Impact of water pollution：練習題

In many regions, global inequalities in sewage treatment lead to severe health risks. If a community lacks a functional wastewater treatment plant, which of the following is the most likely biological consequence for a downstream population using the river as a primary drinking source?

A lake has been affected by acid rain. If the pH of the lake drops from \( 6.5 \) to \( 4.5 \), which of the following ecological impacts is most expected regarding the diversity of organisms?

The impact of water pollution can extend throughout an entire ecosystem. When toxic substances from industrial processes enter a lake, they may increase in concentration as they move up through different trophic levels.

What is the specific term used to describe this process?

A river system is contaminated with a persistent organic pollutant (POP) that does not break down easily. If the concentration of the pollutant is \( 0.000003 \) ppm in the water, \( 0.04 \) ppm in zooplankton, and \( 2.0 \) ppm in small fish, what is the most likely concentration in a predatory bird that feeds on these fish?

The impact of water pollution on aquatic ecosystems often involves a sequence of biological events. Which of the following explains why acid rain specifically harms fish populations in freshwater lakes?

Explain how the discharge of untreated industrial waste into freshwater systems leads to the accumulation of toxic substances in top predators.

A freshwater lake has experienced a significant decline in its fish population due to acid rain. Describe two specific chemical or biological effects that acid rain has on the water and the organisms within this ecosystem to cause such a decline.

Explain the process of bioaccumulation of toxic industrial substances and its impact on top predators in a freshwater food chain.

A study of a local river recorded the following data regarding nutrient levels and aquatic life:
- Upstream: Nitrate concentration \( 2 \) mg/L; High fish biodiversity.
- Near agricultural run-off point: Nitrate concentration \( 28 \) mg/L; Rapid algae growth.
- Downstream: Nitrate concentration \( 15 \) mg/L; Very low dissolved oxygen; Fish deaths recorded.

(a) Explain the process of nutrient enrichment that leads to the rapid growth of algae observed near the run-off point.
(b) Describe the sequence of biological events that causes the dissolved oxygen levels to decrease downstream.
(c) Explain the concept of bioaccumulation and how the presence of toxic industrial substances in this river could affect top predators in the food chain.

A large freshwater lake near an industrial city has shown a significant decline in its predatory fish population. Monitoring data indicates the presence of heavy metals and high levels of nitrates in the water.

(a) Explain why global inequalities in sewage treatment contribute to the varying impacts of water pollution in different regions of the world.
(b) Describe the process of bioaccumulation and explain why top predators in the lake are more severely affected by industrial heavy metals than the primary consumers.
(c) The high nitrate levels have led to eutrophication. Outline the sequence of events, starting from nutrient enrichment, that leads to the death of aerobic organisms in the lake.