Author: Calvin J. Lensink
Publisher:
ISBN:
Category : Bird populations
Languages : en
Pages : 1050
Book Description
Seasonal Distribution and Abundance of Marine Birds, Part I, Shipboard Surveys
Author: Calvin J. Lensink
Publisher:
ISBN:
Category : Bird populations
Languages : en
Pages : 1050
Book Description
Publisher:
ISBN:
Category : Bird populations
Languages : en
Pages : 1050
Book Description
Seasonal Distribution and Abundance of Marine Birds
Author: Calvin J. Lensink
Publisher:
ISBN:
Category : Aerial surveys
Languages : en
Pages : 574
Book Description
Publisher:
ISBN:
Category : Aerial surveys
Languages : en
Pages : 574
Book Description
Seasonal Distribution and Abundance of Marine Birds
Author: Calvin J. Lensink
Publisher:
ISBN:
Category : Bird surveys
Languages : en
Pages : 14
Book Description
"Describes activites by U.S. Fish and Wildlife Service personnel related to shipboard surveys of marine birds in Alaskan waters during the two quarters from 1 January to 30 June 1976"--Leaf 1.
Publisher:
ISBN:
Category : Bird surveys
Languages : en
Pages : 14
Book Description
"Describes activites by U.S. Fish and Wildlife Service personnel related to shipboard surveys of marine birds in Alaskan waters during the two quarters from 1 January to 30 June 1976"--Leaf 1.
The Seasonal Distribution and Abundance of Marine Bird Populations in the Strait of Juan de Fuca and Northern Puget Sound in 1978
Author: David A. Manuwal
Publisher:
ISBN:
Category : Bird populations
Languages : en
Pages : 391
Book Description
Publisher:
ISBN:
Category : Bird populations
Languages : en
Pages : 391
Book Description
Distribution and Abundance of Marine Birds and Mammals Wintering in the Kodiak Area of Alaska
Author: Douglas J. Forsell
Publisher:
ISBN:
Category : Animal populations
Languages : en
Pages : 88
Book Description
Forty-four species of seabirds and ten species of marine mammals were observed during the winter 1979-80 in the Kodiak Archipelago.
Publisher:
ISBN:
Category : Animal populations
Languages : en
Pages : 88
Book Description
Forty-four species of seabirds and ten species of marine mammals were observed during the winter 1979-80 in the Kodiak Archipelago.
Patterns of Distribution, Abundance, and Change Over Time in the Marine Bird Community of Prince William Sound, Alaska, 1989-2012
Author: Daniel Arel Cushing
Publisher:
ISBN:
Category : Bird populations
Languages : en
Pages : 128
Book Description
Over recent decades, the marine ecosystems of Prince William Sound (PWS), Alaska have experienced the concurrent effects of a major anthropogenic disturbance, the 1989 Exxon Valdez oil spill (EVOS), and a dynamic atmospheric-oceanic environment. Studies of top marine consumers can provide insights into processes of ecosystem change. Using data collected during boat-based marine bird surveys in PWS over the period 1989-2012, I used complimentary taxon- and community-centric approaches to investigate patterns of distribution and abundance of marine birds across space and time. In doing so, I sought to provide insight into processes that may have affected both the birds themselves and the ecosystems of which they are a part. I found that the marine bird community as a whole was spatially structured along a primary onshore-offshore environmental gradient, and secondarily structured along an estuarine-marine environmental gradient. I found two patterns of community variability across time. The first temporal community-level pattern was likely related to sustained rates of change in the abundance of some genera, likely caused by demographic processes. This pattern was correlated with climate variability at time-scales of several years to a decade. The second temporal community-level pattern was characterized by fluctuations that correlated with climate variability at an annual time-scale, likely caused by movements of birds between PWS and the adjacent Gulf of Alaska. I also evaluated changes in the abundance of 18 genera of marine birds, and found that seven had declined in abundance and three had increased over the study period; all genera that declined were piscivorous or planktivorous. Furthermore, the rates of population change of genera were related to their position in the onshore-offshore gradient, with the highest rates of decline occurring in offshore-associated genera. I also investigated spatial habitat associations and temporal changes in abundance of a focal taxon, the seabird genus Brachyramphus. Two species within this piscivorous, pursuit-diving genus occur in PWS, the marbled murrelet (B. marmoratus) and the Kittlitz's murrelet (B. brevirostris). Both are species of conservation concern, and both experienced acute mortality in PWS caused by the EVOS. Using a statistical model that accounted for variables affecting observed abundance across space and time, I found that abundance decreased by more than two-thirds over the study period. I found no evidence that rates of change differed along environmental or geographic gradients. There was also no evidence that changes in seasonal patterns of abundance occurred. These results are indicative of a widespread decline in the abundance of Brachyramphus murrelets within PWS. Taken as a whole, the results of my thesis are consistent with the hypothesis that climate change has differentially affected nearshore and offshore components of PWS food webs. This in turn has likely contributed to the failure of some taxa, including Brachyramphus murrelets, to recover from population injury caused by the EVOS.
Publisher:
ISBN:
Category : Bird populations
Languages : en
Pages : 128
Book Description
Over recent decades, the marine ecosystems of Prince William Sound (PWS), Alaska have experienced the concurrent effects of a major anthropogenic disturbance, the 1989 Exxon Valdez oil spill (EVOS), and a dynamic atmospheric-oceanic environment. Studies of top marine consumers can provide insights into processes of ecosystem change. Using data collected during boat-based marine bird surveys in PWS over the period 1989-2012, I used complimentary taxon- and community-centric approaches to investigate patterns of distribution and abundance of marine birds across space and time. In doing so, I sought to provide insight into processes that may have affected both the birds themselves and the ecosystems of which they are a part. I found that the marine bird community as a whole was spatially structured along a primary onshore-offshore environmental gradient, and secondarily structured along an estuarine-marine environmental gradient. I found two patterns of community variability across time. The first temporal community-level pattern was likely related to sustained rates of change in the abundance of some genera, likely caused by demographic processes. This pattern was correlated with climate variability at time-scales of several years to a decade. The second temporal community-level pattern was characterized by fluctuations that correlated with climate variability at an annual time-scale, likely caused by movements of birds between PWS and the adjacent Gulf of Alaska. I also evaluated changes in the abundance of 18 genera of marine birds, and found that seven had declined in abundance and three had increased over the study period; all genera that declined were piscivorous or planktivorous. Furthermore, the rates of population change of genera were related to their position in the onshore-offshore gradient, with the highest rates of decline occurring in offshore-associated genera. I also investigated spatial habitat associations and temporal changes in abundance of a focal taxon, the seabird genus Brachyramphus. Two species within this piscivorous, pursuit-diving genus occur in PWS, the marbled murrelet (B. marmoratus) and the Kittlitz's murrelet (B. brevirostris). Both are species of conservation concern, and both experienced acute mortality in PWS caused by the EVOS. Using a statistical model that accounted for variables affecting observed abundance across space and time, I found that abundance decreased by more than two-thirds over the study period. I found no evidence that rates of change differed along environmental or geographic gradients. There was also no evidence that changes in seasonal patterns of abundance occurred. These results are indicative of a widespread decline in the abundance of Brachyramphus murrelets within PWS. Taken as a whole, the results of my thesis are consistent with the hypothesis that climate change has differentially affected nearshore and offshore components of PWS food webs. This in turn has likely contributed to the failure of some taxa, including Brachyramphus murrelets, to recover from population injury caused by the EVOS.
Comprehensive Bibliography
Author:
Publisher:
ISBN:
Category : Continental shelf
Languages : en
Pages : 764
Book Description
Publisher:
ISBN:
Category : Continental shelf
Languages : en
Pages : 764
Book Description
The Distribution and Abundance of Marine Birds and Mammals in the Gulf of the Farallones and Adjacent Waters, 1985-1992
Author: Sarah Gardner Allen
Publisher:
ISBN:
Category : Ecology
Languages : en
Pages : 414
Book Description
Publisher:
ISBN:
Category : Ecology
Languages : en
Pages : 414
Book Description
Comprehensive Bibliography
Author: Outer Continental Shelf Environmental Assessment Program
Publisher:
ISBN:
Category : Continental shelf
Languages : en
Pages : 632
Book Description
Publisher:
ISBN:
Category : Continental shelf
Languages : en
Pages : 632
Book Description
Marine Bird Distribution and Abundance Off Southern California
Author: Karl David Hyrenbach
Publisher:
ISBN:
Category : Sea birds
Languages : en
Pages : 780
Book Description
Publisher:
ISBN:
Category : Sea birds
Languages : en
Pages : 780
Book Description