Black Spot Disease in the Lower Deschutes

For anyone who has fished the lower Deschutes River this year, it is not news that many of the fish being caught have Black Spot Disease (BSD). How many fish? We’ve received reports of as many as 100% of 30 fish caught over a three-day trip between Trout Creek and Harpham Flat. Most reports are that 60 to 80% of landed trout have obvious evidence of BSD.

Lower Deschutes River bull trout showing obvious Black Spot Disease. Photo courtesy of Nick Wheeler.

We, along with several of our supporters, have contacted representatives of the Oregon Department of Fish and Wildlife about this issue, and have been told there is nothing to be alarmed about. One of our supporters received an email from ODFW that included the following:

“ODFW has done some research on the effects of blackspot [sic] on spring chinook [sic] smolts in the John Day River and found that the parasite had no adverse effects on condition or survival, even fish that were severely infected performed the same as uninfected fish. Our pathologists also have stated that blackspot [sic] is not categorized as a disease, meaning that it does not appear to effect the host. It is also important to note that blackspot [sic] is very cyclical, and most often comes and goes through time.”

We’ve not seen any research reports from ODFW regarding BSD, although it’s not unusual for these reports to not be advertised or be made readily available. What is unusual is that anglers who fish the bodies of water mentioned by ODFW do not report seeing BSD. This is not to say that BSD isn’t present on the John Day and other rivers, but it’s clearly not present right now to the same extent as in the lower Deschutes.

According to the statement from ODFW, BSD “is not categorized as a disease.” This is a curious claim. Why is it called Black Spot Disease? In all of the scientific literature that we searched, it is always referred to as a disease. This is because infection with BSD results in both systemic inflammation and tissue changes in fish. Inflammation is evidenced by increased cortisol (a hormone associated with stress and inflammation) levels. The skin and scale changes seen on fish with BSD are not caused by trauma. So we have a transmissible infective organism causing inflammation and tissue changes. That meets the definition of a disease.

The fish ODFW representatives have observed with BSD are noted to be in good condition. Yes they are, when they are caught. But no one is performing long-term observation to see what the consequences of chronic infection might be. We are now in the third year of BSD being observed in lower Deschutes River fish, so it’s obvious that more fish are being infected for longer periods of time. None of the studies on BSD to date look at longer-term infections, so those consequences are unknown.

What is known is that fish do die of BSD. According to reports, once fish are infected in the eyes or mouth, survival is limited. And fish with high parasite loads tend to be of lower weight.

The ventral surface of a redband trout with Black Spot disease, caught in the lower Deschutes River in late April 2017. Photo by Jamey Mitchell.

Black spot disease is caused by a flatworm (trematode) parasite known in the scientific community as Uvulifer ambloplitis, and also known as “neascus.” This parasite has a complicated life cycle that starts with eggs in water, which hatch and become juveniles known as miracidia, which in turn infect aquatic snails.  In snails this form of the parasite matures into the next life form, known as cercariae.  Cercariae are shed by the snails and become free swimmers, which attach to fish.  Once the cercariae have attached to the flesh of a fish, the fish develops an immune response that causes the dark spot.

Fish-eating birds are the next host, which become infected when they ingest infected fish.  The cercariae develop into adult flatworms, which means that fish-eating birds are internally infected with the parasite.  The parasite then produces eggs, which are shed in feces by fish-eating birds, and deposited in water where the life cycle is reinitiated.

This summer, many have observed decreases in fish-eating birds in the lowest forty miles of the Deschutes. Kingfishers are rarely seen now in that reach of river (they were previously seen in pairs occupying nearly every reach of river), and merganser populations in the lower forty miles have declined. Are these birds becoming infected with neascus and dying? Or is something else going on? Unfortunately, no one seems to be investigating this phenomenon.

Increases in BSD are associated with increased water temperature and increased aquatic snail populations—both conditions that Selective Water Withdrawal Tower operations have created in the lower Deschutes River. Further, research has demonstrated that rather than being “cyclic,” BSD is linked to sustained elevated water temperatures and algae growth.

The likely solution to reducing BSD is a return to cooler water temperatures and less nutrient loading in the lower Deschutes River. This would require that the SWW tower draw more water from the bottom of Lake Billy Chinook before discharging downstream.

Sources

Schaaf, Cody J, Suzanne J. Kelson, Sébastien C. Nussle, & Stephanie Carlson . Black spot infection in juvenile steelhead trout increases with stream temperature in northern California. Environmental Biology of Fish,; April, 2017.

McAllister, CT, R. Tumlison, H.W. Robison, and S.E. Trauth. An Initial Survey on Black-Spot Disease (Digenea: Strigeoidea: Diplostomidae) in Select Arkansas Fishes. Journal of the Arkansas Academy of Science, Vol. 67, 2013

Schaaf, Cody J. Environmental Factors in Trematode Parasite Dynamics: Water Temperature, Snail Density and Black Spot Disease Parasitism in California Steelhead (Oncorhynchus mykiss). Submitted to University of California Berkley for Masters Thesis, May, 2015.


Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River. 

Click here to Donate.

Click here to sign up for the Deschutes River Alliance email newsletter.

Oregon Department of Fish and Wildlife Establishes No-Limit Bass Fishery on the Lower Deschutes River

On Friday, August 4, 2017, the Oregon Fish and Wildlife Commission voted to make the bass fishery in the lower Deschutes River a “no bag limit” fishery, beginning January 1, 2018.

A smallmouth bass caught last week on the lower Deschutes River.

This is a positive step toward dealing with the bass invasion of the past few years. It is also an acknowledgement that we have a problem in the lower Deschutes River. As we’ve noted in previous blogs, bass have been infrequently reported in the lower Deschutes River, in very small numbers, for many years. However, in the past two years the numbers of reported bass have grown significantly, with some anglers this year reporting catches of up to 20 bass per day below Macks Canyon.

These omnivorous and voracious predators feed on a mix of food types including juvenile fish (trout, steelhead, Chinook, shiners, etc.), crawdads, and aquatic insects. As their numbers increase, they pose an increasing threat to the ecology of the lower river.

Unlike in other fisheries where bass have been artificially introduced by well intended, but ill-advised, amateur biologists, the bass in the lower Deschutes River appear instead to have moved up from the Columbia River. This has happened because, remarkably, the lower Deschutes River is now warmer in the spring than the Columbia River. This is due to current selective water withdrawal operations at the tower above Round Butte Dam. During springtime, 100% surface water withdrawal is used to attract juvenile fish to the fish collection facility at Round Butte Dam. This surface water is many degrees warmer than water at the bottom of the reservoir, which was the source of water for dam operations prior to 2010.

The warmer water in the lower Deschutes River attracts bass and allows them to become more active earlier in the year. This gives them more time to feed before the next winter, and an earlier start on spawning.

DRA Board member Steve Pribyl with a smallmouth bass caught last summer.

Perhaps the saddest comment on the new bag limit is that most anglers are releasing the bass they catch in the lower Deschutes, in order to have something to catch in the future as this treasured river continues to change so rapidly. However, we would encourage all anglers to remove these fish from the water. Do not dispose of them on the bank, as that is a violation of rules regarding wasting of game fish.

The need for this change in fisheries management is another unanticipated and unintended consequence of SWW tower operations. And another sign that it’s time to reconsider how the tower is operated, along with current strategies for reintroducing fish above the Pelton-Round Butte Project.


Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River. 

Click here to Donate.

Click here to sign up for the Deschutes River Alliance email newsletter.

Walleye. In the Deschutes River?

The fish have spoken. And those fish are walleye. Remarkably, there are now walleye in the lower Deschutes River. As far as anyone is aware, this has never happened before. We wish this was good news. But it’s not.

We’ve been getting reports of walleye being hooked and landed as far upriver as Kloan, at River Mile 7. We’d not mentioned it yet as we were waiting for documentation of a landed walleye. Now we have it–the walleye in the photo below was landed at River Mile 4.5.

Photo provided by Deschutes River guide Brad Staples, pictured on the right.

In addition to walleye, smallmouth bass continue to be been taken in good numbers in the lower river this summer, for the second straight year. Trout and steelhead, not so much.

What does this mean for the lower river? As the lower river ecology and habitat changes due to Selective Water Withdrawal operations, so do the species that thrive in the new conditions. Warmer water attracts warm water fish. As insect populations decrease, piscivorous fish (fish that feed on other fish) increase.

Further, this is not good news for salmon and steelhead juvenile migration. Juvenile steelhead and salmon are preferred food items for walleye and often for bass, much as they are for northern pikeminnow. Bass and walleye are also capable of feeding on crawdads, worms and insects, and generally are known for being highly predatory feeding machines.

Looking into the mouth of the walleye. Photo from American Expedition.

We are repeatedly told by the agencies responsible for Deschutes River management that nothing has changed in the lower Deschutes River since the implementation of surface water withdrawal at Round Butte Dam. But lets consider the list of easily observable changes:

  • Bass and walleye incursion
  • Increased water temperatures throughout the lower river’s 100 miles, from mid-winter through spring and summer
  • Black Spot Disease widely spread in trout, steelhead, and bull trout
  • Invasive nuisance algae
  • Significant change in insect community structure, and decline in adult insect abundance
  • Observations of declining bird populations

Clearly, this is no longer the river we knew prior to 2010. But fortunately, we know these problems are not inevitable. A return to cooler, cleaner water discharged from the Pelton Round Butte Project can begin alleviating these discouraging ecological changes in the lower river. It’s time for the responsible agencies, dam operators, and other parties to admit that the Selective Water Withdrawal tower is responsible for some serious unintended consequences, and begin charting a new path forward for lower river management.

The Deschutes River Alliance will remain on the front lines of the battle to restore this treasured river. Please join us in our efforts.


Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River. 

Click here to Donate.

Click here to sign up for the Deschutes River Alliance email newsletter.

Announcing the DRA’s 2016 Lower Deschutes River Water Quality Report

We are thrilled to announce the publication of the DRA’s 2016 Lower Deschutes River Water Quality Report. This report—along with three other reports we’ll be releasing over the next two months—is the culmination of the DRA’s most detailed investigation yet of the causes and extent of the ecological changes occurring in the lower Deschutes River.

An important aspect of the report analyzes hourly water quality data collected at River Mile 99, one mile below the Pelton Reregulating Dam, from February 18 through November 22, 2016. All data collected for pH, temperature, and dissolved oxygen are presented and analyzed, and compared against water quality requirements contained in the state-issued Clean Water Act § 401 Certification for the Pelton-Round Butte Complex, as well as Oregon’s water quality standards for the Deschutes Basin. Read the whole thing here.

This report represents the most complete public analysis yet of the impact of Selective Water Withdrawal operations on water quality below the Pelton-Round Butte Hydroelectric Complex. Key findings include:

  • Oregon’s water quality standard for pH in the Deschutes Basin (6.5-8.5 SU) was exceeded on 234 out of 279 days that data were collected (84%). 43% of the days sampled had pH measurements greater than 9.0.
  • Each year since 2011, Project operators have worked with the Oregon Department of Environmental Quality to purportedly weaken the water quality requirements in the Project’s Clean Water Act § 401 Certification. These changes include:
    • The defined spawning season for salmonids was changed from year-round to Oct. 15-June 15. This change allows the application of a lower dissolved oxygen standard during the non-spawning period (June 16-Oct. 14). However, this newly defined spawning period does not take into account the full season of resident trout spawning and egg incubation, as is required by the Oregon Administrative Rules. This has caused dissolved oxygen levels in the lower Deschutes River to fall below levels required to protect resident salmonids through egg incubation and fry emergence.
    • The water temperature that triggers the blending of cool bottom water from Lake Billy Chinook with warmer surface water has been markedly increased since the Selective Water Withdrawal tower began operations. This has allowed the release of 100% surface water into the lower Deschutes River to continue later into the summer.
  • Changes in pH and dissolved oxygen, documented by this study and ODEQ’s own data, clearly indicate that excess nutrients are being released into the lower Deschutes River from the surface waters of Lake Billy Chinook.

DRA’s 2016 Lower Deschutes River Water Quality Report clearly establishes that, in just seven years of operation, the Selective Water Withdrawal tower at Pelton-Round Butte has severely degraded water quality and threatens aquatic life below the Project. We believe this report will serve as an important document for all basin stakeholders in assessing the impact of tower operations on the river we all love.

A special thanks to all of our supporters, whose generosity and passion for the river has made all of our science work possible. We’d like to take this opportunity to specifically thank the various organizations and foundations who have provided funding to support this critical work, including:

  • The Oregon Wildlife Heritage Fund
  • Maybelle Clark MacDonald Fund
  • Flyfishers Club of Oregon/Flyfishers Foundation
  • Clark-Skamania Flyfishers
  • Mazamas
  • American Fly Fishing Trade Association
  • Tualatin Valley Chapter of Trout Unlimited
  • Washington County Fly Fishers

Cooler, cleaner H2O for the Deschutes!

Photo by Brian O’Keefe



Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River. 

Click here to Donate.

Click here to sign up for the Deschutes River Alliance email newsletter.

Lawsuit Update: Court Denies PGE’s Motion to Dismiss

Round Butte Dam and the Selective Water Withdrawal Tower.

Great news! On Monday morning, Judge Simon denied PGE’s motion to dismiss the DRA’s Clean Water Act lawsuit. In its motion, PGE had argued that the Clean Water Act does not authorize lawsuits by private citizens, including groups like the DRA, to enforce water quality requirements at hydro projects like Pelton-Round Butte. Judge Simon’s decision thoughtfully rejected each of PGE’s arguments on the issue, ultimately finding that the company’s interpretation of the Clean Water Act “rewrites the statute.” Read the whole decision here.

Judge Simon’s ruling, which allows the DRA’s lawsuit against PGE to proceed, is great news for lovers of the Deschutes River, and a critical step in our efforts to return cold, clean water to the lower Deschutes. But it’s also a great victory for river advocates across the country: a decision in PGE’s favor would have impacted the ability of citizens and states to protect water quality on all rivers impacted by hydroelectric projects.

This is truly an important decision for the Deschutes River, and we’re eager to finally move on and address the merits of the case. Judge Simon’s ruling ensures that the DRA will have the ability, as the Clean Water Act clearly provides, to hold PGE accountable for violations of water quality requirements at Pelton-Round Butte. This is the first step to restoring the river we all love.

Keep an eye on the blog for more updates on the lawsuit, and on all of the DRA’s science and advocacy efforts. Cooler, cleaner H2O for the Deschutes!

Redband trout, lower Deschutes River. Photo by Brian O’Keefe


Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River. 

Click here to Donate.

Click here to sign up for the Deschutes River Alliance email newsletter.

Smallmouth Bass in the Lower Deschutes River

Many folks who have spent time on the lower Deschutes River this summer have noticed something unusual. Smallmouth bass, typically quite rare in the lower Deschutes, are suddenly present in large numbers. What are they doing there? Where did they come from? How does their presence affect resident fish? Today, we attempt to answer some of these questions, in two parts. In the first part of today’s post, we give an overview of this summer’s bass invasion, and attempt to sort out why we’re suddenly seeing so many of this particular species. In the second part, Steve Pribyl, former Oregon Department of Fish and Wildlife Fisheries Biologist for the lower Deschutes River, provides a history of smallmouth bass in the lower river—a critically important perspective on what we’re seeing in the river this year.

Part One: 2016 Lower Deschutes River Bass Invasion

The weird things happening in the lower Deschutes River and its tributaries just never seem to end. A year ago the big story in the lower river was the two fish die-offs in June and early July. First with sockeye near the mouth, then spring Chinook near the confluence with the Warm Springs River.

This year, like in a science fiction movie, it’s the invasion of smallmouth bass. In a science fiction movie the bass would be from outer space, but in this case they are, in all likelihood, from the Columbia River.

Almost as soon as anglers began fishing for steelhead this summer in the Deschutes River’s lower 40 miles, we started hearing reports of smallmouth bass being caught. There have always been stories and rumors of a bass being caught here or there, perhaps once or twice a season in the lower river. But the reports this summer were of six bass being caught at a time! Or a dozen or more in a single float trip. Far more bass were being caught than steelhead (no surprise given the weak steelhead run this year).

By mid-August we had reports of smallmouth bass being caught as far upstream as Buckhollow Boat Ramp.

The most successful lure or fly for catching smallmouth in the Deschutes this summer was the Blue Fox spinner. We also heard reports of smallmouth bass being taken on steelhead flies, with streamers seeming to be the most productive. It is worth noting that these are not the sorts of flies and lures one would use if purposefully fishing for bass!

The problem with the bass invasion is that no one seems to know if these fish have moved in permanently, or are just visiting. We’ll not know until next year. But there is reason for alarm. If these fish do become residents in the lower Deschutes River, the redband trout population is at certain risk. Smallmouth bass and redband trout do not coexist well. Multiple examples abound of healthy rainbow trout populations being decimated after the introduction of bass into a trout fishery.

Why are smallmouth bass moving into the lower river? The most likely answer anyone has proposed is that warm spring water temperatures in the lower Deschutes River lured bass up from the Columbia River. Bass come out of winter dormancy when water temperatures reach the mid- to upper fifties, or even sixty degrees. They then seek out warm water to increase spawning success. This year the lower Deschutes River reached those sorts of temperatures over a month before the Columbia River did, likely attracting bass at that time. (For a biological discussion of smallmouth bass and temperature influence on bass behavior, see http://www.dfo-mpo.gc.ca/Library/337846.pdf ).

The following graph shows that the Columbia River in The Dalles pool reached 60 degrees F right around June 1.

columbia-graph

And this graph shows that the lower Deschutes River at Moody (just upstream from the confluence with the Columbia River) first reached 60 degrees F in mid-April.

deschutes-graph

Another important question as we unravel this mystery is whether the lower Deschutes River at Moody is warmer now than it was prior to selective water withdrawal operations at the Pelton-Round Butte Complex. There are no data with which to make that determination, as there wasn’t a temperature gauge at Moody until July 2011. However, the following graph shows that temperatures immediately below Pelton-Round Butte are now much warmer in the spring than they were prior to the commencement of selective water withdrawal operations.

graph-3

Previous DRA research has illustrated that these higher discharge temperatures at Pelton-Round Butte impact river temperatures all the way to the confluence with the Columbia River. So it’s quite likely that spring temperatures at Moody are now significantly higher than before SWW operations began. Unfortunately, these higher spring temperatures resulting from SWW operations may very well be responsible for this year’s smallmouth bass invasion.

It has been suggested that bass in the lower Deschutes River might be of little consequence as bass and other species seem to be coexisting in the John Day River. But this is not an analogous situation. There isn’t a redband trout fishery in the John Day River that would be threatened by smallmouth bass. Juvenile anadromous fish are said to migrate down the John Day River somewhat earlier in the year than Deschutes River steelhead and Chinook juveniles. This means that in the John Day River the juveniles are migrating in colder water temperatures, when smallmouth bass are still dormant.

We won’t know the longer-term consequence of this year’s bass invasion until next year. If juvenile bass are present in the lower Deschutes River, it will be safe to assume that they have colonized the lower river.

Part Two: History of Smallmouth Bass in the Lower Deschutes River

By: Steve Pribyl

I worked for the Oregon Department of Fish and Wildlife as a fish biologist on the lower 100 miles of the Deschutes River from 1977 to 1980, and again from 1985 to 2004. In addition to this work experience, I fished the river extensively during those years and have been able to spend even more time fishing since my retirement. I am very familiar with the history of smallmouth bass in the lower Deschutes River.

With the exception of drastically increased smallmouth bass abundance in 1996, which I will discuss below, there has always been a very, very small background number of smallmouth bass in the Deschutes River downstream from Macks Canyon (river mile 25). Before this year, the furthest upstream that I had personally observed a smallmouth bass was at Bull Run (river mile 18), with other very occasional observations downstream from there.

I fished the river downstream from Macks Canyon extensively for both trout and summer steelhead for almost 40 years before catching my first smallmouth bass this summer. Similarly, friends of mine that have guided professionally for steelhead on the river, several for more than 30 years, have caught very few smallmouth bass. Prior to this summer, these friends relate to me that in their entire careers on the Deschutes (with the exception of 1996, as discussed below), they probably caught less than 10 smallmouth bass total in literally thousands of days on the river.

Steve Pribyl with a recent catch.

Steve Pribyl with a recent catch.

1996 was an unusual year in the lower Deschutes River. That year, smallmouth bass were very abundant downstream from approximately Harris Canyon (river mile 12). In August 1996, guides reported catching up to 8 or 10 smallmouth each day while fishing for summer steelhead. I recall rowing an enforcement trip with members of the Oregon State Police, Fish and Wildlife Division, that summer where we contacted two anglers at Sharp’s Bar (river mile 5.5) that were actually targeting smallmouth bass and having considerable success. I specifically remember this event because while we were observing these subjects at a distance through binoculars, it appeared they were catching and keeping trout in excess of the legal size and catch limits. I recall the disappointment of the Oregon State Police troopers when further investigation revealed the fish to be smallmouth and no citations were going to be issued!

Smallmouth bass continued to be caught regularly and in impressive numbers throughout August and into early September of that year, but disappeared from the catch by mid to late September.

The sudden abundance of smallmouth in the lower Deschutes River in 1996 was both troubling and curious to me at the time. Large numbers of smallmouth had been present in the Columbia for many, many years, and the fish were present in Lake Billy Chinook, the reservoir formed by Round Butte Dam at about river mile 110. Yet they were rarely seen in the Deschutes River. I theorized at the time that either water temperatures in the Deschutes were colder than smallmouth bass really preferred, or the gradient of the Deschutes was higher then they could cope with very effectively. Either or both of these factors kept smallmouth bass from colonizing the river from upstream or downstream. Yet suddenly, in the summer of 1996, large numbers of smallmouth bass were present in the lower 12 miles. The temperature regime in the Deschutes had not changed that year, and obviously the gradient had not changed to allow smallmouth to live more effectively there.

With the information at hand, we formed a theory about the sudden increase in smallmouth bass that year. The passage of time, while not proving the theory correct, certainly has not disproved it either.

There was a very large rain on snow flood event in early February, 1996. Without researching flows in the Deschutes basin, I do recall that flows at the Moody gage were in excess of 70,000 cfs and that Warm Springs River at its mouth flowed in excess of 30,000 cfs.   Large volumes of flood water coming into Lake Billy Chinook necessitated a period of spill from the reservoir. Again, without researching it, I don’t recall how much was spilled, or for how long, but it was substantial. We theorized that there were many smallmouth bass entrained in that flood spill and passed through both Lake Simtustus and the Reregulation Dam Reservoir into the flowing Deschutes. These smallmouth bass, finding the upper parts of the Deschutes colder than their preferred temperature, progressively moved downstream until they found the warmer water of late summer in the lower 12 miles more to their liking, where they then took up residence. When water temperatures cooled in mid- to late September below those that smallmouth prefer, the fish again started to move downstream, this time into the Columbia. After 1996, smallmouth were again only a very rare capture, and I largely quit worrying about the species invading the lower Deschutes.

Smallmouth abundance in the lower 12 miles of the Deschutes has changed dramatically in 2016. In July, anglers started to catch five to ten per day while targeting steelhead, with steelhead gear in steelhead water. Several anglers in early August have actually targeted smallmouth and report catch rates of up to 10 smallmouth per hour, catch rates that would be considered good on the John Day River, a regionally famous smallmouth fishery. Smallmouth in excess of 16 inches in length have been reported from the Deschutes this summer. Even more unusual—and almost beyond belief—is the photo documentation of a largemouth bass caught in the Deschutes at river mile 12 in early August! This is the one and only documented largemouth sighting I am aware of in the Deschutes and I can’t even begin to wrap my head around what that means.

The obvious questions are (1) where are these smallmouth bass coming from, and (2) what has changed to allow the species to flourish in the lower Deschutes? With regard to the first question, I believe these fish are traveling up the Deschutes from the Columbia River. The protocol at the Pelton-Round Butte fish passage facility is to not pass smallmouth captured at that facility downstream into the lower Deschutes, so it is unlikely the fish originated above the dams.

So what is allowing smallmouth to flourish in the lower river this summer? While stream gradient in the lower Deschutes has obviously stayed constant, temperatures in the lower Deschutes have changed significantly. I believe PGE’s surface water withdrawal operations, designed to aid downstream juvenile passage at the Pelton-Round Butte Complex, have increased water temperatures in the lower river enough, and for a long enough period of time, that smallmouth bass are now able to invade the Deschutes from the Columbia River and find conditions that have apparently allowed them to flourish.

It remains to be seen how long smallmouth will now continue to use the lower river, but with continued releases of warmer water into the Deschutes from the surface of Lake Billy Chinook the situation is not likely to change. This is certainly troublesome, given the obvious negative impacts to resident salmonids from smallmouth predation.


Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River. 

Click here to Donate.

Click here to sign up for the Deschutes River Alliance email newsletter.

Yellowstone River Closed Due to Fish-Killing Parasite

On Friday, August 19, Montana’s Department of Fish, Wildlife and Parks announced the closure of 183 miles of the Yellowstone River to all recreational use. The reason for the closure was the discovery of over 2,000 dead mountain whitefish and reports of dead rainbow trout and cutthroat trout.

Photo: Google Photos

Photo: Google Photos

The cause of the fish die-off appears to have been proliferative kidney disease (PKD), which is caused by a parasite known as Tetracapsuloides bryosalmonae. In the past, this organism has caused outbreaks of disease and fish death amongst salmonids in various hatcheries and freshwater in the Pacific Northwest. It seems to be most hazardous to fish when water temperatures reach and stay above 54 degrees F. The Yellowstone River has been low and warm this year.   There are no antibiotics to treat the infection.

The Yellowstone River was closed to prevent transmission of the infectious agent to other waters.

Photo: Google Photos

Photo: Google Photos

We want to bring this to everyone’s attention as a reminder that if you travel to different bodies of water to fish, please be sure to clean wading boots, waders, fish nets and boats prior to moving to the next body of water. There has been a fair amount of controversy and disagreement as to what adequate cleaning consists of. We are providing a link to the most recent, and arguably most logical, guidance on the cleaning of fishing equipment. The instructions are relatively easy to follow and don’t include any measures that shorten the life of your gear (bleach, heat, etc.).

The instructions can be found at this link:

http://www.stopans.org/Cleaning/Tips_Careful_Cleaning.pdf

Please help us keep the lower Deschutes River and all bodies of water free of invasive species!


Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River. 

Click here to Donate.

Click here to sign up for the Deschutes River Alliance email newsletter.