New Zealand Journal of Marine and Freshwater Research abstracts
Variability in spatial and temporal abundance of glass eels (Anguilla
spp.) in New Zealand waterways
D. J. Jellyman
National Institute of Water and Atmospheric Research Limited
P.O. Box 8602
Christchurch, New Zealand
email: d.jellyman@niwa.cri.nz
B. L. Chisnall
National Institute of Water and Atmospheric Research Limited
P.O. Box 11 115
Hamilton, New Zealand
J. R. E. Sykes
M. L. Bonnett
National Institute of Water and Atmospheric Research Limited
P.O. Box 8602
Christchurch, New Zealand
Abstract The regional and annual variability in the
abundance of newly arrived glass eels, Anguilla australis (Richardson)
and Anguilla dieffenbachii (Gray), were examined using glass eel densities
(n = 100 m-2) from electric-fishing samples collected at
14-day intervals over 5 years from 13 streams/rivers throughout New Zealand.
Although the density of shortfin eels exceeded that of longfin eels for any
one year, the annual trends for both species were generally similar. Both
species behaved independently, but significant factors affecting density
were “year” and “region”, with the pronounced regional effect for longfin
eels attributed to “coast” (east or west), but not “island” (north or south).
There was no evidence of declining recruitment for longfin glass eels.
Keywords glass eels; density; recruitment variability
M01041 Received 10 May 2001; accepted 26 February 2002; published 17 September 2002
New Zealand Journal of Marine and Freshwater Research, 2002, Vol. 36:
511-517
0028-8330/02/3603-0511 $7.00 © The Royal Society of New Zealand
2002
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