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Sluiceways at hydroelectric dams are designed to enable floating ice and debris to pass through the dams and may be used as an effective, nonturbine, surface route for out-migrating fishes to pass through dams. Each year, the sluiceway at The Dalles Dam on the Columbia River, USA, is normally operated between 1 April and 30 November and the spillway between 10 April and 31 August to enable downstream-migrating juvenile Pacific salmonids to pass. The only route available for fishes to pass the dam between 1 December and 31 March is through the turbines. This study evaluated downstream passage of adult steelheadOncorhynchus mykissat The Dalles Dam during various periods between 1 November and 10 April for years 2008 through 2010. The purpose of the study was to determine the efficacy of operating the sluiceway between 1 December and 31 March to provide a relatively safe, nonturbine, surface outlet for downstream passage of adult steelhead that overwinter in the lower Columbia River (i.e., fallbacks) or for adult steelhead attempting to emigrate back to the marine environment after spawning (i.e., kelts). We applied a fixed-location hydroacoustic technique to estimate downstream passage rates at the sluiceway and turbines. The sluiceway was used by 91–99% of the adult steelhead during all sampling periods; the remaining 1–9% passed through the turbines. This implies that adult steelhead preferred the sluiceway for downstream passage at the dam. Our results indicate that keeping the sluiceway open between 1 December and 31 March may provide an optimal, nonturbine surface route for downstream passage of overwintering or postspawned adult steelhead at The Dalles Dam. Similar operations are relevant at hydroelectric dams with surface-flow outlets, such as sluiceways, for safe downstream passage of fish species of management concern. Received July 19, 2012; accepted March 27, 2013 [ABSTRACT FROM PUBLISHER]

Highbush blueberry pollination depends on managed honey bees (Apis mellifera) L. for adequate fruit sets; however, beekeepers have raised concerns about the poor health of colonies after pollinating this crop. Postulated causes include agrochemical exposure, nutritional deficits, and interactions with parasites and pathogens, particularly Melisococcus plutonius [(ex. White) Bailey and Collins, Lactobacillales: Enterococcaceae], the causal agent of European foulbrood disease, but other pathogens could be involved. To broadly investigate common honey bee pathogens in relation to blueberry pollination, we sampled adult honey bees from colonies at time points corresponding to before (t1), during (t2), at the end (t3), and after (t4) highbush blueberry pollination in British Columbia, Canada, across 2 years (2020 and 2021). Nine viruses, as well as M. plutonius, Vairimorpha ceranae, and V. apis [Tokarev et al., Microsporidia: Nosematidae; formerly Nosema ceranae (Fries et al.) and N. apis (Zander)], were detected by PCR and compared among colonies located near and far from blueberry fields. We found a significant interactive effect of time and blueberry proximity on the multivariate pathogen community, mainly due to differences at t4 (corresponding to ~6 wk after the beginning of the pollination period). Post hoc comparisons of pathogens in near and far groups at t4 showed that detections of sacbrood virus (SBV), which was significantly higher in the near group, not M. plutonius, was the primary driver. Further research is needed to determine if the association of SBV with highbush blueberry pollination is contributing to the health decline that beekeepers observe after pollinating this crop., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America.)