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Book Influence of Physical and Biological Oceanography on the Structure of the Seabird Community in the Northeastern Chukchi Sea

Download or read book Influence of Physical and Biological Oceanography on the Structure of the Seabird Community in the Northeastern Chukchi Sea written by Adrian E. Gall and published by . This book was released on 2015 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Chukchi Sea is losing seasonal ice cover as global temperatures rise, facilitating human access to the region for activities such as oil and gas exploration, shipping, and tourism. Processes and responses to environmental change by marine ecosystems are often challenging to quantify because they are hidden under water. Seabirds, however, offer visible evidence of the health and status of marine ecosystems. I studied the community structure, variability in abundance and distribution, and habitat associations of seabirds in the eastern Chukchi Sea. My results provide insights into the influence of climate change on seabirds and a benchmark against which to evaluate possible impacts of anthropogenic activity. Repeated sampling of systematic transects in the northeastern Chukchi Sea during the ice-free seasons of 2008-2012 showed that the community consisted of ~40 species and was dominated numerically by planktivorous seabirds, particularly Crested Auklets (Aethia cristatella) and Short-tailed Shearwaters (Puffinus tenuirostris). In contrast, benthic-feeding birds were rare. The abundance of seabirds in the offshore northeastern Chukchi Sea varied by up to two orders of magnitude among years and birds generally were more abundant in September than August. Despite these seasonal and interannual variations in abundance, the species composition was similar among years, with anomalies occurring only in years of persistent ice cover. I compared data from this recent period (2008-2012) with data from historical surveys (1975-1981) to evaluate decadal trends in seabird abundance and composition and related those changes to reductions in seasonal ice cover. The seabird community shifted from one consisting primarily of piscivorous seabirds to one consisting primarily of planktivorous seabirds. This shift suggests that zooplankton prey are more accessible now to avian predators as seasonal ice cover has declined. I explored the relationships between seabirds, hydrography, and zooplankton abundance with spatially explicit generalized additive models. The associations of seabirds with habitat characteristics varied with foraging method and preferred prey. Species that fed primarily by pursuit diving were more abundant in warm, weakly stratified water, whereas surface-feeding species were more abundant in cold, strongly stratified water. Planktivorous seabirds (auklets, shearwaters, and phalaropes) were more abundant within 20 km of thermal surface fronts and in contrast, omnivores (gulls and murres) were more abundant far from thermal fronts. For 5 of the 8 seabird species, information about prey biomass improved predictions of seabird abundance, although the relationships were not as clear as they were for the physical habitat characteristics indicative of processes that aggregate prey. Advective processes that transport oceanic species of zooplankton from the Bering Sea to the Chukchi Sea, together with the local influence of sea ice on physical and biological processes, strongly influence the distribution of seabirds, particularly the planktivorous species. Scientists and decision-makers can use the results of this multi-species and multi-disciplinary study as a benchmark to assess the ecological consequences of anthropogenic activity against the backdrop of climate change that is affecting the Chukchi Sea.

Book Seabird Distribution and Abundance in the Offshore Environment Final Report

Download or read book Seabird Distribution and Abundance in the Offshore Environment Final Report written by Katherine J. Kuletz and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of seabird populations of coastal Alaska in the Chukchi Sea, Bering Sea, Western Beaufort Sea and Gulf of Alaska.

Book Seabird Distribution and Abundance in the Offshore Environment

Download or read book Seabird Distribution and Abundance in the Offshore Environment written by Katherine J. Kuletz and published by . This book was released on 2017 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of seabird populations of coastal Alaska in the Chukchi Sea, Bering Sea, Western Beaufort Sea and Gulf of Alaska.

Book Distribution Abundance and Behavior of Endangered Whales in the Alaskan Chukchi and Western Beaufort Seas 1991 with a Review 1982 91

Download or read book Distribution Abundance and Behavior of Endangered Whales in the Alaskan Chukchi and Western Beaufort Seas 1991 with a Review 1982 91 written by Sue E. Moore and published by . This book was released on 1992 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Distribution and Relative Abundance of Marine Mammals in the Northeastern Chukchi and Western Beaufort Seas 2013

Download or read book Distribution and Relative Abundance of Marine Mammals in the Northeastern Chukchi and Western Beaufort Seas 2013 written by Janet T. Clarke and published by . This book was released on 2014 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerial surveys were conducted between July 1 and October 23, 2013 to monitor bowhead whales, gray whales, humpback whales, fin whales, minke whales, belugas, polar bears, walruses, and other pinnipeds in the Chukchi Sea and Beaufort Sea off the Alaskan coast in areas of offshore oil and gas lease sales.

Book Distribution and Relative Abundance of Marine Mammals in the Northeastern Chukchi and Western Beaufort Seas 2012

Download or read book Distribution and Relative Abundance of Marine Mammals in the Northeastern Chukchi and Western Beaufort Seas 2012 written by Janet T. Clarke and published by . This book was released on 2013 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerial surveys were conducted to monitor bowhead whales, gray whales, humpback whales, fin whales, minke whales, belugas, killer whales, polar bears, walruses, and other pinnipeds in the Chukchi Sea and Beaufort Sea off the Alaskan coast in areas of offshore oil and gas lease sales.

Book Abundance Biomass and Caloric Content of Chukchi Sea Bivalves and Influence on Pacific Walrus Odobenus Rosmarus Divergens Abundance and Distribution in the Northeastern Chukchi Sea

Download or read book Abundance Biomass and Caloric Content of Chukchi Sea Bivalves and Influence on Pacific Walrus Odobenus Rosmarus Divergens Abundance and Distribution in the Northeastern Chukchi Sea written by Jordann Kailey Young and published by . This book was released on 2015 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The northeastern Chukchi Sea is a shallow subarctic shelf ecosystem that supports a significant benthic infaunal community. Bivalves are one of the dominant benthic taxa in this region, and represent a vital food resource for consumers such as Pacific walrus (Odobenus rosmarus divergens). The biomass, abundance and species composition of these bivalve communities not only reflect local patterns of productivity, but have the potential to affect upper trophic level consumers through bottom-up processes. Ten dominant bivalve taxa were collected over four cruises in the northeastern Chukchi Sea from 2009-2013 to establish baseline parameters in size frequency distributions, abundance, biomass and caloric content and to quantify their influence on the distribution of Pacific walrus. Pooled size-frequency distributions across all years showed strongly right-skewed distributions for most taxa, with a few showing evidence of a bimodal distribution. Calorimetric measurements revealed significant differences in caloric density between taxa (p-value