Use of High-Resolution DIDSON Sonar to Quantify Attributes of Predation at Ecologically Relevant Space and Time Scales

Abstract

A B S T R A C TPredator-prey interactions of large vagile fishes are difficult to study in the ocean due to limitations in the space and time requirements for observations. Small-scale direct underwater observations by divers (ca. <10 m radius) and large-scale hydroacoustic surveys (10 s m 2 to 100 s km 2 ) are traditional approaches for surveying fish. However, large piscivorous predators identify and attack prey at the scale of meters to tens of meters. Dual-Frequency Identification Sonar (or DIDSON) is a high-resolution acoustic camera operating in the MHz range that provides detailed continuous video-like imaging of objects up to a range of 30 m. This technology can be used to observe predator-prey interactions at ecologically relevant space and time scales often missed by traditional methods. Here we establish an approach for quantifying predation-related behaviors from DIDSON records. Metrics related to predator and prey group size, prey responses to predation, predation rate, predator strategies, and the nonrandom use of landscape features by both predator and prey are described. In addition, relationships between patterns in these attributes are tested and issues regarding sampling strategies for future studies are discussed. We suggest that approaches combining direct visual observation and acoustic sampling at multiple scales are required to quantify variation in these relationships across underwater landscapes.

Spawning behaviour of Allis shad Alosa alosa: new insights based on imaging sonar data

“…A dual-frequency-identification-sonar (DIDSON -Soundmetrics Corp.; www.soundmetrics.com) served for data acquisition. It is independent of light and insensitive to turbidity by delivering video-like sequences (Belcher et al, 2001) with monitoring ranges up to 30 m. Imaging sonar technology has been used successfully in a variety of studies to analyse fish behaviour (Tiffan et al, 2010;Rakowitz et al, 2012;Jůza et al, 2013;Price et al, 2013;Becker & Suthers, 2014;O'Connell et al, 2014). In the present study the imaging sonar was tested for its suitability to monitor A. alosa spawning by means of detection and quantification of mating events.…”

Association behavior between sand tiger sharks and round scad is driven by mesopredators

“…In-situ marine field experiments analyzing fish aggregation dynamics are uncommon, likely given the difficulty to track individual fish in an open setting. Dual frequency identification sonar (DIDSON) has recently become a reliable method to conduct in-situ analysis of fish schooling behavior and has the capability of monitoring the movement of individual fish ( Moursund, Carlson & Peters, 2003 ; Boswell, Wilson & Cowan, 2008 ; Price, Auster & Kracker, 2013 ; Rieucau et al, 2016 ). Auster et al (2013) used DIDSON techniques to effectively analyze prey distribution during predator–prey interactions similar to those observed in this study on hard bottoms in the SAB.…”

Monitoring fish using imaging sonar: Capacity, challenges and future perspective

“…In a large‐scale measurement, the predation and antipredator behaviour are identified indirectly by the abundance change pattern of predator and prey (Becker et al, 2013; Becker & Suthers, 2014; Bolton et al, 2017). In a fine‐scale measurement, the fish school changes in the fish number, density, area and shape when a predator approaches, and the predation‐related measures such as the predation rate, total attacks and duration of one predation, are observed (Price et al, 2013). Furthermore, it has been demonstrated that high‐frequency MFLS is capable of providing finer scale behaviour information such as collective reaction and information transfer in a school (Rieucau et al, 2016).…”