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Wildlife researchers need to understand the effects of biotelemetry tags in order to better weigh benefits versus risks. We describe tag‐site healing and pathology of three beluga whales, Delphinapterus leucas, found dead in Alaska. The tags were secured with two or three nylon rods that pierced the dorsal ridge, and one beluga also had a LIMPET tag. The tag wounds in one Cook Inlet beluga featured a normal healing response with minimal inflammation ~12 years posttagging. Photo‐ID studies of another Cook Inlet beluga demonstrated degeneration of the tag wounds over several years. It died ~12.8 years posttagging of bronchopneumonia and septicemia due to Staphylococcus aureus that also infected the tag wound. A Bristol Bay beluga died 4 months posttagging. Although it may have been predated by a killer whale attack, Orcinus orca, the tag site was inflamed and infected with Streptococcus uberis which spread to an abscessed lymph node. To reduce the risk of infection, researchers should adopt strict sterilization protocols for all implanted parts of tags and continue research into improved tagging methods. Clinical and behavioral assessment of potential preexisting conditions before tag deployment, as well as posttag monitoring, could help reduce tag‐associated mortality and identify immediate impacts and mortality. [ABSTRACT FROM AUTHOR]

Beluga whales (Delphinapterus leucas) from Cook Inlet (CI), Alaska, are listed as "endangered" because of dramatic declines in abundance, with no indications of population recovery. Serum samples from this population are exceedingly rare. Longitudinal samples from aquarium (AQ) belugas can potentially provide health assessment reference ranges for free-ranging beluga, including reproductive and metabolic hormones. We analysed serum hormone concentrations from CI (n = 6, three females and three males) and Bristol Bay (Alaska; BB; n = 5, four males and one female), alongside AQ (n = 3, two females and one male) belugas, to conduct physiological comparisons of reproductive hormones (progesterone, testosterone and total oestrogens) and metabolic hormones (total thyroxine, triiodothyronine and cortisol) in beluga serum. Oestrogen and progesterone profiles from January through May from two AQ female beluga were typical of non-pregnant, cycling females. CI and BB sex steroid concentrations were within AQ hormone ranges, with the exception of elevated progesterone concentrations in four potentially pregnant females. Both CI and BB belugas had elevated metabolic hormones, which may indicate greater metabolic effort required in the wild environment or capture response. Because sample collection from CI belugas is rare, analysis of even the few samples that we analysed may contribute to the conservation of the small and declining population of genetically distinct CI beluga whales. It is important that each sample collected from free-range CI belugas provides the maximum biological information possible. Continued comparison of hormones in AQ and free-ranging beluga will enhance the interpretation of health data in both groups. [ABSTRACT FROM AUTHOR]

1.Cook Inlet beluga whales (CIBWs; Delphinapterus leucas), are an isolated and declining endangered population in Alaska, USA. Their critical habitat has been broadly defined, with little empirical data on habitat use to direct management actions. This article examines data collected during surveys for a long‐term photo‐ID study to gain insight into the use of critical habitat by CIBW groups and individuals, with a focus on areas where belugas were observed feeding, calving, rearing young, and in transit. It also describes patterns of group distribution, size, and composition, according to sex and age class, in order to better understand how CIBWs are distributed throughout critical habitat during the ice‐free season. The results are presented according to survey month and survey zone, so that patterns of habitat use are accessible in a useful format to aid managers in evaluations of how timing and location of human activities occurring in CIBW critical habitat may overlap with CIBW occurrence and use of these areas.2.There were 575 beluga groups encountered during 477 photo‐ID surveys conducted in CIBW critical habitat 2005–2017. CIBW locations were mapped, and models were developed to test for temporal and spatial patterns. Approximately 400 individual whales were identified, and their sighting histories were compiled to examine residency and movement patterns.3.CIBWs were found seasonally in distinct areas, where they aggregate in large groups of both sexes and all age classes while rearing calves and feeding. These areas, and the general corridors connecting them, represent important beluga habitat that warrant focused management attention and protection efforts.4.Whales travelling among distinct areas of Cook Inlet increase their likelihood of exposure to multiple, localized threats.5.Habitat protection and the regulation of anthropogenic activities should consider cumulative effects of all activities in the range of CIBWs and their potential to affect the entire population. [ABSTRACT FROM AUTHOR]

Belugas, I Delphinapterus leucas i , Pallas (1776) are toothed whales of the Monodontidae family which includes only one other species, the narwhal, I Monodon monoceros i . Tooth collection procedures were dependent on when the teeth were collected (protocols changed through the years to include collection of the entire mandible when possible), the length of time the whale was dead, the whale's position on the ground, who collected the teeth, and the physical location of the carcass. Comparing ages for whales with at least one mandible containing all posterior teeth 6-8 (54 whales, I n i = 36 right mandibles, 37 left mandibles; see Table S2), we found these teeth represented 84% of the final ages. Tooth 8 and tooth 9 (when present), provided the oldest ages (i.e., final age) most often (33%-62% of mandibles) compared to tooth 6 and 7 (14%-25%), though it should be noted that sometimes multiple teeth matched the final age (Table S2). [Extracted from the article]

In this study, Lower Bajocian belemnites from Southcentral Alaska are formally investigated and described for the first time. Representatives of the families Megateuthididae (Belemnitina) and Belemnopseidae (Belemnopseina) occur in the Parabigotites crassicostatus to Sphaeroceras oblatum ammonite zones (Propinquans to Humphriesianum chronozones) within the Tuxedni Group of the Cook Inlet region and the Talkeetna Mountains. Among Megateuthididae, we introduce the first records of Brevibelus from Alaska, and the first records of Brevibelus gingensis and Eocylindroteuthis from outside Europe. The new taxa Pseudosimobelus tuxedniensis Dzyuba & C. D. Schraer gen. et sp. nov., Eocylindroteuthis gracilenta Dzyuba & C. D. Schraer sp. nov. and Eocylindroteuthis riegrafi Dzyuba & C. D. Schraer sp. nov. are also described. We conclude from our morphological analysis that Pseudosimobelus gen. nov. represents a transitional form between Megateuthididae and Cylindroteuthididae or may even have been ancestral to the latter. The single rostrum of Belemnopseidae identified herein as Hibolithes? sp. juv. is the earliest record of the family from Alaska. Biogeographically, the belemnites represent pan-Tethyan (Brevibelus and Hibolithes?), typically west Tethyan (Brevibelus gingensis, Brevibelus cf. breviformis and Eocylindroteuthis) and endemic north-east Pacific (Pseudosimobelus gen. nov. and Eocylindroteuthis spp. nov.) elements. These palaeontological data suggest a location of the Peninsular terrane in the Early Bajocian south of the present location. We postulate that the appearance of Brevibelus, Eocylindroteuthis and possibly Hibolithes near the north-western shores of North America in the late Early Bajocian was due to their westward migration via the Hispanic Corridor, the migratory seaway between the western Tethys and the eastern Pacific. [ABSTRACT FROM AUTHOR]

• The minimal opening of the Bering Strait's eastern channel is 1.8 km2. • Much of the eastern channel has eroded by > 1 m between ∼ 1950 and ∼ 2010. • The erosion is most likely caused by increasing currents over recent decades. • Seafloor waves and an offshore bar were discovered in softer sediment areas. • A 75 km riverbed-like feature may be related to Norton Sound paleodrainages. The Bering Strait is the sole gateway and an oceanographic bottleneck for the seasonally warm and comparatively fresh and nutrient-rich Pacific waters to flow into the Arctic, melting ice, lowering salinity, and feeding bird, mammal, and fish populations. The Diomede Islands split this small strait into two main channels, both with northward flow (in the annual mean). The eastern channel, in U.S. waters, also seasonally carries the warmer, fresher Alaskan Coastal Current. Year-round in situ mooring observations (in place since 1990 with annual servicing) show a significant flow increase in the (northward) throughflow, along with seasonal and annual fluctuations. To help with measuring and modelling water flow estimates, we created the first detailed shore-to-shore bathymetric surface of the Bering Strait's eastern channel, located its narrowest cross-section (1.8 km2) as occurring 5–10 km south of the moorings, and quantified the cross-section across the moorings (2.0 km2), both slightly larger than previously estimated (1.6 km2). Overlaps between older (∼1950) and newer (∼2010) bathymetry data sets identified clear areas of erosion and deposition, with much of the eastern channel having eroded by > 1 m. Since the depth is uniformly ∼ 50 m across much of the eastern channel, the 1 m of erosion that we quantified would only slightly (2 %) increase the sizes of the cross-sections. Much of the seafloor is hard substrate and probably composed of cobbles, but we hypothesize that friction from strong (∼1 + knot) seafloor currents is the most likely explanation for the erosion that we observed. In softer and siltier areas, the bathymetry showed additional evidence of potential current impacts in the form of small seafloor waves (∼0.5 to ∼ 1.0 m tall) and a shore-parallel bar offshore of Cape Prince of Wales Spit. There are large (∼2 m tall) seafloor waves seaward of Cape Prince of Wales Shoal. A previously undescribed (∼1 to 2 km wide, ∼4 m deep) seafloor channel of unknown origin occurred along a linear north/south axis for the full 75 km extent of the bathymetric surface. The southern end of this seafloor channel was near the end of three larger seafloor channels extending westerly out of nearby Norton Sound, suggesting a common origin. These Norton Sound channels may be paleodrainages, as their eastern ends point toward Seward Peninsula inlets with large drainages where paleoglaciers were reported to have existed, but the morphology of these channels is also consistent with tidal channels. [ABSTRACT FROM AUTHOR]

Research with wild belugas has indicated that, during mother–calf swims, calves spend more time on their mothers’ right side, which enables the calves to maintain visual contact with their mothers using their left eye. This bias may facilitate processing of social information by the right hemisphere, much like human and non-human primates and other animals. The current study explored the social laterality of the Cook Inlet, AK beluga population in comparison to a beluga population in managed care. As expected, the results indicated that the calves spent more time on the mothers’ right side than the left for both populations. We also examined the developmental trend for the belugas in managed care and found that the calves generally preferred to swim on their mother's right side across most months, although there was an inversion during the third quarter when a left-side preference appeared. Individual differences were present. The results corroborate previous research conducted with two wild beluga populations from the White Sea and from the Sea of Okhotsk in which a left-eye bias was displayed by calves when swimming with their mothers. In conclusion, a preference for a lateralized swim position appears to be conserved across wild and managed care settings, and this lateralized swim position may facilitate the processing of social information or familiar stimuli for the calves. [ABSTRACT FROM AUTHOR]

Abstract: Coastal waters in the northern Gulf of Alaska (GoA) are considered iron-rich and nitrate-poor, in contrast to the iron-poor, high-nitrate, low chlorophyll (HNLC) waters of the central GoA. The degree of mixing between these two regimes, enhanced by mesoscale eddies, is essential to the high productivity observed in the region. As part of a study on iron delivery to the central GoA via mesoscale eddies, extensive work was focused on characterizing the coastal endmember, the Alaska Coastal Current. In surface Alaskan coastal waters between Yakutat and the Kenai Peninsula, dissolved iron concentrations ranged from 0.5 to 4.1nM with an average of ∼2nM. In contrast, leachable particulate iron concentrations were much higher and more variable, ranging from over 1μM in the Alsek River plume to less than 5nM at the base of Cook Inlet. Cross-shelf transport of both surface and subsurface dissolved iron and leachable particulate iron was observed. Throughout the study area, leachable particulate iron values were at least an order of magnitude higher than dissolved values, suggesting that the system''s ability to solubilize this large concentration of leachable particulate iron is overwhelmed by the massive input of glacial-derived particulate iron. Nevertheless, suspended leachable particulate iron remains available for exchange to the dissolved phase and is suggested to maintain a relatively constant (∼2nM) source of dissolved iron in the coastal GoA. [Copyright &y& Elsevier]

During the 2014–2016 Pacific marine heatwave (MHW), seabird die-offs, declines in forage fish populations, and the appearance of subtropical marine taxa (e.g. ocean sunfish, skipjack tuna) occurred in the northern Gulf of Alaska; however, the response of the zooplankton community to the MHW remains poorly understood. As part of the Gulf Watch Alaska program in Cook Inlet, zooplankton, phytoplankton, and a suite of oceanographic variables were collected monthly from 2012 to 2018. Surface zooplankton were collected via vertical tows (0–50 m) with a 333 μm bongo net along with CTD data and chlorophyll a concentration. Generalized additive models showed that seasonal zooplankton abundance peaked mid-June and declined into late January. During the MHW, monthly temperature anomalies ranged from +0.2 to +2.8 °C in 2015 and 2016, but monthly means of large lipid-rich calanoid copepods showed no clear declines in abundance compared to before and after the MHW suggesting that these copepods had some resiliency. An indicator species analysis using 88 of the most common zooplankton taxa produced five groups of zooplankton based on season. A BIO-ENV Best model showed that the environmental variables best explaining the observed zooplankton community structure included SST, temperature of the top 50 m of the water column, mixed layer depth (MLD), MLD temperature, and integrated chl a (ρ = 0.3491, Mantel Test: r = 0.3491, α < 0.05). Seasonal transitions of community groups displayed a phenological shift in 2016 when the late spring group of meroplanktonic larvae and the fall group of warm water copepods (WWC) typical of the Northern California Current system appeared earlier and persisted for longer compared to before and after the MHW. WWC abundance increased during the fall seasons of the MHW. Throughout 2015–2016, the elevated abundance of WWC compared to previous years and before/after the MHW suggested that warmer than average oceanographic conditions in the winter of 2015/2016 may have been sufficient to allow for an overwintering population in this area. A potential overwintering population of a warm water predatory copepod, Corycaeus anglicus , was observed and may have direct fine scale predator/prey impacts on zooplankton in this region. [ABSTRACT FROM AUTHOR]

Presents the short story "Taku,' by Loretto L. Jones.

We calculated seismic moment rates from crustal earthquake information for the upper Cook Inlet region, including Anchorage, Alaska, for the 30 yr prior to and 36 yr following the 1964 Great Alaska earthquake. Our results suggest over a factor of 1000 decrease in seismic moment rate (in units of dyne centimeters per year) following the 1964 mainshock. We used geologic information on structures within the Cook Inlet basin to estimate a regional geologic moment rate, assuming the structures extend to 30 km depth and have near-vertical dips. The geologic moment rates could underestimate the tree rates by up to 70% since it is difficult determine the amount of horizontal offset that has occurred along many structures within the basin. Nevertheless, the geologic moment rate is only 3-7 times lower than the pre-1964 seismic moment rate, suggesting the 1964 mainshock has significantly slowed regional crustal deformation. If we compare the geologic moment rate to the post-1964 seismic moment rate, the moment rate deficit over the past 36 yr is equivalent to a moment magnitude 6.6-7.0 earthquake. These observed differences in moment rates highlight the difficulty in using seismicity in the decades following a large megathmst earthquake to adequately characterize long-term crustal deformation. [ABSTRACT FROM AUTHOR]

Describes the distributional information on white whales or belugas in Cook Inlet, Alaska during the months of June and July from 1993 to 2000. Dispersal of whales from the uppermost portions of the inlet during summer; Factors that influence seasonal distribution of belugas; Comparison of June and July sightings of belugas in upper Cook Inlet relative to the lower inlet.

The article presents an illustrated reference of biophysical environment of Alaska's Cook Inlet, Sustina Flats Deltaic Area, Gulf of Alaska Coast. Topics discussed include coastal belt linked classification (CBLC), related environments and habitats; dominant catenary sequence (DCS): coastal ecological sequence (CES); and related geology, biology, geomorphology, littoral oceanography.

In 2020, the Alaska Board of Fisheries created a new personal use fishery on the Susitna River, effectively expanding the fishing opportunities for personal use fishermen in the already contentious atmosphere of Cook Inlet fishery allocation conflicts. The opening of this fishery happened in tandem with the removal of a "stock of yield concern" status for Susitna River sockeye and additional restrictions for the Cook Inlet drift fishing fleet in order to minimize intercept of salmon bound for the Susitna River drainage. Given the long history of inter-gear group conflicts in this area, these changes are likely to have social and, perhaps, ecological impacts on the salmon stocks and user groups of Cook Inlet fisheries. This article uses scenario development to offer four possible scenarios organized around the potential popularity of the new fishery, and the potential demand for harvestable abundance. These scenarios are intended to give all involved stakeholders an opportunity to understand the landscapes opened up by the new personal use fishery, and the potential winners and losers of each. By drawing from social-ecological coexistence theory, this study also gives thought to how the equity between user groups (inclusive of the environment) may be affected in each scenario, considers the impacts of politicized fisheries management on power dynamics within the region, and discusses how least equitable scenarios might be improved using equalizing mechanisms. https://soundcloud.com/conservechange/pubcast-managing-many-nets [ABSTRACT FROM AUTHOR]

• Hydrologic and geomechanical properties of the reservoir, overlying, and underlying units (including basement). • In-situ stress gradients in the basin. • Fault slip potential due to CO 2 sequestration. Understanding the hydrologic and geomechanical properties of sedimentary rocks and the underlying basement is important for the success of fluid extraction and injection operations, including carbon sequestration. This study analyzes the hydrologic and geomechanical properties of the reservoir (Hemlock Formation), overlying confining unit (Tyonek Formation), and underlying confining unit/basement (Talkeetna volcanics and Mesozoic igneous intrusive - diorite). This study shows the potential of fault slip due to carbon sequestration in the Cook Inlet basin of Alaska. We integrate core, well-log, and 3D seismic data to perform hydrologic and geomechanical analysis of the deep sedimentary formations, basement, and simulation of the fault slip potential (FSP). The FSP results show that faults have the potential to slip, depending on several factors, such as the local in-situ stress conditions, pore pressure, and CO 2 injection rate. The azimuth of the maximum horizontal stress (σ H) with respect to fault orientation is a critical factor for fault stability in the Cook Inlet basin. [ABSTRACT FROM AUTHOR]

Cook Inlet in Alaska has been identified as a prime site in the U.S. for potential tidal energy development, because of its enormous tidal power potential that accounts for nearly one-third of the national total. As one important step to facilitate tidal energy development, a tidal hydrodynamic model based on the unstructured-grid, finite-volume community ocean model (FVCOM) was developed for Cook Inlet to characterize the tidal stream energy resource. The model has a grid resolution that varies from about 1000 m at the open boundary to 100–300 m inside the Inlet. Extensive model validation was achieved by comparing model predictions with field observations for tidal elevation and velocity at various locations in Cook Inlet. The error statistics confirmed the model performs reasonably well in capturing the tidal dynamics in the system, e.g., R2 > 0.98 for tidal elevation and generally > 0.9 for velocity. Model results suggest that tides in Cook Inlet evolve from progressive waves at the entrance to standing waves at the upper Inlet, and that semi-diurnal tidal constituents are amplified more rapidly than diurnal constituents. The model output was used to identify hotspots that have high energy potential and warrant additional velocity and turbulence measurements such as East Foreland, where averaged power density exceeds 5 kw/m2. Lastly, a tidal energy extraction simulation was conducted for a hypothetical turbine farm configuration at the Forelands cross section to evaluate tidal energy extraction and resulting changes in far-field hydrodynamics. [ABSTRACT FROM AUTHOR]