Soft‐sediment habitats and fauna of Omaha Bay, northeastern New Zealand

Abstract

The aim of this paper is to describe the distribution and abundance of animals living in the subtidal soft‐sediments of Omaha Bay in northeastern New Zealand. Animals >4 mm were sampled from 138 subtidal stations, using suction sampler, grab, and dredge. Stations ranged in depth from 1 to 41 m, with sediments comprised mostly of sand and gravelly sand. Two‐hundred‐and‐thirty‐six taxa representing 13 phyla were recorded, with molluscs, arthropods and annelids being the most speciose. Animals sampled by grab and suction sampler formed seven main clusters in multivariate space. These clusters were relatively discrete in terms of the defining variables used to label them and the taxonomic composition of the animals they contained, although depth ranges of most common taxa in the four sand habitats did not correspond particularly well to breaks identified by the cluster analysis. The overall correspondence between the macrofaunal assemblages and the physical variables of depth and sediment type suggests the potential for remote mapping of these broad assemblages over large scales using existing acoustic survey methods.

Keywords:

• benthos
• macrofauna
• soft sediment

Notes

University of Auckland, Leigh Marine Laboratory, PO Box 349, Warkworth 0941, New Zealand. [email protected]

Present address: National Institute of Water and Atmospheric Research Ltd, PO Box 109695, Newmarket, Auckland 1149, New Zealand.

Additional information

Notes on contributors

A. Morrison

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