Scientists from around the country have begun necropsies on more than a dozen harbor porpoises found last spring, hoping to discover whether Navy sonar tests contributed to their deaths.

Experts who examined 11 harbor porpoises that died last spring — around the time a Navy ship conducted sonar tests in the area — found no evidence that the sound waves were a factor.

SEATTLE — An examination of harbor porpoises that washed ashore in Puget Sound last year showed no apparent ear damage from the USS Shoup’s sonar, Navy officials said Monday. More certain ...

It said scientists could not find any definitive evidence of ear damage in the porpoises that could be linked to the Shoup’s sonar. The Navy report, however, was more clear-cut. It took a broade ...

Mexico — Mexico’s Navy said Wednesday it is planning to expand the area where it sinks concrete blocks topped with metal hooks to snag gill nets that are killing vaquita marina porpoises.