A team from the Cawthron Institute in New Zealand is working closely with the Ministry of Marine Resources (MMR) and Kōrero O Te `Ōrau to tackle the issue of ciguatera in the Cook Islands.

MMR senior marine ecologist and fisheries officer Phoebe Argyle said the Cawthron team were in Rarotonga for two weeks where they continued their ongoing work on ciguatera and methods of detecting the toxin-producing microalgae gambierdiscus in the environment.

She said marine scientists Charlee Maclean and herself assisted the Cawthron team collecting samples in Rarotonga where artificial substrates and resin toxin-trackers were used to collect microalgae and detect toxins around the Rarotonga lagoon.

Live samples of microalgae were also collected to look for new toxin producing species.

“During their trip they collected samples from Mangaia and Rarotonga. In collaboration with MMR they will also be analysing samples from Mitiaro and Aitutaki, with further sampling being done as part of MMR’s routine marine surveys.

“It is hoped that there will be an ongoing relationship between Cawthron and the Cook Islands to continue valuable ciguatera research.”

She said these samples will be analysed using methods that detect toxin producing species by looking for their DNA within a sample.

Argyle said this is an important step in ciguatera research as the toxic and non-toxic microalgae look the same under the microscope.

“DNA based methods are constantly becoming cheaper and more accessible, thus it is hoped that these kinds of tools could be used for monitoring around the Pacific in the near future.”

She said this research is important for the Cook Islands because ciguatera is a common occurrence here, and at present there is no method for testing seafood or effectively monitoring microalgae concentrations in order to predict higher ciguatera risk.

“Predicting ciguatera risk from microalgae concentrations is still challenging as the time lag between a microalgae bloom and fish is difficult to quantify, however with ongoing research it is hoped that this phenomena will be better understood.”

She added that Cawthron has worked with MMR in the past on giant clam aquaculture with staff training at Cawthron Institute in Nelson.

The team also came to Rarotonga in 2014 to conduct ciguatera research, during which they found two new species of Gambierdiscus.

The institute’s project leader Dr Kirsty Smith said they are working with Dr Teina Rongo of Kōrero O Te `Ōrau and MMR to investigate the species gambierdiscus - responsible for ciguatera poisoning.

And they are trying to determine its geographical distributions, environmental preferences and toxicity.

Smith said they hoped to develop simple and rapid tools to reduce costs for monitoring programmes and increase confidence in ciguatera risk assessments – reducing the number of illnesses.

She said apart from samples collected from Mangaia and Rarotonga last year December, they have further received samples from Mitiaro and Aitutaki.

She said they were still analysing the samples.