Reports_1

Recent Posts


Tags

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

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