Application of forensic techniques to enhance fish conservation and management: injury detection using presumptive tests for blood

摘要

The detection of injury on the skin of fish has generally been limited to gross macroscopic examination, which has numerous limitations, including researcher subjectivity and a lack of quantitative analytical capacity. The use of chemical enhancers, such as those used by forensic analysts,can aid in the detection and quantification of skin injuries in fish, which can arise from fish interactions with humans and anthropogenic infrastructure (e.g. recreational and commercial fishing, research sampling, fishway passage or guidance, turbines). In this review, we examine several presumptive tests for blood and evaluate their potential usefulness for detecting and quantifying injury in fish. Our evaluation was based on sensitivity, specificity, cost, carcinogenicity and ease of use. Fluorescein and Bluestar? offer the ability to perform whole body detection, but require low-light conditions and a digital camera to capture the emitted light. Several tests (i.e. Hemastix~?, Hemident ~?, phenolphthalein) yield rapid results and do not require large or expensive pieces of equipment, which makes them ideal for field use, although further research is needed to validate these tools for use on different fish species and in different contexts. Collectively, these tools show promise for a variety of fish research, conservation and management applications, including hydropower assessment, commercial fisheries bycatch evaluation, and analysis of the practices and gear regulations associated with recreational angling.