Author: Donna D. W. Hauser Publisher: ISBN: Category : White whale Languages : en Pages : 206
Book Description
Sea ice is disappearing at unprecedented rates in the Pacific Arctic with potential impacts to ice-associated marine predators that migrate to this seasonally accessible and productive ecosystem. In this dissertation I used satellite telemetry data spanning 1993-2012 collected from two migratory populations of beluga whales (Delphinapterus leucas) in the Pacific Arctic (i.e., Eastern Chukchi Sea and Eastern Beaufort Sea populations) to investigate how loss of sea ice and changes in other environmental factors affect distribution, movement, and behavior. I quantified fidelity to summer areas, sexual segregation, and migration timing as well as variations in diving behavior among regions. These analyses illustrate that population-scale patterns of philopatry, migration, and foraging are mediated by the combined effects of seasonal sea ice and oceanographic fluctuations, prey distribution, and social interactions. I also addressed the question of whether belugas would adjust their distribution, migration, and behavior to shifting sea ice conditions and to what extent matrilineally-learned behavior might supersede environmental forcing through the development of resource selection functions. Results indicate that sea ice is a contributing factor but not sole determinant of beluga habitat preferences. One population (Eastern Chukchi Sea) exhibits delayed fall migration in response to later sea ice freeze-up. Changing environmental conditions also seem to favor deeper, longer dives for this population. There were few overall differences in preferred habitat selection during 1990-2014, and summer distribution appears to be governed by philopatry rather than ice conditions. These results correspond to a conclusion that Eastern Chukchi Sea belugas are responding to a changing Pacific Arctic environment through behavioral plasticity in migration timing and foraging behavior. In contrast, there were few examples where migration timing or sea ice associations of Eastern Beaufort Sea belugas changed between the 1990s and 2000s. Taken as a whole, these results suggest population-specific responses by belugas in the face of fluctuating sea ice conditions. Across the circumpolar Arctic, some beluga populations may be more likely than others to adapt and persist in a changing climate.
Author: Lucy F. Romeo Publisher: ISBN: Category : Spatial behavior in animals Languages : en Pages : 92
Book Description
The known distribution of beluga whales ranges from sub-Arctic to Arctic waters where they migrate in pods in response to environmental factors such as the presence of sea ice and prey. This study uses bivariate and multivariate analysis techniques to measure how environmental covariates are associated with the spatial-temporal distribution of beluga whales. Exploratory data analysis was used to determine the relationship among environmental covariates: bathymetry, slope, sea surface temperature, and distance to sea ice. Spatial analyses were used to determine the probability of occurrence of beluga whales in the northeastern Chukchi and southwestern Beaufort seas, based on each environmental covariate for the autumn months of the two study periods, from 2000 to 2006 and from 2008 to 2012. Findings from this study suggest that correlations exist between SST and distance to sea ice, and depth and distance to sea ice, and that beluga whales may prefer areas of relatively steep slope and associated increasing depth along the continental slope. Probability of occurrence maps were created for September and October for each year, based on beluga whale preference and avoidance for each environmental covariate. Areas of preference, or high probability of occurrence, had more beluga whale sightings than expected. And areas of avoidance, or low probability of occurrence, had less beluga whale sightings than expected. Model validation included randomly dividing observational data from September of 2011 into a training (70%) and testing (30%) dataset, then creating a probability of occurrence model based on the training dataset and comparing the results to the locations of the testing dataset. Outputs from the analyses can help guide studies of beluga environmental covariate preferences and the possible influences on their occurrence. Better understanding of the spatial distribution of beluga whales can provide a tool for better management practices. Improved practices in management and conservation of habitat for beluga whales will impact indigenous communities who rely on marine mammals as cultural and consumable resources.
Author: Kristin Westdal Publisher: ISBN: Category : Languages : en Pages : 0
Book Description
Beluga whales (Delphinapterus leucas) are an Arctic cetacean with circumpolar distribution. They are known to have distinct, lengthy and consistent migration paths to and from summer and wintering grounds. The Western Hudson Bay beluga population, the largest summering aggregation in the world, inhabits three main estuaries in the summer season. Little protection is afforded to them here, and little is known of the specific details of their summer distribution and factors affecting that distribution. Using a combination of satellite telemetry, aerial photos, satellite data, and visual observations and historical reports, investigations into factors affecting beluga distribution in Western Hudson Bay were conducted. An examination into beluga age class distribution near the Churchill and Seal River estuaries, using aerial survey imagery, suggested that belugas may not be segregating by age in summer, however the Seal River estuary may be more important from a calf-rearing perspective. Belugas use a greater home range than we would expect, based on historical range data, in the face of predation by their main predator, the killer whale (Orcinus orca). Killer whales are sighted more frequently in Hudson Bay than historically, and results presented here show that ice entrapments, occurring with higher frequency in the future, may impact distribution of beluga as killer whales expand their range and occurrence in Hudson Bay. Finally, an assessment of beluga behaviour in the presence of whale-watching vessels showed that beluga response to vessels varied but the probability of travelling behaviour was significantly greater with distance from vessels; belugas also appear to be spending more time interacting with vessels now, as compared to 15 years ago when there were fewer whale-watching vessels. The results found through this research are useful in informing climate change implications, marine-protected area boundaries, policy and marine spatial planning, and subsistence harvest management.
Author: Regina Anne Guazzo Publisher: ISBN: Category : Languages : en Pages : 165
Book Description
Mysticetes (baleen whales) often make long, annual migrations from high latitude summer feeding areas to low latitude wintering areas. Eastern North Pacific gray whales (Eschrichtius robustus) migrate within a few kilometers from shore for most of their route from summer feeding areas in the Bering, Chukchi, and Beaufort Seas to wintering areas in the lagoons along the south-western coast of the Baja California Peninsula in Mexico. This dissertation combines passive acoustic recordings, infrared camera video, and visual sightings to investigate gray whale behavior and how it changes across different timescales. I use a four-element hydrophone array in central California to present the first published full-season acoustic monitoring and tracking of migrating gray whales. I describe the characteristics of calls produced by migrating gray whales and analyze how these characteristics change due to propagation. I show that gray whale behavior changes on diel and seasonal timescales. Notably, gray whales increase their vocalizations at night but their mean swimming behavior does not change, contrary to previous assumptions used in population size estimates. Over seasonal timescales, vocalizing gray whale swimming behavior aligns with previous observations. I explore how passive acoustic and infrared camera monitoring can help quantify whales by calculating cue rates or call and blow rates for migrating gray whales. Acoustic calling rates indicate that the gray whale population size is greater than estimated using visual sightings alone and that calling rate increases over the southbound migration. Infrared camera blow rates are less affected by whale behavior and are useful for daytime and nighttime monitoring, but are limited by visibility and distance. To understand gray whale behavior over seven migration seasons, I use visual daily counts at two sites and single-hydrophone call detections which indicate that migratory behavior seems to be driven more by intrinsic than the tested environmental factors. I find that the proportion of the population using a coastal route through the Southern California Bight, especially past Los Angeles, increased over these years. Understanding the behavior of migrating gray whales will help improve abundance estimates and determine how these whales may be impacted by nearshore anthropogenic activities and climate change.
Author: Robert Suydam Publisher: CreateSpace ISBN: 9781514722916 Category : Languages : en Pages : 40
Book Description
This report includes data from two efforts to satellite tag beluga whales. The first was conducted by the Alaska Beluga Whale Committee (ABWC) through NOAA grant NA67FX0197, the Alaska Department of Fish and Game (ADF&G), the National Marine Fisheries Service (NMFS), the North Slope Borough (NSB), and the Village of Point Lay. This was the first time belugas in Alaska were instrumented with satellite tags. Ten belugas were tagged in 1998-1999. The second took place in 2000-2002. It was initiated by the ABWC and further supported by Minerals Management Service (MMS) through the Coastal Marine Institute. Other cooperators included NMFS, ADF&G, the NSB, the Village of Point Lay, and Alaska Marine Ecosystems Research.
Author: William F. Perrin Publisher: Academic Press ISBN: 0080919936 Category : Science Languages : en Pages : 1355
Book Description
This thorough revision of the classic Encyclopedia of Marine Mammals brings this authoritative book right up-to-date. Articles describe every species in detail, based on the very latest taxonomy, and a host of biological, ecological and sociological aspects relating to marine mammals. The latest information on the biology, ecology, anatomy, behavior and interactions with man is provided by a cast of expert authors – all presented in such detail and clarity to support both marine mammal specialists and the serious naturalist. Fully referenced throughout and with a fresh selection of the best color photographs available, the long-awaited second edition remains at the forefront as the go-to reference on marine mammals. More than 20% NEW MATERIAL includes articles on Climate Change, Pacific White-sided Dolphins, Sociobiology, Habitat Use, Feeding Morphology and more Over 260 articles on the individual species with topics ranging from anatomy and behavior, to conservation, exploitation and the impact of global climate change on marine mammals New color illustrations show every species and document topical articles FROM THE FIRST EDITION “This book is so good...a bargain, full of riches...packed with fascinating up to date information. I recommend it unreservedly it to individuals, students, and researchers, as well as libraries." --Richard M. Laws, MARINE MAMMALS SCIENCE "...establishes a solid and satisfying foundation for current study and future exploration" --Ronald J. Shusterman, SCIENCE
Author: Steven H. Ferguson Publisher: Springer Science & Business Media ISBN: 9048191211 Category : Science Languages : en Pages : 313
Book Description
In Arctic Canada, Hudson Bay is a site of great exploration history, aboriginal culture, and a vast marine wilderness supporting large populations of marine mammals and birds. These include some of the most iconic Arctic animals like beluga, narwhal, bowhead whales, and polar bears. Due to the challenges of conducting field research in this region, some of the mysteries of where these animals move, and how they are able to survive in such seemingly inhospitable, ice-choked habitats are just now being unlocked. For example, are polar bears being replaced by killer whales? This new information could not be more salient, as the Hudson Bay Region is undergoing rapid environmental change due to global warming, as well as increased pressures from industrial development interests. A Little Less Arctic brings together some of the world’s leading Arctic scientists to present the current state of knowledge on the physical and biological characteristics of Hudson Bay.
Author: Donna D. W. Hauser
Author: Lucy F. Romeo
Author: Kristin Westdal
Author: Regina Anne Guazzo
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Author: Luisa Galgani
Author: Robert Suydam
Author: William F. Perrin
Author: Steven H. Ferguson
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