SANTA BARBARA (CBSLA.com) — Officials are warning swimmers to be cautious after a great white shark sighting near the entrance of the Santa Barbara harbor.

A commercial fisherman spotted the 15-foot shark Monday afternoon between Stearns Wharf and the breakwater, Waterfront Department officials said.

Signs have been posted at more than a dozen locations near City beaches and on lifeguard towers.

Monday’s sighting is the second this month in the waters off the Central Coast.

Surfers spotted a six-foot-long great white on Aug. 14 near Leadbetter Point, officials said.

A seal was also reportedly bitten twice days before that.