Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century.

The benthic macrofauna of a group of small seamounts south of Tasmania was surveyed with a dredge and camera to assess the impact of trawling for orange roughy (Hoplostethus atlanticus; Trachichthyidae) and the efficacy of a proposed marine reserve. The seamounts were generally 300 to 600 m high and the peaks ranged from 660 to 1700 m depth. The fauna was diverse: 262 species of invertebrates and 37 species of fishes were enumerated, compared with 598 species of invertebrates previously reported from seamounts worldwide. On seamounts that peaked at depths <1400 m and that had not been heavily fished, the invertebrate fauna was dense, diverse and dominated by suspension feeders, including a matrix-forming colonial hard coral (Solenosmilia variabilis) and a variety of hard and soft (gorgonian and antipatharian) corals, hydroids, sponges and suspension-feeding ophiuroids and sea stars. Of the invertebrate species, 24 to 43% were new to science, and between 16 and 33% appeared to be restricted to the seamount environment. Trawl operations effectively removed the reef aggregate from the most heavily fished seamounts. The benthic biomass of samples from unfished seamounts was 106% greater than from heavily fished seamounts and the number of species per sample was 46% greater. Living S. variabilis was not found on seamounts peaking at depths >1400 m. These seamounts were dominated by sea urchins and had lower biomass and fewer species per sample. However, few species were restricted to either the shallowest or deepest depths sampled. The fauna unique to the region's seamounts appears to be adequately represented within a recently established 'Marine Protected Area' that encloses 12 seamounts that peak at depths >1150 m.KEY WORDS: Seamount · Benthos · Impacts of trawling · Community structure 213: 111-125, 2001 rockhopper gear -large rubber bobbins and metal discs along the footrope -and precise electronic positioning systems both for the vessel and to monitor net performance. Seamounts are one such environment to become subject to intensive trawl fishing in recent decades. Resale or republication not permitted without written consent of the publisherMar Ecol Prog SerSeamounts provide a unique deep-sea environment due to the topographically-enhanced currents in their vicinity (Roden 1986). In the water column, substantial aggregations of deep-bodied fishes, such as the pelagic armourhead (Pseudopentaceros wheeleri), Sebastes spp., orange roughy (Hoplostethus atlanticus) and oreosomatids are commonly found around seamounts (Boehlert & Sasaki 1988, Koslow 1996, 1997. These aggregations are supported in the otherwise food-poor deep sea by the enhanced flux of prey organisms past the seamounts and the interception and trapping of vertical migrators by the uplifted topography (Tseitlin 1985, Genin et al. 1988, Koslow 1997. Discovery of these aggregations led to seamounts being increasingly targeted by trawlers throughout the world's oceans: i.e. the massive but short-lived fishery for pelagic armourhead in the N...

No part of this publication may be reproduced, stored, transmitted or disseminated, in any form, or by any means, without prior written permission from the publisher, to whom all requests to reproduce copyright material should be directed in writing.This authorization does not extend to any other kind of copying, by any means, in any form, and for any purpose other than private research use. (Bousfield & Kendall, 1994 AbstractA classification is proposed for the order Amphipoda. The Amphipoda includes six suborders, the Pseudingolfiellidea, Hyperiidea, Colomastigidea, Hyperiopsidea, Senticaudata (described in a previous contribution (Lowry & Myers 2013)) and Amphilochidea. The suborder Ingolfiellidea is raised to order status. A cladistic tree, based on morphology, is presented illustrating the relationships of the Amphipoda at parvorder level. A tree for the families of the Physomatidira and Physocephalatidira, a tree for the Maxillipiidira, Oedicerotidira, Eusiridira and Amphilochidira and a tree for the Synopiidira, Haustoriidira and Lysianassidira, are provided. Families are listed together with their included genera. New families are diagnosed.

An introduction to the software package DELTA (DEscription Language for TAxonomy) is given. Th e contribution consists of step by step instructions into the DELTA Editor and the interactive identifi cation program Intkey. It describes how to record taxonomic character information in a database and maintain these data. Standard output functions are simplifi ed in a new starter database. All used commands are commented and it is marked where changes in the command fi les are required. Th e paper explains how to generate text descriptions, interactive identifi cation tools, and how to make keys and species diagnoses.

Prior to this study there were less than 50 species of benthic amphipods known from the Great Barrier Reef (Haswell 18xx; K.H. Barnard 1931; Berents 1983; Myers 1986; Lowry & Stoddart 1990, 1992; Thomas & Barnard 1991; Lowry & Berents 2005; Guerra-Garcia 2006; Peart 2007a, b; Lowry & Azman, 2007; Yerman & Krapp-Schickel, 2008). Examination of the benthic amphipod fauna of the Great Barrier Reef, based on new collections mainly from the Lizard Island Amphipod Workshop in February/March 2005, revealed 45 families, 116 genera, of which 8 (6.9%) are new, and 256 species, of which 107 (45%) are new. The amphipod fauna of the Great Barrier Reef is the richest fauna yet known from any tropical reef area.