Download or read book Stable Isotope Dichotomy in Loggerhead Turtles Reveals Pacific Atlantic Oceanographic Differences written by Mariela E. Pajuelo and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Denitrification and nitrogen fixation processes in the marine environment have been intensively studied, particularly how these processes affect the delta 15N signature of inorganic nutrients and organisms at the base of the food web. The assumption that these delta 15N differences at the base of food webs are reflected in higher trophic level organisms, however, has been neglected. In this study, I evaluated whether an ocean basin delta 15N dichotomy was evident in oceanic juvenile loggerhead turtles (Caretta caretta) by analyzing their stable isotope signatures in both the Pacific and Atlantic oceans. Skin samples from oceanic juvenile loggerheads were collected from Peruvian waters in the southeast Pacific and from waters around the Azores Archipelago in the northeast Atlantic and analyzed for delta 15N and delta 13C. Results that turtles in the two ocean regions have delta 13C signatures from -16.3 to - 16.7\U+2030\ reflect the oceanic feeding behavior of these loggerhead populations. The delta 15N signatures in Pacific loggerheads are consistently higher (17.1 ± 0.9\U+2030\) than those of Atlantic loggerheads (7.6 ± 0.5\U+2030\). This inter-ocean difference in delta 15N values was also observed in organisms at the base of the food web in the two study areas. The characteristic predominant process of the nitrogen cycle in each ocean region, which has an effect on the nitrogen composition at the base of the food web, is subsequently transferred to higher trophic levels. Stable isotope signatures in high trophic level organisms, such as oceanic sea turtles, can reveal differences in oceanographic processes.
Download or read book Proceedings of the Twenty ninth Annual Symposium on Sea Turtle Biology and Conservation written by and published by . This book was released on 2012 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Food webs and stable isotopes volume II written by Jason Newton and published by Frontiers Media SA. This book was released on 2023-09-29 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sea Turtles of the Eastern Pacific written by Jeffrey A. Seminoff and published by University of Arizona Press. This book was released on 2021-11-09 with total page 425 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sea turtles are flagship species for the world's oceans. They traverse international boundaries during their migrations, serve as vehicles for marine nutrients to terrestrial habitats, and embody the often tenuous relationship between human action and ecosystem health. The East Pacific Ocean is home to some of the most dynamic marine ecosystems, and the most unique sea turtles. Marine biodiversity within this massive ocean region abounds in mangrove estuaries, seagrass pastures, coral reefs, the open ocean, and many other habitats, with sea turtles often the most conspicuous species present. The distinctive traits of the Eastern Pacific have resulted in the smallest leatherbacks, a singular morph of the green turtle, dark and steeply domed olive ridleys, and the most cryptic hawksbills on the planet. Only now are we beginning to understand how these varieties have evolved. However, the oceanographic conditions that make this an epicenter of sea turtle activity also promote massive artisanal and industrial fishing efforts that, coupled with illegal harvesting of eggs and turtles, have led to declines of several turtle populations in the region. The essays and stories in Sea Turtles of the Eastern Pacific describe for the first time the history of this exploitation, as well as recent sea turtle conservation initiatives and scientific research in the region. The first third of the book considers the biology of the turtles, focusing on general overviews of current ecological management challenges facing the turtles' survival. The second third treats issues of marine policy related to turtle conservation. In conclusion, the book offers six compelling stories of conservation success. By the end, readers will have gained a in-depth view not only of these magnificent creatures, but also the people involved in research and conservation efforts in one of the most remarkable regions of our planet.
Download or read book Tracking Turtles Back in Time written by Calandra N. Turner Tomaszewicz and published by . This book was released on 2016 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: Of the five species of sea turtles that inhabit the east Pacific Ocean, two, the North Pacific loggerhead (Caretta caretta) and East Pacific green turtle (Chelonia mydas), experience some of the highest rates of globally documented mortality in a productive foraging hotspot near the Baja California Peninsula (BCP), Mexico. This area, the Gulf of Ulloa, overlaps with high levels of fishing, resulting in thousands of dead turtles, many that wash up on the beach of Playa San Lázaro on the BCP. It is unknown how long loggerheads inhabit distinct regions of the North Pacific, and to what degree juvenile individuals in the population demonstrate variation in their life history patterns. Similarly, it is unknown how long green turtles occupy oceanic regions of the eastern Pacific before settling into more nearshore habitats, or how they use the Gulf of Ulloa. My research determined the residency duration at different foraging grounds within the eastern Pacific, as well as basic demographic information such as age-at-settlement, age-at-maturation, and timing of ontogenetic shifts, for these two endangered sea turtle populations. By determining life history parameters and the length of time individuals in these populations spend in distinct high-risk habitats, managers can better understand exposure to spatially explicit threats and prioritize conservation approaches. I focused particularly on duration of time spent in the high-bycatch waters of the Gulf of Ulloa. To this end, I developed a novel technique that combined skeletochronology (the study of growth and age increments in bones) with sequential stable carbon ([delta]13C) and nitrogen ([delta]15N) isotope analysis of humerus bone growth layers. Naturally occurring stable isotope gradients exist in ocean systems such that habitats and foraging behaviors can be distinguished (i.e. nearshore vs. offshore habitats or high vs. low trophic levels). Given these isotope gradients, the combination of skeletochronology with stable isotope analysis of sequentially sampled growth layers provides a multi-year record of location, diet, size, age, and annual growth of individual turtles, allowing the reconstruction of life history and long-term habitat use patterns. The combination of these techniques allowed me to address questions that could not be answered using either technique alone.
Download or read book Pinacoteca Vaticana written by and published by . This book was released on 1900 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Leatherback Turtle written by James R. Spotila and published by JHU Press. This book was released on 2015-10-30 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most comprehensive book ever written on leatherback sea turtles. Weighing as much as 2,000 pounds and reaching lengths of over seven feet, leatherback turtles are the world’s largest reptile. These unusual sea turtles have a thick, pliable shell that helps them to withstand great depths—they can swim more than one thousand meters below the surface in search of food. And what food source sustains these goliaths? Their diet consists almost exclusively of jellyfish, a meal they crisscross the oceans to find. Leatherbacks have been declining in recent decades, and some predict they will be gone by the end of this century. Why? Because of two primary factors: human redevelopment of nesting beaches and commercial fishing. There are only twenty-nine index beaches in the world where these turtles nest, and there is immense pressure to develop most of them into homes or resorts. At the same time, longline and gill net fisheries continue to overwhelm waters frequented by leatherbacks. In The Leatherback Turtle, James R. Spotila and Pilar Santidrián Tomillo bring together the world’s leading experts to produce a volume that reveals the biology of the leatherback while putting a spotlight on the conservation problems and solutions related to the species. The book leaves us with options: embark on the conservation strategy laid out within its pages and save one of nature’s most splendid creations, or watch yet another magnificent species disappear.
Download or read book Sequential Isotopic Analysis to Characterize Ontogenetic Shifts and Growth Dynamics of Loggerhead Sea Turtles Caretta Caretta written by Matthew D. Ramirez and published by . This book was released on 2015 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ontogenetic niche theory predicts that as organisms grow they make size-specific changes in habitat use and diet to optimize growth and survival. A variety of factors contribute to growth and survival in different habitats, ultimately leading to variation in life history that can affect population dynamics. An understanding of the variation in timing of habitat shifts and fidelity to those habitats is critical for population dynamics modeling and evaluation of conservation strategies, especially for species whose population vital rates are sensitive to changes in growth and survival of critical life stages, such as the loggerhead sea turtle (Caretta caretta). Isotopic analysis of sequentially deposited structures, such as sea turtle humerus bone, provides a means of studying intraspecific life history variation. I sequentially analyzed the annual humerus bone growth increments of 84 juvenile loggerhead sea turtles for stable isotopes ([delta]13C, [delta]15N) to reconstruct the diet and habitat use histories of turtles undergoing an oceanic-to-neritic ontogenetic shift. I also used skeletochronological methods to evaluate the growth dynamics surrounding this transition. Generated isotopic transects were used to classify individuals into alternative life history pattern groups and were combined with body size and growth data obtained from skeletal analyses to evaluate differences in the duration, timing, and growth dynamics of ontogenetic shifts. Sea turtles that displayed increases in nitrogen stable isotope ratios ([delta]15N) greater than 3.0[per mille] over one or more years were presumed to have transitioned from oceanic to neritic diets and/or habitats based on oceanic and neritic prey isotopic information collected from the literature, and were classified into one of two life history pattern groups: discrete shifters (n = 23) completed this transition within year, while facultative shifters (n = 16) completed this transition in up to eight years. As differences in isotopic values between neritic and oceanic prey are most likely driven by differences in isotopic baselines, I propose the gradual increases in [delta]15N values within facultative shifters over multiple years is indicative of foraging in both oceanic and neritic habitats within growth years. Size-at-transition between habitats was similar between discrete shifters (55.1 ± 7.6 cm straightline carapace length, SCL) and facultative shifters (52.8 ± 6.9 cm SCL). Growth variance was higher for facultative shifters versus discrete shifters. Yet, mean size at transition, size-at-age relationships, and mean increment-specific growth rates were similar between turtles with alternative life history patterns. Annual growth rates generally peaked within one year of transition (31/38 of turtles), providing support for a short-term (i.e., 1-2 year) ontogenetic shift-associated growth advantage. However, there was considerable variation in the timing of maximal growth rate among turtles with some individuals exhibiting maximal growth in years prior to the ontogenetic shift (14/38 turtles). The lack of substantial differences in the timing of transition and growth dynamics between discrete and facultative shifters likely limits the influence of these alternative life history patterns on time to sexual maturity in this species, though differences in habitat-specific survival probabilities could affect loggerhead population dynamics. This study demonstrates the value of paired isotopic and skeletal analyses to the study of long-term sea turtle life history variation and its affect on growth.
Download or read book Loggerhead Sea Turtles written by Alan E. Bolton and published by Smithsonian Institution. This book was released on 2019-08-06 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sea turtles have been the focus of research and intense conservation efforts for decades and the Loggerhead Sea Turtle, currently listed as a threatened species, is arguably one of the best studied of the seven species. Loggerhead Sea Turtles brings together, for the first time, international experts to synthesize the knowledge of Loggerhead biology and conservation and sets the stage for future ecological, biological, and conservation research. Highly detailed coverage includes diet, growth, nesting, migration, habitat selection, and conservation.
Download or read book Marine epibioses written by Roksana Majewska and published by Frontiers Media SA. This book was released on 2023-07-31 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Stable Isotopes to Determine Foraging Areas of Leatherback Sea Turtles written by Sharon Shu and published by . This book was released on 2020 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Isoscapes written by Jason B. West and published by Springer Science & Business Media. This book was released on 2009-11-25 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stable isotope ratio variation in natural systems reflects the dynamics of Earth systems processes and imparts isotope labels to Earth materials. Carbon isotope ratios of atmospheric CO2 record exchange of carbon between the biosphere and the atmosphere; the incredible journeys of migrating monarchs is documented by hydrogen isotopes in their wings; and water carries an isotopic record of its source and history as it traverses the atmosphere and land surface. Through these and many other examples, improved understanding of spatio-temporal isotopic variation in Earth systems is leading to innovative new approaches to scientific problem-solving. This volume provides a comprehensive overview of the theory, methods, and applications that are enabling new disciplinary and cross-disciplinary advances through the study of "isoscapes": isotopic landscapes. "This impressive new volume shows scientists deciphering and using the natural isotope landscapes that subtly adorn our spaceship Earth.", Brian Fry, Coastal Ecology Institute, Louisiana State University, USA "An excellent timely must read and must-have reference book for anybody interested or engaged in applying stable isotope signatures to questions in e.g. Anthropology, Biogeochemistry, Ecology, or Forensic Science regarding chronological and spatial movement, changes, or distribution relating to animals, humans, plants, or water.", Wolfram Meier-Augenstein, Centre for Anatomy & Human Identification, University of Dundee, UK "Natural resources are being affected by global change, but exactly where, how, and at what pace? Isoscapes provide new and remarkably precise answers.", John Hayes, Woods Hole Oceanographic Institution, USA "This exciting volume is shaping a new landscape in environmental sciences that is utilizing the remarkable advances in isotope research to enhance and extend the capabilities of the field.", Dan Yakir, Weizmann Institute of Science, Israel
Download or read book Sea turtles in the Mediterranean Distribution threats and conservation priorities written by Paolo Casale and published by IUCN. This book was released on 2010 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Biology of Sea Turtles Volume II written by Peter L. Lutz and published by CRC Press. This book was released on 2002-12-17 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: The success of the first volume of The Biology of Sea Turtles revealed a need for broad but comprehensive reviews of major recent advances in sea turtle biology. Biology of Sea Turtles, Volume II emphasizes practical aspects of biology that relate to sea turtle management and to changes in marine and coastal ecosystems. These topics i
Download or read book The Biology of Sea Turtles Volume III written by Jeanette Wyneken and published by CRC Press. This book was released on 2013-03-25 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the first volume of The Biology of Sea Turtles was published in 1997, the field has grown and matured in ways few of the authors would have predicted-particularly in the areas of physiology, behavior, genetics, and health. Volume III presents timely coverage of emerging areas as well as the integration of approaches and information that did n
Download or read book Research and Management Techniques for the Conservation of Sea Turtles written by and published by . This book was released on 1999 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Thirtieth Annual Symposium on Sea Turtle Biology and Conservation 24 30 April 2010 written by Janice Blumenthal and published by . This book was released on 2013 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: "With over 500 participants from over 60 countries, the success of the symposium was reflected in the coming together of ideas in research and lessons in conservation from a diverse range of individuals and groups, both at the local and regional/global scale. Over 400 abstracts were received and a total of 376 were presented after a careful review process by the Programme Committee, overseen by Programme Chairs Matthew Godfrey and Brendan Godley and the Programme Coordinator DuBose Griffin. The symposium was held at the Kala Academy in Panaji, Goa's renowned centre for performing arts, situated on the banks of the Mandovi River. A few workshops were also held at the Taj Vivanta Hotel situated across the road from the Kala Academy. All evening social events were held at the Cidade de Goa hotel at Va inguinim beach in Dona Paula"--Page iii
