Abstract
The number of personal watercraft (PWC) used in coastal and inland waterways has increased recently, potentially disturbing people, fisheries activities, and wildlife and recreational resources. In 1997 we examined the behavior of nesting Common Terns as a function of exposure to PWC and other boats. PWCs traveled faster than motorboats near nesting islands, and came closer to birds. The number of terns that flew up in response to PWCs was greater than to motorboats. On one long-studied tern island, the terns suffered nearly total reproductive failure in 1996 and 1997. Because of these adverse effects, an educational and enforcement campaign was initiated in 1998. Public meetings included presentations by scientists, marine police, state conservation officials, PWC associations, marina owners, and the general public. In addition, an educational campaign was aimed at local PWC rental businesses and docks, and additional signs were posted around tern nesting islands. These measures proved effective: PWC traffic around the nesting islands was reduced, most PWCs that passed the tern nesting island did not venture outside the channel, and most PWCs reduced their speed. Although these measures did not eliminate the problem, they reduced the disturbance to the birds in 1998 and 1999, allowing increased reproductive success, representing a successful co-management program.