Red Tide & Public Safety

Red Tide first occurred in 1976 in Sabah and has been a fairly annual occurrence, although serious outbreaks has occurred only a few number of times. The Red Tide Monitoring System is a system put in effect by the Department of Fisheries, Sabah all year round to determine the occurrence of red tide, and especially the presence of PSP-toxic aquatic sealife. This system involves the collection of PSP-prone species of mollusc and fish and analysed at the Likas Fisheries Research Center. In accordance with this monitoring system, the location and species of the sample sealife are recorded. In addition, seawater samples are taken from the same location which are then analysed to determine the concentration of dinoflagellates and diatoms.

Checking Red Tide-causative organisms in the lab

The method by which the levels of toxins are determined from the sample shellfish and bivalves is the Standard Mouse Bioassay. In this test, mice (mice which are cultured specially for Assay) are injected with the toxin obtained from the clams. The assay is standardized using purified saxitoxin. Results are given as micrograms of saxitoxin equivalents per 100 grams of shellfish meats (g/100g).

Cochlodinium polykrikoides, a Red Tide-causative dinoflagellate

Three motile cells of Pyrodinium bahamense var. compressum in chain form

In conjunction with the Red Tide Monitoring Program is the Public Safety Program. The basic aim of this program is to prevent the threat of PSP poisoning from actually affecting the local population. This is done by informing the public (through the mass media and direct contacts) not to collect or fish, sell or eat affected species of seafood (read a sample Press Release). This activity is carried out by the Department of Fisheries closely in conjunction with the Health Department. The actual activities include warnings and information dissemination regarding the dangers of Red Tide as well as stopping and preventing people from selling these hazardous seafood working under the ambit of the Food Act. As harmful algal blooms are also a threat to aquaculture species, the Department also give advisory to fish farmers and other aquaculture operators.

A newspaper Red Tide Alert on 24th March, 2012

Download a primer on Red Tide ( PDF File 3.59 MB)


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