Why does DDT magnify within food chains when certain other chemicals do not?

Explanation: DDT increases or biomagnifies if we look at a food chain. DDT is fat-soluble, meaning animals store it in fatty tissues. It also takes a relatively long amount of time to break down.

How does DDT become magnified through a food chain?

When an animal consumes food having DDT residue, the DDT accumulates in the tissue of the animal by a process called bioaccumulation. The higher an animal is on the food chain (e.g. tertiary consumer such as seals), the greater the concentration of DDT in their body as a result of a process called biomagnification.

Why does DDT become more concentrated higher in the food chain?

The concentration effect occurs because DDT is metabolized and excreted much more slowly than the nutrients that are passed from one trophic level to the next. So DDT accumulates in the bodies (especially in fat).

Is DDT subject to biomagnification?

DDT is thought to biomagnify and biomagnification is one of the most significant reasons it was deemed harmful to the environment by the EPA and other organizations. DDT is stored in the fat of animals and takes many years to break down, and as the fat is consumed by predators, the amounts of DDT biomagnify.

How does the concentration of DDT change as you move to higher trophic levels?

Correct answer is B. “Higher trophic levels have higher concentrations of DDT”. The general trend is an upward slope, or a positive correlation. As the trophic level increases, the concentration of DDT is higher.

Biomagnification and the Trouble with Toxins

How does DDT move through food chain eventually harming bald eagles?

Larger fish ate the smaller fish and acquired the DDT molecules in their tissues. Eventually, bald eagles ate the larger fish with the DDT and DDT built up even more in the eagle's body tissues. This caused the eagle's egg shells to become soft and easily breakable, limiting their reproductive capacity.

What is the impact of DDT on birds and other higher trophic level organisms?

Rather, DDT and its relatives alter the bird's calcium metabolism in a way that results in thin eggshells. Instead of eggs, heavily DDT-infested Brown Pelicans and Bald Eagles tend to find omelets in their nests, since the eggshells are unable to support the weight of the incubating bird.

What is DDT in food chain?

Dichlorodiphenytrichloroethane (DDT) is an organochlorine insecticide with a broad spectrum of activities such as the control of pest in forest and on agricultural crops, household pests, vector-borne diseases like malaria, typhus, etc.

How does DDT work as a pesticide?

What is the mechanism of action of DDT? DDT affects the nervous system by interfering with normal nerve impulses (2). DDT causes the nerve cells to repeatedly generate an impulse which accounts for the repetitive body tremors seen in exposed animals (2).

Is DDT biologically active?

To put these concentrations in perspective, consider that DDT is not biologically very active or even very toxic. Its great value in malaria control is due to its persistence on house walls and its powerful repellent actions, not its toxicity. As with all living organisms, insects live in a chemical world.

Where is the highest concentration of DDT?

The highest amount of DDT and derivatives residues were found in carnivore fish species, C. striatus which is the top predator of food web. In contrast, the lowest residue levels of DDT and derivatives were found in the omnivores, P. gonionotus.

What is the reason for biomagnification?

Causes of Biomagnification

The agricultural pesticides, insecticides, fertilizers and fungicides are very toxic and are released into the soil, rivers, lakes, and seas. These substances contain small amounts of heavy metals such as mercury, arsenic, copper, lead and cadmium.

What are the causes of biological magnification?

How does DDT affect the aquatic food chain?

It is present in low amount in water and reaches a high concentration in fish-eating birds through biomagnification. Very high concentrations of DDT disturb calcium metabolism in birds, which causes thinning of eggshell and their premature breaking, eventually causing decline in bird populations.

What effect did DDT have on birds specifically Raptors?

Chemicals like DDT interfered with the reproductive cycle of raptors. The poison built up in the falcons' bodies as they ate birds that, in turn, had eaten insects and plants contaminated with the chemicals. The result was diminished fertility, plus eggs with shells so thin, they broke under the parent's weight.

What is DDT biomagnification?

Biomagnification happens when toxic chemicals, like DDT, whose remains in the environment are consumed indirectly by organisms through food. When an organism in the higher food chain consumes the lower organism containing such chemicals, the chemicals can get accumulated in the higher organism.

Why is DDT stable?

DDT is highly environmentally stable with a reported half-life of between 2 and 15 years. The insecticide is immobile in most soils and loss is the result of runoff, volatilization, photolysis, and biodegradation.

What enzyme does DDT target?

DDT is known as a non-genotoxic hepatocarcinogen and has been shown to induce microsomal enzymes through activation of constitutive androstane receptor (CAR) and to inhibit gap junctional intercellular communication (GJIC) in the rodent liver.

Which one shows the least magnification of DDT in aquatic food chain?

Phytoplanktons are the producers in the food chain having the least amount of toxicant DDT, as we move to the successive trophic levels the amount of DDT increases. It becomes maximum in the fish-eating birds (DDT 25 ppm).

How do chemicals affect the food chain?

Environmental toxins, like the chemicals sprayed on food crops, are absorbed by the plants, the primary producers. The toxins we should be most concerned about are the fat-soluble ones, which includes a lot of common chlorinated pesticides and herbicides.

How do pesticides affect the food chain?

Beyond direct toxicity, pesticides can significantly reduce, change the behavior of, or destroy populations of plants and animals. These effects can ripple up and down food chains, causing what is known as a trophic cascade.

Why is DDT considered an environmental pollutant?

DDT is very insoluble in water and very persistent in the environment, making it a highly polluting hazard. It's half life has been reported to be between 2 and 15 years.

Why do high levels of DDT in birds such as bald eagles and brown pelicans lead to declines in population sizes?

The high concentration of DDT interferes with the calcium metabolism of birds and induces eggshell thinning. Premature breakage. This causes the population to decrease. Additional Information: Bald eagle and other bird populations collapsed as DDT thinned their eggs killing their embryos.

What are the effects of DDT?

Following exposure to high doses, human symptoms can include vomiting, tremors or shakiness, and seizures. Laboratory animal studies showed effects on the liver and reproduction. DDT is considered a possible human carcinogen.

Why is DDT harmful to bald eagles?

The culprit was DDT - a widely used pesticide that, when ingested, prevented the eagles from reproducing successfully by weakening their offsprings' eggshells. The bald eagle population declined and became critically endangered.