Juvenile fish shelter among kelp growing in a coastal bay. Sea urchins feed on the kelp, and sea otters eat the sea urchins.
A group of killer whales entered the bay and began eating sea otters. Scientists collected data before the killer whales arrived and one year later.
| Measurement | Before killer whales arrived | One year after killer whales arrived |
|---|---|---|
| Mean number of sea otters seen per 10 km survey | 16 | 5 |
| Mean sea urchin density per m² | 12 | 31 |
| Mean kelp cover | 78% | 36% |
Using the information and the data, explain how the arrival of the killer whales is likely to affect the number of juvenile fish in the bay.
82 exam-style questions on AQA GCSE Biology 7.1 Adaptations, interdependence and competition, covering 7.1.1 Communities, 7.1.2 Abiotic factors, 7.1.3 Biotic factors, and 7.1.4 Adaptations. Each one has a worked solution and a mark scheme showing where the marks go.