Feeding hatchery fish to a wild, starving orca is part of an unprecedented effort by federal scientists to save her life.
In an unprecedented intervention with a wild, free-swimming whale, federal scientists on Sunday attempted to feed live hatchery chinook salmon to a starving orca.
The result of the effort Sunday afternoon was inconclusive. Scientists could not tell what happened to the fish. And the orca appeared to take no note of them.
The orca, J50, is a 31/2-year-old member of the J Pod of the southern-resident clan of killer whales, and believed to be dangerously malnourished. Yet she did not change her swimming pattern or in any other way seem to take note of, let alone eat the salmon, said Brad Hanson, wildlife biologist with the National Oceanic and Atmospheric Administration’s NW Fisheries Center in Seattle.
“Did she detect the fish? We don’t know,” Hanson said. Eight fish in all were fed to the whales — or at least, put in the water. What happened to them is not known.
Monday morning, the whales were headed west, putting them out of range of any further attempts to feed J50, as she is expected to be in Canadian waters for at least several days, Hanson said. NOAA does not have a permit to feed wild orcas in Canadian waters.
If J50 and her family return to Washington later this week, Hanson said scientists will attempt to get another look at her, and decide whether to try feeding her again. Also on the table is the possibility of feeding her fish dosed with medicine.
Intervention began last week, with the administration of a dose of a broad-spectrum antibiotic by shooting J50 with a dart. While it is not known if she has an infection, the medication was administered prophylactically, as is done in captive display animals that don’t seem to be well for undetermined reasons, Hanson said.
The whale, always small for her size, is severely malnourished, with the bones of her cranium showing. J50 appears to be having trouble keeping up with her pod, even falling behind Sunday during periods of strong tides, Hanson said. She was actually going backward, while other members of her family surged by.
Members of the Lummi Nation transported the hatchery fish to the whale’s historic feeding ground off the south end of San Juan Island.
Crew on the Lummi boat put the fish in a tube exiting below the surface of the water about 100 meters in front of J50. “This type of thing has never been tried before. There were lots of things that could potentially go awry; we were very pleased we were able to do this,” Hanson said.
Deborah Giles, research scientist for University of Washington Center for Conservation Biology and research director for nonprofit Wild Orca, said biologists also were able to get fecal samples from members of J Pod over the weekend. Lab analysis this week should reveal whether the sample came from J50 and could reveal other clues as to her condition, including stress hormones.
The feeding operation carries the risk of habituating wild orcas to feeding.
“It’s a situation where with this animal we are concerned about its condition, we felt it was necessary to take this step, to see if we could improve its condition,” Hanson said. “We realize there is a potential for habituation.”
The feeding crew is taking steps to reduce the risk, including feeding the fish from a tube that terminates under the surface of the water, rather than a person pitching the fish off the back of a boat.
Orca whales are very intelligent and also have excellent eyesight, such that they could associate a particular boat, and even a particular person, with being fed.
“They do pick up on these types of things, very quickly,” Hanson said.
The southern-resident killer whales are a critically endangered population unique in the world, with only 75 members. The families of J, K and L pods have been in steady decline, reaching their lowest population in decades. The clan has not successfully reproduced in three years.
Tahlequah, a young mother in the clan, drew world attention as she carried her dead calf for at least 1,000 miles and 17 days.
Ken Balcomb, of the Center for Whale Research, reported over the weekend seeing her with her family — but not the calf. “Her tour of grief is now over,” he reported in a website update on a J35 news release. However, the ordeal of the southern residents, including finding enough to eat and contending with vessel noise and pollution of their urbanized home waters, continues.
Scientists have observed orcas and other mammals carrying their dead young, a behavior widely acknowledged by scientists as an expression of grief, said Joe Gaydos, science director of the SeaDoc Society.
Using field observations provided by Soundwatch, Gaydos plotted Tahlequah’s travels with her dead calf, as she swam, day after day, through the Salish Sea.
She traveled with the rest of her pod as far north as the Fraser River and as far south as Race Rocks in the Strait of Juan de Fuca, and beyond, a sight that brought attention to the plight of the southern residents from around the world.
Their biggest challenge is widely regarded to be lack of adequate food, particularly chinook salmon. Killer whales must eat hundreds of pounds of fish per day to survive, and pregnant mothers need even more.
Not only are they not getting enough to eat, but the fish they are eating is contaminated with toxins.
“The fish the orcas evolved to depend on for at least 80% of their diet are so contaminated with our persistent organic pollutants (POPs) like PCBs, PBDEs and DDTs, and so liberally seasoned with lead and mercury, that the Washington Department of Health guidelines suggest adult humans eat no more than eight ounces per week of Chinook even when they’re caught in what are considered the cleanest waters on the U.S.-side of the Salish Sea,” reports Bob Friel in the Encyclopedia of Puget Sound.
Blackmouth chinook grown in hatcheries for sport fishing in Puget Sound live their whole lives inside the Salish Sea instead of feeding out in the open Pacific for years like other king salmon. Those fish are so toxic the health guidelines limit adults to half that amount.
The southern residents’ diet in summer is made up nearly entirely of chinook salmon, originating from the Fraser River, new analysis shows, but also the urban rivers of Puget Sound, including the Duwamish, a Superfund cleanup site.