n this Wednesday, May 25, 2016 photo, a sign at Chatham Lighthouse Beach beach warns of dangerous currents and sharks in Chatham, Mass. Additional Cape Cod towns have installed the signs this year. Officials and researchers from Cape Cod to the Carolinas are looking at responses ranging from the high-tech to the decidedly low-tech as they deal with a growing great white shark population. (AP Photo/Philip Marcelo)