9.4 Human Influences on the Environment

Draw a ring around the most appropriate word from each of the square brackets to complete the sentence. 

Which of A - D is most likely to lead to a biodiverse ecosystem?

Figure 1 shows a food web from a marine ecosystem.

Figure 1

Using one example from Figure 1, describe the effect on this ecosystem if the fish were removed by human activity (too much commercial fishing).

Identify the producer species in Figure 1.

Which of the factors A - D is not likely to have a negative impact on biodiversity of the marine ecosystem shown in Figure 1?

Figure 1 shows how the production of fish from fish farms has changed between 1950 and 2010.

Figure 1

Describe the trend shown in Figure 1

(1)

Suggest an explanation for the trend described in part (i)

(2)

Describe how fish farming methods ensure maximum yield.

Fish farms are sometimes responsible for eutrophication due to excess nutrients which leak into the surrounding ecosystems. 

Explain how these excess nutrients can lead to eutrophication in the surrounding ecosystems.

Sometimes fish from fish farms may escape into the nearby waterways with negative impacts on the native species in the surrounding ecosystems.

Identify two possible negative impacts of non-indigenous species.

State the term given for the introduction of new diseases by non-indigenous species to a native population.

Complete Table 1 below by identifying whether the given scenario describes a competition effect on native species caused by a non-indigenous species.

Table 1

List, in order, the stages of eutrophication, starting from the runoff of fertilisers and ending with the decrease in dissolved oxygen.

Give two consequences of the increasing demand for land to sustain the growing human population.