less toxic sprays which include using microorganisms that will cause disease among the budworms without affecting the whole web of forest life. • It is important to realize that chemical spraying of forest insects is neither the only way nor the best way.

9. Rivers of DeathPesticide Threat to Fishes • One threat of spraying is to the fishes of running streams in northern forests and to the single problem of forest spraying. • Another is vast, sprawling, and diffuse, for it concerns the many kinds of fishes: bass, sunfish, crappies, suckers, and others. • Fish are most sensitive to chlorinated hydrocarbons which make up most of the modern insecticides. • Reports of fish kills, some of disastrous proportions, have now become so common that the United States Public Health Service has set up an office to collect such reports from the states.

10. Rivers of DeathEconomic Affects • 40 million Americans look to fishing as a major source of recreation and they spend 3 billion dollars annually. • Anything that deprives them of their sport will reach out and affect a large number of economic interests. • The commercial fisheries need fish in order to produce food. Inland and coastal fisheries yield an estimated 3 billion bounds a year. • The spraying of pesticides is now a threat to both recreational and commercial fishing

11. Rivers of DeathDestruction of Fish • Agricultural crop sprayings are everywhere to be found. • In California, the loss of 60,000 game fish followed an attempt to control the rice leaf miner with dieldrin. • In Louisiana, 30 or more instances of heavy fish mortality occurred in one year alone because of the use of endrin on sugarcane fields. • The use of heptachlor in the southern U.S. was for fire ants. This chemical killed thousands of fish in the south. This led to a halt in aerial spraying. • Toxaphene was used to kill cotton insects but ended up killing hundred of fish due to chemicals washed into the rivers by rain.

12. Rivers of DeathDestruction of Fish (cont.) • In 1961 , Austin, Texas, was shocked to see dead fish for nearly 200 miles. • Texas Game and Fish Commission discovered that the chemicals killing all of the fish were coming form a chemical plant. • The manager of the plant knew that they were disposing chemicals into storm sewers and they had been doing this for the past 10 years. • 27 different species of fish were observed, about 1000 pounds to a mile of riverbank. • Florida salt marshes were sprayed with dieldrin and the results were catastrophic. The Entomology Research Center of the State Bored of Health stated that 1,175,000 fish died of 30 species. • Pesticides are also a threat to shrimp fisheries. The insecticide tolerance for shrimp was found to be very low by the Bureau of Commercial Fisheries especially at a young age. • Clams and oysters are vulnerable to pesticides too.

13. Chapter 10: Indiscriminately from the Skies People have had misgiving about aerial sprayings because of two programs: The gypsy moth program in Northern parts of the United States and the Fire Ant program in the Southern parts of the United States.

14. Indiscriminately from the SkiesGypsy Moth (cont.) • A few individuals from this species had escaped in 1869 from a laboratory in Massachusetts. It had spread in the North mainly due to wind. The Adirondacks have served as a barrier to stop the gypsy moths from spreading towards the rest of the US. • The above statement is an example of dispersal which is the moving of individuals away from their area of origin. (50.2) • Before the aerial spraying programs started, 13 predators and parasites were imported from outside the US. Along with that and local spraying, achieved praises from the Department of Agriculture in 1955. • Gypsy moths are ectoparasites which means they feed off the external surface of the host. (53.1)

15. Indiscriminately from the SkiesGypsy Moth (cont.) • In 1956, a program was started to eradicate the gypsy moth, despite protests against citizens. It covered a million acres in Pennsylvania, New Jersey, and New York. It included New York City and Long Island, two areas where gypsy moths would not normally live (their normal habitat is forests, not fields, marshes, and cities). Spray planes had been paid by the gallon than by acre, and many properties were sprayed several times. • Animals and fields had been contaminated. This made it harder for farmers to sell their farm produce since the FDA prohibits no residues in milk. Leaf crops were also burned and spotted, which hurt truck gardeners. • After 1957, the spraying programs was curtailed, and the area sprayed had decreased to 100 acres in 1959, 1960, and 1961. People could not sue against the firm who handled the spraying since it was out of state, had no local address, and did not register with state officials.

16. Indiscriminately from the SkiesFire Ant • Named for its fiery sting, it was first found in Mobile, Alabama shortly after WWI. By 1928, it had spread to the suburbs of Mobile and started to invade the rest of the Southern states. • Before 1957, it was not considered a threat, but rather as a nuisance, because of the large nests it tends to built. Also, it was proved to be helpful since it preyed on harmful insects. • In 1957, the Department of Agriculture launched a propaganda program to get supporters for their spraying program against the fire ant. The program mainly showed the fire ant as a dangerous insect which spoils crops and kills living organisms. • Because of the program, wildlife in the sprayed area became devastated. For example opossums, armadillos, and raccoon had disappeared in Hardin County, Texas. Populations of the bob-white quail and wild turkey were decimated. Woodcocks were found to have up to 20 parts per million of heptachlor 6 months after. A two moth calf was tested by a scientist by Dr. Pointevint, and was found to have 79 parts per million of heptachlor in its fat. • The above bullet is an example of biological magnification. Toxins such as insecticides become more concentrated in the fat tissues of an organism in a successive tropic levels of a food web. (54.5)

17. Indiscriminately from the SkiesFire Ant (cont.) • After three years, the rate of application went down to ¼ a pound. Also, to offset the dissatisfaction with the program, the Agriculture Department offered free chemicals to farmers in exchange for them taking responsibility for their damage. Alabama had stopped funding the program, and farmers in Louisiana gradually showed reluctance to sign up for the program.