When Channel 2 reported that Delta Lake would be closed for swimming due to a Hazardous Algae Bloom (HAB), I'll admit, at first I was confused. Not because of the bloom, per say. But because I eat algae. All different sorts. And some are blue-green too. Granted, I get mine in a package from the health food store, not from a random patch of greenery floating to shore. Although, I do know of foraging types who do. In fact, NPR reported in an article called,

Bountiful Beach Buffet: Fresh Seaweed Is Making Waves Among Foragers

As seaweed continues to gain popularity for its nutritional benefits and culinary versatility, more people are skipping the dried stuff in the grocery store and going straight to the source: the ocean itself. At low tide on West Coast beaches, foragers hop between rocks looking for bladderwrack, sea lettuce and Irish moss to take home with them. Sea vegetable foraging has become so common, in fact, that you can take a class to learn what to harvest and what to avoid.

So. Algae is edible. Like, you can go to the beach and see something floating and potentially take it home for brunch. Except, all algae isn't fit for snacking.

Brown, Red and Green algae are edible for the most part. You can learn more about such things here.

But the stuff you can't eat is often prevalent in bodies of fresh water. According to the ASPCA website,

Blue-green algae, otherwise known as cyanobacteria, is most likely to thrive in bodies of fresh water when the weather is warm—75 degrees and over—and sunny. Warmer weather promotes the growth of cyanobacteria which, in turn, causes more algae intoxications during this time. Cyanobacteria is incredibly toxic and is known to cause poisoning in dogs, cats, livestock, wildlife, birds, fish and even humans.

ASPCA  goes on to say that, 

Water containing toxic blue-green algae will often appear as a pea-green paint or as slime on the surface of the water. If certain wind conditions are present, the film will often concentrate along the shoreline in areas where animals may drink or swim. Dogs can develop poisoning when they drink from, or even swim in, contaminated water sources. If blue-green algae is ingested, it can cause severe neurologic or liver damage.

The New York State Federation of Lake Associations reports that,

Harmful Algal Blooms, or HABs, are an increasing concern in freshwaters around the world.  New York lakes are no exception. Certain types of blue-green algae, also known as cyanobacteria, produce toxins that can harm other organisms, including humans. Not all algae is blue green, and not all of the blue green species that are capable of producing toxins do so all of the time.

So please, heed all warnings about HAB when they pop up (for you and your pet) because the ASPCA is clear:

Signs of blue-green algae toxicity includes:

• Seizures
• Panting
• Excessive drooling
• Respiratory failure
• Diarrhea
• Disorientation
• Vomiting
• Liver failure
• Ultimately death