Reports_1

Recent Posts


Tags

Tarpon Sandy River Trout Bum Road Trip pay it forward Small Streams March Browns roll cast Christmas Steelhead Kickstarter ODFW Travalley Sea-run Cutthroat McKenzie River Green Drakes on-line fly shop Instagram Salmon habitat Conway Bowman Soft Hackles Poachers Craig Montana Steamboat Inn Brian Silvey Morrish's Fluttering Stone Bruce Buckmaster Pelton Dam Deschutes River Alliance Mountain Goats Native Fish Society Black Spot Cuba Cutthroat Trout Metolius Chinook Salmon Sweden Sea Trout PGE Kate Koff Salmonflies Kamchatka Casting for Recovery Costa Deschutes National Forest Oregon Steelhead Sanctuary saltwater Permit Rogue River Dry Fly Trout-a-Thon John Day River British Columbia Caddis Smithers Big Trout #keepemwet "Clipped" Tying Contest Kispiox Snow Simms Road Trip Alaska Nautilus Reels Bill Black Trout Salmonfly hatch PMDs Vets Winter Steelhead Senator Jeff Merkley Dale La Follette Sr. Grand Teton New Zealand Bamboo Steamboat Creek Renzetti Trout Spey Dolly Vardon Fly Fishing Film Tour Carp SA Big Bugs Sharks flies Project Healing Waters Prineville Pyramid Lake Deschutes State of Jefferson Redfish Warm Water Skaters Guided Fishing Sage Atlantic Salmon Fly Expo Little Creek Outfitters Native Trout fly fishing Marty Sheppard Keepemwet Fishing Travally Black Friday McKenzie Roamerica Jurassic Lake Abel Reels Mexico Sage Fly Rods Redside Rainbow Nevada Bill Bakke Senator Ron Wyden Mending Press Release Chum Salmon Coat Drive Rob Crandall Spring Chinook Parasite Bamboo Rods Willamette Falls tippet rings Bass Klamath Dams Invasives Brown Trout Elk River Frank Amato Green River Scientific Anglers Patagonia Wader Maker Contest Soul River Pacific ocean Bauer Fly Reels Winter Spey Strategies Goldenstones hatcheries Fly Tying G3 Waders Fall River hot water Seychelles Christmas Trees Hardy Reel Sea lions Williamson River Bozeman John Day Bears Willamette River Metolius River Salmon Fly history A River Between Us Fishing Report Bull Trout Rainbow Trout Willamette Klamath Lake Ochoco Creek Mousing Montana Fly Reels Olympic National Park Oregon Back Roads Wild Steelhead Coalition Salmon Sea-runs The Creel frying pan river Bulkley Yellowstone Spirit River Douglas County Salmon-Trout Trailer Trash Thursday Klamath River Elk & Sixes Boston Whaler Deschutes River Rio Fly Lines Winston Water Time Outfitters native fish Fishing License Spey Fishing Tips Redband Trout Fly Fishers Club of Oregon photography Catch Magazine Columbia River Lahontan Cutthroat FarBank small creeks Legos Coho Oregon Trout Trail Northern California North Coast: Trask Bonefish Summer Steelhead Lost and Found Jason Atkinson Echo boat cleaning stations Maupin Jay Nicholas Argentina Bryan Huskey Frank Moore Klamath Oregon Department of Fish and Wildlife Florida Keys Dean Finnerty Colorado Home Waters for the Holidays Salmon Watch invasive species Adventure CFR Wild fish Port Orford Corey Koff F3T Simon Gawesworth Tenkara Film Contest North Umpqua Kenny 5 Legs Spey-O-Rama Southern Coast Atlantic Salmon How to Cookie Lady Whitefish Nehalem River Eric Neufeld Blast from the Past Mako Shark Extinction Brian O'Keefe Fly Fishing Collaborative Streamers Rio Products Crooked River BC Outdoor Adventure Day Kevin Callaway LaFollette homestead Mia Sheppard Coho Salmon Owyhee River Puget Sound Todd Moen Clackamas River West Slope Cutthroat Rio Lincoln Motor Company vintage news Stefan Tritscher Kenny Morrish Oregon Trout Bum Trout Unlimited Twin Bridges Clackamas A River for Christmas Winston Fly Rods

Archive

Camp Water

Camp water is close to home. Here you will find information on stuff happening here in the shop and on our local waters. You'll also find our weekly newsletter feature, Trailer Trash Thursday, a fun collection of fly fishing videos, perfect for a midweek distraction. If you don't get the newsletter, be sure to sign up today!

What is Black Spot?

Joel La Follette - Wednesday, May 03, 2017

This photo of a Deschutes Bull Trout infected with Black Spot was taken by Nick Wheeler on May 1st on the Warm Springs to Trout Creek section of the Deschutes. 

A few weeks ago I mentioned that a parasite that infects salmonids was becoming more prevalent in the Deschutes with many anglers reporting catches infected with the telltale “black spots.” To answer some the questions floating around I turned to biologist Greg McMillan and asked “Just what is Black Spot and why are we seeing an increase in cases in the Deschutes?”

Greg responded, "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 fish, the fish develops an immune response that causes the dark spot.

Kingfishers are the next host, which become infected when they ingest infected fish.  The cercariae develop into adult flatworms.  The parasite then produces eggs, which are shed in feces by kingfishers, and deposited in water where the life cycle is reinitiated.

These flatworms do not appear to be fatal to fish, or other hosts.  There are scattered reports of fish stressed from other sources dying while infected.  No human infections have been reported, but there is no real surveillance mechanism to detect human infections.  Although probably safe for human consumption after thorough cooking, there is no study data to confirm that.

None of us who have fished the lower Deschutes River for decades can say that we’ve seen many, if any fish with this condition until a year ago.  There are reports indicating there have been infected fish in the lower Deschutes River and tributaries in the past, but they aren’t common.  So what has changed?  Is this random?  Or linked to the ongoing ecological changes we are all seeing in the lower river?

This might be related to an increase in the snail population in the lower Deschutes River. Portland General Electric’s Year 1 Data Summary Report from their Lower Deschutes River Macroinvertebrate and Periphyton Report Study published in 2014, indicates that there has been a significant increase in snail populations in the lower Deschutes River.  This increase in population in the intermediate host (snails) might be related to the increase in black spot disease noted in fish.  The snail population increase is likely linked to the increase in algae in the lower river.

Is this a catastrophic occurrence?  Probably not, but it could be another indication of ecological change in the lower Deschutes River."

As Greg said, Black Spot is probably not catastrophic, but it is of concern. Finding out more information on the disease occurrence in Oregon is hard as it seems to not be of concern to ODFW at this time. Perhaps if more cases are reported by anglers, ODFW will finally take notice and look into the cause of this increase in cases. 



I would suggest that anglers fishing the Deschutes carefully photograph and report cases of Black Spot to ODFW. Take note of where the catch was made and how many cases were observed. Please make an effort to leave fish in the water when handling and photographing them. If you send a photo of infected fish to me I'll add it to this blog post. Again, please handle all wild fish with respect and care.

1
Contact Us

21570 Willamette Drive West Linn, OR 97068
503.850.4397

2014 Royal Treatment Fly Fishing
Privacy | Legal