An experimental comparison of three Towed Underwater Video Systems using species metrics, benthic impact and performance
|Author(s)||Sheehan Emma V.1, Vaz Sandrine2, Pettifer Erin3, Foster Nicola L.1, Nancollas Sarah J.1, Cousens Sophie1, Holmes Luke1, Facq Jean-Valery4, Germain Gregory4, Attrill Martin J.1|
|Affiliation(s)||1 : Plymouth Univ Marine Inst, Plymouth PL4 8AA, Devon, England.
2 : IFREMER, UMR MARBEC, Av Jean Monnet,Ave Jean Monnet,CS 30171, F-34203 Sete, France.
3 : Sussex Inshore Fisheries Commiss Author, Shoreham By Sea BN43 6RE, W Sussex, England.
4 : IFREMER, Lab Comportement Struct Mer, Ctr Manche Mer Nord 150, F-62200 Boulogne, France.
|Source||Methods In Ecology And Evolution (2041-210X) (Wiley-blackwell), 2016-07 , Vol. 7 , N. 7 , P. 843-852|
|WOS© Times Cited||23|
|Keyword(s)||environmental management, marine protected area, meta-analyses, sampling impact, towed video, underwater imagery|
|Abstract||Managing ecological systems, which operate over large spatial scales, is inherently difficult and often requires sourcing data from different countries and organizations. The assumption might be made that data collected using similar methodologies are comparable, but this is rarely tested. Here, benthic video data recorded using different towed underwater video systems (TUVSs) were experimentally compared.
Three technically different TUVSs were compared on different seabed types (rocky, mixed ground and sandy) in Kingmere Marine Conservation Zone, off the south coast of England. For each TUVS, species metrics (forward facing camera), seabed impact (backward facing camera) and operational performance (strengths and limitations of equipment and video footage) were compared with the aim of providing recommendations on their future use and comparability of data between different systems.
Statistically significant differences between species richness, density, cover and assemblage composition were detected amongst devices and were believed to be mostly due to their optical specifications. As a result of their high image definition and large field of vision both the benthic contacting heavy and benthic tending TUVS provided good quality footage and ecological measurements. However, the heaviest TUVS proved difficult to operate on irregular ground and was found to cause the most impact to the seabed. The lightest TUVS (benthic contacting light) struggled to maintain contact with the seabed. The benthic tending TUVS was able to fly over variable seabed relief and was comparably the least destructive.
Results from this study highlight that particular care should be given to sled and optic specifications when developing a medium- or long-term marine protected area monitoring programme. Furthermore, when using data gathered from multiple sources to test ecological questions, different equipment specifications may confound observed ecological differences.
A benthic tending TUVS is recommended for benthic surveys over variable habitat types, particularly in sensitive areas, such as marine protected areas.