Lake Erie’s annual summer bloom is underway, and it's shaping up to be one of the most severe in the past decade.

Pseudo-nitzschia cells under a microscope

From Alaska's Aleutian Islands to southern California, impacts since May have ranged from record-high concentrations of neurotoxins, to shellfish harvesting bans, to reports of sick and dead ocean life. 

It's the time of year for potentially toxic algae blooms in Lake Erie. But the stage for most blooms is set in spring.

Shallow melt ponds on the surface of consolidated sea ice act as skylights that promote massive under-ice phytoplankton blooms. These under-ice blooms may boost estimates of Arctic phytoplankton productivity by a factor of 10.

Phytoplankton productivity has increased 20 percent over the past decade as sea ice extent declines and more open water habitat is available.