The row continued yesterday over whether the devastation of the red tide could have been better predicted or prevented. Calling the algae spread the 'worst natural disaster' in living memory, acting assistant director for Agriculture and Fisheries Joseph Sham Chun-hung said it was unavoidable. But fishermen and campaigners said satellites could have been used to watch the growth of the red tide from when it began in March and to issue warnings. 'Firstly, what they should have done in March is to detect the source,' ousted Democrat legislator Dr John Tse Wing-ling said. 'The tide was detected as coming from the east so at that stage Fisheries and Environmental Protection Department officers should have made close connections with the mainland Government to monitor the situation and take measures. '[But they took] a passive approach. You cannot prevent 100 per cent loss but at least the loss would not be as disastrous as now.' The criticisms were rejected by Mr Sham who said satellites could not monitor movements and trends such as the red tide's flow. 'This is a natural disaster. The worst in Hong Kong as far as I can remember. I doubt if satellites could have monitored it,' he said. 'Satellites are used where the area is large. Hong Kong is small.' Fishermen continued to increase their demands for compensation from the Government yesterday. Fish traders' representative Wong Yung-kun said almost all of the SAR's fish farms were affected by the red tide, escalating the cost to the industry to $120 million. Increasing numbers of dead fish were found in Yung Shue O and Tai Tau Chau in Sai Kung, as well as Yim Tin Tsai near Tolo Harbour, he said. Red tide is a generic term for micro-organisms called dinoflagellates, that occur naturally in low wind, poor water aeration and temperatures of about 25 degrees Celsius. The algae - which varies in its colour and production of toxins - is aggravated by organic pollution. Warm air and low wind are forecast to continue, creating ideal conditions for the further spread of red tide.