Research methods for freshwater animals

This chapter reviews general considerations and procedures for the capture and handling of freshwater animals, including fish, reptiles, amphibians and mammals. The study of freshwater animals can range from observational studies to sophisticated capture-based research where animals are released after observations, held for other procedures or euthanased. Investigators can use the general operating procedures (GOPs) described in this chapter as a guide while also drawing on their own and other experienced researchers’ knowledge and skills to develop detailed project-specific protocols. Protocols for field monitoring and sampling procedures for freshwater animals are also described in other documents, which can be considered in tandem with the GOPs presented here. For example, DES (2018) describes procedures for sampling fish with a range of equipment types in Queensland, DPI (2015) provides a guide for acceptable procedures and practices in fish research in New South Wales, and DSEWPC (2011) outlines national survey guidelines for Australian threatened fish. Methods for biological sampling, tagging, transport and handling of freshwater fishes are similar to the corresponding methods for marine and estuarine fishes (see Chapter 13), so are not reiterated in this chapter. Researchers need to ensure that the biological requirements of their particular study species are met. Additional considerations specific to freshwater fishes are provided in Chapter 32. Other chapters that are also relevant to freshwater research, include Chapter 4 (eDNA monitoring), Chapter 12 (tagging and identification of marine mammals), and Chapter 16 (veterinary procedures). Methods for capturing and monitoring aquatic birds are detailed in Chapters 15 and 35, and crustaceans in Chapter 28.