A persistent heatwave in Finland is fueling dense blue-green algae blooms in the Baltic Sea’s Gulf of Finland and Archipelago Sea, with freshwater sightings remaining stable.

The Kachemak Bay National Estuarine Research Reserve detected Pseudo-nitzschia at bloom levels in Kachemak Bay starting July 4. This diatom can produce the toxin domoic acid, associated with amnesic shellfish poisoning, though toxin production is not yet confirmed. Observed bird deaths and marine mammal strandings have spurred collection of mussel samples for lab testing.