New Zealand Journal of Marine and Freshwater Research abstracts
Macroinvertebrate distribution in the littoral zone of Lake Coleridge, South
Island, New Zealand --effects of habitat stability, wind exposure, and
macrophytes
M. R. JAMES
M. WEATHERHEAD
C. STANGER
E. GRAYNOTH
National Institute of Water & Atmospheric
Research Ltd
P. O. Box 8602
Christchurch, New Zealand
Abstract The macroinvertebrate community was surveyed at
eight littoral zone sites in Lake Coleridge, New Zealand. Sites covered a range
of conditions including exposure to prevailing winds, shore-line topography,
and proximity to river inputs--which are a major source of suspended sediment
to the lake. The littoral zone contained an abundant and diverse
macroinvertebrate fauna (47 taxa). Three communities were identified: a
shallow-water community inhabiting the wave-break zone, dominated by
Trichoptera and chironomid larvae; a middle-zone community associated with
macrophyte beds, with high macroinvertebrate abundance and dominated by
gastropods and oligochaetes; and a community in fine sediments below the
macrophytes dominated by oligochaetes. The depth distribution of these
communities was related to substrate, macrophyte abundance, and shore-line
profile. Superimposed on this pattern were the effects of hillside slope and
exposure to prevailing north-west winds. Greatest abundance was associated with
macrophytes on stable shores at 4-7.5 m depth, i.e., below the effective
wavebase depth. Sediment deposition had only a localised direct effect close to
where river water enters the lake. Indirect effects were mediated through the
effects of suspended solids on water clarity, bottom limits, and production of
macrophytes and periphyton. Estimates of the proportion of littoral
macroinvertebrate biomass to whole-lake zooplankton biomass was 10:1 and for
production was 1.3:1, indicating the potential importance of the littoral zone
to whole-lake production.
Keywords macroinvertebrates; littoral zone; Lake Coleridge;
snails; macrophytes; macroinvertebrate production
M97054
Received 17 September 1997; accepted 22 December 1997
PDF file of entire paper: medium quality (1313K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
