New Zealand Journal of Marine and Freshwater Research abstracts

---

Effect of localised nutrient enrichment on the shallow epilithic periphyton of oligotrophic Lake Taupo, New Zealand

IAN HAWES ROB SMITH

NIWA-Freshwater
National Institute of Water & Atmospheric
Research Ltd P. O. Box 8602 Christchurch, New Zealand

Abstract A localised increase in nutrient concentrations in the shallow littoral zone of Lake Taupo, New Zealand, resulted from injection of secondary-treated, nitrified sewage effluent into the groundwater close to the lake. Coincident with this enrichment, there was an increase in periphyton abundance. This increase was restricted to the zone of enrichment and a biomass of up to 1000 mg chlorophyll a m"² was attained. There was also a change in species composition from a diatom/heterocystous cyano-bacteria-dominated assemblage to one dominated by two diatoms, Synedra ulna and Gomphoneis herculeana. Interpretation of the effect of nutrient enrichment on periphyton was complicated by occasional dramatic biomass declines in response to physical variables, notably strong wind events and lake level changes.

Keywords lake periphyton; nutrients; sewage effluent; species composition; chlorophyll a

New Zealand Journal of Marine and Freshwater Research, 1993: Vol. 27: The Royal Society of New Zealand 1993
Received 5 November 1992; accepted 20 May 1993

PDF file of entire paper: medium quality (479K); (scanned from paper original: notes about this process)

---

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