Each tow was described by the percentage of records assigned to each class of substratum and overlying epibenthos, and the occurrence of individually marked organisms. These data also contributed to an overall quantitative perspective of the various habitats occurring in these waters. Additionally, Principal Coordinates Analysis was used to explore the relationships among sites. An extended version of the Manhattan distance matrix was used and the data were fourth root transformed to improve the multivariate normality of the data matrix. The data were presented as a multivariate biplot.

BRUVS

With stationary video, species abundance estimates are limited to the maximum number of individuals sighted in any one field of view (MaxN), as re-appearances of a single fish image cannot generally be assigned to a specific individual. The use of MaxN was reviewed by Cappo et al. (2003, 2004) as a conservative measure of relative abundance. The fish data was analysed with the same multivariate techniques as the habitat data. Species with a strong group association were identified from the ordination plots.