New Zealand Journal of Marine and Freshwater Research abstracts
Habitat use and longitudinal distribution patterns of native fish from a
near pristine Stewart Island, New Zealand, stream
W. LINDSAY CHADDERTON*
Department of Conservation
P. O. Box 743
Invercargill, New Zealand
email: lchadderton@doc.govt.nz
RICHARD M. ALLIBONE
National Institute of Water & Atmospheric
Research Ltd
P. O. Box 11 115
Hamilton, New Zealand
email: r.allibone@niwa.cri.nz
*Present address: Department of Conservation, Northern
Regional Office, P. O. Box 112, Hamilton, New Zealand.
Abstract Distribution, abundance, and habitat preferences of
native fish were investigated down the length of a relatively pristine,
medium-sized, fourth-order stream on Stewart Island, New Zealand. A limited
fish fauna was recorded (six species), including three threatened large
galaxiid species (Galaxias argenteus, Galaxias fasciatus, and
Galaxias brevipinnis), which have restricted distributions on mainland
New Zealand. Results indicated that these large galaxiids occupy diverse
habitats including pools and backwaters within the mainstems of this stream.
Their extensive distributions and wide habitat usage were attributed to factors
such as the intact catchment vegetation, unmodified stream channel, and the
absence of introduced fishes, particularly salmonids. Results suggest that some
native species have been excluded from mainstem habitats elsewhere in New
Zealand. It was also evident that interactions among the native species
influenced habitat use; G. brevipinnis avoided backwaters, runs, and
pools in reaches occupied by G. fasciatus and Anguilla
dieffenbachii; whereas G. fasciatus appeared to avoid habitats
occupied by G. argenteus and A. dieffenbachii. Maximum densities
and biomass of galaxiids and eels occurred in deepwater habitats
(>0.75 m). Furthermore the fish inhabiting these deeper waters were
larger and more likely to be female. These findings have significant
implications for the design and application of sampling protocols for native
New Zealand fishes and for the protection of their habitats. If deeper waters
are not sampled then species, sex, and size biased data may result.
Keywords Galaxias; Anguilla; habitat use;
forest stream; native fish; distribution
M98035
Received 30 June 1998; accepted 30 January 2000
PDF file of entire paper: medium quality (923K); (scanned from paper original: notes about this process)
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