Absolute Population Estimates by Sampling a Unit of Aquatic Habitat

Methods for quantitative sampling of open marine and freshwaters are described, including fishing nets, plankton nets, pump samplers, the Patalas–Schindler volume sampler, and specialized methods for freshwater insects. Specialist methods for sampling freshwater floating, emergent, and submerged vegetation are described. Methods for quantitatively sampling the bottom fauna in the various substrates found in streams, rivers, lakes, and the sea bed are reviewed. The use of various poisons and anaesthetics for sampling fish are described.

Qualitative Sampling Methods

Qualitative sampling methods differ from quantitative sampling methods. It is important that one understands those differences, as well as, appropriate qualitative sampling techniques. Appropriate sampling choices enhance the rigor of qualitative research studies. These types of sampling strategies are presented, along with the pros and cons of each. Sample size and data saturation are discussed.