New hatchery management strategies in the Columbia River Basin focus on conservation of naturally spawning populations as an equal priority to providing fish for harvest—a difficult halance to achieve. The Hatchery Scientific Review Group (HSRG) assessed 178 hatchery programs and 351 salmonid populations to determine how to achieve managers’ goals for conservation and sustainable fisheries. Modeling determined the best strategy, using an approach based on best available science, goal identification, scientific defensibility, and adaptive management to refocus from an aquaculture paradigm to a renewable natural resource paradigm. We concluded that hatcheries and natural populations must be managed with the same biological principles. HSRG solutions improved the conservation status of many populations (25% for steelhead trout, more than 70% for Chinook and coho salmons) while also providing increased harvest. Natural‐origin steelhead trout and coho salmon spawners increased by 6,000 to 10,000; Chinook salmon increased by more than 35,000 compared to current numbers. Hatchery juvenile production decreased slightly, and in most cases production shifted from populations of concern. Overall harvest potential increased from 717,000 to 818,000 fish by focusing on selective fishing and by reheating some in‐river harvest closer to where the fish originate. With habitat improvements, often the number of natural‐origin fish nearly doubled.

We assessed noncompliance with angling regulations on three Idaho waters using random response, a technique designed to quantify embarrassing or criminal behavior. We searched for associations between positive random response answers and angler regulation awareness across a number of demographic variables. Illegal use of bait and creeling of westslope cutthroat trout Oncorhynchus clarki lewisi within two catch‐and‐release zones ranged from –0.4 to 3.0%. Creeling of illegal‐sized cutthroat trout was a more common violation (5 to 8%) in two zones managed with a minimum size regulation. Estimated noncompliance with barbless hook regulations for the same zones was high (29%), but nearly 75% of these violations were accidental. Noncompliance with harvest restrictions was greatest on Henrys Lake where 9.5% of anglers violated the two‐trout creel limit each day. We observed statistically significant associations between the types of regulations and angler ability to correctly recite them on a given stream. Several demographic variables including age, residence, and gear type used were also associated with regulation awareness. We conclude that random response is a viable method for estimating rates of angler noncompliance with regulations. Additional analyses are needed to evaluate potential biological effects of noncompliance on the trout populations.

The use of captive broodstocks is becoming more frequently employed as the number of species facing endangerment or extinction throughout the world increases. Efforts to rebuild the endangered Snake River sockeye salmon, Oncorhynchus nerka, population have been ongoing for over a decade, but the use of microsatellite data to develop inbreeding avoidance matrices is a more recent component to the program. This study used known genealogical relationships among sockeye salmon offspring to test four different pairwise relatedness estimators and a maximum-likelihood (M-L) relatedness estimator. The goal of this study was to develop a breeding strategy with these estimators that would minimize the loss of genetic diversity, minimize inbreeding, and determine how returning anadromous adults are incorporated into the broodstock along with full-term hatchery adults. Results of this study indicated that both the M xy and R QG estimators had the lowest Type II error rates and the M-L and R R estimators had the lowest Type I error rates. An approach that utilizes a combination of estimators may provide the most valuable information for managers. We recommend that the M-L and R R methods be used to rank the genetic importance of returning adults and the M xy or R QG estimators be used to determine which fish to pair for spawning. This approach provides for the best genetic management of this captive, endangered population and should be generally applicable to the genetic management of other endangered stocks with no pedigree.

As part of the Snake River Sockeye Salmon Oncorhynchus nerka recovery effort, a dedicated smolt rearing facility was constructed in 2013 near Springfield, Idaho. In‐hatchery performance and survival were typical for the species, but unexpectedly high mortality rates were observed in the first cohorts of Springfield‐reared smolts upon release into Redfish Lake Creek (RFLC) and during out‐migration. In response, a series of iterative experiments was conducted to identify the cause of the morbidity and mortality observed and to test a range of strategies to mitigate effects on postrelease survival. In the search for possible contributing factors, a difference in water chemistry was noted: whereas Springfield Hatchery's water source is “hard” and has high calcium concentrations, water at the RFLC release site is “soft” and has very low calcium concentrations. In both manipulative experiments and field evaluations, we demonstrated that juvenile Snake River Sockeye Salmon are profoundly affected by instantaneous transitions from high‐ to low‐hardness water. Furthermore, we established a causal link between differences in water chemistry, the associated physiological stress, and morbidity/mortality observed during smolt releases and subsequent out‐migration. A variety of mitigation strategies, including water mixing and water softening, was tested, but stepwise acclimation from high‐ to medium‐hardness water and then from medium‐ to low‐hardness water proved to be the most biologically and logistically effective means of addressing the identified water chemistry differences. Estimates of postrelease survival to Lower Granite Dam (~430 river kilometers downstream) indicated significantly higher survival for acclimated groups (68.7–75.5%) compared to smolts directly released into RFLC (18.1%). Although Snake River Sockeye Salmon smolt survival rates will undoubtedly fluctuate annually with environmental conditions, it is clear that the elevated morbidity and mortality observed in previous years can be addressed through proper acclimation of smolts prior to release.

No abstract