A harmful plankton bloom and poor water conditions caused large mortalities at three Cermaq salmon farms in northern Clayoquot Sound near Tofino, with up to 185,000 fish lost at one site. DFO says disease was ruled out; critics warn the die-off could affect wild salmon and the marine environment.

Authorities have detected blue-green algae in Loch Moy, south of Inverness, and are urging the public and pet owners to avoid contact with the water. Warning signs are being posted as agencies investigate potential health risks.

Alaska health officials issued an alert after wild shellfish from Kachemak Bay’s inner bay tested above regulatory limits for paralytic shellfish poisoning toxins. Residents are warned not to harvest or eat untested wild shellfish; monitoring and test results are being posted by the Alaska Harmful Algal Bloom Network.

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.

Sustained high temperatures have led to algal blooms at several sites in the Haparanda Archipelago, and local authorities are advising people to avoid bathing.

A blue-green algae bloom detected at Lower Thetis Lake’s main beach prompted a Capital Regional District health advisory on July 20, 2025, warning humans and pets to avoid the water.

An algal bloom was detected at the municipal Lulsundet beach in Luleå on July 15, prompting warning signs and questions from residents about potential health and safety risks.

A rapid, multi-agency response is underway on St. George Island, Alaska, to investigate a multispecies mortality event linked to a harmful algal bloom, with concerns that paralytic shellfish poison (PSP) toxins may be affecting local wildlife and human health.

Observers from a small plane reported unusual green color in lakes and ponds, raising concerns about lake health and the potential for invasive species.

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.

An algal bloom in Northern Norway dominated by Chrysochromulina and Phaeocystis has caused massive fish die-offs in recent weeks, with up to one million farmed fish reported dead around Astafjorden.

A bloom of non-toxic Noctiluca algae is lining Saanich Inlet’s shoreline; safe for swimmers and shellfish consumption so far. Scientists say the bloom is not producing toxins yet, but could as the water gets warmer. “This one is a bit early!” said Galbraith.

Domoic acid poisoning is stranding marine mammals as warnings are issued to beachgoers of the threat posed by animals that are transformed by their illness.