The largest specimens of nanophytoplankton are nearly as wide as the thinnest strand of a human hair, while the incredibly tiny picophytoplankton are 10 to 100 times smaller.
Although virtually invisible, these two self-sufficient, microscopic organisms are the beginnings of the food chain across the planet’s aquatic mammal populations, including those that thrive in Australia’s major marine habitats. represents.
But scientists say these microbes are threatened by ozone depletion and global warming.
Join our team of South Australian scientists to learn if we can do something about it.
Their multi-year research focus has been on precisely how pico- and nanophytoplankton underpin the hitherto stable resources of animal or zooplankton species that support vast and diverse food webs within the Great Australian Bight. was to establish
Think vast seagrass plains and kelp forests, ranging from protected reef sea dragons, great white sharks to mighty blue whales and other exotic animal species.
The bay has long been thought to have low plankton biomass, but during the summer months rising ocean currents provide nutrients, causing phytoplankton blooms on the western shelf and coastal waters of Kangaroo Island. .
However, the research team found that the region actually produces enough pico- and nanophytoplankton to sustain a relatively constant supply of important zooplankton species.
“Our findings dispel the myth that the Greater Bay is an oligotrophic sea (lacking plant food),” said Associate Professor Jochen Kempf, an oceanographer at Flinders University. increase.
“Instead, our findings indicate an annual supply of nutrients that fuel the marine food web, possibly related to the region’s high degree of nutrient recycling.”
Project co-author and PhD student Michelle Newman said the study features the analysis of phytoplankton pigment markers and requires a laborious and costly process to collect water samples. I was.
To this end, Dr Mark Davell of the South Australian Research and Development Institute has led over 100 cruises employing the capabilities of the federally funded Integrated Ocean Observing System (IMOS).
The program uses underwater vehicles, moorings, research vessels, satellites and radar to obtain information about the oceans and provide high quality scientific data.
“The phytoplankton project is made possible by the IMOS investment,” says Doubell.
“Each drop of seawater contains thousands of individual plankton.
“Analysis of over a decade of water samples conducted in this study has advanced our knowledge of the health and productivity of marine ecosystems and the composition of plant ecosystems underlying the fisheries they support.”
Kaempf said the ongoing research is important “to seize the opportunity to understand the impacts of climate change on this important marine ecosystem, such as the increased risk of marine heatwaves.”