Four shark sightings temporarily close three Cape beaches

A shark advisory at Marconi Beach in Wellfleet, as pictured in 2017.CRAIG F. WALKER/GLOBE STAFF/FILE

Marconi and Newcomb Hollow beaches in Wellfleet and Nauset Beach in Orleans were closed temporarily Thursday after shark sightings, the Atlantic White Shark Conservancy said.

The shark at Marconi Beach was spotted at 11:39 a.m., so the beach was closed for an hour, a spokeswoman from the Cape Cod National Seashore said.

Newcomb Hollow Beach was closed for an hour at 11:45 a.m. after a shark sighting, said Suzanne Thomas, a Wellfleet Beach administrator. A buoy detected a shark at 1:40 p.m., so the beach was closed for one hour again.

Nauset Beach was closed for an hour when a shark was spotted 50 yards offshore at 1:18 p.m., according to the Atlantic White Shark Conservancy Sharktivity app.

These sightings bring the total number of shark sightings on Cape Cod and the Islands to 42 since Aug. 1. This was the seventh sighting at Marconi and the eighth sighting at Newcomb Hollow since July 1, according to a Globe tally. This is the third day in a row Newcomb Hollow and Nauset beaches were closed because of sharks in the water.