A field and video analysis guide for diver operated stereo‐video

Abstract

There has been rapid uptake of stereo‐video‐based sampling techniques to collect species, abundance and body‐size information on fish assemblages and their associated habitats. Stereo‐video methods provide highly accurate estimates of body‐size, range and sampling area as well as a permanent record that can be cross‐checked or resampled for additional data. Due to these advantages, diver‐operated stereo‐video (stereo‐DOV) is becoming an increasingly popular alternative to underwater visual census. We provide a comprehensive guide for researchers using stereo‐DOVs to survey fish assemblages and their associated habitat. Information on stereo‐DOV design, video camera settings, field operations and video analysis are outlined. Stereo–DOV surveys permit rapid and simultaneous collection of data on fish diversity, abundance, length and behaviour as well as their associated habitat. However, biases associated with diver presence in the water and variation in detectability should be considered and are dependent on the location and focal species of the survey. We recommend using stereo‐DOVs for diver‐based surveys of non‐cryptic fish assemblages, given the advantages described. An increased uptake of this methodology, following the standard procedures described herein, will reduce variation in methodology, assist in the synthesis of data on continental and global scales and provide accurate information to improve fisheries management and conservation.

A Decade of Monitoring an Indo-Pacific Grouper Spawning Aggregation: Benefits of Protection and Importance of Survey Design

“…The sizes of fishes at the aggregation were measured during surveys in August 2014 and June/July 2019 using a diveroperated stereo-video system (stereo-DOV; Goetze et al, 2019), first available to us in 2014, to determine any changes in body sizes over time which could indicate new recruits and to establish the size range of fish aggregating. This system consists of two video cameras in underwater housings mounted separately on a base bar, their fields of view converging at a fixed angle (∼6-degree inwards convergence).…”

A Response to Scientific and Societal Needs for Marine Biological Observations

“…Some new technologies expand traditional data streams, while others open new ones. Thirty years of remote sensing support detailed analysis of trends in ocean color and surface productivity (e.g., Dunstan et al, 2018), while advances in artificial intelligence and machine learning provide increasingly rapid and consistent classification and processing of underwater imagery and marine fauna (Goetze et al, 2019). Advances in 'omics support new monitoring approaches such as Close-Kin Mark Recapture which can census adult populations without ever sampling an adult (Hillary et al, 2018), and environmental DNA which can identify species and populations from the water they swim in (Sigsgaard et al, 2016).…”

Shifts in Labridae geographical distribution along a unique and dynamic coastline

“…In order to record the marine biota and habitat, stereo‐DOVs were manoeuvred by SCUBA divers along transects. Stereo‐DOVs were developed and described by Harvey and Shortis () to eliminate diver identification bias and increase the accuracy and precision of length and distance estimates (Goetze et al, ; Harvey, Fletcher, Shortis, & Kendrick, ).…”