HATCHERY STEELHEAD IMPACT WILD STEELHEAD

In a recent conversation with an executive of the ODFW fish division about releasing hatchery steelhead in the Sandy River, Oregon, the assertion was made that these hatchery fish had no impact on wild steelhead.  That is a statement of fact, so I asked for the supporting data.  After a bit of dithering, he admitted that this conclusion was indeed only an assumption. 

Apparently, biologists that hold important political positions within an agency or those that have an agenda regardless of their pecking order within the agency, feel comfortable making factual statements even though they have no facts to back them up.  Typically, the public has been conditioned to accept a strongly stated assertion at face value.  After all, why would they lie?  The public trust is easily violated by agenda driven agency functionaries. 

Years of scientific studies costing thousands of dollars have shown that the release of hatchery steelhead has an impact on the health, abundance, and status of wild steelhead in our rivers.  The public pays for these studies and should expect that what is learned would be applied to management decsions by government agencies, but there is no obligation for an agency or its personnel to use this information in their work.  

What are some of the facts about releasing hatchery steelhead in streams already occupied by wild steelhead? 

“Hatchery steelhead displaced wild O. mykiss in 79% of the contests observed between these groups. Our results indicate that the behavior of hatchery steelhead can pose risks to preexisting wild O. mykiss where the two interact.”

That is a startling fact discovered in 1999 by McMichael and others doing a study of hatchery and wild steelhead interactions on the Yakima River.  That fact was documented 12 years ago.  I wonder why it the ODFW biologist did not use it to at least question his assumption that releasing hatchery steelhead had no effect on wild steelhead in Oregon?  Maybe he did not know about this study and maybe since it was from a Yakima River study in the state of Washington, it somehow does not apply to Oregon rivers. 

What else did the scientists find out about hatchery steelhead impacts on wild steelhead in the Yakima River?

“Strategies to minimize undesirable risks associated with behavior of released hatchery steelhead should be addressed if protection and restoration of wild steelhead stocks is the management goal.”

That is interesting.  Maybe this ODFW biologist is not interested in the protection and restoration of wild steelhead in the Sandy River?  But I am sure he must be concerned for after all the wild steelhead are threatened with extinction and their recovery is his responsibility. His agency has even underscored that responsibility in the form of policy when in 2003 the ODFW commission adopted a rule that says protection of native fish is the primary goal of the agency.   Even Oregon state law directs the agency to prevent the serious depletion of native species.  That has been confirmed by the Oregon Department of Justice to mean that the department and the commission have an overriding obligation to prevent the depletion of native species.  I would be surprised if this legal direction did not also include agency biologists and executives. 

I was surprised by the comment of an ODFW biologist that had left the agency for another in state government.  When I asked him why he had left ODFW he simply replied: “I wanted to work for an agency where I did not get in trouble for following the rules.”

Reference

McMichael, Geoffrey A.; Todd N. Pearsons; Steven A. Leider. 1999. Behavioral interactions among hatchery-reared steelhead smolts and wild Oncorhynchus mykiss in natural streams. North American Journal of Fisheries Management. Vol. 19, Issue 4. pages 948-956.

ADDING NUTRIENTS TO STREAMS GIVES A BOOST TO STEELHEAD

Fertilizers boost declining B.C. fish populations

Fry grow up to 95-per-cent bigger in streams treated with nutrients, fisheries biologists say

BY RANDY SHORE, VANCOUVER SUN FEBRUARY 14, 2011

Young steelhead and salmon grew dramatically in streams seeded with sacks of slow-release fertilizer, a method that shows real promise to help rebuild collapsed spawning populations, according to B.C. biologists.

VANCOUVER - Young steelhead and salmon grew dramatically in streams seeded with sacks of slow-release fertilizer, a method that shows real promise to help rebuild collapsed spawning populations, according to B.C. biologists.

The method has proven effective at improving steelhead growth and survival in Vancouver Island streams in programs dating back to 1989.

Steelhead fry in treated areas are typically about 95-per-cent larger than those in untreated streams, while coho fry are about 40-per-cent bigger. Fish counts in the Keogh River found a 50-per-cent increase in the number of coho that survived the freshwater stage of life.

Fisheries biologists are using fertilizers to replace the nutrients that would be added to the stream naturally by the rotting carcasses of fish that die after spawning, said Kevin Pellett of the B.C. Conservation Foundation. Enhancement programs are operating in 15 watersheds and 28 rivers on the Island and southwestern B.C.

When spawners fail to return, die and rot due to overfishing or ecological conditions, the entire food chain of the stream, from algae and insects to fish fry, goes into decline.

The fertilizers are designed to stimulate growth of certain algaes that in turn cause the populations of insects such as mayfly and stonefly to thrive. Juvenile salmon and steelhead fry feed on those insects.

“When you fertilize a stream it really stimulates algae growth,” said Pellett. “It’s the brown slime that we are really after because the key insects prefer the brown diatomaceous algae.”

Steelhead fry growing downstream from the fertilizer caches are bigger and typically 75- to 250-per-cent heavier than those upstream, which would not be expected to benefit from the improved food supply, according to the most recent data. Larger, more robust fish are more likely to survive and return as spawning adults.

“When those fish go into key overwintering periods, that’s where you see a lot of mortality,” Pellett said.

“The bigger those fish are, the more of them will survive.”

The first application of fertilizer is timed to benefit the tiny steelhead and coho fry that hatch and emerge from the stream bed gravel in the early spring.

Since the first stream enhancement programs started in 1989, a variety of fertilizers and delivery systems have been employed, including liquid fertilizers and fish meal.

“We’ve since switched to a new product called Crystal Green,” he said.

Crystal Green is a slow-release agricultural fertilizer comprised of nitrogen and phosphate recovered from municipal waste water using a technology invented by civil engineers at the University of B.C. The Vancouver-based manufacturer, Ostara, is harvesting a waste material called struvite for the fertilizer from the sewage stream in suburban Portland.

“This is not a panacea, but it is a good tool to increase productivity and it may increase the rate of rebuilding [spawning populations] if we see an increase in the ocean survival,” according to Greg Wilson of the Ministry of Natural Resource Operations.

“Struvite is one of the most cost-effective techniques that we have to help out populations,” said Wilson. “Using recycled phosphorus really reduces the carbon footprint of the project, because fertilizer is quite energy intensive to make.”

Testing on Crystal Green showed the material is extraordinarily pure with few measurable contaminants or metals.

“It’s the cleanest fertilizer we’ve ever worked with,” said Wilson.

Metro Vancouver is running a pilot project at the Lulu Island sewage treatment facility to produce its own version of the fertilizer to be used in the Seymour River, Wilson said.

Crystal Green Pellets are dropped into the stream in burlap sacks, which decay over time. That simple system eliminates the need for expensive liquid fertilizer delivery systems that require maintenance and that are prone to vandalism.

The concept of fertilizing fish habitat dates back thousands of years to China, where carp ponds were fertilized with human feces, Wilson explained.

More recently, the federal and provincial governments have partnered with conservation organizations since the 1990s to fertilize a number of lakes in B.C. with the aim of improving trout and kokanee salmon populations.

Nutrient additions to the Allouette Reservoir in 1999 generated a 12-fold increase in the resident kokanee population and sparked the first adult sockeye returns to the reservoir since 1928, he said.

That unexpected result gives fisheries biologists hope that this approach could help B.C.’s collapsed salmon spawning populations recover enough to become self-sufficient again.

Steelhead and coho in the test streams benefit from two seasons of enhanced growth, the first as tiny fry and the second as a smolt ready to begin its adult life.

Pellett says hatchery data show that the larger salmon smolts are when they leave freshwater for salt water, the more adult spawners return. Fertilizer-based enhancement programs are sending bigger smolts to sea and more smolts overall.

“The more smolts we send out the more adults we get back,” he said.

As spawning populations grow, the rotting carcasses of dead spawners are expected to regain their position as the natural source of elemental nutrients in spawning streams.

“We are starting to see critical mass developing in the steelhead and coho populations on Vancouver Island,” Pellett said.

The Vancouver Island fertilizer enhancement programs are run by the B.C. Conservation Foundation with support from the province, Living Rivers — Georgia Basin Vancouver Island, Habitat Conservation Trust Foundation and a handful of other conservation organizations.

rshore@vancouversun.com

© Copyright (c) The Vancouver Sun

Transgenic salmon and humility

MARCH 17, 2011, 8:30 PM

Frankenfish Phobia

By TIMOTHY EGAN

Timothy Egan on American politics and life, as seen from the West.

At a time when the shell of the earth has cracked and the ocean heaved a mortal wave upon a shore of vulnerable nuclear plants, a small miracle is playing out in the biggest river of the American West. Spring Chinook salmon, the alpinists of the maritime world, are following biological imperative and climbing their way up the Columbia to spawn and die.

They are returning from a life in the distant Pacific, swimming home to a grave in gravel, some going almost 1,000 river miles inland. Chinook are the largest salmon, easily the most tasty, and perhaps the most imperiled.

Given the demand for salmon, it is no surprise that a Frankenfish has emerged — a lab-created hybrid that could soon become the first genetically engineered animal approved by the Food and Drug Administration for human consumption. The company behind these manufactured fish promises that they will not affect ones from an ancient and wild gene pool.

Here we go again. It is human to think we can trick nature, or do it one better. It is human to think a tsunami would never knock out a nuclear plant, a hurricane would never bury a city and a deepwater oil drill would never poison a huge body of water. In the gods of technology we trust.

Until they fail. And then, we feel helpless and small and wonder what they — or we — were thinking.

The fate of wild salmon and a panic over power plants that no longer answer to human commands would not seem to be interlinked. But they are, in the belief that the parts of the world that have been fouled, or found lacking, can be engineered to our standards — without consequence. You see this attitude in the denial caucus of Congress, perhaps now a majority of Republicans in power, who say, in the face of all evidence to the contrary, that climate change is a hoax.

The newfangled fish comes from AquaBounty Technologies, a company in New England, where many species of the water world are now extinct. They have patented an “AquAdvantage Salmon,” a sterile Atlantic female with a Chinook gene that can “grow to market size in half the time of conventional salmon,” says the company.

Consumer groups, and a bipartisan cluster of Congress that has not forsaken reason, are fighting fast-track Food and Drug Administration approval. They are also insisting that if the Frankenfish comes to market, the new salmon would have to be labeledtransgenic — over the company’s objections.

Wild salmon require so much work: they need clean water, a bountiful ocean and restraint to ensure that they aren’t fished out of existence. Vigilance, and a small amount of sacrifice — what a drag.

The alternative, some feel, is to create something under human control. What AquaBounty would do is to take the Chinook gene and splice it into a farm-raised Atlantic. A third fish, an ocean pout, which looks like an eel on a bad fin day, would provide the genetic code that allows AquAdvantage Salmon to grow so fast. Voila: fast fish from the factory, without the hassle of habitat preservation.

I’m not reflexively afraid of living better through chemistry. Genetically modified corn and soybeans have been around for some time. If we can grow food and fiber with less demand on water and nutrients, that’s often worth pursuing.

But the Frankenfish is a much bigger step, and not just because it opens the door to federal approval of all kinds of freaks from the farm. Splice a breast-heavy chicken with a pellet-loving pig and you’re into some seriously modified “other white meat.”

With wild salmon, many people wonder what all the fuss is about. In the Northwest, salmon is our symbol, even if we’ve so mismanaged their spawning grounds with dams and overfishing. Where once there were perhaps 20 million salmon returning to the Columbia, that number now is barely a million in some years.

Alaska has done much better. They have the world’s largest wild salmon runs because they’ve protected habitats, kept water quality fairly good and regulated fishermen.

These new salmon, AquaBounty says in its pleadings before the government, will not harm the ones handed down by the ages. There is “virtually no possibility of escape and interaction with the wild population,” company officials say.

Why do I not feel reassured? The last quarter century has bred skepticism into me, beginning with a personal experience in 1986. We were in Italy, my wife pregnant with our first child, when the Chernobyl nuclear plant blew. The Soviets lied, and covered up the accident.

But what soon became clear — that a runaway reactor had spewed more than 400 times the amount of radioactivity into the environment than that released by the atomic bomb over Hiroshima — made us tremble. For days, along with the rest of Europe, we watched the pattern of a huge radioactive plume, as officials warned that pregnant women were at particularly high risk.

Luckily, the radioactive cloud never came our way. But given the choice between the hard work of trying to respect the laws of nature, and the engineered solution, I’ll take the seasonal miracle of wild salmon — and try to learn something about humility.

Lubchenco Is The New Cheerleader For The Status Quo

By Demian Ebert 

In a recent commentary in The Oregonian, Jane Lubchenco, administrator of the National Oceanic and Atmospheric Administration, stated that salmon recovery in the Columbia Basin is now being guided by science and pointed to increased survival of juvenile salmon and improved returns of adult salmon as validation of recovery efforts. But attributing improvements in salmon and steelhead returns to the recovery program alone is misleading. 

Survival of juvenile salmon in the Columbia River has increased because of improved passage conditions, due largely to increased spill at the dams -- ironically, an action that was imposed on federal agencies by court order. Improved ocean conditions have resulted in increased adult returns for some populations of salmon and steelhead. Unfortunately, most of the returning fish are from hatcheries. Wild fish populations remain far below recovery levels. 

Although Lubchenco asserted that science supports the NOAA plan, a comprehensive review by the Western Division of the American Fisheries Society concluded the plan relied more on monitoring than on specific actions -- monitoring that's adequate for tracking the status of salmon, but not adequate for ensuring their protection and recovery. 

Let's face it: Science alone will not guide salmon recovery; ultimately it will be a societal decision. But the public should not be misled into believing that the best available science has been fully implemented, as NOAA contends. Many human actions have contributed to the decline of the Columbia runs of salmon and steelhead, including habitat degradation, overharvest and poor hatchery programs. Dams, reservoirs and operation of the hydropower system have been major contributors to the decline -- especially for Snake River populations -- and are also contributing to the decline of other native species, notably the Pacific lamprey and white sturgeon. Yet much of the NOAA recovery approach is a tacit acceptance of the status quo when it comes to the hydropower system. 

In 2000, the Oregon Chapter of the American Fisheries Society -- representing hundreds of fishery professionals -- passed a resolution that "The four lower Snake River dams are a significant threat to the continued existence of remaining Snake River salmon and steelhead stocks; and if society wishes to restore these salmonids to sustainable, fishable levels, a significant portion of the lower Snake River must be returned to a free-flowing condition by breaching the four lower Snake River dams, and this action must happen soon." We reaffirmed this resolution in 2009. The Idaho Chapter and Western Division of the American Fisheries Society, collectively representing thousands of aquatic scientists, have also passed similar resolutions. 

Furthermore, results from a scientific assessment -- a five-year effort of regional scientists convened by NOAA -- indicate that the action with greatest certainty of recovering Snake River salmon and steelhead is breaching the lower four Snake River dams. 

Yet NOAA now considers even the study of breaching the Snake River dams to be essentially an action of last resort, triggered only when fish runs fall to perilously low numbers. Should society decide to implement dam breaching, many years of study and planning would be required. Comprising several generations of fish, this could severely limit the value of the action if important salmon and steelhead populations go extinct before the first shovel of dirt were moved. 

Lacking the information necessary to assess the technical, physical and biological effects of breaching the Snake River dams, NOAA cannot meet its stated objective of using the "best available science" to develop recovery actions. 

The Oregon Chapter of the American Fisheries Society encourages a proactive, comprehensive study of dam breaching, with independent and open scientific review, so that this recovery action could be thoroughly considered and implemented in a timely manner. Hundreds of dams in the United States have been removed, with a growing record of immediate and positive responses by rivers and native fish. If society decides recovery of these imperiled fish is truly important, we should consider this science-supported recovery action for the Snake River and its fish. 

Demian Ebert is president of the Oregon Chapter of the American Fisheries Society. 


Published in The Oregonian March 11,2011

Multiple Sources of Gene Flow into Wild Steelhead Populations

Molecular Biology 2011

Who are the missing parents? Grandparentage analysis identifies multiple sources of gene flow into a wild population

MARK R. CHRISTIE, MELANIE L. MARINE and MICHAEL S. BLOUIN

Department of Zoology, Oregon State University, Corvallis, OR 97331-2914, USA

Abstract

In order to increase the size of declining salmonid populations, supplementation programmes intentionally release fish raised in hatcheries into the wild. Because hatchery-born fish often have lower fitness than wild-born fish, estimating rates of gene flow from hatcheries into wild populations is essential for predicting the fitness cost to wild populations. Steelhead trout (Oncorhynchus mykiss) have both freshwater resident and anadromous (ocean-going) life history forms, known as rainbow trout and steelhead, respectively. Juvenile hatchery steelhead that ‘residualize’ (become residents rather than go to sea as intended) provide a previously unmeasured route for gene flow from hatchery into wild populations. We apply a combination of parentage and grandparentage methods to a three-generation pedigree of steelhead from the Hood River, Oregon, to identify the missing parents of anadromous fish. For fish with only one anadromous parent, 83% were identified as having a resident father while 17% were identified as having a resident mother. Additionally, we documented that resident hatchery males produced more offspring with wild anadromous females than with hatchery anadromous females. One explanation is the high fitness cost associated with matings between two hatchery fish. After accounting for all of the possible matings involving steelhead, we find that only 1% of steelhead genes come from residualized hatchery fish, while 20% of steelhead genes come from wild residents. A further 23% of anadromous steelhead genes come from matings between two resident parents. If these matings mirror the proportion of matings between residualized hatchery fish and anadromous partners, then closer to 40% of all steelhead genes come from wild trout each generation. These results suggest that wild resident fish contribute substantially to endangered steelhead ‘populations’ and highlight the need for conservation and management efforts to fully account for interconnected Oncorhynchus mykiss life histories.

 http://nativefishsociety.org/wp-content/uploads/Christie-et-al-w-M-Blouin-ME-2011-steelhead-missing-parents.pdf

New Study: Hatchery Fish Reduce Productivity of Wild Fish

Can. J. Fish. Aquat. Sci. 68(3): 511–522 (2011)  |  doi:10.1139/F10-168  |  Published by NRC Research Press   

Reduced recruitment performance in natural populations of anadromous salmonids associated with hatchery-reared fish

M. W. Chilcote, K. W. Goodson, and M. R. Falcy

Abstract: We found a negative relationship between the reproductive performance in natural, anadromous populations of steelhead trout (Oncorhynchus mykiss), coho salmon (O. kisutch), and Chinook salmon (O. tshawytscha), and the proportion of hatchery fish in the spawning population. We used intrinsic productivity as estimated from fitting a variety of recruitment models to abundance data for each population as our indicator of reproductive performance. The magnitude of this negative relationship is such that we predict the recruitment performance for a population composed entirely of hatchery fish would be 0.128 of that for a population composed entirely of wild fish. The effect of hatchery fish on reproductive performance was the same among all three species. Further, the impact of hatchery fish from “wild type” hatchery broodstocks was no less adverse than hatchery fish from traditional, domesticated broodstocks. We also found no support for the hypothesis that a population's reproductive performance was affected by the length of exposure to hatchery fish. In most cases, measures that minimize the interactions between wild and hatchery fish will be the best long-term conservation strategy for wild populations.

The full study can be seen at the Native Fish Society:

http://nativefishsociety.org/wp-content/uploads/Chilcote-et-al-2011-h-w-redu
ced-recruitment.pdf

SINGLE BARBLESS HOOKS REQUIRED FOR CONSERVATION

Introduction

When there is a conservation concern for a wild salmonid population such as one listed as threatened under the Endangered Species Act, each fish is valuable for its potential contribution to recovery of the population.  The loss of juvenile steelhead and salmon can negatively affect adult abundance several years later.  It is important to consider all sources of mortality and take appropriate action over those that can be affected by management.  Reducing the mortality associated with angling by requiring single barbless hooks is an important policy decision.  Doing so can increase survival of juvenile and adult fish by reducing handling time required to take out the hook, and injury from handling as well as exposure to the air.

The following peer-reviewed studies provide a scientific basis for angling regulations to include barbless hooks as a factor important to conservation of native, wild salmonids.  While there is ample justification to use barbless hooks on adult fish as required in ocean commercial fisheries to promote easy release with less handling and a goal of reducing mortality, there is also a measurable conservation benefit from using barbless hooks when adult salmonids are captured by angling in freshwater. These studies provide the verification for this conclusion.  Using barbless hooks to reduce injury and mortality for juvenile salmon and steelhead is often overlooked when setting angling regulations.  Steelhead juveniles rear in freshwater for 2 to 3 years and are exposed to angling mortality in fisheries targeted on trout and adult steelhead and salmon. It only makes sense to include juvenile fish protection as a benefit of barbless hook fisheries. 

With a few exceptions such as the Metolius River, the Oregon Department of Fish and Wildlife has adopted a position opposed to the use of barbless hooks as a conservation tool for vulnerable wild salmonid populations.  They base this policy on a scientific literature review done by staff in 2001.  Oregon stands alone among entities that are concerned about recovery and protection of wild salmon, trout and steelhead.  British Columbia requires single barbless hooks province wide, Washington requires single-point barbless hooks in areas designated as "fly fishing only" or "selective gear rules; California requires single barbless hooks on most trout and steelhead fisheries; Idaho says only barbless hooks may be used when fishing for steelhead in the Salmon and Clearwater river drainages and the Snake River below Hells Canyon Dam.

The studies provided below provide the scientific justification for the Oregon Department of Fish and Wildlife and Commission to adopt single barbless hooks as a conservation management tool to protect native, wild salmonids throughout the state.  In waters where these fish are threatened, a more precautionary management approach is appropriate to reduce mortality.  In waters where wild fish harvest is allowed, a barbless hook regulation would provide a conservation benefit for those that are released.  For example, in some rivers a limit of one wild steelhead per day and 5 per year is allowed.  In those fisheries a hatchery fish may also be taken.  This means that the angler may release one or more wild fish in order to take a legal limit that includes a hatchery fish.  There is also evidence that wild steelhead contribute more to the fishery than their numbers would suggest, so single barbless hooks would not only help prevent mortality, they could contribute to more angler satisfaction through multiple catches.  

The point of this paper is to provide the Department and the Commission with information that provides the scientific justification and benefit of using barbless single hooks in Oregon waters for adult and juvenile fish.

WHAT THE SCIENCE SAYS:

Wright, Sam. 1992. Guidelines for selecting regulations to manage open-access fisheries for natural populations of anadromous and resident trout in stream habitats. North American Journal of Fisheries Management 12:517-527.

“Adding restrictions requiring single hooks, barbless hooks, or flies can provide only relatively small incremental improvements in trout survival.  However, managers have realized that these can become important in situations where individual fish are hooked many times.  The chance of mortality from a single hooking event was examined for various unweighted combinations of terminal gear from our compilation of research results.  The categories and single-event losses were as follows:

Barbless hooks with flies                                1.76%

All barbless hooks (with flies or lures),         2.16%

Barbless hooks with lures,                             3.00%

All hooks with flies,                                       3.34%

Barbed hooks with flies,                                3.88%

All barbed hooks,                                           5.86%

Barbed hooks with lures,                               6.86%

“The most fundamental rule to remember in managing any open-access trout fishery is that effective regulatory control must be applied to every individual fish (Hunt 1970).  Fishing seasons and daily bag limits, when used by themselves, are not effective management tools, because they do not apply to each fish that is captured.”

Meka, Julie, M. 2004. The influence of hook type, angler experience, and fish size on injury rates and duration of capture in an Alaskan catch-and-release rainbow trout fishery. North American Journal of Fisheries Management 24:1309-1321.

“Recent studies have emphasized a holistic approach to evaluating the effects of catch-and-release angling on fish by evaluating both sublethal and lethal effects.  When fish are subjected to angling stress, they are affected by stressors that may not cause immediate mortality; in fact, some may influence ultimate survival.  These stressors include physiological disruptions from landing time, handling time, and exposure to air during the hook removal process or when photographed, as well as the potentially confounding effects of nonlethal hooking injuries.”

“…fishing methods and whether J hooks were barbed or barbless significantly influenced new overall injury rates.  Fish caught by spin-fishing had similar injury rates as those caught by fly-fishing; thus, significance was from higher injury rates with barbed hooks for both fishing methods as well as higher injury rates for barbed hooks between fishing methods.”

“…novice anglers injured proportionally more fish than experienced anglers.  The number of new injuries per capture was more significant in small fish.  Small fish were hooked in more than one location more frequently than large fish (small fish <440 mm or 17-inches)…small fish were injured more frequently, and bleeding was most significant in fish hooked in sensitive areas and in small fish…small fish had higher bleeding rates.   Bleeding was more prevalent in small fish.  This presumably was because they were injured in sensitive areas more often as well as injured more often.”

“…hook removal time was significantly longer when barbed J hooks were used compared to barbless J hooks.  Mortality was also higher for fish caught with treble hooks compared with single hooks, presumably because the increase in hook-point penetrations increased the probability of injury to critical locations and associated bleeding. My results indicate that smaller fish (<17-inches) may be more vulnerable to mortality.”

“In this study, barbed J hooks caused significantly more new hooking injuries, took longer to remove, and were more efficient at catching fish than barbless hooks.  Higher injury rates and longer handling times for barbed hooks were mostly likely due to difficulty in hook removal and hooks becoming tangled in landing nets, both of which were observed to intensify injuries and bleeding.  Barbless hooks have been found to cause a lower incidence of injury and bleeding than barbed hooks and decrease the amount of time fish are handled and exposed to air while removing hooks.”

“The results of this study indicate that the use of barbless J hooks may minimize injury and reduce the amount of time fish are handled during hook removal and that angler experience can contribute to hooking injury.”

“However, a slight reduction in hooking injuries and less handling time are two important benefits to consider in support of a regulation change or promotion of angler education programs for catch-and-release trout fisheries.”

“…focus future research on the prolonged sublethal effects of hooking injury on trout populations, and develop angler education programs and gear restrictions to minimize injury.”

Schreer, Jason, F., Dayna M. Resch, and Malachy L. Gately. 2005. Swimming performance of brook trout after simulated catch-and-release angling: looking for air exposure thresholds. North American Journal of Fisheries Management 25:1513-1517.

“Air exposure has been hypothesized as one of the primary stressors present during catch-and-release angling.  However, there are few studies that systematically vary air exposure duration and evaluate the consequences on individual fish.  Here we evaluated the short-term sublethal effects of exercise (to simulate angling) and air exposure on the swimming performance of hatchery brook trout at 10 degrees C. (50 degrees F.).  Nearly half of the fish held out of the water for 120 seconds were unwilling or unable to swim at all.  This work suggests that fish possess air exposure thresholds that, once exceeded, result in performance impairments.  Fish released after extended air exposure may become easy prey for predators or could be displaced downstream .  We conclude that air exposure should be restricted to less than 60 seconds and ideally should be avoided entirely.”

(Note:  Barbless hooks decrease the amount of time fish are handled and exposed to air while removing hooks in the  study by Meka.)

Taylor, Mathew, J., and Karl R. White. 1992. A meta-analysis of hooking mortality of nonanadromous trout. North American Journal of Fisheries Management 12:760-767.

“…fish caught on barbed hooks had higher mortality rates than fish caught on barbless hooks.

“…the mortality rate for fish caught with barbed flies or lures is almost double the mortality rate of fish caught with barbless flies or lures.

“”…the effects of handling on hooking mortality have been sparsely investigated.  It would be nice to know about variables such as net use, resuscitation techniques, time out of water, and the effect of barbs on handling time.  Research on these variables would give a clearer understanding of how to increase survival rates.

“The overall average mortality rate in these 18 studies was just under 12%.  Under the best conditions, with barbless flies or lures, the percentage dropped to under 3%.

Reingold, Melvin. 1979. Mortality and catch rates of juvenile steelhead trout caught on single versus treble barbless hooks.  Idaho Department of Fish and Game.

“…even at the low level of mortalities observed, losses from treble barbless hooks were 4.5 times that of losses from single barbless hooks.  In an intensive catch-and-release fishery, this could be meaningful…anglers hooked and released 75,000 cutthroat trout on the Middle Fork Salmon River in 1978.  Applying the percent mortality observed, single barbless hooks would account for 428 deaths versus 1,928 for treble barbless hooks, a difference of 1,500 trout; predominately spawner size individuals.  This is 83% of the estimated season trout harvest in that stream in 1969 (1,800) when it was catch and keep.”

Pollard, Herbert, A., and Ted C. Bjornn. 1973. The effects of angling and hatchery trout on the abundance of juvenile steelhead trout. Transactions of the Americana Fisheries Society No. 4: 745-752

“A large proportion of juvenile steelhead trout in a stream can be removed with a moderate amount of angling.  Age II-plus steelhead are especially susceptible to harvest by angling and 70 to 100% of those present in a 122 m (400 ft) section of stream were removed with 4 angler hours of effort.  The normal sport fishery may take as many as half of the catchable size (age II-plus) juvenile steelhead from a stream such as the Crooked Fork each year, and thus may reduce the number of smolts produced.”

“Hatchery reared, catchable sized rainbow trout did not act as a buffer to reducing the angling harvest of juvenile steelhead…”

“Removal of the larger pre-smolts by angling could decrease adult returns due to fewer smolts and decreased survival of the remaining, small smolts.”

(Note:  This study was included to show how vulnerable juvenile steelhead are to a trout fishery and the impact of a fishery on the future abundance of adult returns.  Angling with barbed hooks increases tissue damage, handling time, exposure to air, and causes a reduction in smolt numbers and adult returns.)

Cowen, Laura. 2007. Effects of angling on chinook salmon for the Nicola River, British Columbia, 1996-2002. North Americana Journal of Fisheries Management 27:256-267

“Gjernes (1990) found that barbed hooks caused higher hooking mortality rates.  Bartholomew and Bohnsack (2005) reported three studies that showed increased mortality when using barbed versus barbless hooks.  We did not use barbed hooks in this study.”

“The optimal angling gear and techniques used in our study included soft, knotless-mesh landing nets, suitable hook sizes, barbless hooks, short playtime, short handling time, little or no air exposure, angling only at water temperatures less than or equal to 20 degrees C, and leaving deep hooks in or removing them gently with pliers.  In addition, Bartholomew and Bohnsack (2005) advocate fishing actively and setting the hook as soon as possible, use of dehooking tools, and avoidance of touching gills and handling the soft underbelly of the fish.”

Pelletier, Christine, Kyle C. Hanson, and Steven J. Cooke. 2007. Do Catch-and-release guidelines from state and provincial fisheries agencies in North America conform to scientifically based best practices. Environ Manage 39:760-773

“Barbless hooks were recommended by 34 (or 69%) agencies as an alternative to barbed hooks.”

“However, there is compelling evidence that barbless hooks are easier to remove than barbed hooks.  Ease of removal results in reduced handling time and tissue damage, thereby decreasing associated mortality.”

“The Ontario Ministry of Natural Resources and the Utah Division of Wildlife Resources explained that replacing treble hooks with single hooks will make live release easier.  Because air exposure tends to occur when anglers remove hooks, these agencies have taken a positive approach in stressing the importance of a timely live release.”

“Air exposure was the most widely discussed catch-and-release issue among agencies. It was found that 44 of 49 agencies provided advice on the subject.  The most common recommendation (64%) was to keep the fish in the water at all times.  This is consistent with studies showing that air exposure is extremely harmful in fish that have experienced physiological disturbances associated with angling.  Tufts (1992) found that when rainbow trout were exposed to air for either 30 or 60 seconds after exhaustive exercise, mortality increased from 38% to 72%, receptively.”

“…removing hooks (in deeply hooked fish) often results in mortality associated with increased handling time and air exposure.”

“Considering that water temperature is regarded as the ‘master factor’ in the biology of fishes, it is surprising that angling at extreme temperatures was not incorporated into all agency guidelines.”

“…mortality among Atlantic salmon is minimal when angled at water temperatures between 8 degrees C and 18 degrees C., but as water temperatures increased to greater than 18 degrees C, the risk of angling-induced mortality increases considerably.”

“…we believe that natural resource agencies are the appropriate target of initial attempts to ensure that catch-and-release guidelines are consistent with the best scientific information.”

Conclusion

In recent angler surveys by Oregon and Washington fish management agencies, a larger proportion of the respondents practiced catch-and-release fishing.  Anglers are embracing live release fishing as a conservation measure.  It also does not substantially deplete fish numbers like a kill fishery, and provides at least the expectation that the fish will survive to reproduce or be caught again. 

The use of single barbless hooks complements the growing interest in catch-and-release fisheries.  As these studies show, their use reduces sublethal and lethal impacts on juvenile and adult fish. 

The Oregon Department of Fish and Wildlife and the Commission ought to review their opposition to the use of barbless hooks in selective fisheries.  The goal of selective fisheries is to allow angling opportunity while achieving conservation objectives. Barbless hooks advance the conservation objectives of selective fisheries.