A global review of the spatial, taxonomic, and temporal scope of freshwater fisheries hydroacoustics research

Abstract

This review assessed the status and scope of freshwater hydroacoustic fisheries research in global aquatic ecosystems with emphasis on (i) geographical and spatial scope, (ii) taxonomic range at the species and family levels (restricted to bony fishes of the Actinopterygii and Sarcopterygii), and (iii) temporal scope. Hydroacoustic measures have been used by ecologists and managers of freshwater systems for several decades, with major progress in technology and methods in recent years. A literature review indicated 296 research contributions that employed hydroacoustics to study freshwater fisheries in 294 different aquatic ecosystems. Spatially, hydroacoustics research in freshwater systems have thus far been concentrated in developed countries, particularly in North America and Northern and Central Europe (83% of the studies reviewed here). Most studies were small in spatial scale and short-term, with 80% including only a single body of water and 63% conducted over a single year or season (75% spanning less than two years). In addition, effects of fish morphology and behavior on acoustic target strength (TS) and taxonomic identification are not well parameterized, with only 21 species receiving empirical study of TS. Despite progress, the present study reveals gaps in the knowledge needed for wider applications to management. These include larger biogeographical and temporal scales of study and further empirical research on TS and taxonomic identification. Recent advances in size rather than species-based methods and theory offer potential solutions to this issue but require further investigation. We conclude with recommendations for systematic hydroacoustic research to enable more effective monitoring, management, and conservation of fisheries and freshwater ecosystems.

Manual fish length measurement accuracy for adult river fish using an acoustic camera (DIDSON)

“…Hydroacoustic devices are increasingly used for ecological studies particularly for fish monitoring and studies (Budnik & Miner, 2017;Lenihan et al, 2018;Lucas & Baras, 2000;Pollom & Rose, 2016;Ransom et al, 1998;Rudstam et al, 2012;Samedy et al, 2015). They are considered as non-intrusive and represent the only way to penetrate water over long distance, even with a high turbidity (Mueller et al, 2006).…”

Acoustic Target Strength of the Endangered Chinese Sturgeon (Acipenser sinensis) by Ex Situ Measurements and Theoretical Calculations

“…Therefore, only TS value without consideration of tilt angle (swimming behavior) obtained from a single frequency was not enough to judge whether the echoes were from the Chinese sturgeon. In addition, the 200 kHz echosounder is the most popular frequency in freshwater environments in the world [28]. In the near future, more than one frequency on the Chinese sturgeon survey should be applied to identify the species more accurately from other species.…”

“…The KRM method was further used to estimate the TS of Chinese sturgeon as a function of body length, acoustic frequency, and tilt angle. The TS as a function of the body length at six frequencies (38 kHz, 70 kHz, 120 kHz, 200 kHz, 333 kHz, and 420 kHz), which are commonly used in freshwater environments [9,28], was calculated. To know the body length of female and male adult sturgeon, we utilized references (Table 3).…”

“…Figure 4b shows the interval distribution of TS: the interval between −32.0 and −30.0 dB had 25 samples, which occupied 32.1% of the entire tracks. in freshwater environments [9,28], was calculated. To know the body length of female and male adult sturgeon, we utilized references (Table 3).…”

Comparing Fish Density and Echo Strength Distribution Recorded by Two Generations of Single Beam Echo Sounders

“…Pelagic salmonids and cyprinids predate zooplankton in temperate lakes, and affect the species composition and size structure of the zooplankton community, which in turn affects the abundance of planktonic algae [1,2], and further, influencing water quality and its suitability for public use [3][4][5]. The hydroacoustic assessment is an efficient method to estimate the density and size distribution of pelagic fish, and has been used in lakes for more than three decades, and in marine environments for much longer [6,7]. The available equipment has been developing, and single beam transducers from the early stage are replaced by split beam echosounders.…”