Ghasemzadeh, J. (1993). The zooplankton of Cooks River, N.S.W., with special reference to the biology of Gladioferens pectinatus (Brady). M.Sc. Thesis, University of New South Wales, Sydney, Australia. 190 pp.

126501

Ghasemzadeh, J.

1993

190 pp.

Publication

Available for editors   [request]

Monthly, daytime zooplankton samples were taken over a period of seventeen months at six sites in the Cooks River estuary from May 1991 to September 1992. A survey over a full tidal cycle in the lower estuary and a diurnal survey at all sampling sites were also carried out. Major changes in the hydrology were two heavy floods, (June 1991 and February 1992) during which the whole river was flushed into Botany Bay and low salinities were established throughout the estuary. A quick post-flood recovery of zooplankton, especially the extension of Gladioferens pectinatus to the lower estuary, was observed but the estuary reverted to dry conditions in a few days. A drought period from August to November 1991 was associated with a marked decrease in the numbers of taxa and density of zooplankton. A total of 41 planktonic taxa were recorded and the number of taxa decreased greatly from marine to freshwater zone. Barnacle nauplii were most numerous in daylight surveys but calanoid copepods formed the bulk of the zooplankton community, being most abundant in diurnal surveys. The seasonal abundance and distribution of different zooplankton are discussed. The genus Acartia was the most abundant calanoid in the marine zone. Six other taxa were also confined to the marine zone with occasional intrusions to the upper estuary with tidal movements. Sulcanus conflictus was the most numerous copepod in daytime surveys and was always associated with Gladioferens pectinatus. G. pectinatus dominated in August and September 1992. Bentho-pelagic behaviour of G. pectinatus a n d Pseudodiaptomus sp was observed by their strong vertical migration in diurnal surveys. Eleven other taxa also exhibited a marked vertical migration in night time samples. In the laboratory G. pectinatus survived and grew to maturity in 18-23 days, depending on salinity and temperature. It could tolerate a gradual increase in salinity up to 580/oo. N o significant differences were found in the mean egg number and body length between laboratory bred G. pectinatus and individuals from field samples.

RIS (EndNote, Reference Manager, ProCite, RefWorks)
BibTex (BibDesk, LaTeX)

[Back to search]