Jochen Halfar, an associate professor from UTM’s Department of Chemical and Physical Sciences, has found a new method of modelling climate change by use of the algae Clathromorphum compactum. This species of algae is distributed throughout the Arctic and sub-Arctic oceans, and forms calcite crusts on the seafloor of shallow waters 15- to 17-metres deep.
Halfar worked with colleagues from Germany, Newfoundland, and the Smithsonian Institution to collect and analyze samples of this algae species. It was determined that C. compactum can provide information for climate reconstruction because its growth rate depends on the temperature and amount of light received in water.
The algae will stop growing when snow-covered sea ice accumulates on the water over the algae, and will resume growing when the sea ice melts. This climate-dependent growth cycle creates layers in the calcite crusts of the algae that demonstrate long-term annual growth.
C. compactum is a long-lived species, and can provide almost 650 years of information on annual sea ice cover change. According to Halfar, this is the first time coralline algae have been used to track changes in Arctic sea ice, and the algal record demonstrates a significant decrease in ice cover since 1850.
