A sturdy, resilient starfish from Antarctica is giving Kiwi scientists insight into how climate change can affect the life cycles of sea creatures.
From a scientific perspective, the Odontaster validus is hardy, travels well, and does well in lab conditions, making it an ideal deep-sea lab rat. The starfish thrives in the cold temperatures of the antarctic, and lives up to 940m deep. That's why researchers at the University of Otago identified it as an ideal candidate to see how the effects of global warming would affect their life cycle.
The aim was not just to see if the sea stars would survive at higher temperatures, but how they would change, in terms of reproduction, growth and behaviour if they were subjected to changing ocean conditions. That doesn't just mean higher temperatures, but also more acidic water as a result of CO2 dissolving into the ocean.
A team of American divers assisted with the collection of 700 of the sea stars from the ice-clogged waters of the McMurdo Sound. From there, they were flown to Dunedin in temperature-controlled tanks.
Over the last two years, marine biologist University of Otago Associate Professor Miles Lamare has led a research team which observes how the starfish responded to conditions ranging between 1 and 4 degrees Celsius, and with differing levels of carbon dioxide.
The key finding was that the starfish were able to maintain the same level of reproduction, but that they were growing less. That was in line with the computer models developed by the team to predict how animals would respond to the conditions.
University of Otago Associate Professor Miles Lamare and Dr Antonio Agüera in Antarctica
"It was pleasing to see the real-life response matched these predictions," Lamare said.
"Interestingly, preliminary results indicate that the animals are quite happy in water up to 5 degrees warmer, but they change how they allocate resources which is important to know."
Antarctica New Zealand Chief Scientific Advisor Dr Fiona Shanhun said the research provided insights which could show climate change would affect a wide variety of animals.
"It is awesome to see the results of this research coming to fruition.
"The predictive computer model will be a great starting point for similar experiments with other creatures and how they might react to a change in conditions," she said.
The study has plans to soon expand to observing Laternula elliptica, a common clam also found in Antarctic regions.