– Virginian Pilot – Navy testing and training could kill dozens of dolphins, whales and other sea mammals and injure thousands more over the next five years, according to the service’s own analysis. But while environmental groups say those estimates only scratch the surface of the impact that sonar and explosives can have on sea life, the Navy believes that most of those injuries would be temporary, that the numbers will likely be lower and that the long-term effects on the species will be negligible.