FRIDAY HARBOR, Wash. (AP) - Hydrophones near Washington's San Juan Islands have picked up dozens of sonar pings, raising worries the noise could harm marine mammals.

The coordinator of the Salish Sea hydrophone network, Scott Veirs, says at least 82 mid-frequency sonar pings were recorded early Monday. He says one observer found a Canadian navy vessel entering Haro Strait as she heard pings on the hydrophone located at nearby Friday Harbor, Wash.

A call to the Royal Canadian Navy late Tuesday was not immediately returned.

Veirs says the sounds weren't as intense as in May 2003, when whales were observed acting strangely after a U.S. Navy vessel emitted mid-frequency sonar signals in Haro Strait. But he says it's still not known what impact, if any, it will have on marine mammals.

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