The passage describes the ecological impacts of organic pollution and eutrophication in a freshwater stream. Complete the passage by writing a suitable word or words in each of the spaces.

The discharge of concentrated organic slurry from an intensive dairy farm into a freshwater stream triggers a cascade of ecological changes. Rainwater washes these pollutants from the fields into the stream channel by the process of [1] $\text{\_________________}$ . The slurry is rich in inorganic mineral ions, notably [2] $\text{\_________________}$ , which stimulate the rapid growth of [3] $\text{\_________________}$ near the surface of the water, forming a dense mat that blocks light.

Additionally, the slurry contains high amounts of organic nitrogenous waste, such as [4] $\text{\_________________}$ . Saprobiotic [5] $\text{\_________________}$ feed on this organic matter, multiplying rapidly. As these decomposers carry out aerobic [6] $\text{\_________________}$ , they severely deplete the concentration of dissolved [7] $\text{\_________________}$ in the water column, causing death of fish and other aerobic aquatic organisms.

The passage describes the ecological impacts of organic pollution and eutrophication in a freshwater stream. Complete the passage by writing a suitable word or words in each of the spaces.

Human influences on the environment

Question 33

Markscheme

Human influences on the environment

Question 33

Markscheme

Human influences on the environment

Question 33

Human influences on the environment Questions

Human influences on the environment

Question 33

Human influences on the environment Questions