A field and video-annotation guide for baited remote underwater stereo-video surveys of demersal fish assemblages

Researchers TL, BG, JW, NB and JM were supported by the Marine Biodiversity Hub through funding from the Australian Government's National Environmental Science Program. Data validation scripts and GlobalArchive.org were supported by the Australian Research Data Commons, the Gorgon-Barrow Island Gorgon Barrow Island Net Conservation Benefits Fund, administered by the Government of Western Australia and the BHP/UWA Biodiversity and Societal Benefits of Restricted Access Areas collaboration.1. Baited remote underwater stereo-video systems (stereo-BRUVs) are a popular tool to sample demersal fish assemblages and gather data on their relative abundance and body-size structure in a robust, cost-effective, and non-invasive manner. Given the rapid uptake of the method, subtle differences have emerged in the way stereo-BRUVs are deployed and how the resulting imagery are annotated. These disparities limit the interoperability of datasets obtained across studies, preventing broad-scale insights into the dynamics of ecological systems. 2. We provide the first globally accepted guide for using stereo-BRUVs to survey demersal fish assemblages and associated benthic habitats. 3. Information on stereo-BRUV design, camera settings, field operations, and image annotation are outlined. Additionally, we provide links to protocols for data validation, archiving, and sharing. 4. Globally, the use of stereo-BRUVs is spreading rapidly. We provide a standardised protocol that will reduce methodological variation among researchers and encourage the use of Findable, Accessible, Interoperable, and Reproducible (FAIR) workflows to increase the ability to synthesise global datasets and answer a broad suite of ecological questions.Publisher PDFPeer reviewe

Observed and predicted number of priority fish species seen on video.

<p>Spatial predictions for the number of priority fish species on video were made at average values of all other predictor variables in the generalized additive model, and are shown from orange (indicating many species predicted) to blue (indicating low number of species predicted). Open circles show the mean observed number of species on video in 2011–2014 for each 0.25 × 0.25 degree cell.</p

Locations of video samples included in the analyses from the Southeast Reef Fish Survey.

<p>Data is from the southeast United States, 2011–2014 (gray points; <i>N</i> = 4,855 videos in total). Note that points often overlap. Gray isobaths indicate 30-, 50-, and 100-m depths, and arrows indicate the general path of the Gulf Stream.</p

Locations of selected uncommon reef fish species seen on videos.

<p>Note that some points overlap. Gray isobaths indicate 30-, 50-, and 100-m depths.</p

Spatial Distribution of Reef Fish Species along the Southeast US Atlantic Coast Inferred from Underwater Video Survey Data

<div><p>Marine fish abundance and distribution often varies across spatial scales for a variety of reasons, and this variability has significant ecological and management consequences. We quantified the distribution of reef-associated fish species along the southeast United States Atlantic coast using underwater video survey samples (<i>N</i> = 4,855 in 2011–2014) to elucidate variability within species across space, depths, and habitats, as well as describe broad-scale patterns in species richness. Thirty-two species were seen at least 10 times on video, and the most commonly observed species were red porgy (<i>Pagrus pagrus</i>; 41.4% of videos), gray triggerfish (<i>Balistes capriscus</i>; 31.0%), black sea bass (<i>Centropristis striata</i>; 29.1%), vermilion snapper (<i>Rhomboplites aurorubens</i>; 27.7%), and red snapper (<i>Lutjanus campechanus</i>; 22.6%). Using generalized additive models, we found that most species were non-randomly distributed across space, depths, and habitats. Most rare species were observed along the continental shelf break, except for goliath grouper (<i>Epinephelus itajara</i>), which was found on the continental shelf in Florida and Georgia. We also observed higher numbers of species in shelf-break habitats from southern North Carolina to Georgia, and fewer in shallower water and at the northern and southern ends of the southeast United States Atlantic coast. Our study provides the first broad-scale description of the spatial distribution of reef fish in the region to be based on fishery-independent data, reinforces the utility of underwater video to survey reef fish, and can help improve the management of reef fish in the SEUS, for example, by improving indices of abundance.</p></div

Sampling information for the 32 most common species seen on video in the Southeast Reef Fish Survey.

<p>Sampling information for the 32 most common species seen on video in the Southeast Reef Fish Survey.</p

Depth distribution of reef fish species seen on at least 10 videos.

<p>Bars show the proportion of videos within each depth zone (m) that the species was seen. The thick black line shows the mean generalized additive model fit for each species, and is absent if it was insignificant. Horizontal dashed lines show the overall proportion of videos in which the species was present. Note different y-axes among panels.</p

Relationships between the predicted number of priority fish species seen on video and predictor variables.

<p>The generalized additive model was built using Southeast Reef Fish Survey video data, 2011–2014. Points (for categorical variables) or solid lines (for smoothed continuous variables) show the mean predicted number of species seen and the dashed lines show 95% confidence intervals.</p

Distribution of reef fish species across substrates that were seen on at least 10 videos.

<p>Bars show the proportion of videos within each substrate type that the species was seen. The thick black line shows the mean generalized additive model fit for each species, and is absent if it was insignificant. Horizontal dashed lines show the overall proportion of videos in which the species was present. Note different y-axes among panels.</p