Using action cameras to estimate the abundance and habitat use of threatened fish in clear headwater streams

Abstract

Snorkel and electrofishing surveys are the traditional baseline methods for fish surveys in clear headwater streams. However, action cameras  provide a non-harmful alternative to monitor freshwater fish populations to develop informed conservation management initiatives. In this paper, estimates from photographs and videos from action cameras are compared with snorkel survey estimates of the density of a threatened endemic minnow species in a headwater stream, Eastern Cape, South Africa. Photograph-based relative abundances of fish summed over five microhabitats in each pool returned equivalent results to snorkel surveys, whereas the equivalent video-based abundance estimates were approximately 50% greater than the snorkel estimates. Therefore, photograph-derived estimates could be used as an alternative to snorkel surveys for fish population monitoring and habitat use studies in clear headwater streams.

Keywords: freshwater fish, MaxN, monitoring, photographs, snorkel surveys, underwater video analysis