Bradford et al.--Hydrology, plankton, nutrients-Pelorus Sound

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Home < Publications < Our Journals < nzjmfr < 1987 < Bradford et al.--Hydrology, plankton, nutrients-Pelorus Sound

New Zealand Journal of Marine and Freshwater Research abstracts

Hydrology, plankton, and nutrients in Pelorus Sound, New Zealand, July 1981 and May 1982

JANET M. BRADFORD

FOOK HOE CHANG

RUTH BALDWIN

BRUCE CHAPMAN

MALCOLM DOWNES

PAUL WOODS

Division of Marine and Freshwater Science Department of Scientific and Industrial Research Private Bag, Kilbirnie Wellington, New Zealand

Abstract The distribution of temperature, salinity, dissolved inorganic nutrients, and chlorophyll a is described along a transect in Pelorus Sound, as are phytoplankton populations and zoo-plankton biomass. River water contributed dissolved inorganic nutrients to Pelorus Sound; silicon was a conservative property. Pelorus Sound was a sink, and the open sea a source for nitrate-nitrogen. Havelock Arm and Cook Strait water appeared to be a source for ammonium-nitrogen. Winter cooling at the head of Kenepuru Sound produced high-density water which sank at the confluence with Pelorus Sound; this is a mechanism (in addition to internal tides) whereby low-salinity high-nutrient water is mixed downwards. Phytoplankton biomass was dominated by diatoms in July 1981. Zoo-plankton biomass in outer Pelorus Sound in May 1982 was dominated by Amelia aurita. The distribution of chlorophyll a is discussed in relation to the input of river water, inorganic nutrients, and variations in zooplankton grazing pressure. The proposition that more mussel farms would result in long-term food limitation of cultured mussel production is discussed.

Keywords Pelorus Sound; hydrology; nutrients; chlorophyll a

PDF file of entire paper: medium quality (876K); (scanned from paper original: notes about this process)

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