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Discussion Starter · #1 ·
Can't wait to read the actual manuscript. The results could impact steelhead fishery management (season duration). I wonder how many OP anglers will cringe and think what could have been if WA used the post-release mortality value stated here for management purposes (as well as post-release mortality for fish caught more than once i.e. the encounter narrative). Keep in mind these are summer steelhead that have migrated 300 plus miles through the Columbia when water temperatures are warm.

ONG: Study shows Snake River steelhead anglers more likely to catch hatchery than wild fish; catch-and-release mortality is low
Steelhead: A University of Idaho study indicates anglers catch wild steelhead at a lower rate than hatchery steelhead and both survive being caught and released fairly well. Eric Barker/Tribune
By Eric Barker/Lewiston Tribune
Anglers are more likely to catch hatchery than wild steelhead in the Snake River Basin, according to a study by a University of Idaho graduate student.
The student, guided by a professor with the Idaho Cooperative Fish and Wildlife Research Unit, documented catch-and-release mortality rates to be less than the 5% level assumed by state and federal fisheries officials. Both findings could help fisheries managers justify sometimes controversial recreational fishing seasons that target hatchery fish but also involve the handling of protected wild steelhead.
“Overall hatchery fish encounter rates are in fact greater than wild fish encounter rates, and we saw that pretty consistently across both spawn years,” said graduate student Will Lubenau, who recently defended his master’s thesis based on the work. “It’s about 20% higher on average.”
Lubenau spent two years tracking steelhead on the Snake River and its tributaries. In a cooperative study that involved the Idaho Department of Fish and Game, UI and the U.S. Geological Survey, Lubenau placed visible tags on both wild and hatchery adult steelhead intercepted at Lower Granite Dam or caught by him and UI professor Michael Quist on the Clearwater River. Anglers who subsequently caught tagged fish were asked to remove and report the tags, some of which carried rewards of as much as $200.
The fish also were implanted with tiny passive integrated transponder tags that can be detected by PIT tag readers placed at the mouths of spawning tributaries, at hatchery facilities and at downstream dams.
The combination of tags allowed Lubenau and Quist to track the study fish and determine how many were documented to have been caught or not caught, and how many from each group were later detected entering spawning streams, hatcheries or attempting to pass Snake or Columbia river dams on a bid to return to the ocean after spawning.
The researchers also were able to calculate a mortality rate for caught-and-released fish by comparing the later detection rate of fish known to have been caught with fish that were not documented to be caught.
Lubenau said during the 2019-20 season about 30% of the wild steelhead in the study were caught at least once and 57% of the hatchery fish were caught. In the 2020-21 season, 37% of wild fish and 52% of hatchery fish were documented to have been caught. Across both years, about 35% of the wild fish and 53% of hatchery fish were encountered by anglers.
He documented a catch-and-release mortality rate of about 3.8%. When he looked at the mortality rate just for fish with reward tags, he found a mortality rate of 3.9%.
Quist said the work gives Idaho Fish and Game biologists a better idea of more accurate wild fish encounter rates. The agency now assumes that wild and hatchery steelhead are caught at the same rate.
Wild steelhead in the Snake River Basin are listed as threatened under the Endangered Species Act and anglers who catch them while fishing for hatchery steelhead are required to release them. State fisheries agencies must obtain federal permits to ensure their fisheries don’t further harm imperiled species. Throughout the Northwest, state fisheries agencies assume 5% of the wild steelhead that are caught and released die from the encounters.
The study showed the 5% assumption is close and likely appropriately conservative. It also illustrated the assumed encounter rate of wild fish is substantially higher than what is happening. Work by a former UI graduate student, Stacey Feeken, suggested wild fish likely are caught at a lower rate. Feeken tracked hatchery and wild steelhead in an earlier study, as well as where anglers concentrate their fishing efforts, and showed wild and hatchery fish often occupy different stretches of river, and anglers tend to concentrate their efforts in areas with more hatchery fish.
Lubenau’s study built on Feeken’s work, and Quist said the results are good news for anglers, wild fish and fisheries managers.
“It’s relevant for conservation of wild fish and it’s also relevant for the recreational fishery, so it’s good news in all ways, truthfully, because it shows the impact rate — how many wild fish are handled by anglers and ultimately die as result of the fishery — is going to be fairly trivial,” he said.
The study found some fish are caught more than once, about 31 across both years. But those twice-caught fish had nearly identical post-catch detection rates as fish documented to have been caught one time.
“Those fates are essentially the same, 70% versus 71%, which is going to suggest that multiple captures — first of all, they don’t occur that often in the basin, and when they do occur, they seem to survive being encountered multiple times pretty well,” Lubenau said. “It just doesn’t seem to be a huge concern.”
Brett Bowersox, a Fish and Game fisheries biologist at Lewiston, said the results aren’t likely to prompt the agency to make any changes to how it manages steelhead fishing seasons in the short term.
“It illustrates the management scheme or the way we are calculating the impact of the fishery has been conservative,” he said. “That is the correct side of that equation we want to be on, of managing conservatively when it comes to a valuable wild fish resource and a valuable recreation fishery.”
Lance Hebdon, chief of fisheries for the Idaho Department of Fish and Game at Boise, said the study results may prompt the agency to look at how it calculates wild fish encounter rates, but he would like to see it repeated. He noted the work was done during a period of low steelhead abundance.
“The last five years we have been operating on fairly low wild runs and low hatchery runs. It would be good to repeat this when the runs bounce back.”
Barker may be contacted at [email protected] or at (208) 848-2273. Follow him on Twitter @ezebarker.

Eric Barker
Outdoor and Environmental Editor
Lewiston Tribune
(208) 848-2273
Follow him on Twitter @ezebarker
 

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Thanks for posting. This is encouraging though I agree that the numbers might be different when fish numbers are higher - more fishermen pounding fish-holding areas. I'm thinking of how quiet the Deschutes has been the last several years, even before the shutdown. I am also curious if there are hook/gear or bait rules in the study area? I think that must have a bearing on steelhead survival.
 

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The item this doesn't address is water temperature. Snake River water is going to be much cooler than middle and lower Columbia and tributaries. Tiring a fish in cold water is less stressful than in warm water.
 

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Discussion Starter · #5 ·
The item this doesn't address is water temperature. Snake River water is going to be much cooler than middle and lower Columbia and tributaries. Tiring a fish in cold water is less stressful than in warm water.
Indeed. I think the implications from this research are most notable for winter steelhead fisheries where the water is even cooler than where this study was conducted (i.e. impact rates for catch and release fisheries on the coast).
 

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Just FYI. In 2019, NMFS reviewed a broad range of studies concerning recreational catch and release impacts (including sublethal impacts) to steelhead in the context of evaluating Snake River fisheries. The agency concluded a 5% C&R mortality rate was appropriate for steelhead. See NMFS, Endangered Species Act (ESA) Section 7(a)(2) Biological Opinion and Magnuson-
Stevens Fishery Conservation and Management Act Essential Fish Habitat (EFH) Consultation,
Recreational and Tribal Treaty Steelhead Fisheries in the Snake River Basin, Consultation
Number: WCR-2018-10283, 2019, p. 66-71, https://media.fisheries.noaa.gov/dam
migration/opinion_snake_river_steelhead_fisheries_031419.pdf. Available at Recreational and Tribal Treaty Steelhead Fisheries in the Snake River Basin (noaa.gov)

Per its steelhead management plan, WDFW uses a 10% C&R mortality rate in evaluating management options and post-season numbers (except, I believe, where ESA-approved management plans provide a different number). The 10% rate is designed to be conservative and to account for a number of uncertainties (e.g., number of encounters, sublethal impacts, etc.). While the difference between the 5 and 10% figures may not seem that much, when numbers are crunched, the 10% figure results in twice the estimated number of mortalities from the same recreational fishery compared to the 5% rate -- which obviously can be significant when evaluating various management options (e.g., fishing from a floating device, season length, etc.) or in post-season run reconstructions.
 

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Discussion Starter · #7 ·
Just FYI. In 2019, NMFS reviewed a broad range of studies concerning recreational catch and release impacts (including sublethal impacts) to steelhead in the context of evaluating Snake River fisheries. The agency concluded a 5% C&R mortality rate was appropriate for steelhead. See NMFS, Endangered Species Act (ESA) Section 7(a)(2) Biological Opinion and Magnuson-
Stevens Fishery Conservation and Management Act Essential Fish Habitat (EFH) Consultation,
Recreational and Tribal Treaty Steelhead Fisheries in the Snake River Basin, Consultation
Number: WCR-2018-10283, 2019, p. 66-71, https://media.fisheries.noaa.gov/dam
migration/opinion_snake_river_steelhead_fisheries_031419.pdf. Available at Recreational and Tribal Treaty Steelhead Fisheries in the Snake River Basin (noaa.gov)

Per its steelhead management plan, WDFW uses a 10% C&R mortality rate in evaluating management options and post-season numbers (except, I believe, where ESA-approved management plans provide a different number). The 10% rate is designed to be conservative and to account for a number of uncertainties (e.g., number of encounters, sublethal impacts, etc.). While the difference between the 5 and 10% figures may not seem that much, when numbers are crunched, the 10% figure results in twice the estimated number of mortalities from the same recreational fishery compared to the 5% rate -- which obviously can be significant when evaluating various management options (e.g., fishing from a floating device, season length, etc.) or in post-season run reconstructions.
The significance of your last sentence cannot be understated.
 

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If we assume that incidental sport mortality is 5% instead of 10% ... then halve the green bars below and transfer that sliver to blue. OP steelhead are in bad shape either way.

If we want to question the numbers, then the more significant question is whether a 2400 minimum escapement goal is sufficient given estimated historic runs of 45K

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Discussion Starter · #9 · (Edited)
If we assume that incidental sport mortality is 5% instead of 10% ... then halve the green bars below and transfer that sliver to blue. OP steelhead are in bad shape either way.

If we want to question the numbers, then the more significant question is whether a 2400 minimum escapement goal is sufficient given estimated historic runs of 45K

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It doesn’t change the fact the returns are down but it sure as heck changes the perception of our take and the impact there of on total escapement. The reduced take should impact conservation decisions like eliminating fishing out of a boat or season duration. This is a big deal to many who don’t use a two handed fly rod. Bottom line is the best available data should be used to ensure both conservation and opportunity are preserved. Studies using empirical data like this one will ensure that is occurring.

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The C&R release mortality rate is one part of the total recreational mortality equation. Angler catch is another. A big challenge for managers with respect to OP steelhead is that they do not have a reliable estimate of rec angler catch notwithstanding long term creel surveys on the Hoh and Quillayute. It turns out these surveys are thought to be significantly underestimating catch (which also impacts the accuracy of past run size reconstructions). So, in light of declining run sizes everywhere, managers are taking a precautious approach (perhaps overly precautious depending on one's risk tolerance) to rec angling on the Hoh and Quillayute, where run size forecasts are above escapement goals.

The run size forecasts on the Queets and Quinault, in contrast, are projected to be below WDFW escapement goals and these rivers are closed to rec angling. I don't know the status of tribal fishing on these rivers, but I suspect some is occurring -- but that's another story.

While I support taking a reasonably precautious approach, one of my concerns is that managers may be essentially "double buffering" to account for angler catch uncertainty. The 10% release mortality figure is already specifically designed to account for uncertainty in angler catch. Yet, managers appear to be also accounting for angler catch uncertainty (e.g., potential effort shifts) in evaluating season parameters (such as no fishing from boats, etc.). The result being that both the release mortality rate and angler catch estimate parts of the equation are buffered for angler catch uncertainty and accordingly we end up with quite restrictive seasons and regulations that I'm not confident will have much of a conservation benefit.

In any event, I guess it's time to leave my hot shots and tadpollys at home, and dust off my spey rod. Oh, wait a minute, is that an old side planer I see gathering dust in the corner? Hummmm!
 

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SSPey, re your question whether the 2400 escapement goal is sufficient? Sufficient for what? To maintain a viable population? To achieve MSY? To produce the maximum smolts the current habitat will allow (in order to mitigate poor marine survival)? To maximize diversity as a hedge against climate change?

The current management paradigm is MSY, as mandated by the Boldt decision. The current MSY escapement goal of 2400 for Hoh steelhead was developed in the 1980s by WDFW (Gibbons et al.) in response to that ruling. It was based on limited S/R data and used a habitat/potential parr production model to estimate MSY escapement. I talked with the principal author Bob Gibbons a number of times back in the 1990s. The intent was always to up-date the escapement goals once sufficient river specific S/R data was available.

WDFW and the Hoh Tribe now have about 4 decades of S/R data. And, of course, fisheries science has also significantly evolved during that time as well.

In 2017, a group of well-known fisheries scientists (Hilborn, Quinn, Ohlberger at the UW school of fisheries, Dr. George Pess at Northwest Fisheries Science Center, among others), at the request of Olympic Nat. Park, re-evaluated the 2400 goal, along with other escapement goals for salmon and steelhead on the Queets, Quinault, Hoh, and Quillayute. These scientists found the current goal was in good agreement with their estimate for MSY. In particular, for Hoh steelhead, their MSY escapement estimate at the median of the probability distribution (i.e., equal probability being under or over actual MSY) was 2073 (slightly below the current objective), and the MSY escapement at the 95% level of precaution (i.e., only a 5% chance of under escaping the stock) was 2782 (slightly above the current objective). With the current 2400 goal falling between these two points, the authors did not recommend changing it. See Ohlberger, J, et al., Evaluating Productivity, Capacity, and Management Objectives for Selected Salmonid Populations in Olympic National Park, Washington, 2017.

For other steelhead stocks (Queets, Quinault), the authors recommended using the median MSY number as a minimum escapement goal, and the 95% precaution level number as a maximum escapement goal. So, for example, on the Queets, where the current WDFW escapement goal is 4200 (based on Gibbons et al.) and the Quinault Indian Nation’s goal is 2500 (which I understand is based on river specific S/R data), the authors recommended a minimum MSY goal of 3350 (the median) and a maximum goal of 4560 (the 95% precaution level).

The authors noted a lot of uncertainties and that the role of marine derived nutrients fell outside of the current MSY management paradigm. I don’t know if this study was published in a peer reviewed journal as it was provided to me by WDFW.

This paper, uncertainties and all, represents the best available science that I’m aware of. I'm not a scientist, just an enthusiast. The math and some of the methodology (Bayesian parameter estimation, etc.) are way over my head. My reliance on it reflects the credentials and reputations of the authors.

If you’d like a copy, please send me your email.

Sorry to highjack the thread.
 

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The runs overall are very low. Recreational mortality - buffered or not - seems only a small part of the total equation (green bars). When we argue whether 5 vs 10% should drive regs, I feel we miss the bigger picture. It is arguing over scraps. But I agree that better estimates of escapement and mortality can only help clarify that picture, even if we’re stuck with MSY criteria that haven’t really served fisheries conservation in general.

To me it is about the fish, that's the motivation ... just because my moniker has “spey” in it misses my overall angling and intent like assuming that an “Alsea Assassin” only fishes the Alsea.
 
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