New Zealand Journal of Marine and Freshwater Research abstracts

---

Picophytoplankton in the Hauraki Gulf, New Zealand

WEBBER E. BOOTH

MORTEN S0NDERGAARD*

Department of Botany
University of Auckland
Private Bag, Auckland, New Zealand

Abstract Qualitative and quantitative data for picophytoplankton from the Hauraki Gulf, northeast New Zealand, were gathered from May 1986 to February 1987. Records for both whole and size-fractionated samples (net-, nano-, and picophytoplankton) allowed the relative contribution by the picophytoplankton to total biomass and overall rates of carbon fixation to be estimated. Picophytoplankton represented a mean value of over 30% of the total chlorophyll a in winter and c. 20% in other seasons. In terms of total carbon fixation, values of 23% and 13% contribution were obtained. The picophytoplankton were composed of chroococcoid cyanobacterial cells, 0.7-1.2 ^im in diameter, at densities between 10³ and 10⁴ ml"¹ together with larger (1-2 |im) eukaryote cells at densities up to 10³ ml"¹. Winter counts were lower than those for summer. Cyanobacteria displayed subsurface peak densities higher in the water column than the eukaryotes. The cyanobacterial cells at depth tended to be larger and more brightly fluorescing than those in the surface waters.

Keywords marine picophytoplankton; qualitative data; quantitative data

New Zealand Journal of Marine and Freshwater Research, 1989, Vol. 23: 69-78 0028-8330/89/2301-O069$2.50/0 © Crown copyright 1989 Received 9 November 1987; accepted 16 May 1988

PDF file of entire paper: medium quality (778K); (scanned from paper original: notes about this process)

---

This year's abstracts | Journal home page | All abstracts | Publishing home page