Scientific voyage maps deep ocean changes across Cook Islands EEZ

A month long expedition underway in the Cook Islands is looking to further understand how climate change affects the ocean.

The voyage, which is a joint initiative between Climate Change Cook Islands and Earth Science New Zealand, aims to establish the first comprehensive baseline of conditions across the Cook Islands Exclusive Economic Zone (EEZ).

Researchers aboard New Zealand's state-of-the-art ocean research vessel Kaharoa II are collecting water samples, measuring ocean temperatures and currents, mapping the seafloor and testing for microplastics.

Voyage lead and oceanographer Denise Fernandez from Earth Science New Zealand said the expedition is the first step in building a long-term picture of the state of the Cook Islands ocean.

"Basically, we are trying to gather information from the ocean to describe the state of the ocean of the Cook Islands exclusive economic zone, so we can, in the future, know whether changes have been happening in this ocean. We can always come back to this reference period," Fernandez said.

Scientists are collecting data from the surface to depths of more than five thousand meters, with a particular focus on the Northern Cook Islands where 'ocean heat content' has increased significantly.

Fernandez said this study is vital as the changes happening below the surface, directly affects local livelihoods.

"If climate change will have some impacts in the heat and the salinity and the currents - that will also cascade on affecting ecosystems in this area.

"We know that from Cook Islands ecosystems and supporting the food chains, is very important for many industries and for people, so we are trying to try to give a description of this area in this time."

Predicting ocean changes

Climate Change Cook Islands director Wayne King said the expedition is helping develop a long-term ocean monitoring program.

"We don't know ourselves with 100 percent accuracy what is in our ocean. We generally know, of course there's fish and there's whales, and in some parts of it there's manganese nodules. But what we don't know is what else is there, if anything."

"The idea of it is to capture what we call baseline. That's all the information from the surface of the ocean right to the very bottom, and that will that will allow us to then know what changes will occur to that ocean over time."

For King, the information will help the Cook Islands understand how climate change is affecting fisheries, coral reefs, ocean chemistry and carbon storage - which he added, directly impacts the livelihoods of everyday Cook Islanders.

"That will be valuable to us as a country to better understand because we are an ocean state. Very small country land wise, very big country ocean wise. So we need to understand if there is change in those oceans."

Fernandez said the data can be used to predict changes in the ocean, long before it happens.

"All of the information that we collect now to state how much the ocean is changing, how much heat the ocean can receive, it is helping models that can forecast what's going to happen in 10 years.

"For a model to perform well, it needs a baseline, it needs the real observation to understand the processes that happen in the ocean. The more information we gather, the more information we can provide to those models, the more we can know about the future."

She added these predictions will support not only the Cook Islands resilience efforts, but those of the whole region.

"Because the ocean doesn't have hard boundaries, so what happens in Cook Islands can expand and move somewhere else. So this is important that we do now, not only for the benefit of Cook Islands, but also for the South Pacific community."

Empowering local youth

On board as an observer is Tangimetua 'Tango' Paerau from youth and environmental NGO Korero O Te Orau.

While he described the voyage as "outside his comfort zone", he believes it is important for Cook Islanders to be involved in scientific expeditions carried out in their waters - even if it is research they are unfamiliar with.

"This sort of stuff is way out of my comfort zone. But what I took from this experience [is] the ocean deserves our attention before any problems become massive," Paerau said.

"There's changes happening beneath the ocean that we don't know about as people... It's not visible, but it always influences our fisheries, coral reefs, the ecosystems, that so many of us depend on."

As a youth leader, he believes young Cook Islanders need to be included so they can be better prepared to make decisions as the country's future leaders.

"It is important to share that sort of knowledge with our youth to allow them to understand what's happening...

the ocean is changing quite a lot, and for the island nations, like the Cook Islands, those changes affect us all."

For Fernandez, involving Cook Islanders directly in researching their own ocean is just as important as the data itself.

"Information is power. Giving information to the people living in these waters is giving them the power to make decisions."

The voyage is scheduled to conclude on 23 July.