New Zealand Journal of Marine and Freshwater Research abstracts
Summer spatial patterns of the fish community in a large, shallow, turbid
coastal lake
G. J. GLOVA
P. M. SAGAR
National Institute of Water & Atmospheric
Research Ltd
P. O. Box 8602
Christchurch, New Zealand
email: g.glova@niwa.cri.nz
Abstract Several water quality parameters, marginal
vegetation, and the fish community in Lake Ellesmere, a large, shallow, turbid
lake situated on the east coast of the South Island, New Zealand, were sampled
along selected transects in late summer to determine species spatial patterns.
Thirteen species of fish were caught, with seven of them comprising major
populations, although only four of these were adequately sampled by the method
used--they included inanga (
Galaxias maculatus), common smelt
(
Retropinna retropinna), shortfinned eel (
Anguilla australis),
and common bully (
Gobiomorphus cotidianus). Inanga were almost
exclusively confined to areas on the western side of the lake which has a
convoluted shoreline with a variety of small embayments with scattered
vegetation along the margins. Common smelt occupied both marginal and offshore
areas, but they too were more abundant along the margins particularly on the
western side. Both the common bully and shortfinned eel were widespread and
abundant in the lake, although their abundance and biomass were higher within
the vicinity of the lake outlet, major inflowing tributaries, and other
marginal habitats. All three species of flounders of the genus
Rhombosolea
were poorly represented in our samples. However, in commercial catches they
were reasonably abundant, with the sand flounder (
R. plebeia) and
yellowbelly (
R. leporina) being more common in offshore than inshore
catches, whereas the black flounder (
R. retiaria) showed no difference
in the catches between areas. Our overall findings are consistent with the
hypothesis that bottom-dwelling species (eels, bullies, flounders) are more
widely distributed than free-swimming forms (inanga, common smelt), which were
largely confined to areas sheltered from prevailing winds. The highly turbid
nature of the lake, primarily because of re-suspension of fine bottom sediments
by frequent winds, is considered an important factor in the distribution of the
fish fauna.
Keywords coastal lake; water quality; marginal vegetation;
habitat; fish community; abundance; biomass; spatial patterns
M99047
Received 12 August 1999; accepted 20 January 2000
PDF file of entire paper: medium quality (1142K); (scanned from paper original: notes about this process)
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