Cape Town - Beach and ocean users should expect an increase in in-shore shark activity over the spring and summer months, the City of Cape Town has warned."Typically, shark sightings start in late August, and continue through to April, with most sightings being reported in mid-summer," mayoral committee member for energy, environmental and spatial planning, Johan van der Merwe, said."White sharks are present in our waters all year. However, surfers are asked to be especially vigilant in the stretch between Sunrise and Macassar beaches during the spring and summer months, as research has shown that the shark presence in these waters increases at this time of year."He thanked the city's staff and Shark Spotters for helping to ensure the safety of beach-goers.The Shark Spotters’ information centre at Muizenberg Surfer’s Corner is open to the public from 08:00 to 18:00 seven days a week. "The exclusion net has proven to be an effective shark safety measure, by creating a physical barrier that prevents sharks from entering the bathing area. It will be in full operation during the 2015/2016 summer season.""The Shark Spotters will keep beach users informed about the deployment of the net via Twitter and Facebook, and signage is displayed when the net is deployed," Van der Merwe said.Members of the public are encouraged to report any sightings of white sharks to the Shark Spotters.Safety tips:- Use beaches where Shark Spotters are on duty.- Use the Shark Spotters signs to familiarise yourself with the four-flag warning system and warning siren.- Do not swim, surf or surf-ski when birds, dolphins or seals are feeding nearby, or trek-netting, fishing or spear fishing is taking place.- Do not swim in deep water beyond the breakers.- Do not swim near river mouths.- Do not swim, surf or surf-ski if there has been a whale stranding nearby.- Be aware that the rate of encounters with white sharks rises significantly when the water temperature is warmer (18°C or higher), and during new moon, due to increased opportunities for feeding.