Nick Caloyianis
Coralline Algae
Over the span of their long lives, coralline algae preserve thousand-year-old records of environmental conditions in their hard, calcified crusts: their seasonal growth bands mirror the expansion and retreat of sea ice. Smithsonian botanist Walter Adey discovered that the seasonal growth of these algae provides evidence that sea ice has rapidly declined over the past 150 years.
Photo by Nick Caloyianis
