EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book Cetacean Abundance in the California Current Estimated from a 2008 Ship based Line transect Survey

Download or read book Cetacean Abundance in the California Current Estimated from a 2008 Ship based Line transect Survey written by Jay Barlow and published by . This book was released on 2010 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The abundance of most cetaceans along the US West Coast was estimated from data collected on a 2008 ship-based survey. Line-transect methods were used on the survey, and analyses were based on the multiple-covariate line-transect approach used by Barlow and Forney (2007) in their analysis of previous West Coast Surveys. Shortbeaked common dolphins, long-beaked common dolphins and Dall's porpoises were the most abundant small cetaceans with abundances of ~370,000, ~62,000 and ~30,000 (respectively). Fin whales and humpback whales were the most abundant large whales, with abundances of ~3,000 and ~1,000 (respectively). In total, abundances were estimated for 17 cetacean species plus several categories of cetaceans that could not be identified to species.

Book Changes in Cetacean Abundance in California Coastal Waters

Download or read book Changes in Cetacean Abundance in California Coastal Waters written by Jay Barlow and published by . This book was released on 1993 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Preliminary Estimates of Cetacean Abundance Off California Oregon and Washington Based on a 1996 Ship Survey and Comparisons of Passing and Closing Modes

Download or read book Preliminary Estimates of Cetacean Abundance Off California Oregon and Washington Based on a 1996 Ship Survey and Comparisons of Passing and Closing Modes written by Jay Barlow and published by . This book was released on 1997 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Visual sighting surveys on two ships in summer/fall 1996 were used to estimate the abundance of most cetaceans found within 555 km (300 nmi) of the coasts of California, Oregon, and Washington. Surveys systematically covered 14,400 km of pre-determined transect lines within this study area... The 1996 survey was conducted using two National Oceanographic and Atmospheric Administration (NOAA) research vessels... Teams of three observers searched from the flying bridge deck of both vessels using line-transect methods... Two observers searched through 25x pedestal-mounted binoculars while the third observer searched with unaided eyes and a 7x hand-held binocular..."--p.1-2.

Book Fishery Bulletin

Download or read book Fishery Bulletin written by and published by . This book was released on 2014 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Effective Strip Widths for Ship based Line transect Surveys of Cetaceans

Download or read book Effective Strip Widths for Ship based Line transect Surveys of Cetaceans written by Jay Barlow and published by . This book was released on 2011 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Effective strip width is a key parameter in estimating abundance and density from line- transect surveys. Here we estimate effective strip widths for 58 categories (genera, species, subspecies, stocks, or other groups) of cetaceans based on 13,500 sightings from 32 line-transect surveys conducted in the eastern Pacific Ocean by the Southwest Fisheries Science Center from 1991 to 2008. Generalized linear models (GLMs) are used to first identify factors that are important in determining the perpendicular sigh ting distances using stepwise model selection based on AIC. Six species groups of similar taxa are created and modeled separately. Important factors for most species groups include Beaufort sea state, swell height, visibility, group size, species, and a survey-specific categorical variable (Cruise#). Interactions between species and the other factors generally do not improve GLM fits, indicating that the effects of those factors are relatively consistent for species within a species group. Factors selected for the best-fit GLMs are included as potential covariates in a line-transect model fit to a subset of the same data, again using stepwise model selection based on AIC. The best-fit line-transect models do not include Cruise# and are generally simpler than the GLMs, likely because distant sightings were eliminated by truncation. Species-specific differences in ESW are seen within the species groups indicating that species of cetacean do differ in the distances at which they can be detected, even after accounting for the effects of group size and other covariates that affect sighting distances. Results from this analysis of multiple surveys can be used to improve estimates of effective strip widths for any survey using the same methods and similar vessels. This is especially true for seldom-seen species whose abundance is difficult to estimate from a single survey"--Abstract.

Book Identifying and Comparing Important Areas for Marine Sustainable Use and Conservation

Download or read book Identifying and Comparing Important Areas for Marine Sustainable Use and Conservation written by Sofie Van Parijs and published by Frontiers Media SA. This book was released on 2024-05-24 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ocean is under increasing threat from the expansion of human activities. The combined impacts of these threats as well as the potential impacts of climate change and ocean acidification have placed thousands of species at risk of extinction, and have impaired the structure, function, productivity and resilience of marine ecosystems. Currently, some parts of the world's oceans are significantly impacted, yet are without any form of effective management. Only a small proportion of the oceans are within protected area systems. Globally, measures are being taken to increase protection and sustainable management, but application is uncoordinated and not always effective. In order to support effective policy action by countries and competent international and regional organizations, it is critical to build a sound understanding of the most ecologically and biologically important ocean areas that support healthy marine ecosystems so that the necessary steps to ensure the long-term function and resilience of these systems can be taken.

Book Predictive Modeling of Cetacean Densities in the California Current Ecosystem Based on Summer fall Ship Surveys in 1991 208

Download or read book Predictive Modeling of Cetacean Densities in the California Current Ecosystem Based on Summer fall Ship Surveys in 1991 208 written by Elizabeth Ann Becker and published by . This book was released on 2012 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: "We use data from six ship-based cetacean and ecosystem assessment surveys in the California Current Ecosystem (CCE) to update habitat-based density models for 11 species and one small-beaked-whale guild. We previously had modeled cetacean density as a function of oceanic variables for the same 12 species/guild using data collected during four line-transect ship surveys conducted in the CCE in summer and fall of 1991, 1993, 1996, and 2001. An independent set of survey data collected in the summer and fall of 2005 was used to validate the models. These estimates were incorporated into a web-based system that allows users to estimate cetacean density within any user-defined region within the CCE study area. In this study, data from an additional line-transect survey conducted in 2008 were pooled with the 1991-2005 data and used to re-build the habitat-based density models. We also refit the 1991-2008 data to the previous 'best' models to compare model performance. The additional year of data provided increased sample sizes and a greater range of oceanic conditions for robust model development. Predicted densities for each year were smoothed and then averaged to produce a composite grid that represents our best estimate of CCE cetacean density over the past 20 years. The final model predictions were used to update the web-based system and also provided to the U.S. Navy to help assess potential impacts from their at-sea training and testing activities"--Abstract.

Book Population Abundance and Trend Estimates for Beaked Whales and Sperm Whales in the California Current from Ship based Visual Line transect Survey Data 1991 2014

Download or read book Population Abundance and Trend Estimates for Beaked Whales and Sperm Whales in the California Current from Ship based Visual Line transect Survey Data 1991 2014 written by Jeffrey E. Moore and published by . This book was released on 2017 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: For several species -- fin whale, sperm whale, and beaked whales -- Bayesian trend models were previously fit to data from six visual line-transect surveys conducted in the California Current between 1991 -- 2008. In 2014, the NOAA Southwest Fisheries Science Center conducted another, seventh, comparable line-transect survey: the California Current Cetacean and Ecosystem Assessment Survey (CalCurCEAS). Updated trend estimates incorporating the new survey data have been published for fin whales but not yet for beaked whales or sperm whales. Here, new trend model estimates (of population trend and abundance) are presented for beaked whales and sperm whales. There is little evidence of trends in overall sperm whale abundance, but the new analysis supports prior evidence for an increasing number of sperm whales that occur in small groups (presumed to be adult or near-adult males). Cuvier’s beaked whales appear to have decreased in abundance from high values in 1991-93, but that decline now appears to have leveled off. There is some weak evidence of an increasing trend in Baird’s beaked whales. Mesoplodon beaked whales showed markedly higher abundance in 2014, reversing a declining trend from 1991-2008 that had been noted in a previous analysis. The increase may have be driven by an influx of tropical species of Mesoplodon during the unusually warm ocean conditions in 2014. [doi:10.7289/V5/TM-SWFSC-585(http://doi.org/10.7289/V5/TM-SWFSC-585)]

Book Cetacean Abundance Estimates in US Northwestern Atlantic Ocean Waters from Summer 2011 Line Transect Survey

Download or read book Cetacean Abundance Estimates in US Northwestern Atlantic Ocean Waters from Summer 2011 Line Transect Survey written by Debra L. Palka and published by . This book was released on 2012 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: "As part of the AMAPPS (Atlantic Marine Assessment Program for Protected Species) project, the Northeast Fisheries Science Center (NEFSC) and Southeast Fisheries Science Center (SEFSC) of NOAA Fisheries Service conducted line-transect aerial and shipboard abundance surveys to estimate the abundance of cetaceans and sea turtles in the northwestern Atlantic Ocean during Jun - Aug 2011. This manuscript focuses on abundance estimates of cetaceans detected during the NEFSC surveys that covered waters from North Carolina to the lower Bay of Fundy, from the shore to the Gulf Stream, which is about 370 km (200 nmi) offshore. In a study area of about 463,000 km2, over 9100 km of track lines were covered. To estimate abundance the two-independent team data-collection method and the mark-recapture distance sampling (MRDS) and multiple covariate distance sampling (MCDS) analysis methods were used. Overall, approximately 342,000 cetaceans of 18 species were estimated to be present in the study area. Species specific abundance estimates for the surveyed area range from 300 - 400 sei whales (Balaenoptera borealis) and humpback whales (Megaptera novaeangliae) each, to over 40,000 animals per species of harbor porpoises (Phocoena phocoena), Atlantic white-sided dolphins (Lagenorhynchus acutus), striped dolphins (Stenella coeruleoalba) and short-beaked common dolphins (Delphinus delphis). The abundance estimates of species that also reside south of the NEFSC survey area will be updated when the SEFSC abundance estimates are available"--Abstract.

Book Cetacean Survey Line transect Verification and Management

Download or read book Cetacean Survey Line transect Verification and Management written by Alan Robert Jackson and published by . This book was released on 2001 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Line transect Abundance Estimates of Cetaceans in U S Waters Around the Hawaiian Islands in 2002 2010 and 2017

Download or read book Line transect Abundance Estimates of Cetaceans in U S Waters Around the Hawaiian Islands in 2002 2010 and 2017 written by Amanda L. Bradford and published by . This book was released on 2021 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Cetaceans of Central and Northern California 1980 1983

Download or read book Cetaceans of Central and Northern California 1980 1983 written by Thomas P. Dohl and published by . This book was released on 1983 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: