Swimmers in Sydney’s northern beaches have been warned to exercise caution after two sharks were reported in separate sightings. According to Marine Rescue Sydney, a vessel about 200m off North Narrabeen reported seeing a shark longer than 6m. As part of standard practice, lifeguards shutter beaches after a shark sighting and deploy jetskis to patrol the waters, according to the Northern Beaches Council. Photo: NewsWire Credit: News Corp AustraliaLong Reef and Dee Why beaches were closed for three days by the Northern Beaches Council as authorities patrolled the area. “We have erred on the side of caution to keep beaches closed and our teams will remain vigilant in the days and weeks ahead,” Mayor Sue Heins said.