Tom Chorneau, Chronicle Sacramento Bureau
PDT West Sacramento, Yolo county -- Wildlife rescuers will give a 45-foot humpback whale and her calf the weekend off after attempts to lure the two out of a river channel 70 miles from the ocean failed again Friday.
The two whales have been calmly circling since Sunday in a turning basin that serves the Port of Sacramento. Experts believe the whales inadvertently turned inland from the ocean during their annual migration north.
While the two whales appear to be in good shape, marine experts are growing concerned about their welfare in the unnatural setting that can provide almost no food.
Their plan is to suspend efforts to lure the two back down the river using whale recordings broadcast underwater until Monday. If the same strategy fails again, however, federal and state officials said they are likely to organize a herding operation employing a flotilla of boats on Tuesday.
"The longer they are in the (river) system, the more at risk they are," said Rod McInnis, southwest regional director for the National Marine Fisheries Service. "But they are not in immediate danger right now."
Left unsaid, however, are the prospects of the two whales remaining in the river over next week's Memorial Day holiday, which traditionally attracts big crowds to Sacramento's rivers and waterways.
The two whales set an inland travel record for their species by traveling more than 70 miles up the delta. Somewhere along that journey, both sustained injuries thought to have been caused by a ship propeller.
But a recreational boater told The Chronicle on Friday that he believes the keel of his sailboat may have been the source of the injuries.
Karl Miller of Sacramento said he was on his 38-foot sailboat in the shipping channel when he collided with something. He described a sudden lurch and a jerk that lifted the 8-ton boat about 2 feet out of the water.
"It just picked us straight up and set us back down,'' said Miller, who did not see a whale at the time. "I've hit lots of things with boats, and this is the strangest encounter I've ever had."
Miller, the part-owner of an office supply store in Sacramento, has been sailing in the delta for about 25 years. He said he had initially thought he had ran aground on a sandbar, but his depth finder was reading between 10 and 18 feet at the time.
Federal marine officials said they planned to talk to Miller about the accident but could not speculate further.
Meanwhile, Dr. Frances Gulland, director of veterinary science at the Marine Mammal Center in Sausalito, told reporters that while the wounds don't appear to be life-threatening, they are nonetheless of great concern and part of the reason that rescuers wanted to take their time coaxing the animals back down river.
The rescue team spent much of Friday broadcasting a series of whale recordings underwater in the hope that the two animals might follow the source boat downstream.
The same tactic had been tried Thursday; both efforts were unsuccessful.
Gulland said the recordings were from whales that lived in both Alaska and California. Many of the recordings were sounds of whales feeding.
McInnis said they would try to transmit recordings again Monday but did not seem confident that it would work.
Still, researchers said that as things stand, the whales are not currently at risk.
"These animals are not in a terribly bad situation, they are actually pretty normal," said Pieter Folkens, director of the Alaska Whale Foundation. "We don't have a level of urgency that others might be having; we are taking it slowly and deliberately. We don't want to make any mistakes."
Public interest in the two whales drew several thousand onlookers to the dusty West Sacramento levee banks both Thursday and Friday afternoon.
Lt. Gov. John Garamendi, who played a key role in organizing the rescue of another humpback whale, "Humphrey," in the Sacramento River in 1985, urged local residents not to come to the site but instead follow the events through the media.
Garamendi was pressed by reporters about naming the two whales. Several news organizations have been running contests to name them. After a quick moment, Garamendi announced that the mother should be named Delta -- because of the location; and the calf, Dawn, because "this is a new beginning."