Tag Archives: NOAA’s Northwest Fisheries Science Center

Steelhead could be running into a trap at the Hood Canal Bridge

Fishermen fish for salmon north of the Hood Canal bridge, but researchers say the bridge may be an obstacle to the migration of young steelhead. Kitsap Sun photo by Larry Steagall
Fishermen fish for salmon north of the Hood Canal bridge last week, while researchers say the bridge could be an obstacle to the migration of young steelhead. // Kitsap Sun photo by Larry Steagall

I’ve often wondered if the Hood Canal bridge might be an obstruction for killer whales, which could simply choose to back away from the wall of floating pontoons, which are anchored to the seabed by a confusing array of crisscrossing cables. Old-timers have told me that orcas used to come into Hood Canal more frequently before the bridge was built.

What I never considered seriously, however, was that the bridge could be an obstacle for fish as well. In Sunday’s Kitsap Sun, I wrote about recent findings from a study tracking juvenile steelhead by means of implanted acoustic transmitters. The study was conducted by researchers at NOAA’s Northwest Fisheries Science Center.

GraphicTemp

The bottom line is that something is happening at the bridge, where many of the transmitters either disappeared or winded up staying in one place near the bridge, continuing to send out their signals for weeks. The leading hypothesis is that seals or other predators are eating the young steelhead, and some of the acoustic tags are being digested and excreted near the bridge.

Why the bridge serves as an obstacle to steelhead remains unclear. But other studies have suggested that steelhead swim near the surface. As they move out of the canal, the fish may encounter the bridge pontoons as a physical barrier, since the concrete structures go down 12 feet underwater. Also, currents around the pontoons could be a strange condition for the fish. If a young steelhead slows down in the process, a harbor seal or other predator could be waiting to take advantage of the situation.

We’ve all heard about sea lions capturing adult salmon by hanging out at fish ladders at Seattle’s Ballard Locks in Seattle or at Bonneville Dam on the Columbia River. Maybe the same thing is happening at the Hood Canal bridge with smaller prey as the target of the marine mammals.

I was also intrigued by an analysis conducted by Tarang Khangaonkar, a researcher at Pacific Northwest National Laboratory in Seattle. He told me that in all the models of circulation in Puget Sound and Hood Canal, the bridge tended to be ignored. Since the pontoons go down 12 feet, the bridge disrupts the relatively thin low-salinity surface layer moving out of Hood Canal.

Tarang calculates that the bridge could reduce the circulation by 10 percent or more, which has serious implications, not just for steelhead at the bridge but for the ecological health of all of Hood Canal.

“We have to examine what the bridge is doing,” Tarang told me. “It slows the entire system down. Water quality is maintained in Puget Sound by the flushing effect, which flushes the system out and maintains a balance. Our preliminary finding is that it could slow down by about 10 percent. That effect is cumulative.”

The bridge, he said, could effectively create a more stagnant body of water, where oxygen can become depleted. More study is needed, he said.

Most of the folks I interviewed for this story agreed that the first priority for further research was to see what is happening to the steelhead — and possibly chinook and chum salmon — at the bridge. Studies could focus on the fish, predators and currents at the bridge.

The project is gaining support, but it could require a special legislative appropriation of about $2 million.

Orca-tagging project comes to an end for now

A research project that involved tracking the travels of K pod for more than three months in the Pacific Ocean apparently has ended, as the transmitter seems to have run out of battery power, according to research biologist Brad Hanson.

Tagged whale

“This has been a phenomenal deployment,” Brad told me yesterday after it appeared he had logged the final transmission from K-25. “It has been a quantum leap forward for us in terms of understanding what is going on.”

K-25 is a 22-year-old male orca who was implanted with a satellite tag on Dec. 29. The battery was expected to last for 32,000 transmissions, and it actually reached about 35,000, said Hanson of NOAA’s Northwest Fisheries Science Center. No data arrived yesterday during the normal transmission period.

The three months of satellite tracking data will be combined with fecal and prey samples from a 10-day research cruise to serve up a wealth of information about where the Southern Resident killer whales go and what they eat during the early part of the year, Brad said. Until now, this has been a major blank spot in the understanding of these whales, he noted.

The information gathered over the past three months should prove valuable in management efforts to protect and restore these orcas, which are familiar to human residents of the Puget Sound region. After the data are analyzed, federal officials should be able to say whether they have enough information to expand “critical habitat” into coastal areas for the endangered killer whales. If not, we should know what additional information may be required.

Brad says he feels a high level of anticipation from his fellow killer whale experts who are eager to learn of the research findings, especially the results of what the whales are eating.

“We have a tremendous amount of data, and we’re trying to push it through as quickly as we can,” he said.

Brad says he won’t release the findings until the analysis is further along. But he did dangle this intriguing tidbit in front of me: The whales are NOT eating chinook salmon exclusively.

The tracking project has another benefit, Hanson said. It will bring new meaning to more than three years of acoustic data (recorded sounds) picked up by hydrophones dispersed along the Washington Coast. Until now, it was not possible to determine the locations of the whales from their sounds alone, because the sounds could be picked up from many miles away. Now, thanks to tracking data, the intensities of their calls and echolocation clicks can be correlated with distance to a greater extent. Researchers are developing a computer model to identify possible locations from as much as seven years of hydrophone data in some places.

The tracking project began on Dec. 29, when K-25, named Scoter, was darted with a satellite tag near Southworth in Kitsap County. K-25 and presumably the rest of K pod then moved out into the ocean. Check out the tracks on NOAA’s satellite tagging website.

“We were extremely lucky to get that tag at the end of the season,” Hanson said.

It was K pod’s last trip into Puget Sound for several months, he noted, and it is a real challenge to get close enough to dart a killer whale, especially when only certain ones are candidates for the tag.

By Jan. 13, the whales had reached Northern California, where they continued south, then turned around at Point Reyes north of San Francisco Bay. They continued to wander up and down the West Coast, including Northern California, into early March. After that, they began to stay mainly off the Washington Coast with trips into northern Oregon. They seemed to focus much of their attention near the Columbia River, where early runs of salmon may be mingling.

The research cruise, originally scheduled for three weeks, ran from March 1 to March 10, cut short by the federal budget sequestration. By following the whales, researchers were able to collect 24 samples of prey (scales and/or tissues of fish) plus 21 fecal samples from the whales themselves. Shortly before the cruise, K pod met up with L pod, probably off the Washington Coast.

The ability to track the whales and the fortune of decent weather were major factors in the success of the research cruise, Brad said. In contrast, several previous cruises had netted only two prey samples and no fecal samples.

“We are ecstatic about the amount of data we collected in such a short period of time,” Brad told me. “If we would have had 21 days instead of 10, just think what we could have done.”

Tagging the whales with a dart, which penetrates the skin, has been controversial among whale observers. Some contend that we already know that the whales spend time in the Pacific Ocean, and maybe that’s enough.

But Brad says many detailed findings from the past three months were never known before — such as how much time the whales spend off the continental shelf and how much time they spend in and around canyons at the edge of the shelf.

The sampling of fish scales and fish tissues should reveal not only the species of fish, but also specific stocks of salmon as well as their age, Brad said.

“Are they actually targeting the larger and older fish?” he wondered. “Some fish are resident on the continental shelf. Are they targeting those? Are they going after the ones they can easily detect, which means not going after the smaller fish?”

The cruise also collected all kinds of information about the ecosystem, ranging from ocean depths to zooplankton to the kinds of birds seen in the area. All that information will feed into a description of the essential habitat the whales need during their winter travels.

During the cruise, another whale, L-88, a 20-year-old male named Wave Walker, was tagged as an “insurance policy” to allow the whales to be tracked if K-25′s transmitter failed. A shorter dart was used on L-88, and the tag apparently fell off about a week later.

The ocean environment is very different from Puget Sound, where the habits of the whales are well known, Brad explained. In the San Juan Islands, groups of whales are rarely far apart compared to the scale of the ocean, he noted.

In the ocean, the orcas were generally grouped up during resting periods. Sometimes Ks and Ls were together; other times they were apart. When they were foraging, however, the individual animals might be spread out for miles.

Brad said he expects to put the new information into some kind of agency report, probably followed by a peer-reviewed journal article.

“We have put a lot of time and effort to get to this point,” he said, adding that the researchers feel a sense of accomplishment now that the effort has paid off.

Researchers attach new tag to orca in L pod

A research team led by Brad Hanson of NOAA’s Northwest Fisheries Science Center has been tracking K and L pods off the coast of Oregon and California, most recently offshore of Washington’s Willapa Bay.

Tags from two killer whales, K-25 and L-88, show their pods crossing the Columbia River this morning. Map by Robin Baird with data from NOAA
Satellite transmissions from two killer whales, K-25 and L-88, show their pods crossing the Columbia River this morning.
Map by Robin Baird with NOAA data

The team left Newport, Ore., on Friday aboard the 209-foot research vessel Bell M. Shimada. The crew caught up with K pod the following day with the help of a satellite transmitter attached to K-25, according to reports. Most if not all of L pod was seen swimming with the K pod whales near Cape Blanco, off the southern coast of Oregon.

The research team attached a new satellite tag to L-88, a 20-year-old male named Wave Walker. The new tag will provide another method of following the whales if the tag attached to K-25 should fall off, as expected sooner or later. It has already stayed attached for more than two months, about twice the average life of the satellite tags.

I have not yet connected with Brad Hanson, but I talked to Robin Baird of Cascadia Research, who has been getting reports from the crew. Robin told me that the researchers have been able to obtain multiple fecal and/or fish-scale samples on most of the days they have been at sea.

Those samples will aid in meeting the primary goal of the cruise, which is to figure out where the whales are going and what they are eating during the winter months while away from Puget Sound.

The satellite tags have allowed the research ship to stay with the whales even when the weather and their lack of vocalizations have made them hard to find, Robin said. As a result, this research cruise has been more efficient than past ones in terms of both time and fuel.

The research trip, which was scheduled for 21 days, will be cut in half because of the federal spending cuts related to the sequester, according to a statement issued by this afternoon by the Northwest Fisheries Science Center.

The travels of K-25 over the past two months are shown in an animation produced by staff at Northwest Fisheries Science Center. (In my browser, the north and sound portions of the map are cut off even in full-screen view, but the movements shown are still amazing.)

The latest report shows both tagged whales swimming offshore of Willapa Bay on the Washington Coast, having crossed the Columbia River mouth this morning. The full trip can be viewed on maps posted on the website called Southern Resident Killer Whale Satellite Tagging.

Researchers are tracking K and L pods aboard the NOAA vessel Bell M. Shimada. Click on the image and insert the ship's name to view its recent travels.
Researchers are tracking K and L pods aboard the NOAA vessel Bell M. Shimada. Click on the image and insert the ship’s name to view its recent travels. / NOAA photo

Highway runoff can kill coho before they can spawn

Stormwater runoff from highways has been found to contain one or more toxic compounds that can bring on sudden death in coho and possibly other salmon as well.

Researchers Kate Macneale (left) and Julann Spromberg place a coho salmon into a tub of stormwater at Grover's Creek Hatchery in North Kitsap. Their studies have revealed that urban stormwater can kill coho before they are able to spawn in a stream. Photo courtesy of Tiffany Royal / Northwest Indian Fisheries Commission
Researchers Kate Macneale (left) and Julann Spromberg place a coho salmon into a tub of stormwater at Grover’s Creek Hatchery. Their studies have revealed that urban stormwater can kill coho before they are able to spawn.
Photo: Tiffany Royal/Northwest Indian Fisheries Commission

Researchers from NOAA’s Northwest Fisheries Science Center first noticed the problem in Seattle’s Longfellow Creek, which gets a high volume of stormwater when it rains. Returning adult coho were dying in the stream before they could spawn.

The problem was confirmed last fall at Grover’s Creek Hatchery in North Kitsap, where coho were placed into tanks containing highway runoff. Even after days of rain, the runoff was deadly, causing the fish to become disoriented and die within hours. This was not a disease process but a severe physiological disruption of the salmon’s metabolism.

On Monday, I reported on these dramatic new findings made by Nat Scholz and his colleagues at NOAA. Since then, the story was picked up by the Associated Press and has appeared in dozens of publications and news digests across the country.

I won’t go into detail about the study here, because most of what I know is the story. See Kitsap Sun, Jan. 21. Toward the end, I describe some actions that Kitsap County officials are taking to keep highway dirt and debris from getting into local streams, even before the deadly compounds are identified.

I’ll continue to follow this story as scientists try to narrow down the list of possible toxic compounds that are causing the problem. The next step will be to take clues from tissues removed from the dying salmon at Grover’s Creek Hatchery.

Naturally, these new findings raise many questions about how the unknown chemicals affect the fish so rapidly and where these compounds come from. Could it be from automobile tires or exhaust, or could it be something in the road material itself? Are certain chemicals acting synergistically to heighten the problem? Answering these questions could make a significant difference for urban streams and possibly for rural streams as well.

Personally, I can’t help wondering about the salmon that survive. It’s not easy to find a coho stream where highway runoff does not contribute something to the flow. If these compounds can kill a fish in concentrations found in stormwater, what are they doing to fish exposed to lower concentrations? Are the salmon that survive as successful in finding a mate and conducting their spawning rituals as salmon not exposed at all?

I’m not sure where this line of research will lead, but the early implications appear to be quite serious. On an optimistic note, if the compounds can be identified, Washington state has a reputation for reducing or eliminating toxic chemicals at the source.

Deadly blow to orca: blast or glancing impact?

Numerous tests focused on a dead killer whale have so far failed to determine whether the fatal injury was caused by an underwater explosion or possibly a glancing blow, such as from a boat or even another animal.

L-112 in happier times. The 3-year-old orca died in February, and her death is the subject of an intense investigation.
Photo by Jeanne Hyde, Whale of a Porpoise
(Click on image to see Jeanne's tribute page)

For the first time, all the key members on a committee studying the death of L-112 got together last week. Their latest conclusions were updated in a report released yesterday.

More tests on tissues taken from the injury site are planned, even as the investigation continues into what human activities may have been occurring in or near the Columbia River at the time of L-112’s death.

The female orca was found dead at Long Beach on Feb. 11. For information, check out my previous reports in Water Ways:

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