Genetic diversity and kinship relationships in one of the largest South American fur seal ( Arctocephalus australis ) populations of the Pacific Ocean

This paper deals essentially with ecosystems, biomes, and habitats, of the Pacific realm, that are in need of restoration and conservation programmes for saving endangered vertebrates through the establishment of ‘ecological reserves’. Besides zoogeographic factors, the matter of conservation urgency is reflected in the criteria by taking into account the rate of vertebrate extinction in historic time and the number of vertebrate species and subspecies that are endangered or threatened with extinction in each area.In this paper and its successor (Part 2), twenty-two zoogeographic subregions have been defined in the Pacific realm, to which have been added three others—namely the Australian, North American, and South American coasts of the Pacific Ocean. Table I shows the division of these zoogeographic subregions within each faunal region. The Oceanian or ‘Central’ region is here introduced as a particular faunal region comprising Hawaii, Micronesia, Melanesia, and Polynesia. This complex of islands cannot, in the Author's opinion, be conveniently grouped with any of the continental faunal regions, although it has clear affinities with near-by continents to the west.

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Genetic Diversity and Population Structure of the Pelagic Thresher Shark (Alopias pelagicus) in the Pacific Ocean: Evidence for Two Evolutionarily Significant Units

PLoS ONE ◽

10.1371/journal.pone.0110193 ◽

2014 ◽

Vol 9 (10) ◽

pp. e110193 ◽

Cited By ~ 29

Author(s):

Diego Cardeñosa ◽

John Hyde ◽

Susana Caballero

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Pacific Ocean ◽

Evolutionarily Significant Units ◽

The Pacific ◽

Thresher Shark ◽

The Pacific Ocean

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Quaternary glaciolacustrine deposits around a Triple Junction site: Paleolakes at the foot of the Northern Patagonian Ice field (Argentina and Chile)

Andean geology ◽

10.5027/andgeov48n1-3173 ◽

2021 ◽

Vol 48 (1) ◽

pp. 94

Author(s):

Federico Ignacio Isla ◽

Marcela Espinosa

Keyword(s):

Pacific Ocean ◽

Triple Junction ◽

Tectonic Activity ◽

South American ◽

The West ◽

South American Plate ◽

The Pacific ◽

Junction Site ◽

Ice Field ◽

The Pacific Ocean

The area involved by the triple junction between the South American, Nazca and Antarctic plates activity was affected by Quaternary glaciations. Before 12,800 yrs BP an extended ice field occupied the top of the Patagonian Andes, irradiating glaciers towards the east and the west dominantly. Towards the east, the ice melted in piedmont lakes; towards the west, fjords melted into the Pacific Ocean. The Upper-Pleistocene climate amelioration caused the recession of those glaciers. Some piedmont lakes reversed their Atlantic outflow towards to the Pacific Ocean. The glaciers retreat caused the fluvial reactivations along crustal former faults that were located below the ice. The Patagonian ice field became therefore split into present Northern and Southern fields. At the second largest lake of South America, the Buenos Aires-General Carrera Lake, the water level dropped from about 500 m over present mean sea level to 230 m. Several glaciolacustrine deposits from this area are indicating significant variations caused by climatic changes, volcanism and tectonics, differing in spatial and temporal magnitudes. The triple junction activity involved subduction of the Chile Ridge below the continental South American plate, volcanic activity and faulting. During the glacier melting the Baker River captured three eastern-moving glacial systems towards the southwest, towards the Pacific Ocean. This rapid event is thought to occur 12,800 yrs BP. The lowering of these glaciolacustrine systems should be also interpreted in terms of the tectonic activity in the region and considering other processes operating in the lakes and within the watersheds.

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Abundance and Genetic Diversity of Aerobic Anoxygenic Phototrophic Bacteria of Coastal Regions of the Pacific Ocean

Applied and Environmental Microbiology ◽

10.1128/aem.06268-11 ◽

2012 ◽

Vol 78 (8) ◽

pp. 2858-2866 ◽

Cited By ~ 43

Author(s):

Anna E. Ritchie ◽

Zackary I. Johnson

Keyword(s):

Genetic Diversity ◽

Pacific Ocean ◽

Environmental Variables ◽

Anoxygenic Phototrophic Bacteria ◽

Bacterial Populations ◽

Content Type ◽

The Pacific ◽

Near Shore ◽

The Pacific Ocean ◽

Abundance And Diversity

ABSTRACTAerobic anoxygenic phototrophic (AAP) bacteria are photoheterotrophic microbes that are found in a broad range of aquatic environments. Although potentially significant to the microbial ecology and biogeochemistry of marine ecosystems, their abundance and genetic diversity and the environmental variables that regulate these properties are poorly understood. Using samples along nearshore/offshore transects from five disparate islands in the Pacific Ocean (Oahu, Molokai, Futuna, Aniwa, and Lord Howe) and off California, we show that AAP bacteria, as quantified by thepufMgene biomarker, are most abundant near shore and in areas with high chlorophyll orSynechococcusabundance. These AAP bacterial populations are genetically diverse, with most members belonging to the alpha- or gammaproteobacterial groups and with subclades that are associated with specific environmental variables. The genetic diversity of AAP bacteria is structured along the nearshore/offshore transects in relation to environmental variables, and unculturedpufMgene libraries suggest that nearshore communities are distinct from those offshore. AAP bacterial communities are also genetically distinct between islands, such that the stations that are most distantly separated are the most genetically distinct. Together, these results demonstrate that environmental variables regulate both the abundance and diversity of AAP bacteria but that endemism may also be a contributing factor in structuring these communities.

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