“The clock is running out for right whales, and further delay is unacceptable," Kristen Monsell, oceans legal director at the Center For Biological Diversity, said in a statement.
The center filed the lawsuit along with the groups Whale and Dolphin Conservation, Defenders of Wildlife and Conservation Law Foundation.
The conservationists are asking a federal judge to force the National Marine Fisheries Service to issue a decision on petitions they filed seeking expanded protections in 2012 and again last August.
They want speed limits imposed on vessels smaller than 65 feet (20 meters) long, which are currently exempt. They are also seeking expanded speed-limit zones in some areas and for reduced speeds to become mandatory in certain cases where they are now voluntary.
National Marine Fisheries Service spokeswoman Allison Garrett said the agency does not comment on pending litigation.