New Zealand Journal of Marine and Freshwater Research abstracts
Comparison of fish communities and abundance in unmodified streams of
Kahurangi National Park with other areas of New Zealand
I. G. JOWETT
National Institute of Water & Atmospheric
Research Ltd
P. O. Box 11 115
Hamilton, New Zealand
J. W. HAYES
Cawthron Institute
Private Bag 2
Nelson, New Zealand
N. DEANS
Nelson/Marlborough Fish & Game
P. O. Box 2173, Stoke
Nelson, New Zealand
G. A. ELDON
240B The Esplanade
Kaikoura, New Zealand
Abstract New Zealand landscapes were extensively modified
after European settlement in the late 1800s. Large areas of native forest were
converted to pasture and few large areas of unmodified forest remain. Trout
(
Salmo trutta and
Oncorhynchus mykiss) were introduced into the
rivers at the same time, and these two changes are thought to have affected
native fish communities. Kahurangi National Park is a large area of unmodified
native forest with few introduced trout in smaller rivers draining to the west.
A survey of these streams was made to determine whether their communities
differed from those in other areas of New Zealand. No non-diadromous native
fish were found, suggesting a biogeographic separation from adjacent eastern
and southern areas since the Pliocene or early Pleistocene. Contrary to popular
expectation, fish diversity and abundance was often lower than at equivalent
elevations in other areas of New Zealand. Lowland fish communities comprised a
small stream community dominated by inanga (
Galaxias maculatus), a small
stream community containing a mixed galaxiid population but dominated by banded
kokopu (
Galaxias fasciatus), and two large stream communities containing
the fastwater species bluegilled bully (
Gobiomorphus hubbsi), and
dominated by either redfinned bully (
Gobiomorphus huttoni) or bluegilled
bully. Large streams usually contained no in-stream cover with margins of
exposed streambed, whereas small streams contained plentiful cover with margins
of native forest, native grasses, or swamp. Upland fish communities were
dominated by koaro (
Galaxias brevipinnis) and/or longfinned eels
(
Anguilla dieffenbachii). Large-stream fish communities in Kahurangi
National Park were similar to the fastwater communities in medium-large rivers
in other areas of New Zealand. However, in the smaller streams of Kahurangi
National Park, galaxiid communities were encountered more frequently than in
similar sized streams in other parts of New Zealand.
Keywords freshwater; fish; abundance; community;
distribution; land use; habitat; biogeography
M97011
Received 26 March 1997; accepted 2 December 1997
Review
PDF file of entire paper: medium quality (1243K); (scanned from paper original: notes about this process)
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