Epibenthic macrofauna off southeastern New Zealand and mid‐shelf bryozoan dominance

Abstract

A survey was made of epibenthic macrofauna on the continental shelf and upper continental slope (canyons) off the Otago Peninsula. Three major bottom faunas, recognised by site‐grouping and species‐grouping classification, are related to depth zones, sediment types, and water masses. An inner shelf benthos, to a depth of about 30 m, is associated with sand and neritic water. A mid‐shelf to uppermost slope benthos, extending in places to 360–370 m, occurs on gravelly sediments in the path of the Southland Current (subtropical in origin), and a submarine canyon benthos, best developed on muddy sediments below about 450 m, is probably mainly influenced by Antarctic Intermediate Water. Bryozoans, especially the cyclo‐stome Filicea elegans, dominate the mid‐shelf where there is pebbly substratum for colony attachment, little fine sediment deposition, and continuous flow of the Southland Current.