An aquatic ecologist wanted to investigate the concentration of microplastic fibers in the digestive tracts of two predatory fish species, brown trout (Salmo trutta) and European perch (Perca fluviatilis), within a national park's lake system. The researcher randomly selected 8 lakes from the 12 major lakes in the park. Only 6 of these 8 selected lakes were granted access permits for scientific gillnetting. From each of these 6 permitted lakes, the researcher captured and analyzed the stomach contents of 12 brown trout and 12 European perch.
Identify the sample used by the researcher in this study.
689 exam-style questions on AQA A Level Psychology Scientific processes. Each one has a worked solution and a mark scheme showing where the marks go.