What is a common method for sampling aquatic organisms in a lake?

Net sampling is a widely used method for collecting aquatic organisms in a lake because it effectively captures a variety of species, including fish, invertebrates, and phytoplankton. This method typically involves using different types of nets, such as seine nets, cast nets, or plankton nets, depending on the target organisms and the specific environment.

By deploying nets at different depths or in various habitats within the lake, researchers can obtain a representative sample of the aquatic community present. This sampling technique is essential for understanding the biodiversity of the lake, assessing the health of the ecosystem, and providing data for management practices.

The other methods mentioned, while useful in certain contexts, do not specifically target the collection of live aquatic organisms in the same effective manner as net sampling. Sounding primarily measures the depth of the water body, core sampling is used for studying sediments rather than live organisms, and three-dimensional mapping focuses on the physical layout and structure of the underwater environment rather than direct organism collection.