Archive for chinook

First chinook cross Lower Granite Dam

Bellingham Herald
April 8, 2013

This year’s chinook run is expected to be smaller than in recent years, and early dam counts are backing that. But there could be a bright spot for Idaho anglers. Three spring chinook had crossed Lower Granite Dam as of Monday, April 8. That’s the last dam the fish cross before entering Idaho. The first dam on the Columbia River is Bonneville, and 618 chinook have crossed there, which is substantially lower than the 10-year average of 4,757 by that date.

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The one that got away…

A handy feature of the VAKI Riverwatcher system is that it allows us to record video clips of each fish that passes through our fish counting weirs. In addition to identifying the fish species, length, and passage date when we review the video, we also document the condition of each fish. We look for abrasions, lacerations, fungal infections, lamprey scars, hook scars—and in this case the actual hook! In this video you can see the shiny fishing lure dangling from a Chinook salmon’s dorsal fin. The angler is probably disappointed that he or she foul-hooked this salmon and lost not only the catch, but the lure to boot—although it does make for a flashy fish accessory.

Smile, you’re on salmon camera!

Considering how much gear we station underwater or deploy floating in California’s rivers, it’s remarkable that we’re able to keep track of and recover it all—well, almost all. We have a few good stories of gear lost and found (see Lost), but this one is a winner. You may be familiar with our method of setting up underwater digital cameras to record Chinook spawning behavior, since we recently posted a few videos and stories on the topic (see One-to-one spawning, Casual spawning). Back in November 2011, we set up an underwater camera in a local river to try and film salmon spawning. While the vast majority of fish pay no mind to our equipment and just go about their business, one female salmon didn’t take too kindly to our Peeping Tom tactic. She thrashed the offending camera until it unscrewed from its base and drifted away.

How do we know? Because last week, more than a year after the incident, a California Department of Fish and Game crew conducting carcass surveys stumbled across the camera on the riverbank. Recognizing it as ours, they returned it to a FISHBIO team conducting redd surveys nearby. To our surprise, the inside of the camera housing was still dry and the camera still worked! Its surveillance video (below) caught the culprit in the act; you can see the salmon whacking the camera until it floated downstream to its temporary resting place. So other feisty Chinook, take notice: we’ve got an eye on you.

Salmon in Patagonia

Although salmon are native to the northern Pacific and Atlantic oceans, it’s not uncommon to travel to the other side of the globe and find freshly caught salmon in the local fish market. We were not surprised to see salmon on the menu in Chile. Salmonids have been introduced to South America since the early 1900s, and salmon farming has taken off in Chile more recently. Four salmonid species are commercially cultivated in the country: Atlantic salmon, coho salmon, Chinook salmon and rainbow trout (Norambuena and Gonzalez 2005). Chile is the second largest producer of Atlantic salmon in the world, behind Norway. Salmon smolts are reared at land-based facilities, then transferred as yearlings to cages in lakes or rivers, and finally raised as adults in floating cages or net pens. This practice has attracted some controversy: environmental organizations have expressed concerns about the harmful effects of salmon farming on the local lake and marine ecosystems, such as pollution, disease, and escaped salmon competing with native fish. An epidemic of the virus Infectious Salmon Anemia, which may have started with eggs shipped from Norway, nearly decimated the Chilean salmon industry in 2007, but it quickly rebounded.

Not only are salmonids an important seafood export, but fly-fishing for ‘wild’ or ‘naturalized’ salmonids has become a significant tourist attraction in Patagonia. Fishing for freshwater brown and rainbow trout is a common pastime. Anglers prize the rarer Atlantic, Chinook and coho salmon so much that they encourage catch and release methods. Often it is not known whether these ‘wild’ salmon originated from salmon that escaped the farm net pens, or if they descended from purposefully stocked salmon. In the case of Chinook, eggs and alevins (newly hatched salmon) from Washington State were intentionally planted in Chile (Astorga et al. 2008). Research has documented Chinook salmon from Chile migrating into rivers on the Atlantic (Argentinian) side of Patagonia, prompting concerns that they will compete with Magellanic penguins for food resource. But clearly, not everyone is upset that salmon and trout from Europe and North America have expanded their range. As evidence of the popularity of fly-fishing, The Trout Bum Diaries 1: Patagonia was showing in our hotel lobby in Patagonia.

Is salmon program a risk to endangered fish?

Santa Cruz Sentinel
By Jason Hoppin
October 3, 2012

The county’s secret fishing hole sits in plain sight, with those in on it having spent weeks reclining on riprap, their poles in the water, pulling salmon after salmon from the back of the Santa Cruz Small Craft Harbor.

But what is good for the dinner table may not be good for the area’s endangered species. A state fish hatchery program located near the harbor mouth helped 2012′s salmon season be the best in recent years, but is now raising questions about ecological blow back.

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Red eye Chinook

red-eye-chinook

Although we regularly catch red eye bass, an introduced fish now common throughout California’s lower tributaries, red eye Chinook are a different story. Whereas the bass species has a red eye coloration that makes for easy identification, in this case the red eye color is caused by an acute injury. We’ve captured similar fish in different rivers using different sampling techniques, so it’s not an uncommon injury and apparently not related to any one sampling technique.

Photo source: FISHBIO

Imitation is the sincerest form of flattery…

river-otter_sm

As west coast fall-run Chinook salmon migration is winding down, this river otter (Lontra canadensis) keeps one of our underwater fish monitoring cameras busy by repeatedly tripping the infrared detection system. Each time he enters our field of view, the camera automatically snaps five pictures and several seconds of video, such that we are very familiar with his migration routine.

The North American River Otter is a semi-aquatic mammal that establishes a burrow close to the edge of a water body. They prey on fish, amphibians, turtles, and crayfish. Although their populations have declined throughout portions of their historic range, populations have rebounded in the northern US and Canada.

Photo source: FISHBIO

West coast fall-run Chinook escapement variable in 2009

chinook_lamprey_scar_sm

Winter means the end of fall-run Chinook salmon escapement along the Pacific coast. Although some fish are still trickling in, this year salmon returns are variable throughout their range. Chinook returns to Columbia Basin streams in Oregon and Washington are estimated to be about 425,000 fish, an increase of about 14% (71,000) over 2008.

So far only about 1,400 have Chinook returned to California’s San Joaquin Basin, a decrease of about 1,000 fish from 2008. Stanislaus River returns are about the same as in 2008, but Tuolumne and Merced escapement is down from last year.

Escapement has not been reported for the Sacramento Basin yet, but the U.S. Fish and Wildlife service is only expecting about 8,000 fall-run Chinook to return to Battle Creek, roughly a 40% decrease from 2008. We don’t have final Chinook counts on the Feather River yet, but in November escapement was nearing 10,000 fish, almost double the 5,238 returning in 2008.

This post-spawning male was photographed a few days ago showing well defined secondary sexual characteristics in the form of a large kype, teeth, and red coloration. He has completed his 4 year life-cycle and will die within a week or two. The circular wound above his pectoral fin appears to be an old lamprey scar.

Photo source: FISHBIO

Geeks rule

One study on coho salmon found that 75% of jacks passed on their genes, whereas only 58% of older, larger males were successful at reproducing.

During mating, male salmon frequently cross from side-to-side just downstream from the female as she prepares her redd (nest). From this position, the male can drive off competing males and detect odors indicating the female’s readiness to lay her eggs so that he can fertilize them. If multiple males are present, they will typically line up in order of dominance with the most dominant male closest to the female. However, jacks (young male fish that typically return to the rivers as two-year olds) are smaller and can often sneak in close to the female to pass on their genes.

The fish in this video are fall-run Chinook salmon spawning in a California tributary.

Highlights from Salmon Festival 2009

This last weekend was the first annual Stanislaus River Salmon Festival and it was a huge success! Thank-you to everyone who helped make is such a great event.