Project number: 1995-085
Project Status:
Budget expenditure: $20,000.00
Principal Investigator: Gustaaf Hallegraeff
Organisation: University of Tasmania (UTAS)
Project start/end date: 23 Jan 1996 - 29 Aug 1997


1. To improve the sensitivity of current algal watch programmes in Tasmanian waters, designed to protect shellfish and finfish aquaculture by means of frequent microscopic plankton analyses

Final report

Author: G.M. Hallegraeff and C. Ashworth
Final Report • 1997-06-25 • 2.06 MB


A prototype of an automatic algal monitoring buoy was developed for unattended operation in shellfish and finfish farm waters. The instrument employs novel antifouling and self-calibration strategies (subject to a provisional patent ) based on a battery-powered actuator extending into the seawater medium at 15 min intervals both a light source and a solid state sensor from a protective PVC cylinder. The optical sensor measures both ambient light and the signal from a high intensity LED light source, with separate readings being taken after travelling through an optical fibre reference path (internal standard) and after travelling through a 60 cm horizontal path of natural seawater. The optical system is suspended at 1 m depth (can be varied) from a float with the systems control and data acquisition system located above water.

Financial constraints ($20,000 FRDC budget) prevented us to also implement a radiomodem link to laboratory computer as originally planned. We are now seeking further funds to develop the instrument to a commercial stage (estimated market value per unit Aus $10,000) and extensively test its field performance under a range of environmental and algal bloom conditions.

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