Chapter 50Chapter 50Ecology & The Ecology & The BiosphereBiosphere

By: Justin Martinez, By: Justin Martinez, Izabela Kolodziejska, Anne Izabela Kolodziejska, Anne Simonetti, Ashley Davis Simonetti, Ashley Davis

Ecology and evolutionary biology are closely related sciences. Events that occur in the framework of ecological time (minutes, months, and years) will translate into effects over the longer scale of evolutionary time ( decades, centuries , millennia).

In Silent Spring, Rachel Carson writes about the shocking and dangerous reduction of all the earth’s natural resources for balancing insect populations. She recognized that chemical poisoning kills insects only for a short span of time; the insects will begin the develop resistance to these chemicals, an evolutionary effect. The chemicals kill the natural predators of the insects and allow insects to grow greater and greater in number.

Ecology is the study of interactions between organisms and their environment. Rachel Carson shows her readers that in an environment one poisoned creature could upset the whole system.

Carson states “In this unseen world, minute causes produce mighty effects.”

A population is a group of individuals of the same species living in a particular geographic area. Population ecology focuses on factors that affect how many individuals of a particular species live in an area. A community contains all the organisms of all the species that inhabit a particular area.

Throughout Silent Spring, Rachel Carson discusses various populations and communities that were affected greatly by the use of pesticides. The massive spraying operations had caused most of the bird population to die. These birds were killed in massive number because the birds ate the insects and worms that contained DDT. The salmon population of the Miramichi river community was also greatly affected by a massive spraying campaign that was supposed to kill off the spruce budworm that was threatening forest life. A massive amount of the salmon population was killed by these pesticides. The whole river community was affected. Even the salmon that weren’t killed were affected since their food was killed.

The environment of any organism includes abiotic and biotic components. Abiotic components are nonliving components such as temperature, light, water, and nutrients. Biotic components are living components including all organisms.

In her book, Rachel Carson writes about the affects of the insecticides on abiotic and biotic components.

An abiotic component that was affected, for example, was water. The use of pesticides caused water pollution. The chemicals from these pesticides were washed into bodies of water and seeped into the soil.

Carson tell us that “it is not possible to add pesticides to water anywhere without threatening the purity of water everywhere.”

Biotic components were also affected by the pollution of the groundwater. An example of this in the book is when poisonous chemicals flowed through the groundwater from a manufacturing plant in Colorado to a farming district. The wells became poisoned, thus causing the death of animals and crops.

Environmentalism is advocating for the protection or preservation of the natural environment. We need to understand the complicated relationships between organisms and the environment in order to address environmental problems. These relationships could be understood through the science of ecology. 

In 1962, our society became aware of certain environmental issues through Rachel Carson’s Silent Spring. Rachel Carson warned the public that the widespread use of pesticides caused population declines in many organisms that were non-target species. These pesticides contaminated soil, water, and food.

Carson’s says “the control of nature is a phrase conceived in arrogance born of the Neanderthal age of biology and philosophy, when it was supposed that nature exists for the convenience of man”.

Interactions between organisms and the environment

limit the distribution of species … Biotic Factors In Silent Spring by Rachel Carson, DDT and other

insecticides were the cause of countless deaths amongst flourishing species.

The insecticides would poison the animals once they encountered the deadly chemicals, attacking their nervous systems and causing them to die slowly from the outrageous amounts of poison that their bodies took in.

The insecticides were somewhat like what a disease would do if it were naturally occurring and not introduced by man. Like a disease, the insecticides caused the rapid deaths of animals, and the unstoppable spreading of these life threatening chemicals through the interaction of species with one another. The insecticides caused a mass disturbance, which is a force that changes a biological community and usually removes organisms from it.

An example in the book where insecticides portray a deadly disease that cause life long effects occurs when Endrin was used to have a house sprayed for cockroaches. The child was removed from the house during the spraying of the chemical. The house was then cleaned and the child was taken back inside the house. The child went into convulsions and lost consciousness causing him to go into a vegetative state permanently.

S o I lSoil limits the distribution of plants and

thus of the animals that feed upon them. In streams and rivers, the composition of the substrate can affect water chemistry, which in turn influences the resident organisms.

Soil is created from living and non-living things. Without it land plants wouldn’t exist, and without plants animals wouldn’t survive.

Insecticides damage the soil and prevent it from following through with vital processes; one of these being nitrification which makes nitrogen in the air available to plants to help them grow.

Insecticides also alter the soil by killing off certain organisms while allowing the organisms who survive to ultimately become over populated and pestilences.

Pesticides remain in the soil for up to twelve years after one spraying; therefore after countless sprayings it is almost impossible to remove the chemicals from the soil, which contaminates the crops growing in this soil.

Water-The dramatic variation in water availability among habitats is another important factor in species

distribution. Freshwater and marine organisms live submerged in aquatic environments, but most are restricted to either freshwater or saltwater habitats by their limited ability for osmoregulation. Water is essential for the well-being of all organisms, and in Rachel Carson’s Silent Spring, the gruesome effects of radioactive wastes, nuclear explosions, domestic waste, and chemical sprays are shown.

-Because chemical sprays are carried through the air from forest spraying, or seep into nearby rivers and streams, water is contaminated, causing the innumerable deaths of fish and other species living in these waters. Chemicals were found stored in the fat of fishes.

-Ground water is the most disturbing case of all. Ground water comes from rain fall that settles in the earth and creates its own underground sea. This water is contaminated with chemicals, thus poisoning the earth and whatever streams and rivers it enters. All the water on earth was once ground water, therefore all the water on earth is being affected by pesticides.

-An example of this was when the Rocky Mountain Arsenal of the Army Chemical Cops, located near Denver, began to manufacture war materials. Eight years later the facilities of the arsenal were leased to a private oil company for the production of insecticides. After this, mysterious reports came in stating that farmers several miles away from the plant began to report unexplained sickness among livestock and crop damage. The irrigation waters on these farms were derived from shallow wells. When the well waters were examined they were found to contain an assortment of chemicals including 2,4-D, thus explaining the mysterious events happening on near by farms.

-A second example includes the case of Clear Lake where DDD was dumped into the lakes to stop gnats and other unwanted organisms in or around the lake. The pesticide was stored in all the animals of lake from plankton to birds. Species were dying off rapidly and the chemical couldn’t be detected because it had gone into “the fabric of life the lake supports.” Twenty-three months went by, and still the chemical was still present in plankton.

• As previously mentioned, Rachel Carson brings up the problem of water pollution by pesticides in her novel Silent Spring.

90% of wetlands have been destroyed in some regions due to draining and filling.

Many lakes are now faced with algal blooms, oxygen deletion, and fish kills because pollution

by runoff from fertilized land and dumping of wastes.

Filling, dredging, and pollution from upstream have disrupted estuaries worldwide.

Pollution of our waterways comes from laboratories, reactors, and hospitals that release radioactive wastes. Chemical wastes are discharged from factories and domestic wastes are yielded from towns and cities. Chemical spraying, as Carson writes, has added more chaos to this mess.

“The human race is too ingenious for its own good … Man has acquired the power to alter the nature of his own world.”

-Rachel Carson