XN000022-1984-02-11 — Page 2

SATURDAY, FEBRUARY 11, 1984

PLAN READY TO DEAL WITH RED TIDES

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A CONTINGENCY PLAN HAS BEEN DRAWN UP AND A COORDINATION NETWORK ESTABLISHED BY THE GOVERNMENT TO MINIMISE HEALTH HAZARDS POSED BY TOXIC RED TIDES.

MAKING UP THE NETWORK ARE THE HEALTH AND WELFARE BRANCH, THE ENVIRONMENTAL PROTECTION AGENCY, THE ROYAL HONG KONG AUXILIARY AIR FORCE, THE AGRICULTURE AND FISHERIES, URBAN SERVICES, MEDICAL AND HEALTH AND MARINE DEPARTMENTS.

THE PLAN, INCORPORATING RECOMMENDATIONS BY THE WORLD HEALTH ORGANISATION, WAS DRAWN UP LAST SUMMER BY AN AD HOC GROUP ON TOXIC RED TIDES.

→WHEN THE FIRST TOXIC RED TIDE BROKE OUT IN OCTOBER LAST YEAR IN TAL PO HOI, THE VARIOUS DEPARTMENTS ACTED SWIFTLY TO ELIMINATE ANY POSSIBLE HEALTH RISK, + SAID MR PAUL HOLMES, EPA'S PRINCIPAL ENVIRONMENTAL PROTECTION OFFICER (WATER) WHO HEADS THE GROUP.

+ THE CONCENTRATION OF TOXINS FOUND WAS NO MORE THAN 1 200 UNITS PER KILOGRAM, WELL BELOW THE DANGER LEVEL OF 3 000 UNITS. THE KEY PROBLEM IS TO IDENTIFY A TOXIC RED TIDE BEFORE IT BECOMES HARMFUL TO HEALTH, HE SAID.

AT PRESENT, IT IS NOT POSSIBLE TO PREVENT RED TIDES WHICH ARE A WORLDWIDE PROBLEM AND, TO AN EXTENT, A NATURAL PHENOMENON.

THEY USUALLY OCCUR IN COASTAL WATERS AS A RESULT OF THE COMPLEX INTER-ACTION OF MANY FACTORS, INCLUDING THE PRESENCE OF NUTRIENTS IN THE WATER, TEMPERATURE, SALINITY AND LIGHT CONDITIONS, MR HOLMES EXPLAINED.

+A RED TIDE CAN BE IDENTIFIED BY THE CHARACTERISTIC PINK OR REDDISH BROWN COLORATION OF SEAWATER, CAUSED BY THE RAPID GROWTH OF DRIFTING MICROSCOPIC ORGANISMS KNOWN AS DINOFLAGELLATES, SOME OF WHICH PRODUCE TOXINS HARMFUL TO BOTH MARINE ORGANISMS AND HUMAN HEALTH.

MOST RED TIDES EXPERIENCED IN HONG KONG HAVE BEEN NON-TOXIC. THEY POSE AESTHETIC AND ECONOMIC RISKS RATHER THAN HEALTH HAZARDS, DISRUPTING COASTAL RECREATION AND KILLING FISH THROUGH OXYGEN DEPLETION.

BUT THE DANGER OF POISONING CAUSED BY SEAFOOD CONTAMINATED BY TOXINS SHOULD NOT BE OVERLOOKED, MR HOLMES EMPHASISED.

THE GOVERNMENT IS ALSO TAKING PRECAUTIONS AGAINST +PARALYTIC SHELLFISH POISONING+ CAUSED BY TOXIC RED TIDES THOUGH THIS TYPE OF INCIDENT HAS NEVER OCCURRED IN HONG KONG.

OFFICERS OF THE GOVERNMENT DEPARTMENTS WHO HABITUALLY SURVEY THE MARINE ENVIRONMENT REPORT ANY RED TIDE SIGHTED TO THE AGRICULTURE AND FISHERIES DEPARTMENT'S ABERDEEN FISHERIES RESEARCH STATION, THE FOCAL POINT OF THE INFORMATION NETWORK.

/CO-ORDINATION WORK