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... Data on age and growth of fishes is critical for effective management; however, growth rates documented in one location may not be representative of other locations, especially for species that occur across wide geographic ranges. Sebastes maliger, quillback rockfish, occur across a broad latitudinal range, but their growth patterns have been quantified only in the southern part of their range. To ...
Alaska, etc ; perfluorocarbons; pollutants; technology; California; Show all 5 Subjects
Abstract:
... Trifluoroacetate (TFA) is a persistent perfluorinated alkanoic acid anion that has many anthropogenic sources, with fluorocarbon refrigerants being a major one. After an initial burst of research in the late 1990s and early 2000s, research on this ubiquitous pollutant declined as atmospheric emissions of the precursor compounds grew rapidly. Thus, there is little contemporaneous information about ...
Alaska, etc ; geophysics; research; subduction; volcanic activity; Show all 5 Subjects
Abstract:
... An oceanic plateau, the Yakutat terrane, has entered the subduction system across southcentral Alaska. Its down‐dip fate and relationship to overlying volcanism is still debated. Broadband seismometers from the Wrangell Volcanism and Lithospheric Fate (WVLF) temporary experiment were deployed with <20 km spacing across southcentral Alaska to study this region. An array‐based deconvolution procedur ...
Alaska, etc ; Oncorhynchus nerka; models; rivers; salmon; Show all 5 Subjects
Abstract:
... Accurate forecasts of sockeye salmon (Oncorhynchus nerka) in Bristol Bay, Alaska, play an important role in management and harvesting decisions for this culturally and ecologically vital species. We used a suite of parametric and nonparametric models to assess the frontiers in forecast accuracy of Bristol Bay sockeye salmon possible given currently available data. In retrospective performance test ...
Alaska; Gulf of Alaska, etc ; Sebastes ruberrimus; data collection; expert opinion; fisheries law; interviews; life history; research; rockfish; Pacific Ocean; Show all 11 Subjects
Abstract:
... Rockfishes (Sebastes spp.) and the fisheries they support along the northeastern Pacific Ocean have undergone dynamic changes over the last century. The unique life history traits of rockfishes pose a host of challenges that make them difficult to monitor and susceptible to overfishing. Previous research has demonstrated that fishers’ knowledge and scientific data can help to create a more complet ...
Alaska; Gulf of Alaska, etc ; Cottidae; community structure; estuaries; estuarine fish; fish communities; freshwater; glaciation; glaciers; latitude; river deltas; watersheds; Show all 13 Subjects
Abstract:
... Along the Gulf ofAlaska, rapid glacier retreat has driven changes in transport of freshwater, sediments, and nutrients to estuary habitats. Over the coming decades, deglaciation will lead to a temporary increase, followed by a long-term decline of glacial influence on estuaries. Therefore, quantifying the current variability in estuarine fish community structure in regions predicted to be most aff ...
Alaska, etc ; climate; data collection; glaciers; inventories; landscapes; models; Show all 7 Subjects
Abstract:
... Glaciers are important sentinels of a changing climate, crucial components of the global cryosphere and integral to their local landscapes. However, many of the commonly used methods for mapping glacier change are labor-intensive and limit the temporal and spatial scope of existing research. This study addresses some of the limitations of prior approaches by developing a novel deep-learning-based ...
Alaska, etc ; data collection; earthquakes; geodesy; geophysics; research; subduction; tsunamis; Show all 8 Subjects
Abstract:
... With five earthquakes (1938, 1946, 1957, 1964, and 1965), the Aleutian‐Alaska subduction plate boundary ruptured a length of 3,548 km. We revisit these five earthquakes—first studied in detail by Sykes (1971, https://doi.org/10.1029/JB076i032p08021)—through probabilistic relocation of carefully selected mainshocks and aftershocks. Our final catalog of 324 events is established from a set of 12 mai ...
Alaska, etc ; animals; case studies; glaciers; remote sensing; uncertainty; wildlife; Show all 7 Subjects
Abstract:
... Recent technological advancements have seen a rapid growth in the use of imagery data to estimate the abundance and spatial distribution of animal populations. However, the value of imagery data may not be fully exploited under traditional analytical frameworks. We developed a method that leverages aerial imagery data for population modeling through entity resolution, a technique that stochastical ...
Alaska, etc ; geophysics; glaciers; ice; lakes; research; spring; temporal variation; Show all 8 Subjects
Abstract:
... To characterize the spatiotemporal variations of glacier surface speed on the Kenai Peninsula, Alaska (∼3,900 km²), we derived 92 surface speed fields between October 2014 and December 2019 using intensity offset tracking on Sentinel‐1 data. On average, speeds are 50% greater in spring (March‐May) than the annual mean (69 m a⁻¹) while winter speeds are close to the annual mean. While marine‐termin ...
Alaska, etc ; algorithms; freeze-thaw cycles; hydrology; latitude; permafrost; temporal variation; Show all 7 Subjects
Abstract:
... In the context of global warming, permafrost degrades gradually. To cope with the instability of the cryosphere, it is very important to strengthen the monitoring of the seasonal freeze–thaw cycle. At present, active and passive microwave remote sensing data are widely used in freeze/thaw (F/T) onset detection. There is some potential to improve accuracy through the combination of active and passi ...
Alaska, etc ; coasts; earthquakes; geometry; geophysics; heat flow; subduction; temperature; water content; Show all 9 Subjects
Abstract:
... The data include the 3-D temperature field (degrees Celsius), water content (wt%), dehydration rate (wt%/km), and subduction velocity field (cm/yr) of the subducting plate, as well as the coastline and volcano distribution in Alaska. The data of the model region have dimensions of 800 × 1600 × 400 km (length × width × depth). The geometry of the subducted plate is well constrained by Slab2.0, and ...
Sarah B. Traiger; James L. Bodkin; Heather A. Coletti; Brenda Ballachey; Thomas Dean; Daniel Esler; Katrin Iken; Brenda Konar; Mandy R. Lindeberg; Daniel Monson; Brian Robinson; Robert M. Suryan; Benjamin P. Weitzman
Gulf of Alaska, etc ; Mytilus trossulus; littoral zone; marine science; mussels; temperature; Show all 6 Subjects
Abstract:
... Mussels occupy a key middle trophic position in nearshore food webs linking primary producers to predators. Climate‐related environmental changes may synergistically combine with changes in predator abundance to affect intertidal ecosystems. We examined the influence of two major events on mussel (Mytilus trossulus) abundance in the northern Gulf of Alaska: the recent Pacific marine heatwave (PMH, ...
Alaska, etc ; animal behavior; copulation; females; males; monogamy; paternity; polyandry; progeny; spermatozoa; Show all 10 Subjects
Abstract:
... In socially monogamous species, extrapair paternity typically results from extrapair copulations, but it can also be due to rapid mate switching. Oring, Fleischer, Reed, and Marsden (1992, Nature, 359 (6396), 631–633) proposed a mechanism to explain the occurrence of extrapair paternity in sequentially polyandrous species: sperm stored by females from within-pair copulations with a previous mate c ...
Alaska Natives, etc ; American Indians; education; geography; poverty; rural health; surveys; telemedicine; Show all 8 Subjects
Abstract:
... INTRODUCTION: Broadband access is a “super determinant of health.” Understanding the spatial distribution and predictors of access may help target government programs and telehealth applications. Our aim was to examine broadband access across geography and sociodemographic characteristics using American Community Survey (ACS) data. METHODS: We used 5‐year ACS estimates from 2014 to 2018 to evaluat ...
Alaska, etc ; Bayesian theory; blood; cameras; diet; stable isotopes; tundra; Arctic region; Show all 8 Subjects
Abstract:
... Intra- and inter-specific resource partitioning within predator communities is a fundamental component of trophic ecology, and one proposed mechanism for how populations partition resources is through individual niche variation. The Niche Variation Hypothesis (NVH) predicts that inter-individual trait variation leads to functional trade-offs in foraging efficiency, resulting in populations compose ...
Alaska, etc ; Populus tremuloides; bark; growth chambers; mortality; pathogens; plant pathology; pycnidia; Show all 8 Subjects
Abstract:
... Neodothiora populina Crous, G.C. Adams & Winton was determined to be a new pathogen of trembling aspen (Populus tremuloides) growing in Alaska, based on completion of Koch’s Postulates in replicated forest and growth chamber inoculation trials. The pathogen is responsible for severe damage and widespread rapid mortality of sapling to mature aspen (≥ 80 years) in the boreal forests of interior Alas ...
Alaska; Gulf of Alaska, etc ; Leptocottus armatus; Oncorhynchus; Platichthys stellatus; community structure; data collection; dominant species; estuaries; estuarine fish; fish communities; glaciers; habitats; juveniles; salinity; spring; summer; temperature; turbidity; watersheds; Show all 20 Subjects
Abstract:
... Coastal ecosystems in Alaska are undergoing rapid change due to warming and glacier recession. We used a natural gradient of glacierized to non-glacierized watersheds (0–60% glacier coverage) in two regions along the Gulf of Alaska—Kachemak Bay and Lynn Canal—to evaluate relationships between local environmental conditions and estuarine fish communities. Multivariate analyses of fish community dat ...
Alaska, etc ; aircraft; dust; glaciation; ice; latitude; liquids; spring; temperature; winter; Arctic region; Show all 11 Subjects
Abstract:
... This paper analyzes the temperature, cloud type, and life stage dependencies of phase partitioning in mixed-phase clouds spanning tropics, midlatitudes, and the Arctic, using data from ground-based remote sensing measurements in Alaska and aircraft measurements from three field campaigns. The results show: (1) The liquid fraction in Arctic stratiform clouds decreased from 1 to 0.6 between 0 °C and ...
Alaska, etc ; Dytiscidae; Gyrinidae; Haliplidae; Nearctic region; fauna; surveys; Arctic region; Yukon Territory; Show all 9 Subjects
Abstract:
... The Amphizoidae, Dytiscidae, Gyrinidae and Haliplidae (Coleoptera: Adephaga of Alaska (USA) and the Yukon Territory (Canada) were surveyed during the years 1994, 2016, 2017 and 2019. By adding specimens collected through the Arctic Shorebird Demographic Network survey and those from the collection of the University of Alaska, Fairbanks, a total of 5305 individuals are newly reported, which substan ...