Annual Calf Indices for Beluga Whales (Delphinapterus Leucus) in Cook Inlet, Alaska 2006-2010 PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Annual Calf Indices for Beluga Whales (Delphinapterus Leucus) in Cook Inlet, Alaska 2006-2010 PDF full book. Access full book title Annual Calf Indices for Beluga Whales (Delphinapterus Leucus) in Cook Inlet, Alaska 2006-2010 by Roderick C. Hobbs. Download full books in PDF and EPUB format.
Author: Roderick C. Hobbs Publisher: ISBN: Category : White whale Languages : en Pages : 29
Book Description
Beluga whales (Delphinapterus leucas) in Cook Inlet, Alaska, form an isolated, depleted population that is now listed as endangered. One monitor of population health is through documenting calving rates. This study provides an index of the number of calves seen in Cook Inlet in August. Although the August survey is the focus for the calf index, given most births are thought to occur by late July, data collected during the annual June abundance survey are used for comparison. Analyses cover the period from 2006 to 2010 (a feasibility and techniques study occurred in August 2005). Systematic aerial surveys covered primary habitat for belugas in Cook Inlet, and paired video cameras provided images used in laboratory analysis. A total of 44 groups of whales from the August surveys were examined, of which most contained images of calves that were identified by color (darker than adults), small size, and proximity to adults. Among these whale groups, 688 usable images were found and examined. By rating inter-whale proximity in five categories, and estimating the ages represented, we developed criteria for recognizing young calves, an index that represents primarily young-of-the-year calves, and a second index that represents young-of-the-year, yearling calves, and some young juveniles. It appears that more calves were born in 2006 (12%) than in subsequent years (2007-2010 ranged from 0.5% to 3%). However, these calving rates have several potential biases and should be used for trend analysis only, not for absolute estimates of calf production. Overall, the 5-year average (2006-2010) birth rate was 3.6%. With mortality rates per year of roughly 3% or more (based on counts of beach-cast carcasses), this would suggest that the birth rate estimated here is probably at or below the replacement level necessary for recovery of this population.
Author: Roderick C. Hobbs Publisher: ISBN: Category : White whale Languages : en Pages : 29
Book Description
Beluga whales (Delphinapterus leucas) in Cook Inlet, Alaska, form an isolated, depleted population that is now listed as endangered. One monitor of population health is through documenting calving rates. This study provides an index of the number of calves seen in Cook Inlet in August. Although the August survey is the focus for the calf index, given most births are thought to occur by late July, data collected during the annual June abundance survey are used for comparison. Analyses cover the period from 2006 to 2010 (a feasibility and techniques study occurred in August 2005). Systematic aerial surveys covered primary habitat for belugas in Cook Inlet, and paired video cameras provided images used in laboratory analysis. A total of 44 groups of whales from the August surveys were examined, of which most contained images of calves that were identified by color (darker than adults), small size, and proximity to adults. Among these whale groups, 688 usable images were found and examined. By rating inter-whale proximity in five categories, and estimating the ages represented, we developed criteria for recognizing young calves, an index that represents primarily young-of-the-year calves, and a second index that represents young-of-the-year, yearling calves, and some young juveniles. It appears that more calves were born in 2006 (12%) than in subsequent years (2007-2010 ranged from 0.5% to 3%). However, these calving rates have several potential biases and should be used for trend analysis only, not for absolute estimates of calf production. Overall, the 5-year average (2006-2010) birth rate was 3.6%. With mortality rates per year of roughly 3% or more (based on counts of beach-cast carcasses), this would suggest that the birth rate estimated here is probably at or below the replacement level necessary for recovery of this population.
Author: Alaska Fisheries Science Center Nationa Publisher: BiblioGov ISBN: 9781289033231 Category : Languages : en Pages : 40
Book Description
In the 1970's the National Oceanic and Atmospheric Administration (NOAA) was made to manage our oceanic and atmospheric resources. The Alaska Fisheries Science Center is the research branch for marine life and coastal oceans off parts of the U.S. west coast and Alaska. This includes the Eastern Bering Sea where some the worlds most important commercial fishing takes place. Their mission is to develop and maintain scientific exploration to help understand and manage that region's environment. Over the years there have been many reports published which discuss their findings; this is one of them.
Author: Kim E. W. Shelden Publisher: ISBN: Category : Aerial surveys in wildlife management Languages : en Pages : 122
Book Description
The National Marine Fisheries Service (NMFS) has conducted aerial surveys of the beluga population in Cook Inlet, Alaska, each June and/or July since 1993. Results from 1993 to 2000 and 2001 to 2004 were published previously. The current document is a compilation of data from field reports for the subsequent years, from 2005 to 2012. Surveys during these year occurred 31 May-9 June 2005 (54.5 flight hours), 6-15 June 2006 (58.4 flight hours), 7-15 June 2007 (47.2 flight hours), 3-12 June 2008 (47.7 flight hours), 2-9 June 2009 (39.4 flight hours), 1-10 June 2010 (48.4 flight hours), 31 May-9 June 2011 (47.0 flight hours), and 29 May-7 June 2012 (53.0 flight hours). All surveys were flown in twin-engine, high-wing aircraft (i.e., an Aero Commander or Twin Otter) at a target altitude of 244 m (800 ft) and speed of 185 km/hour (100 knots), consistent with NMFS' surveys of Cook Inlet conducted in previous years. Tracklines were flown 1.4 km from the shoreline, along the entire Cook Inlet coast, including islands. Offshore transects were designed to run the length of Cook Inlet or in a sawtooth pattern across the inlet, minimizing overlap within each season, as well as between years. These aerial surveys effectively covered 25% to 34% of the total surface area of Cook Inlet in each of the 8 years and nearly 100% of the coastline (with the exception of 2007: 71%). In particular, most of the upper inlet, north of the Forelands where beluga whales are consistently found, was surveyed five to six times each year. Paired, independent observers searched on the coastal side of the plane, where virtually all beluga sightings occur, while a single observer searched on the offshore side. A computer operator/data recorder periodically monitored distance from the shoreline (1.4 km) with a clinometer (angle 10°). After finding beluga groups, a series of aerial passes allowed all four observers to each make four or more independent counts of every group, (i.e., typically 16 counts of each group conducted during 8 passes). In addition, whale groups were video recorded for later analysis and more precise counts in the laboratory. During the 8 years of surveys from 2005 to 2012, belugas were not seen in lower Cook Inlet (south of East and West Foreland) nor in the upper inlet south of North Foreland and Point Possession until 2012 when a group of at least seven belugas was observed headed toward West Foreland on 31 May. Before 1996, it was common to see beluga groups south of North Foreland in Trading Bay. Since the mid-1990s to early 2000s, only one or two beluga groups have been found in lower Cook Inlet south of East and West Foreland and none in the region between the Forelands and North Foreland. Groups of more than one or two whales have not been seen in the lower inlet since 1995. During the 2012 survey, this beluga group moved into the upper inlet and was observed in Trading Bay for the remainder of the survey (highest median count = 21 whales). The annual sums of medians from aerial counts provide a quick index of relative abundance, not corrected for estimates of whales missed and assuming there may be some exchange of whales between areas. Annual index counts from 2005 to 2012 (192, 153, 224, 126, 303, 291, 208, and 319, respectively) included the lowest (2008) and highest (2012) counts recorded since surveys began in 1993 (1993-2004 counts: 302, 276, 322, 287, 261, 192, 217, 184, 210, 181, 174, and 187).
Author: Kim E. W. Shelden Publisher: ISBN: Category : Mammal surveys Languages : en Pages : 226
Book Description
Cook Inlet beluga whales, Delphinapterus leucas, are currently listed as 'Endangered' under the U.S. Endangered Species Act (ESA). The National Marine Fisheries Service (NMFS) began monitoring this population during the 1990s after it was added to the ESA Candidate Species list in 1988. Monitoring efforts included aerial surveys, and in 1995, the first attempts to capture and satellite-tag whales. Working with Canadian scientists and Alaska Native subsistence hunters in 1995 and 1997, tagging methods were adapted to conditions in Cook Inlet (muddy water, extreme tides, and extensive mudflats), culminating in successful capture and tracking of a whale during the summer of 1999. This was followed by three more years of capture and tagging studies during late summer. Tags were attached to 18 whales between 1999 and 2002. We do not have detailed accounts of these later tagging seasons (e.g., similar to the Appendix chronicling events from the 1997 and 1999 seasons in Ferrero et al. (2000)). Litzky et al. (2001) summarized field operations for the 2000 tagging season, but no reports exist for 2001 and 2002. A reanalysis of the tag dataset (Goetz et al. 2012) led to questions about the captures and how tags were programmed during this time period. Given the Cook Inlet population has continued to decline (Hobbs et al. 2015, Shelden et al. 2017), and was listed as an Endangered Distinct Population Segment under the ESA in October 2008 (NOAA 2008), future recommendations for tagging will depend on lessons learned from these past projects. Lacking detailed field reports, we consolidated information from multiple sources. Herein, we bring these varied sources together to provide a thorough documentation of the tagging operations undertaken in Cook Inlet each summer in 2000, 2001, and 2002. We include revised tag transmission timelines, monthly movement maps, dive behavior data, and ice-association graphs and maps for all whales (where applicable) tagged in 1999, 2000, 2001, and 2002. Whale locations were compared to sighting records (opportunistic and systematic) to determine how many whales were likely proximate to tagged whales. Animations of whale movements are available at http://www.afsc.noaa.gov/News/Cook_Inlet_Beluga_Range_Contracted.htm (accessed 17 Aug. 2016). Beginning with the 2000 season, each whale underwent a health assessment at the time of tagging. Results from laboratory analyses of the blood, blubber, skin, and mucus samples are presented. These include results obtained for hematology and serum chemistry values, hormones, DNA extractions, blubber lipid composition, fatty acid profiles, stable isotope ratios, and persistent organic pollutant profiles. We also provide a follow-up to the tagging study, describing captured and tagged whales that have been photo-documented since 2005 by the Cook Inlet Beluga Whale Photo-identification Project (https://www.cookinletbelugas.com/).
Author: Kristin L. Laidre Publisher: ISBN: Category : White whale Languages : en Pages : 33
Book Description
The following report contains detailed information on the movement patterns of beluga whales that were satellite-tagged in 1999 and 2000 in Cook Inlet, Alaska. The seasonal movements and dive patterns of three whales CI-9901, CI-0001, and CI-0002 were analyzed, and movement data from the whales tagged in 2000 were referenced to in a subsequent paper by Hobbs et al. (2005). However, the detailed analyses of diving behavior and movement patterns of these individual whales were never made available until now. The seasonal movements and dive patterns of three belugas in Cook Inlet, Alaska, were monitored between June and January 1999-2000 using satellite telemetry. One adult male whale was tagged on 30 May 1999 and tracked until 16 September 1999 (109 days), and one juvenile female and one adult male were tagged on 13 September 2000 and tracked until 2 (115 days) and 18 January 2001 (124 days), respectively. Whales remained in the inlet the entire time they were tracked. Mean dive depths across the entire tracking period ranged from 2.6 m (SD = 5.2) to 5.2 m (SD = 8.8). Mean dive durations ranged from 1.4 minutes (SD = 2.0) to 3.1 minutes (SD = 4.1). Overall mean time at surface (between 0 and 1 m) ranged from 23% to 70% and appeared to be related to season and location. Behavioral periods were identified for each whale (4-60 days) based on stationary movements in a particular part of the inlet and unique diving behavior during that time. Significant differences were found between diving behavior and tidal rate of change and direction, as well as whale location and average sea-ice concentration. Belugas in Cook Inlet display seasonal variation in dive behavior and movement patterns, both of which have implications for sightings rates, correction factors, and abundance estimates obtained for the population. [doi:10.7289/V5AFSC-PR-2017-08 (https://doi.org/10.7289/V5/AFSC-PR-2017-08)].
Author: Hans Slabbekoorn Publisher: Springer ISBN: 1493985744 Category : Medical Languages : en Pages : 322
Book Description
Over the past several years, many investigators interested in the effects of man-made sounds on animals have come to realize that there is much to gain from studying the broader literature on hearing sound and the effects of sound as well as data from the effects on humans. It has also become clear that knowledge of the effects of sound on one group of animals (e.g., birds or frogs) can guide studies on other groups (e.g., marine mammals or fishes) and that a review of all such studies together would be very useful to get a better understanding of the general principles and underlying cochlear and cognitive mechanisms that explain damage, disturbance, and deterrence across taxa. The purpose of this volume, then, is to provide a comprehensive review of the effects of man-made sounds on animals, with the goal of fulfilling two major needs. First, it was thought to be important to bring together data on sound and bioacoustics that have implications across all taxa (including humans) so that such information is generally available to the community of scholars interested in the effects of sound. This is done in Chaps. 2-5. Second, in Chaps. 6-10, the volume brings together what is known about the effects of sound on diverse vertebrate taxa so that investigators with interests in specific groups can learn from the data and experimental approaches from other species. Put another way, having an overview of the similarities and discrepancies among various animal groups and insight into the “how and why” will benefit the overall conceptual understanding, applications in society, and all future research.
Author: Roderick C. Hobbs
Author: Roderick C. Hobbs
Author: Alaska Fisheries Science Center Nationa
Author: Donald J. Hansen
Author: 
Author: Kim E. W. Shelden
Author: Kim E. W. Shelden
Author: Kristin L. Laidre
Author: 
Author: Kimberly T. Goetz
Author: Hans Slabbekoorn