The Cook Islands Marine Resources Ministry has begun an intensive short-term study to detect harmful algae that may be the source of health problems in a small area of Titikaveka lagoon, the Cook Island News reports.
The study is being done on the recommendation of two scientists from New Zealand whovisited Rarotonga last month to evaluate the problem and is an extension of a programme of regular water testing started by the ministry early this year.
It uses chemical and biological methods to identify harmful algal species in fresh and marine water samples, as well as marine biotoxins in the lagoon and the air.
Acting Secretary of Marine Resources Ian Bertram said some algae were difficult to capture.
On top of that, some species were toxic at low levels, making the reliability of sampling relatively low.
The intensive study is designed to overcome these problems and will be conducted over a period that includes at least one occasion when the irritant syndrome that has been affecting Titikaveka is evident, or over a six-week period.
Two control sites outside the contamination area are also being sampled identically. The samples are collected during the incoming tide of each week and sent to New Zealand by courier.
When Titikaveka residents complain of throat, nose or eye irritation, the sampling programme will be increased to cover the full tidal cycle for two days after the problems are first noted.
Shellfish is also being collected from the same sites every week and the ministry has put Aitutaki clams in the lagoon for later toxin analysis in New Zealand.
Clams are used because they filter particles from the water and may have retained harmful algae over time.
