By Dan Joling

ANCHORAGE, Alaska -- An environmental group is suing to list ringed seals, the main prey of polar bears, as a threatened species because of diminishing Arctic Ocean sea ice.

The Center for Biological Diversity says the National Marine Fisheries Service has failed to act on its petition to list ringed seals and bearded seals, another ice-dependent species. Both are found off Alaska's northern coasts.

The group in June gave a required 60-day notice that it would sue the agency for missing a deadline on deciding whether to list ringed and bearded seals.

A listing would trigger additional protections for the animals.

The Center for Biological Diversity first petitioned to list the seals in 2008. A final decision was due in December but NMFS officials announced they would extend the deadline for six months.

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