Climate change

Global heating impact on phytoplankton represented in 90 years of data

written by Oceanographic Staff

Australian researchers from the University of Technology Sydney (UTS) have found a significant warming signature in the phytoplankton community, using data from one of the longest time series of phytoplankton in the Southern Hemisphere.

The data set used was gathered over the course of nearly 90 years, ranging from 1931 to 2019 and collected from a Pacific Ocean coastal station offshore from Sydney.

Ninety years of data shows global warming impacts on foundation of marine ecosystems phytoplankton

“We examined the phytoplankton community response to this long-term ocean warming using the Community Temperature Index (CTI*),” said lead author, Dr Penelope Ajani. “We found a significant increase in the CTI overtime which suggests that the relative proportion of warm-water to cold-water species has increased.”

She added that environmental data showed ocean temperature had risen 1.8°C over the course of 90 years in south-eastern Australia, one of the greatest warming regions in the world.

The research team said that an almost 40% increase in the chain-forming diatom species Leptocylindrus danicus may provide a glimpse of the functional traits required to be a potential survivor of climate change.

“This species does well in warmer water, reproduces rapidly and can survive in a wide temperature range,” said Dr Ajani. “Together with the formation of resting spores and a high degree of variability in size, shape and physiology, these traits may point to the adaptive capacity or survivability of species under climate change.”

This research provides insights into the potential traits that may determine the adaptive capacity or survivability of species under climate change. The researchers’ findings are also important for identifying sensitive indicators for further monitoring and any possible flow on effects for biodiversity and fisheries production under global warming.

*The CTI is an index of the preferred temperature of a phytoplankton community.

For information regarding co-authors and to read the full study, “Global Warming Impacts Micro-Phytoplankton at a Long-Term Pacific Ocean Coastal Station”, click here

For more from our Ocean Newsroom, click here.

Current issue

Back issues

Enjoy so much more from Oceanographic Magazine by becoming a subscriber.
A range of subscription options are available.