During the past 100 years, most large rivers in North America have been altered for flood control, hydropower, navigation or water supply development. Although these activities clearly provide important human services, their associated environmental disturbances can profoundly affect stream‐dwelling organisms. We used dynamic multi‐species occupancy models combined with a trait‐based approach to estimate the influence of site‐level and species‐level characteristics on patch dynamic rates for 15 darter species native to the Elk River, a large, flow‐regulated Tennessee River tributary in Tennessee and Alabama. Dynamic occupancy modelling results indicated that for every 2.5 °C increase in stream temperature, darters were 3.94 times more likely to colonize previously unoccupied stream reaches. Additionally, large‐bodied darter species were 3.72 times more likely to colonize stream reaches compared with small‐bodied species, but crevice‐spawning darter species were 5.24 times less likely to colonize previously unoccupied stream reaches. In contrast, darters were 2.21 times less likely to become locally extinct for every 2.5 °C increase in stream temperature, but high stream discharge conditions elevated the risk of local extinction. Lastly, the presence of populations in neighbouring upstream study reaches contributed to a lower risk of extinction, whereas the presence of populations in neighbouring downstream study reaches contributed to higher rates of colonization. Our study demonstrates the application of a trait‐based approach combined with a metapopulation framework to assess the patch dynamics of darters in a regulated river. Results from our study will provide a baseline for evaluating the ecological consequences of alternative dam operations. Copyright © 2014 John Wiley & Sons, Ltd.

Sixteen darter species, including the federally endangered Boulder Darter Etheostoma wapiti, are known to occur in the Elk River, a large, flow‐regulated tributary of the Tennessee River, Tennessee–Alabama. Since the construction of Tims Ford Dam (TFD) in 1970, habitat modification caused by cold, hypolimnetic water releases and peak‐demand hydropower generation has contributed to population declines and range reductions for numerous aquatic species in the main‐stem Elk River. We developed Bayesian hierarchical multispecies occupancy models to determine the influence of site‐ and species‐level characteristics on darter occurrence by using presence–absence data for 15 species collected from 39 study sites. Modeling results indicated that large‐river obligate species, such as the Boulder Darter, were 6.92 times more likely to occur for every 37‐km increase in the distance downstream from TFD. In contrast, small‐stream species were 2.35 times less likely and cosmopolitan species were 1.88 times less likely to occur for every 37‐km increase in distance downstream from TFD. The probability of occurrence for darter species also had a strong negative relationship with the absence of cobble and boulder substrates and the presence of high silt levels, particularly for species that require boulder substrates during spawning. Although total darter species richness was similar across all 39 sample sites, the composition of darter assemblages varied substantially among locations, presumably due in part to species‐specific habitat affinities and hydrothermal conditions. The use of multispecies occupancy models allowed us to account for the incomplete detection of species while estimating the influence of physical habitat characteristics and species traits on darter occurrences, including rarely observed species that would have been difficult to model individually. Received August 23, 2015; accepted May 31, 2016 Published online August 12, 2016

Largemouth Bass Micropterus salmoides are the focus of a billion-dollar (US$1 × 10 9 ) recreational fishery in North America and are subject to widespread hatchery supplementation efforts. Parentage-based tagging (PBT) uses genetic samples taken from hatchery broodstock to genetically "tag" offspring and represents a valuable approach to inform fisheries management and assess hatchery contributions in the wild. This study used a robust microsatellite panel for PBT with Largemouth Bass that reliably discriminated among individuals and siblings and that had low parentage error rates (i.e., false assignments). Genetic data from three cohorts of hatchery broodstock (184 individuals sampled across 3 years) were used to quantify the impacts of planting 150,346 fingerling Largemouth Bass into Lake Mattamuskeet, North Carolina. Parentage-based tagging detected low overall levels of hatchery contributions in the wild (4.1%), which varied as a function of collection year (range = 1.5-7.7%). Furthermore, hatchery contributions varied by broodstock cohort, with PBT detections being attributed to broodstock from only two of the three stocking years. The application of PBT for Largemouth Bass represents a cost-effective and practical approach to tag large numbers of hatchery offspring, monitor supplementation efforts, and evaluate the efficacy of different hatchery practices.