Environmental group Natural Resources Defense Council (NRDC) has filed a lawsuit against the National Marine Fisheries Services for violating a federal law by approving the use of sonar technology for the U.S Navy's training exercises.

According to the analysis made by the environmental group, the training exercises, which are practiced off the coast of California and Hawaii, will be responsible for the deaths of 155 marine mammals, at least 2,000 permanent injuries, disruption of marine animals' vital behaviors, and an estimate of 9.6 million cases of temporary hearing loss. This damage constitutes a 1, 100 percent climb over a period of five years.

Furthermore, the NRDC argued that beaked whales and the endangered blue whales will be the most affected species by the use of anti-submarine and amphibious training exercises. The agency also reported that there have been 10 cases of beaked whaled deaths and 13 cases of blue whale deaths caused by vessel strikes done during the training exercises.

The lawsuit also stated that the fisheries service have violated the Marine Mammal Protection Act by ruling that the training exercises will pose a "negligible impact" on the marine ecosystem. It also questioned the Navy's claim that the exercises followed the rules of the California's Coastal Management Program, despite the rejection of that claim by the California Coastal Commission.

"This is an unprecedented level of harm," a lawyer with Natural Resources Defense Council, Zak Smith, said to L.A Times. "In order to authorize these impacts on marine mammals, the service had to turn its back on the best available science."

As a response to the lawsuit, the Navy, together with the fisheries service stated that they have created "practical and reasonably effective" safety guidelines which will ensure the protection of marine mammals. This safety measures include lookouts on the bridges of ships and decreasing the sonar power of shutting it down completely if a group of whales are swimming nearby.

The lawsuit was filed in the U.S District Court of San Francisco. Last week, a similar lawsuit was also made by Earth justice together with five other environmental groups.