SAN DIEGO -- The battle over Children's Pool appears ready to escalate, with news Saturday that the federal government is ready to go bat to protect a colony of seals that has taken over La Jolla Cove.

The National Marine Fisheries Service has asked the city of San Diego to take immediate steps to keep people away from the herd of harbor seals during their calving season, which begins now and lasts through the spring.

The NMFS says it will act to enforce the federal law they say mandates that the city prevent swimmers at the beach from annoying or distracting the protected pinnipeds, the San Diego Union-Tribune reported Saturday.

But the city is under a state court order to maintain the beach as a facility for humans, and to remove a buildup of sand at the cove's western end that has built up over decades and become a seal rookery.

The Union-Tribune reported Saturday that the federal government wants a rope barrier placed along the beach to keep people away from the seals and their cubs. A special agent in charge at NMFS told the city in a recent letter that "the rope barrier has been a needed step in the right direction, but closing the beach would make a safer environment for the nursing seals."

But the city is under a court order to remove the creatures, and restore the beach to the condition it was in 1931, when it was deeded to the city for use as a public swimming facility. The cove is the only east-facing ocean beach in all of Southern California, and its wave-free waters were used for decades for swimming before a rancorous crowd of seals colonized it about 15 years ago.

A federal lawsuit was filed by the Animal Protection and Rescue League of San Diego last week aimed at getting the state order overturned as contrary to federal law, which should supercede a state law. But federal courts often defer to local laws on matters of public safety, and the swimmers' legal use of the beach predates the enactment of federal law.

That makes the La Jolla seal issue a legal novelty. "This is the case that never ends," swimmers' attorney Paul Kennerson told the Union-Trbune.