Distribution of reactive phosphorus and plankton in relation to upwelling and surface circulation around New Zealand

For the New Zealand region, the distributions of reactive phosphorus, chlorophyll a , surface primary productivity, integrated primary productivity, and zooplankton biomass are collated, mainly from previously published data. The hydrology of the New Zealand region intimately affects the amount of reactive phosphorus available for phytoplankton growth. Winter cooling of surface waters is important in promoting nutrient recycling. Also, the New Zealand land mass and its submarine plateau disturb the general eastward flow of water, causing nutrient renewal, especially in summer, by upwelling associated with topographic features. Some statistically significant positive correlations exist between reactive phosphorus, phytoplankton, and zooplankton data averaged by 5° squares of latitude and longitude. In some upwelling areas (Three Kings Islands, Mernoo Gap, and Challenger Plateau) high reactive phosphorus concentrations are found in conjunction with maxima in chlorophyll a , primary productivity, and zooplankton biomass.