When the Navy announced its plans to use dolphins and sea lions as a swimmer interdiction system at Naval Base Kitsap-Bangor more than two years ago, an outcry about the perceived impacts of the cold water on dolphins arose.

That led to a two-year study on the actual impacts.

The results were contrary to that perception, said Navy Systems Center San Diego Spokesman Thomas LaPuzza at Wednesday’s open house at the Silverdale Community Center.

“We’ve had them in Norway, Denmark and Alaska in the winter and we’ve had them in Connecticut at a time when it was freezing,” LaPuzza said.

The Navy did a couple of studies, which showed the animals weren’t impacted by the cold water, LaPuzza said, referring to work done by research scientist Dorian Houser, who is a consultant for the Navy.

“We asked how cold could it be before we saw an increase in metabolism, which is the best way to measure the effect,” Houser said, noting that 42 degrees Fahrenheit was found to be the temperature at which a dolphin’s metabolism increased, but that on average the Hood Canal waters only reach 44 degrees Fahrenheit.

The studies were done with the animals remaining relatively motionless, so since they are going to be moving around, there should be no perceivable impact, he said.

“We’re going to keep their enclosed pens at 52 degrees (Fahrenheit), because for smaller and older animals it was 51 degrees,” he said.

While dolphins are found along the northernmost stretches of the East Coast, a few of the reasons they aren’t found as far north on the West Coast have to do with the lack of shallow waters on the West Coast and the availability of the dolphins’ preferred prey, Houser said.

The Navy had plans to use dolphins at Bangor as early as 1988, but that effort was the subject of a lawsuit filed by a few animal rights groups, LaPuzza said. Because of that lawsuit, the Navy has had to go through an extensive Environmental Impact Statement process unlike it did at King’s Bay, Ga., where dolphins have been used since 2005.

One of the issues from the earlier public hearings that has been resolved is the handling of animal waste that might drift into shellfish beds and impact water quality, he said.

“The animals will be in enclosed cases and we will collect the waste from it and put it into the Bangor sewer system,” he said.

The Navy also examined using only sea lions as a result of the earlier public hearings, but that comes with its own set of limitations, he said.

“You have to tell a sea lion where something is and get it close, but a dolphin can look out 300 yards and tell you if something is out there,” he said, adding that a dolphin can tell if a person is facing toward it or away from it at 300 yards underwater.

While remotely operated vehicles (ROVs) have worked well in places like Iraq in detecting underwater mines, LaPuzza said that unlike the Gulf seabed, which is relatively flat and debris-free, the Hood Canal seabed is littered with obstacles like coral that make it more difficult for ROVs to function to the level of dolphins and sea lions.

Currently, marine animals provide the best way for the Navy to comply with the Department of Defense mandate that security be improved at installations including Naval Base Kitsap-Bangor, he said.

“We’re not going to do anything that puts the animals at risk or that is unethical or inhumane,” he said.

In a video shown about the work of dolphins and sea lions in providing security, each animal was accompanied by a raft with sailors on board and at no time were the animals unaccompanied.

The Navy is accepting comments through March 1 at www.nbkeis.gcsaic.com or www.NBKEIS@spawar.navy.mil.