Marine mammal distribution and abundance in an offshore sub-region of the northeastern Chukchi Sea during the open-water season

AbstractThe western Arctic Ocean (WAO) has experienced increased heat transport into the region, sea-ice reduction, and changes to the WAO nitrous oxide (N2O) cycles from greenhouse gases. We investigated WAO N2O dynamics through an intensive and precise N2O survey during the open-water season of summer 2017. The effects of physical processes (i.e., solubility and advection) were dominant in both the surface (0–50 m) and deep layers (200–2200 m) of the northern Chukchi Sea with an under-saturation of N2O. By contrast, both the surface layer (0–50 m) of the southern Chukchi Sea and the intermediate (50–200 m) layer of the northern Chukchi Sea were significantly influenced by biogeochemically derived N2O production (i.e., through nitrification), with N2O over-saturation. During summer 2017, the southern region acted as a source of atmospheric N2O (mean: + 2.3 ± 2.7 μmol N2O m−2 day−1), whereas the northern region acted as a sink (mean − 1.3 ± 1.5 μmol N2O m−2 day−1). If Arctic environmental changes continue to accelerate and consequently drive the productivity of the Arctic Ocean, the WAO may become a N2O “hot spot”, and therefore, a key region requiring continued observations to both understand N2O dynamics and possibly predict their future changes.

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Spatiotemporal patterns of marine mammal distribution in coastal waters of Galicia, NW Spain

Hydrobiologia ◽

10.1007/s10750-011-0722-4 ◽

2011 ◽

Vol 670 (1) ◽

pp. 87-109 ◽

Cited By ~ 24

Author(s):

Evangelos Spyrakos ◽

Tania C. Santos-Diniz ◽

Gema Martinez-Iglesias ◽

Jesus M. Torres-Palenzuela ◽

Graham J. Pierce

Keyword(s):

Coastal Waters ◽

Marine Mammal ◽

Spatiotemporal Patterns ◽

Nw Spain ◽

Mammal Distribution

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RELATING MARINE MAMMAL DISTRIBUTION TO PREY ABUNDANCE

10.23860/diss-orphanides-christopher-2019 ◽

2019 ◽

Author(s):

◽

Christopher Orphanides

Keyword(s):

Marine Mammal ◽

Prey Abundance ◽

Mammal Distribution

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Arctic Fog Detection Using Infrared Spectral Measurements

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-18-0100.1 ◽

2019 ◽

Vol 36 (8) ◽

pp. 1643-1656

Author(s):

Li Yi ◽

King-Fai Li ◽

Xianyao Chen ◽

Ka-Kit Tung

Keyword(s):

Sea Ice ◽

Chukchi Sea ◽

Open Water ◽

Detection Algorithm ◽

Probability Of Detection ◽

Satellite Observations ◽

The Arctic ◽

Water Surface Area ◽

Infrared Spectral ◽

Fog Detection

AbstractThe rapid increase in open-water surface area in the Arctic, resulting from sea ice melting during the summer likely as a result of global warming, may lead to an increase in fog [defined as a cloud with a base height below 1000 ft (~304 m)], which may imperil ships and small aircraft transportation in the region. There is a need for monitoring fog formation over the Arctic. Given that ground-based observations of fog over Arctic open water are very sparse, satellite observations may become the most effective way for Arctic fog monitoring. We developed a fog detection algorithm using the temperature difference between the cloud top and the surface, called ∂T in this work. A fog event is said to be detected if ∂T is greater than a threshold, which is typically between −6 and −12 K, depending on the time of the day (day or night) and the surface types (open water or sea ice). We applied this method to the coastal regions of Chukchi Sea and Beaufort Sea near Barrow, Alaska (now known as Utqiaġvik), during the months of March–October. Training with satellite observations between 2007 and 2014 over this region, the ∂T method can detect Arctic fog with an optimal probability of detection (POD) between 74% and 90% and false alarm rate (FAR) between 5% and 17%. These statistics are validated with data between 2015 and 2016 and are shown to be robust from one subperiod to another.

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Sustaining ecological and subsistence functions in conservation areas: eider habitat and access by Native hunters along landfast ice

Environmental Conservation ◽

10.1017/s0376892918000103 ◽

2018 ◽

Vol 45 (4) ◽

pp. 361-369 ◽

Cited By ~ 2

Author(s):

JAMES R. LOVVORN ◽

AARIEL R. ROCHA ◽

ANDREW H. MAHONEY ◽

STEPHEN C. JEWETT

Keyword(s):

Chukchi Sea ◽

Open Water ◽

The Arctic ◽

Cash Income ◽

Migration Route ◽

Conservation Areas ◽

Subsistence Hunting ◽

Industrial Activities ◽

Landfast Ice ◽

Ice Edge

SUMMARYIn the Arctic, rapid climate change has kindled efforts to delineate and project the future of important habitats for marine birds and mammals. These animals are vital to subsistence economies and cultures, so including the needs of both animals and hunters in conservation planning is key to sustaining social-ecological systems. In the northeast Chukchi Sea, a nearshore corridor of open water is a major spring migration route for half a million eider ducks that are hunted along the landfast ice. Zoning areas for industrial activities or conservation should consider both eider habitat and hunter access to those habitats from the variable ice edge. Based on benthic sampling in 2010‒2012, a model of eider foraging energetics and satellite data on ice patterns in April and May 1997‒2011, we mapped the range of positions of the landfast ice edge relative to a given dispersion of habitat suitable for eider feeding. In some sectors, feeding areas were too limited or too far from landfast ice to provide regular hunting access. In other sectors, overlap of the ice edge with eider feeding habitat was quite variable, but often within a consistent geographic range. Areas accessible to hunters were a small fraction of total eider habitat, so areas adequate for conserving eiders would not necessarily include areas that meet the hunters’ needs. These results can inform spatial planning of industrial activities that yield cash income critical to subsistence hunting in less developed locations. Our study provides an approach for mapping ‘subsistence conservation areas’ throughout the Arctic and an example for such efforts elsewhere.

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Transboundary marine mammal management in the Northern Bering-Chukchi Sea Large Marine area

Polar Geography ◽

10.1080/1088937x.2020.1798539 ◽

2020 ◽

Vol 43 (4) ◽

pp. 313-332

Author(s):

Kelsey B. Aho ◽

Chanda L. Meek

Keyword(s):

Marine Mammal ◽

Chukchi Sea ◽

Marine Area

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Observations on gray whale (Eschrichtius robustus) utilization patterns in the northeastern Chukchi Sea, July–October 1982–1987

Canadian Journal of Zoology ◽

10.1139/z89-374 ◽

1989 ◽

Vol 67 (11) ◽

pp. 2646-2654 ◽

Cited By ~ 7

Author(s):

Janet T. Clarke ◽

Sue E. Moore ◽

Donald K. Ljungblad

Keyword(s):

Sexual Activity ◽

Chukchi Sea ◽

Open Water ◽

Gray Whale ◽

Gray Whales ◽

Aerial Surveys ◽

Abundance Estimates ◽

Point Hope ◽

Utilization Patterns ◽

Cow Calf

A total of 821 gray whales were seen during aerial surveys in the northeastern Chukchi Sea from July through October 1982–1987. Gray whale distribution extended from south of Point Hope to northeast of Point Barrow, Alaska, between 0.5 and 166 km offshore. Monthly abundance estimates (number of whales/survey hour) were highest in July (6.81) and lowest in October (0.40). Gray whales were usually in open water (82%, n = 670) or in light ice (16%, n = 134) and were seldom associated with heavy ice (2%, n = 17). Most whales were feeding (63%, n = 514), with the majority of the others swimming and diving (24%, n = 193) or forming part of a cow–calf association (9%, n = 72). One group of three whales was involved in sexual activity. Feeding whales were seen most often within 40 km of the shore, but also occurred offshore. Thirty-six gray whale calves were seen. Calf abundance (number of calves/survey hour) was significantly higher (p < 0.001) in July, when 92% (n = 33) of all calves were seen, than in any other month. Most cow–calf pairs were seen nearshore between Point Hope and Point Barrow. Monthly calf ratios (number of calves/number of whales) ranged from 0.09 in July to 0.00 in October, with an overall rate of 0.04.

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Seasonal spatial patterns in seabird and marine mammal distribution in the eastern Chukchi and western Beaufort seas: Identifying biologically important pelagic areas

Progress In Oceanography ◽

10.1016/j.pocean.2015.05.012 ◽

2015 ◽

Vol 136 ◽

pp. 175-200 ◽

Cited By ~ 48

Author(s):

Kathy J. Kuletz ◽

Megan C. Ferguson ◽

Brendan Hurley ◽

Adrian E. Gall ◽

Elizabeth A. Labunski ◽

...

Keyword(s):

Spatial Patterns ◽

Marine Mammal ◽

Mammal Distribution

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Airborne Lidar Observations of a Spring Phytoplankton Bloom in the Western Arctic Ocean

Remote Sensing ◽

10.3390/rs13132512 ◽

2021 ◽

Vol 13 (13) ◽

pp. 2512

Author(s):

James H. Churnside ◽

Richard D. Marchbanks ◽

Nathan Marshall

Keyword(s):

Arctic Ocean ◽

Phytoplankton Bloom ◽

Chukchi Sea ◽

Open Water ◽

Horizontal Distribution ◽

Airborne Lidar ◽

The Arctic ◽

Spring Phytoplankton Bloom ◽

Vertical And Horizontal Distribution ◽

Western Arctic

One of the most notable effects of climate change is the decrease in sea ice in the Arctic Ocean. This is expected to affect the distribution of phytoplankton as the ice retreats earlier. We were interested in the vertical and horizontal distribution of phytoplankton in the Chukchi Sea in May. Measurements were made with an airborne profiling lidar that allowed us to cover large areas. The lidar profiles showed a uniform distribution of attenuation and scattering from the surface to the limit of lidar penetration at a depth of about 30 m. Both parameters were greater in open water than under the ice. Depolarization of the lidar decreased as attenuation and scattering increased. A cluster analysis of the 2019 data revealed four distinct clusters based on depolarization and lidar ratio. One cluster was associated with open water, one with pack ice, one with the waters along the land-fast ice, and one that appeared to be scattered throughout the region. The first three were likely the result of different assemblages of phytoplankton, while the last may have been an artifact of thin fog in the atmosphere.

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Phytoplankton Bloom Changes under Extreme Geophysical Conditions in the Northern Bering Sea and the Southern Chukchi Sea

Remote Sensing ◽

10.3390/rs13204035 ◽

2021 ◽

Vol 13 (20) ◽

pp. 4035

Author(s):

Jinku Park ◽

Sungjae Lee ◽

Young-Heon Jo ◽

Hyun-Cheol Kim

Keyword(s):

Heat Flux ◽

Sea Ice ◽

Bering Sea ◽

Phytoplankton Biomass ◽

Phytoplankton Bloom ◽

Chukchi Sea ◽

Open Water ◽

The Arctic ◽

Atmospheric Conditions ◽

Northern Bering Sea

The northern Bering Sea and the southern Chukchi Sea are undergoing rapid regional biophysical changes in connection with the recent extreme climate change in the Arctic. The ice concentration in 2018 was the lowest since observations began in the 1970s, due to the unusually warm southerly wind in winter, which continued in 2019. We analyzed the characteristics of spring phytoplankton biomass distribution under the extreme environmental conditions in 2018 and 2019. Our results show that higher phytoplankton biomass during late spring compared to the 18-year average was observed in the Bering Sea in both years. Their spatial distribution is closely related to the open water extent following winter-onset sea ice retreat in association with dramatic atmospheric conditions. However, despite a similar level of shortwave heat flux, the 2019 springtime biomass in the Chukchi Sea was lower than that in 2018, and was delayed to summer. We confirmed that this difference in bloom timing in the Chukchi Sea was due to changes in seawater properties, determined by a combination of northward oceanic heat flux modulation by the disturbance from more extensive sea ice in winter and higher surface net shortwave heat flux than usual.

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