A federal appeals court on Friday upheld many restrictions on the Navy’s use of mid-frequency sonar off the coast of Southern California, reinforcing a lower court ruling from last month. President Bush had tried to exempt the Navy from the relevant environmental laws in January, but the appeals court agreed with an earlier ruling that questioned the constitutionality of Bush’s attempted exemption, finding that there was no unforeseen “emergency” that would warrant it. Despite the slapdown, the appeals court granted the Navy a 30-day reprieve from some of the more restrictive requirements, such as shutting off the sonar when marine mammals come within 2,200 yards, if the sonar is being used “at a critical point in the exercise.” The reprieve also allows the Navy time to appeal to the Supreme Court.