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:

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.

Download or read book Global Coverage of Cetacean Line transect Surveys Status Quo Data Gaps and Future Challenges written by Kristin Kaschner and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ichthyoplankton and Station Data for California Cooperative Oceanic Fisheries Investigations Survey Cruises in 1999 written by and published by . This book was released on 2001 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ichthyoplankton and Station Data for California Cooperative Oceanic Fisheries Investigations Survey Cruises in 2000 written by and published by . This book was released on 2001 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ichthyoplankton and Station Data for Manta surface Tows Taken on California Cooperative Oceanic Fisheries Investigations Survey Cruises in 1977 and 1978 written by and published by . This book was released on 2001 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Assessment Approaches to Support Bycatch Management for Marine Mammals written by Tessa Francis and published by Frontiers Media SA. This book was released on 2022-06-21 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Density and Spatial Distribution Patterns of Cetaceans in the Central North Pacific Based on Habitat Models written by Elizabeth Ann Becker and published by . This book was released on 2012 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Habitat-based density models were developed for cetaceans in the Central North Pacific based on cetacean survey data collected by the Southwest Fisheries Science Center in 1997- 2006. Cetacean sighting data were collected on systematic line-transect surveys in the temperate eastern Pacific, around Hawaii and other Pacific Islands, and in the eastern tropical Pacific west of 120 degrees longitude. Habitat variables, derived from satellite data, included sea surface temperature, sea surface chlorophyll, sea surface height root-mean-square, primary productivity, distance to land, latitude, and longitude. Models were developed for the pantropical spotted dolphin, spinner dolphin, striped dolphin, rough-toothed dolphin, common bottlenose dolphin, false killer whale, short-finned pilot whale, sperm whale, Bryde's whale, and an 'other dolphins' group that included the short-beaked common and Pacific white-sided dolphin. Uniform densities were estimated for species/guilds that had insufficient sightings for modeling, including pygmy killer whale, Risso's dolphin, killer whale, a small beaked whale guild (including Cuvier's beaked whale and beaked whales of the genus Mesoplodon), and pygmy/dwarf sperm whale. Although validation using an independent survey was not possible, modeled density estimates for the 10 species/species group were compared to previously published line-transect density estimates derived within the U.S. Exclusive Economic Zone around Hawaii. The modelbased estimates of abundance fall within the 95% confidence limits of the standard line-transect analyses, and they provide greater spatial resolution of the density estimates based on habitat associations. These new models are intended as baseline density estimates for Navy planning and environmental impact statements, to be updated and improved as additional survey data become available in the future"--Abstract.

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.

Download or read book Ecological and behavioral traits of apex predators in oceanic insular ecosystems Advances and challenges in research and conservation written by Filipe Alves and published by Frontiers Media SA. This book was released on 2023-09-07 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Marine Mammal Ecology and Conservation written by Ian L. Boyd and published by Oxford University Press. This book was released on 2010-08-12 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: Much of our knowledge about marine mammals is derived from a long-term and dedicated research effort that is evolving rapidly due to the introduction and invention of new methods.This book reflects the inventiveness of marine researchers as they try to find ways around the problems presented to them by these unusual and challenging animals.

Download or read book Coastal Stock s of Atlantic Bottlenose Dolphin written by and published by . This book was released on 1994 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Journal of Cetacean Research and Management written by and published by . This book was released on 2008 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Distance Sampling written by S.T. Buckland and published by OUP Oxford. This book was released on 2004-08-19 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This advanced text focuses on the uses of distance sampling to estimate the density and abundance of biological populations. It addresses new methodologies, new technologies and recent developments in statistical theory and is the follow up companion to Introduction to Distance Sampling (OUP, 2001).

Download or read book Marine Mammal and Seabird Study Central and Northern California written by University of California, Santa Cruz. Center for Coastal Marine Studies and published by . This book was released on 1981 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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.

Download or read book Marine Mammal and Seabird Survey of the Southern California Bight Area written by University of California, Santa Cruz and published by . This book was released on 1978 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: