It wouldn’t be Fourth of July week on the Cape without some shark alerts.

As predicted by shark experts, the apex predator sightings are picking up just as beachgoers head to the Cape for the holiday week.

Great white shark alerts were popping up on the Atlantic White Shark Conservancy’s Sharktivity app on Wednesday, shutting down beaches to swimming for some time.

“!! SHARK ALERT !! white sharks spotted by pilot off Head of the Meadow and Beachcomber,” posted MA Sharks, which is run by shark biologist John Chisholm.

“Download @sharktivity to stay up to date,” Chisholm added.

A shark was spotted west of Truro’s Head of the Meadow beach, and about a mile off of Wellfleet’s Beachcomber.

Shark alerts are issued when a great white shark sighting is confirmed close to a public beach. A Sharktivity notification goes out with each alert.

Before the shark alerts started popping up, researchers had reminded beachgoers to be safe this week.

“As we head into the holiday weekend here’s a shark safety limerick I made to remind people to be alert and stay safe at the beach. Remember: WHEN THE PURPLE IS OUT, SHARKS ARE ABOUT!!” Chisholm wrote about the purple shark warning flags at beaches.

Great white sharks in recent summers have come here to hunt for seals, feeding on the prey in shallow water close to shore. While white shark bites on humans are rare, they have occurred off the Cape — with the most recent bite, in 2018, resulting in a man’s death.

Some shark safety tips for those heading to the beach include: staying close to shore, avoiding areas where seals are present, staying away from schools of fish, avoiding murky water, limiting splashing, and adhering to flag warnings at beaches.