An ecology textbook states: "An estuary is a dynamic coastal transition zone where freshwater from rivers mixes with saltwater from the sea. This environment supports a diverse range of organisms, including crabs, saltmarsh grasses, and migratory birds. The fluctuating salinity levels and tidal currents heavily influence which organisms can thrive in different zones of the estuary."
Which of the following terms applies to this description of the estuary?
a community
an ecosystem
a habitat
a niche
37 exam-style questions on OCR A A Level Biology Ecosystems. Each one has a worked solution and a mark scheme showing where the marks go.