scholarly journals Viral emergence in marine mammals in the North Pacific may be linked to Arctic sea ice reduction

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
E. VanWormer ◽  
J. A. K. Mazet ◽  
A. Hall ◽  
V. A. Gill ◽  
P. L. Boveng ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Sea Ice ◽  
North Pacific ◽  
Marine Mammals ◽  
North Pacific Ocean ◽  
Arctic Sea Ice ◽  
Sea Ice Extent ◽  
The North ◽  
Arctic Sea ◽  
The North Pacific

Abstract Climate change-driven alterations in Arctic environments can influence habitat availability, species distributions and interactions, and the breeding, foraging, and health of marine mammals. Phocine distemper virus (PDV), which has caused extensive mortality in Atlantic seals, was confirmed in sea otters in the North Pacific Ocean in 2004, raising the question of whether reductions in sea ice could increase contact between Arctic and sub-Arctic marine mammals and lead to viral transmission across the Arctic Ocean. Using data on PDV exposure and infection and animal movement in sympatric seal, sea lion, and sea otter species sampled in the North Pacific Ocean from 2001–2016, we investigated the timing of PDV introduction, risk factors associated with PDV emergence, and patterns of transmission following introduction. We identified widespread exposure to and infection with PDV across the North Pacific Ocean beginning in 2003 with a second peak of PDV exposure and infection in 2009; viral transmission across sympatric marine mammal species; and association of PDV exposure and infection with reductions in Arctic sea ice extent. Peaks of PDV exposure and infection following 2003 may reflect additional viral introductions among the diverse marine mammals in the North Pacific Ocean linked to change in Arctic sea ice extent.

scholarly journals Ocean–Atmosphere State Dependence of the Atmospheric Response to Arctic Sea Ice Loss

2017 ◽  
Vol 30 (5) ◽  
pp. 1537-1552 ◽  
Author(s):  
Joe M. Osborne ◽  
James A. Screen ◽  
Mat Collins
Keyword(s):  
Sea Ice ◽  
North Pacific ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
The North ◽  
Arctic Sea ◽  
Ocean Atmosphere ◽  
Arctic Sea Ice Loss ◽  
The North Pacific ◽  
Sst Anomalies

Abstract The Arctic is warming faster than the global average. This disproportionate warming—known as Arctic amplification—has caused significant local changes to the Arctic system and more uncertain remote changes across the Northern Hemisphere midlatitudes. Here, an atmospheric general circulation model (AGCM) is used to test the sensitivity of the atmospheric and surface response to Arctic sea ice loss to the phase of the Atlantic multidecadal oscillation (AMO), which varies on (multi-) decadal time scales. Four experiments are performed, combining low and high sea ice states with global sea surface temperature (SST) anomalies associated with opposite phases of the AMO. A trough–ridge–trough response to wintertime sea ice loss is seen in the Pacific–North American sector in the negative phase of the AMO. The authors propose that this is a consequence of an increased meridional temperature gradient in response to sea ice loss, just south of the climatological maximum, in the midlatitudes of the central North Pacific. This causes a southward shift in the North Pacific storm track, which strengthens the Aleutian low with circulation anomalies propagating into North America. While the climate response to sea ice loss is sensitive to AMO-related SST anomalies in the North Pacific, there is little sensitivity to larger-magnitude SST anomalies in the North Atlantic. With background ocean–atmosphere states persisting for a number of years, there is the potential to improve predictions of the impacts of Arctic sea ice loss on decadal time scales.

Trophic relationships of albatrosses associated with squid and large-mesh drift-net fisheries in the North Pacific Ocean

1997 ◽  
Vol 75 (4) ◽  
pp. 549-562 ◽  
Author(s):  
Patrick Gould ◽  
Peggy Ostrom ◽  
William Walker
Keyword(s):  
Pacific Ocean ◽  
Trophic Level ◽  
North Pacific ◽  
Marine Mammals ◽  
North Pacific Ocean ◽  
Transitional Zone ◽  
Trophic Relationships ◽  
Commercial Fishing ◽  
The North ◽  
The North Pacific

The diets of Laysan (Diomedea immutabilis) and black-footed albatrosses (D. nigripes) killed in squid and large-mesh drift nets in the transitional zone of the North Pacific Ocean were investigated by examining the contents of the digestive tracts and determining δ13C and δ15N values in breast-muscle tissue. The results show that (i) the combined prey of the two species of albatross consists of over 46 species of marine organisms including coelenterates, arthropods, mollusks, fish, and marine mammals; (ii) both species supplement their traditional diets with food made available by commercial fishing operations (e.g., net-caught squid and offal); (iii) while obtained from drift nets, diets of nonbreeding Laysan and black-footed albatrosses are dominated by neon flying squid (Ommastrephes bartrami); (iv) in the absence of drift-net-related food, Laysan albatrosses feed most heavily on fish and black-footed albatrosses feed most heavily on squid; and (v) based on δ15N values, nonbreeding adult Laysan albatrosses from the transitional zone of the North Pacific Ocean and Laysan albatross nestlings fed by adults from Midway Island in the subtropical Pacific feed at one trophic level and one-third of a trophic level lower than black-footed albatrosses, respectively.

scholarly journals The contributions of the leading modes of the North Pacific sea surface temperature variability to the Arctic sea ice depletion in recent decades

2019 ◽  
Author(s):  
Lejiang Yu ◽  
Shiyuan Zhong ◽  
Timo Vihma
Keyword(s):  
Global Warming ◽  
Sea Ice ◽  
North Pacific ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Boreal Summer ◽  
The North ◽  
Arctic Sea ◽  
Arctic Sea Ice Loss ◽  
The North Pacific

Abstract. Arctic sea ice decrease in extent in recent decades has been linked to sea surface temperature (SST) anomalies in the North Pacific Ocean. In this study, we assess the relative contributions of the two leading modes in North Pacific SST anomalies representing external forcing related to global warming and internal forcing related to Pacific Decadal Oscillation (PDO) to the Arctic sea ice loss in boreal summer and autumn. For the 1979–2017 period, the time series of the global warming and PDO modes show significant positive and negative trends, respectively. The global warming mode accounts for 44.9 % and 50.1 % of the Arctic sea ice loss in boreal summer and autumn during this period, compared to the 20.0 % and 22.2 % from the PDO mode. There is also a seasonal difference in the response of atmospheric circulations to the two modes. The PDO mode excites a wavetrain from North Pacific to the Arctic; the wavetrain is not seen in the response of atmospheric circulation to the global warming mode. Both dynamic and thermodynamic forcings work in the relationship of atmospheric circulation and sea ice anomalies.

Contemporary Practice of the United States Relating to International Law

1992 ◽  
Vol 86 (4) ◽  
pp. 792-810
Author(s):  
Marian Nash
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Marine Mammals ◽  
Pacific Salmon ◽  
North Pacific Ocean ◽  
The United States ◽  
Anadromous Fish ◽  
The North ◽  
The North Pacific ◽  
High Seas

On May 19, 1992, President George Bush transmitted to the Senate for advice and consent to ratification the Convention for the Conservation of Anadromous Stocks in the North Pacific Ocean, with Annex, signed at Moscow on February 11, 1992. An accompanying report by Secretary of State James A. Baker III, dated May 14, 1992, stated, in major part: The Convention has as its centerpiece a prohibition on high seas fishing for Pacific salmon, which will protect valuable migrating U.S.-origin salmonids. It also establishes a new international organization to promote the conservation of anadromous stocks (primarily Pacific salmon) throughout their migratory range in the high seas area of the North Pacific Ocean and its adjacent seas, as well as ecologically related species that interact with these resources, including various marine mammals, seabirds, and non-anadromous fish species. The new organization, which is to be known as the North Pacific Anadromous Fish Commission, will also serve as a needed venue for consultation and coordination of high seas fishery enforcement activities by the contracting parties.

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