Bioaccumulation & Biomagnification (College Board AP® Environmental Science): Exam Questions

Which of the following substances is least likely to bioaccumulate in organisms?

Read the passage below and answer the following question:

Toxic substances such as mercury, polychlorinated biphenyls (PCBs), and pesticides like DDT can accumulate in organisms through a process known as bioaccumulation. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than it can be metabolized or excreted. Over time, these substances build up in the tissues of the organism, often stored in fat deposits.

As these toxic substances move through the food chain, a phenomenon called biomagnification occurs. Biomagnification refers to the increasing concentration of a substance in organisms at higher trophic levels. For example, plankton in contaminated water may absorb mercury. Small fish that feed on the plankton accumulate higher concentrations of mercury in their tissues. Predatory fish that consume multiple small fish further increase their mercury levels. Finally, top predators, such as eagles or humans, who consume contaminated fish, may experience dangerously high toxin levels, leading to severe health effects, including neurological damage and reproductive issues.

Factors influencing bioaccumulation and biomagnification include the chemical properties of the toxin (such as solubility and persistence), the feeding relationships within an ecosystem, and the lifespan of organisms. Persistent organic pollutants (POPs), such as PCBs, do not easily degrade in the environment, allowing them to remain in food webs for decades. Some species are more vulnerable to these effects due to their high-fat content, long lifespan, or position in the food chain.

In coastal ecosystems, marine mammals like seals and whales often exhibit high levels of biomagnification due to their diet of contaminated fish. In terrestrial ecosystems, apex predators such as eagles and large cats may also suffer from toxin buildup. In some cases, bioaccumulation has led to population declines, as seen in the thinning of bird eggshells due to DDT exposure, which contributed to the near-extinction of species like the bald eagle and peregrine falcon.

Governments and environmental organisations have taken steps to limit exposure to bioaccumulative toxins. The banning of DDT in the 1970s and international agreements such as the Stockholm Convention on Persistent Organic Pollutants have helped reduce some of the most harmful effects. However, many toxic substances still persist in the environment, posing risks to both wildlife and humans.

Why do persistent organic pollutants like PCBs pose a long-term risk in ecosystems?

Read the passage below and answer the following question:

Toxic substances such as mercury, polychlorinated biphenyls (PCBs), and pesticides like DDT can accumulate in organisms through a process known as bioaccumulation. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than it can be metabolized or excreted. Over time, these substances build up in the tissues of the organism, often stored in fat deposits.

As these toxic substances move through the food chain, a phenomenon called biomagnification occurs. Biomagnification refers to the increasing concentration of a substance in organisms at higher trophic levels. For example, plankton in contaminated water may absorb mercury. Small fish that feed on the plankton accumulate higher concentrations of mercury in their tissues. Predatory fish that consume multiple small fish further increase their mercury levels. Finally, top predators, such as eagles or humans, who consume contaminated fish, may experience dangerously high toxin levels, leading to severe health effects, including neurological damage and reproductive issues.

Factors influencing bioaccumulation and biomagnification include the chemical properties of the toxin (such as solubility and persistence), the feeding relationships within an ecosystem, and the lifespan of organisms. Persistent organic pollutants (POPs), such as PCBs, do not easily degrade in the environment, allowing them to remain in food webs for decades. Some species are more vulnerable to these effects due to their high-fat content, long lifespan, or position in the food chain.

In coastal ecosystems, marine mammals like seals and whales often exhibit high levels of biomagnification due to their diet of contaminated fish. In terrestrial ecosystems, apex predators such as eagles and large cats may also suffer from toxin buildup. In some cases, bioaccumulation has led to population declines, as seen in the thinning of bird eggshells due to DDT exposure, which contributed to the near-extinction of species like the bald eagle and peregrine falcon.

Governments and environmental organisations have taken steps to limit exposure to bioaccumulative toxins. The banning of DDT in the 1970s and international agreements such as the Stockholm Convention on Persistent Organic Pollutants have helped reduce some of the most harmful effects. However, many toxic substances still persist in the environment, posing risks to both wildlife and humans.

Which of the following organisms in an aquatic food chain would likely have the highest concentration of mercury?

Read the passage below and answer the following question:

Toxic substances such as mercury, polychlorinated biphenyls (PCBs), and pesticides like DDT can accumulate in organisms through a process known as bioaccumulation. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than it can be metabolized or excreted. Over time, these substances build up in the tissues of the organism, often stored in fat deposits.

As these toxic substances move through the food chain, a phenomenon called biomagnification occurs. Biomagnification refers to the increasing concentration of a substance in organisms at higher trophic levels. For example, plankton in contaminated water may absorb mercury. Small fish that feed on the plankton accumulate higher concentrations of mercury in their tissues. Predatory fish that consume multiple small fish further increase their mercury levels. Finally, top predators, such as eagles or humans, who consume contaminated fish, may experience dangerously high toxin levels, leading to severe health effects, including neurological damage and reproductive issues.

Factors influencing bioaccumulation and biomagnification include the chemical properties of the toxin (such as solubility and persistence), the feeding relationships within an ecosystem, and the lifespan of organisms. Persistent organic pollutants (POPs), such as PCBs, do not easily degrade in the environment, allowing them to remain in food webs for decades. Some species are more vulnerable to these effects due to their high-fat content, long lifespan, or position in the food chain.

In coastal ecosystems, marine mammals like seals and whales often exhibit high levels of biomagnification due to their diet of contaminated fish. In terrestrial ecosystems, apex predators such as eagles and large cats may also suffer from toxin buildup. In some cases, bioaccumulation has led to population declines, as seen in the thinning of bird eggshells due to DDT exposure, which contributed to the near-extinction of species like the bald eagle and peregrine falcon.

Governments and environmental organisations have taken steps to limit exposure to bioaccumulative toxins. The banning of DDT in the 1970s and international agreements such as the Stockholm Convention on Persistent Organic Pollutants have helped reduce some of the most harmful effects. However, many toxic substances still persist in the environment, posing risks to both wildlife and humans.

Which factor most contributes to biomagnification in apex predators?

Read the passage below and answer the following question:

Toxic substances such as mercury, polychlorinated biphenyls (PCBs), and pesticides like DDT can accumulate in organisms through a process known as bioaccumulation. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than it can be metabolized or excreted. Over time, these substances build up in the tissues of the organism, often stored in fat deposits.

As these toxic substances move through the food chain, a phenomenon called biomagnification occurs. Biomagnification refers to the increasing concentration of a substance in organisms at higher trophic levels. For example, plankton in contaminated water may absorb mercury. Small fish that feed on the plankton accumulate higher concentrations of mercury in their tissues. Predatory fish that consume multiple small fish further increase their mercury levels. Finally, top predators, such as eagles or humans, who consume contaminated fish, may experience dangerously high toxin levels, leading to severe health effects, including neurological damage and reproductive issues.

Factors influencing bioaccumulation and biomagnification include the chemical properties of the toxin (such as solubility and persistence), the feeding relationships within an ecosystem, and the lifespan of organisms. Persistent organic pollutants (POPs), such as PCBs, do not easily degrade in the environment, allowing them to remain in food webs for decades. Some species are more vulnerable to these effects due to their high-fat content, long lifespan, or position in the food chain.

In coastal ecosystems, marine mammals like seals and whales often exhibit high levels of biomagnification due to their diet of contaminated fish. In terrestrial ecosystems, apex predators such as eagles and large cats may also suffer from toxin buildup. In some cases, bioaccumulation has led to population declines, as seen in the thinning of bird eggshells due to DDT exposure, which contributed to the near-extinction of species like the bald eagle and peregrine falcon.

Governments and environmental organisations have taken steps to limit exposure to bioaccumulative toxins. The banning of DDT in the 1970s and international agreements such as the Stockholm Convention on Persistent Organic Pollutants have helped reduce some of the most harmful effects. However, many toxic substances still persist in the environment, posing risks to both wildlife and humans.

What was one major ecological consequence of DDT exposure?

Read the passage below and answer the following question:

Toxic substances such as mercury, polychlorinated biphenyls (PCBs), and pesticides like DDT can accumulate in organisms through a process known as bioaccumulation. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than it can be metabolized or excreted. Over time, these substances build up in the tissues of the organism, often stored in fat deposits.

As these toxic substances move through the food chain, a phenomenon called biomagnification occurs. Biomagnification refers to the increasing concentration of a substance in organisms at higher trophic levels. For example, plankton in contaminated water may absorb mercury. Small fish that feed on the plankton accumulate higher concentrations of mercury in their tissues. Predatory fish that consume multiple small fish further increase their mercury levels. Finally, top predators, such as eagles or humans, who consume contaminated fish, may experience dangerously high toxin levels, leading to severe health effects, including neurological damage and reproductive issues.

Factors influencing bioaccumulation and biomagnification include the chemical properties of the toxin (such as solubility and persistence), the feeding relationships within an ecosystem, and the lifespan of organisms. Persistent organic pollutants (POPs), such as PCBs, do not easily degrade in the environment, allowing them to remain in food webs for decades. Some species are more vulnerable to these effects due to their high-fat content, long lifespan, or position in the food chain.

In coastal ecosystems, marine mammals like seals and whales often exhibit high levels of biomagnification due to their diet of contaminated fish. In terrestrial ecosystems, apex predators such as eagles and large cats may also suffer from toxin buildup. In some cases, bioaccumulation has led to population declines, as seen in the thinning of bird eggshells due to DDT exposure, which contributed to the near-extinction of species like the bald eagle and peregrine falcon.

Governments and environmental organisations have taken steps to limit exposure to bioaccumulative toxins. The banning of DDT in the 1970s and international agreements such as the Stockholm Convention on Persistent Organic Pollutants have helped reduce some of the most harmful effects. However, many toxic substances still persist in the environment, posing risks to both wildlife and humans.

Which of the following would be the most effective strategy to reduce biomagnification in an aquatic ecosystem?