Red tide is no joke. Too many local beachgoers, however, are treating it that way.

Red tide, of course, is actually not a tide at all. It’s an algae bloom that chokes out oxygen in the water, and it’s a poison — “paralytic shellfish poison,” to be exact. If you ingest it, it can cause everything from drowsiness and diarrhea to paralysis and death.

When the poison makes its way into the local shellfish population — think soft-shell clams, blue mussels and quahogs — it creates a dangerous situation. The state of Massachusetts conducts a robust testing program for red tide, and shuts down local clam flats when it finds an outbreak.

That’s what happened June 18, when the Bay State announced that local flats from Essex to Salisbury would be closed until further notice. It will be at least three weeks until testing reveals whether the flats can reopen.

Most, if not all, of the region’s commercial harvesters have honored the ban. However, many recreational clammers — licensed or unlicensed — remain ignorant of the ban or are choosing to ignore it. In doing so, they are putting lives at risk.

Local shellfish constables have reported a spate of violations across the region, as casual clammers pull shellfish from the sand for summer parties or to share with friends. And the harvesting is going on in spite of the threat of fines that range from $300 to $2,000.

Just last week, Gloucester officials documented 16 violations, including one that involved 70 pounds of illegally harvested surf clams, and one on Independence Day that involved 40 pounds of surf clams culled from Wingaersheek Beach.

That’s a lot of shellfish. And it can poison a lot of people.

“We’re really trying to alert all beach-goers to the health dangers of taking shellfish during the closure,” Gloucester Shellfish Warden Peter Seminara told reporter Sean Horgan last week. “It presents a danger to the public’s health, and it does have an economic impact on our commercial clamming industry if people start getting sick from shellfish harvested in Gloucester.”

And it’s not just the clamming industry’s reputation at risk. If visitors to the region hear of people getting sick, they’ll steer clear of the restaurants that have made a name for themselves serving fried clams and steamed mussels — even though those establishment take great pains to serve “clean” shellfish.

Pulling a few shellfish from the sand may seem like a fun summer pastime. Under these situations, however, it ranks up there with shooting off illegal fireworks or drinking and boating.