Cook Islands non-governmental organisation Te Kōrero O Te ‘Ōrau has surged past its target of removing 10,000 taramea (crown-of-thorns starfish), a notorious coral predator, from the deep blue of Rarotonga.

The environmental NGO consisting of Cook Islanders who are passionate about protecting our culture, environment, wellbeing and indigenous peoples, initiated Operation Taramea in 2020.

Close to 15,000 taramea have been collected, surpassing the initial target of 10,000.

Last year alone, over 6000 taramea were pulled from the sea – the highest number removed in a year.

Kōrero O Te ‘Ōrau chairman and marine biologist Doctor Teina Rongo said last year’s effort was concentrated on the western side of the island between The Edgewater Resort to The Rarotongan Beach Resort and Lagoonarium.

“What we are learning is that the taramea moves,” Dr Rongo said. “When we were focused in town there wasn’t much in Arorangi. We kept hammering the town area. I think we were able to control that situation now.”

Then they starting to see a population of taramea showing up on the other side of the island.

This year, the group started collecting taramea at Avana Harbour because of reports they were seen in the passage.

Dr Rongo said there wasn’t much in Avana, not as heavy as the other areas, “they were probably the local taramea population, since their numbers haven’t gone up”.

Kōrero O Te ‘Ōrau has been studying and documenting the movements of the taramea.

“What we are finding is that taramea tend to aggregate around areas where there are streams,” said Dr Rongo.

In Arorangi, the taramea congregated around the Kavera stream area.

“We would have taken about 5000 of the 6000 taramea last year from there,” he said.

Avarua and Nikao were the same, taramea were located in areas where the freshwater streams flow into the sea.

“We’ve done stock checks on the south side of the island like Titikaveka, its beautiful, pristine, the corals are really healthy,” Dr Rongo said.

Kōrero o te 'Ōrau may not undertake much more taramea collection this year, as most of it has already been removed. However, the group will continue to monitor problem areas.

This will provide an opportunity for the project to focus more on the Pa Enua, specifically Atiu and Mauke. The team has already been supporting Aitutaki in the eradication of taramea.

According to Dr Rongo, Rarotonga, like Mangaia, is isolated in terms of support from other islands with regards to recruitment – the process of small, young fish, or coral transitioning to an older, larger life stage.

“Whether it’s fish, or coral, they’re not getting much of that (recruitment) as opposed to Nga Pu Toru (Atiu, Mauke, Mitiaro),” Dr Rongo said.

“You can think of them (Nga Pu Toru) as one, when one is in trouble the others are supporting and their recovery is a lot faster than Rarotonga.

“But that doesn’t mean those islands are not important, we were more focused on Rarotonga because of its isolation.”

Kōrero O Te ‘Ōrau and Dr Rongo continue to do the science to confirm what they have learnt.

“Right now, this is what we think is happening,” he said. “We are also doing research to confirm this and we are doing genetic studies with the taramea to use the taramea to help us understand the connection between these islands. This in the long term will help us manage these islands properly.”