WEDNESDAY, APRIL 30, 1980
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FISH LOSS CAN BE REDUCED
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ABOUT 35 TONNES OF FISH WERE LOST AS A RESULT OF TWO OUTBREAKS OF RED ALGAE WHICH AFFECTED FISH FARMS EARLIER THIS MONTH, THE LEGISLATIVE COUNCIL WAS TOLD TODAY (WEDNESDAY).
REPLYING TO A QUESTION FROM DR THE HON HO KAM-FAI, THE DIRECTOR OF AGRICULTURE AND FISHERIES, THE HON J.M. RIDDELL-SWAN, SAID SUPPRESSION OF THE ALGAE WAS EXTREMELY DIFFICULT BUT CHEMICALS WHICH COULD POSSIBLY BE USED TO CONTROL PLANKTON WERE BEING INVESTIGATED AND MIGHT PROVE USEFUL. THE USE OF BOOMS TO CONTAIN OUTBREAKS WAS ALSO BEING EVALUATED.
HE POINTED OUT THAT THE ADVERSE EFFECTS OF THE ALGAE ON FISH FARMS COULD BE REDUCED BY TOWING THE FISH RAFTS TO UNCONTAMINATED WATERS AND LOWERING THE FISH CAGES WHERE POSSIBLE.
+FISH FARMERS IN THE AFFECTED AREAS WERE ADVISED TO DO THIS AND AS A RESULT SOME FARMERS MINIMISED THEIR LOSSES, + HE SAID.
AS LACK OF OXYGEN WAS SUCH A SIGNIFICANT FACTOR IN FISH MORTALITY DUE TO RED ALGAE, HIS DEPARTMENT ALSO ADVISED FISH FARMERS TO USE ANY MEANS AVAILABLE TO INCREASE AERATION OF THE WATER, SUCH AS PROPELLERS OR SIMPLE PADDLING WHEN AN OUTBREAK OCCURRED.
STAFF OF THE DEPARTMENT HAVE DESIGNED A MECHANICAL AERATOR WHICH CAN BE USED FOR THIS PURPOSE AND INTEND TO INTRODUCE IT TO FISH FARMERS, MR RIDDELL-SWAN ADDED.
+AT PRESENT ALL OUTBREAKS ARE THOROUGHLY INVESTIGATED AND MONITORED TO TRY TO GET CLOSER TO THE FACTORS THAT CAUSE THEM WITH A VIEW TO PREDICTING POTENTIAL OUTBREAKS AND GIVING FARMERS AN OPPORTUNITY TO AVOID LOSSES,+ HE SAID.
THE FIRST RECENT OUTBREAK OF RED ALGAE OCCURRED BETWEEN APRIL 17 AND 19 IN THE NORTH EASTERN COASTAL WATERS OF THE TERRITORY, INCLUDING DEEP BAY, CHEK KENG AND SHA TAU KOK. THE LOSS WAS ABOUT 10 TONNES VALUED AT ABOUT $400 000. IT AMOUNTED TO SOME THREE PER CENT OF THE FISH FARMED IN THESE WATERS AND OCCURRED MOSTLY IN THE KAT O AREA.
THE SECOND OUTBREAK WAS ON APRIL 27 AND 28 IN THE YIM TIN TSAI AREA OF TOLO HARBOUR. ABOUT 25 TONNES OF FISH VALUED AT ABOUT $900 000 WERE LOST.
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