title: Assessing Caribbean Shallow and Mesophotic Reef Fish Communities Using Baited-Remote Underwater Video (BRUV) and Diver-Operated Video (DOV) Survey Techniques.
abstract: Fish surveys form the backbone of reef monitoring and management initiatives throughout the tropics, and understanding patterns in biases between techniques is crucial if outputs are to address key objectives optimally. Often biases are not consistent across natural environmental gradients such as depth, leading to uncertainty in interpretation of results. Recently there has been much interest in mesophotic reefs (reefs from 30-150 m depth) as refuge habitats from fishing pressure, leading to many comparisons of reef fish communities over depth gradients. Here we compare fish communities using stereo-video footage recorded via baited remote underwater video (BRUV) and diver-operated video (DOV) systems on shallow and mesophotic reefs in the Mesoamerican Barrier Reef, Caribbean. We show inconsistent responses across families, species and trophic groups between methods across the depth gradient. Fish species and family richness were higher using BRUV at both depth ranges, suggesting that BRUV is more appropriate for recording all components of the fish community. Fish length distributions were not different between methods on shallow reefs, yet BRUV recorded more small fish on mesophotic reefs. However, DOV consistently recorded greater relative fish community biomass of herbivores, suggesting that studies focusing on herbivores should consider using DOV. Our results highlight the importance of considering what component of reef fish community researchers and managers are most interested in surveying when deciding which survey technique to use across natural gradients such as depth.
authors.affiliation: Department of Zoology, University of Oxford, The Tinbergen Building, South Parks Road, Oxford United Kingdom.|Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire United Kingdom.
authors.forename: Dominic A
authors.identifier: http://orcid.org/0000-0001-5191-5225
authors.initials: DA
authors.lastname: Andradi-Brown
authors.affiliation: Department of Zoology, University of Oxford, The Tinbergen Building, South Parks Road, Oxford United Kingdom.|Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras, Santiago, Chile.
authors.forename: Consuelo
authors.initials: C
authors.lastname: Macaya-Solis
authors.affiliation: Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire United Kingdom.
authors.forename: Dan A
authors.initials: DA
authors.lastname: Exton
authors.affiliation: Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire United Kingdom.
authors.forename: Erika
authors.initials: E
authors.lastname: Gress
authors.affiliation: Operation Wallacea, Wallace House, Old Bolingbroke, Spilsby, Lincolnshire United Kingdom.
authors.forename: Georgina
authors.initials: G
authors.lastname: Wright
authors.affiliation: Department of Zoology, University of Oxford, The Tinbergen Building, South Parks Road, Oxford United Kingdom.
authors.forename: Alex D
authors.initials: AD
authors.lastname: Rogers
mesh_terms: D000818:Animals; D044822:Biodiversity; D018533:Biomass; D049628:Body Size; D002138:Calibration; D017691:Caribbean Region; D057894:Coral Reefs; D004784:Environmental Monitoring / Q000379:methods; D005399:Fishes; D005843:Geography; D011156:Population Density; D014741:Video Recording