Habitats of two albatross species during the non-breeding season in the North Pacific Transition Zone

2015 ◽  
Vol 162 (4) ◽  
pp. 743-752 ◽  
Author(s):  
Bungo Nishizawa ◽  
Daisuke Ochi ◽  
Hiroshi Minami ◽  
Kotaro Yokawa ◽  
Sei-Ichi Saitoh ◽  
...  
Keyword(s):  
Transition Zone ◽  
Breeding Season ◽  
North Pacific ◽  
The North ◽  
The North Pacific

scholarly journals Geolocator tagging links distributions in the non-breeding season to population genetic structure in a sentinel North Pacific seabird

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0240056
Author(s):  
J. Mark Hipfner ◽  
Marie M. Prill ◽  
Katharine R. Studholme ◽  
Alice D. Domalik ◽  
Strahan Tucker ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Pacific Ocean ◽  
Genetic Differentiation ◽  
Breeding Season ◽  
North Pacific ◽  
Western Pacific ◽  
The North ◽  
Wintering Areas ◽  
The North Pacific ◽  
Rhinoceros Auklet

We tested the hypothesis that segregation in wintering areas is associated with population differentiation in a sentinel North Pacific seabird, the rhinoceros auklet (Cerorhinca monocerata). We collected tissue samples for genetic analyses on five breeding colonies in the western Pacific Ocean (Japan) and on 13 colonies in the eastern Pacific Ocean (California to Alaska), and deployed light-level geolocator tags on 12 eastern Pacific colonies to delineate wintering areas. Geolocator tags were deployed previously on one colony in Japan. There was strong genetic differentiation between populations in the eastern vs. western Pacific Ocean, likely due to two factors. First, glaciation over the North Pacific in the late Pleistocene might have forced a southward range shift that historically isolated the eastern and western populations. And second, deep-ocean habitat along the northern continental shelf appears to act as a barrier to movement; abundant on both sides of the North Pacific, the rhinoceros auklet is virtually absent as a breeder in the Aleutian Islands and Bering Sea, and no tagged birds crossed the North Pacific in the non-breeding season. While genetic differentiation was strongest between the eastern vs. western Pacific, there was also extensive differentiation within both regional groups. In pairwise comparisons among the eastern Pacific colonies, the standardized measure of genetic differentiation (FꞌST) was negatively correlated with the extent of spatial overlap in wintering areas. That result supports the hypothesis that segregation in the non-breeding season is linked to genetic structure. Philopatry and a neritic foraging habit probably also contribute to the structuring. Widely distributed, vulnerable to anthropogenic stressors, and exhibiting extensive genetic structure, the rhinoceros auklet is fully indicative of the scope of the conservation challenges posed by seabirds.

scholarly journals Seasonal photoacclimation in the North Pacific Transition Zone

2021 ◽  
Author(s):  
Gregory L Britten ◽  
Christine Padalino ◽  
Gaël Forget ◽  
Michael J. Follows
Keyword(s):  
Transition Zone ◽  
North Pacific ◽  
The North ◽  
The North Pacific

scholarly journals Summertime Tintinnid Community in the Surface Waters Across the North Pacific Transition Zone

2021 ◽  
Vol 12 ◽  
Author(s):  
Haibo Li ◽  
Jun Xuan ◽  
Chaofeng Wang ◽  
Zhaohui Chen ◽  
Gérald Grégori ◽  
...  
Keyword(s):  
Transition Zone ◽  
North Pacific ◽  
Warm Water ◽  
Type I ◽  
Water Type ◽  
The North ◽  
Important Region ◽  
Oceanic Species ◽  
The Common ◽  
The North Pacific

Located from 35° to 45° latitude in both hemispheres, the transition zone is an important region with respect to the planktonic biogeography of the sea. However, to the best of our knowledge, there have been no reports on the existence of a tintinnid community in the transition zone. In this research, tintinnids along two transects across the North Pacific Transition Zone (NPTZ) were investigated in summer 2016 and 2019. Eighty-three oceanic tintinnid species were identified, 41 of which were defined as common oceanic species. The common oceanic species were further divided into five groups: boreal, warm water type I, warm water type II, transition zone, and cosmopolitan species. Undella californiensis and Undella clevei were transition zone species. Other species, such as Amphorides minor, Dadayiella ganymedes, Dictyocysta mitra, Eutintinnus pacificus, Eutintinnus tubulosus, Protorhabdonella simplex, and Steenstrupiella steenstrupii, were the most abundant in the NPTZ but spread over a much larger distribution region. Species richness showed no obvious increase in the NPTZ. Boreal, transition zone, and warm water communities were divided along the two transects. Tintinnid transition zone community mainly distributed in regions with water temperatures between 15 and 20°C. The tintinnid lorica oral diameter size classes were dominated by the 24–28 μm size class in three communities, but the dominance decreased from 66.26% in the boreal community to 48.85% in the transition zone community and then to 22.72% in the warm water community. Our research confirmed the existence of tintinnid transition zone species and community. The abrupt disappearance of warm water type I species below 15°C suggested that this group could be used as an indicator of the northern boundary of the NPTZ.

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