Antarctic stars in their eyes
Antarctic starfish are taking centre stage in revealing their resilience to climate change.
The initial results of a study looking at how Antarctic starfish adapt to climate change show they would continue to thrive and reproduce in a warmer, more acidic ocean - but may not grow as big.
The study carried out by marine biologist University of Otago Associate Professor Miles Lamare has just reached its two year milestone.
Five hundred Antarctic sea stars, scientifically known as Odontaster validus, were collected from the sea floor at McMurdo Sound in 2016. They were flown to Dunedin in special temperature-controlled tanks and have been grown in varying conditions in a special containment facility ever since. The tanks have water temperatures between 1 and 4 degrees Celsius and varying Carbon Dioxide levels, they replicate future conditions predicted for Antarctic seas.
Professor Lamare says the research team created computer models to then predict how animals may respond to the future in terms of growth and reproduction, and compared the models to real life results.
“The model predicted that if you increase the temperature, the sea stars can maintain reproduction but it would be at the cost of growth, so it was pleasing to see the real-life response matched these predictions.
“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,” he says.
A further 200 sea stars were collected in November with the help of American divers based at McMurdo Station. These will allow scientists to drill further into physiological responses to environmental stresses and changes.
“They are really good animals to work with, they’re hardy, travel well and do well in lab conditions – they’re the perfect Antarctic lab rat for us,” says Lamare.
Antarctica New Zealand Chief Scientific Advisor Dr Fiona Shanhun says the research provides valuable climate change insights.
“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 says.
The study continues with the additional sea stars and offspring from the original 500. There are also plans to use the computer model that predicted the changes on other species, next on the list is Laternula elliptica, an abundant Antarctic clam.
Lamare is carrying out the research alongside Dr Antonio Agüera of the Université Libre de Bruxelles and Biomar.
It is funded by the New Zealand Antarctic Research Institute with support from the Belgian Science Policy Office and the international Scientific Committee on Antarctic Research.