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Broad-scale effects of marine salmonid aquaculture on macrobenthos and the sediment environment in southeastern Tasmania


Edgar, GJ and MacLeod, C and Mawbey, RB and Shields, D, Broad-scale effects of marine salmonid aquaculture on macrobenthos and the sediment environment in southeastern Tasmania, Journal of Experimental Marine Biology and Ecology, 327, (1) pp. 70-90. ISSN 0022-0981 (2005) [Refereed Article]

DOI: doi:10.1016/j.jembe.2005.06.003


A comparison of sediments and associated macrobenthos at sites sampled within 20 fish farm leases distributed across southeastern Tasmania indicated major natural changes along a regional cline. Introduced taxa were strongly represented in the fauna, comprising 45% of total macrofaunal biomass. Large differences were evident between sites affected by different levels of organic farm waste. Sites located adjacent (< 10 m) to farm cages possessed significantly depressed sediment redox levels, a dominance of capitellid and dorvilleid polychaetes, and low macrofaunal species richness. Subtle impacts extended across farm lease areas in the form of depressed redox potential at 40 mm depth and changes to the macrobenthic community, including a prevalence of the dogwhelk Nassarius nigellus and a paucity of the heart urchin Brissus sp. and the maldanid polychaetes Asychis sp. and Rhodine sp. Minor farm effects were also evident at sites sampled 35 m outside farm lease boundaries, most notably as elevated population numbers of the polychaete Terrebellides sp., bivalve Mysella donaciformis and heart urchin Echinocardium cordatum. Amongst the univariate metrics examined, redox potential at 40 mm depth and the ratio of bivalves to total molluscs provided the most sensitive indicators of farm impacts, with the latter metric relatively insensitive to spatial variation between locations within the region studied. © 2005 Elsevier B.V. All rights reserved.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - aquaculture
Objective Field:Fisheries - aquaculture not elsewhere classified
UTAS Author:Edgar, GJ (Professor Graham Edgar)
UTAS Author:MacLeod, C (Professor Catriona MacLeod)
ID Code:38193
Year Published:2005
Web of Science® Times Cited:52
Deposited By:TAFI - Marine Research Laboratory
Deposited On:2005-08-01
Last Modified:2006-04-11

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