Download or read book Using Stable Isotopes to Study Dietary Patterns and Foraging Ground Theory in the Loggerhead Sea Turtle Caretta Caretta written by Brigid Elyse Carr and published by . This book was released on 2016 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Stable Isotope Analysis delta13C and Delta 15N of Blood and Skin from Mid Atlantic Loggerhead Sea Turtles Caretta Caretta to Understand Foraging Patterns and Fishery Interactions written by Samantha Louise Badgett and published by . This book was released on 2018 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 A Long term Dietary Analysis of Loggerhead Sea Turtles Caretta Caretta Based on Strandings from Cumberland Island Georgia written by Dale A. Youngkin and published by . This book was released on 2001 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessing Resource Use Patterns of Mediterranean Loggerhead Sea Turtles Caretta Caretta Linnaeus 1758 Through Stable Isotope Analysis written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantifying the Abundance Distribution and Behaviour of a Generalist Marine Consumer the Loggerhead Turtle in Coastal Foraging Habitat written by Jordan Alexander Thomson and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conservation of large-bodied marine taxa, many of which have undergone population declines, is often hindered by difficulty in quantifying spatiotemporal patterns of abundance. This is especially true for diving species that spend little time at the surface, and is largely responsible for gaps in our understanding of the habits of highly migratory, long-lived marine turtles in coastal foraging areas. Here, I use a variety of field and analytical techniques to study these elusive ectotherms on a foraging ground, focusing on loggerhead turtles (Caretta caretta) in Shark Bay, Western Australia. First, I combine stable isotope analysis, animal-borne video and mark-recapture data to describe loggerhead foraging ecology. Low stable isotope (13C and 15N) variance in slow-turnover tissue, particularly among large individuals, combined with evidence of a general diet and strong fidelity to a foraging location suggest that adult loggerheads in Shark Bay are foraging generalists and site specialists. While isotopic evidence of polymodal foraging has been found among females on nesting grounds, this may reflect isotopic characteristics of preferred migratory routes or foraging habitat as opposed to prey specialization within foraging areas. Subsequently, I focus on an important methodological problem in population ecology: detection probability during abundance surveys. During transects for long-diving taxa (e.g., marine turtles, beaked whales) a large proportion of the population will be missed because they are submerged, leading to 'availability bias' in count data. I collected dive data for loggerhead and green turtles (Chelonia mydas) and demonstrated that dive-surfacing patterns were highly heterogeneous and correlated with water temperature and habitat depth. Current approaches do not incorporate diving variability, without which abundance indices can be biased and spatiotemporal comparisons unreliable. For example, in seasonal environments marine turtle counts often decrease in colder months. Usually interpreted as emigration, this may also reflect reduced availability (extended dive times), leading to misinterpretation of local population dynamics. Finally, Bayesian methods of incorporating diving variability are applied to survey data, revealing that seasonality, habitat depth and regional characteristics drive variation in loggerhead distribution. Loggerhead density was stable over ten years, and the foraging population in Shark Bay may be substantially larger than believed.
Download or read book Life History and Environmental Requirements of Loggerhead Turtles written by David A. Nelson and published by . This book was released on 1988 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Life History and Environmental Requirements of Loggerhead Turtles written by David Arthur Nelson and published by . This book was released on 1988 with total page 48 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 Stable Delta 13 Carbon and Delta 15 Nitrogen Isotope Values from Nesting Leatherback Sea Turtles in Florida and Effects of Preservatives on Stable Delta 13 Carbon and Delta 15 Nitrogen Isotope Analyses written by Lindy Michelle Barrow and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In my study, epidermis tissue from two green sea turtle (Chelonia mydas), two loggerhead sea turtles (Caretta caretta), and two red-eared slider turtles (Trachemys scripta elegans) were subjected to 4 methods of preservation: dried at 60°C for 24 h (the control), placed in 70% ethanol solution, placed in saturated NaCl (sodium chloride) aqueous solution, frozen at -10 degrees C in a frost-free freezer, and placed in DMSO (dimethyl sulfoxide) buffer (250 mM EDTA (ethylenediaminetetraacetic acid) pH 7.5; 20% DMSO). In this study, I found that tissues preserved in 70% ethanol and NaCl aqueous solution showed no significant difference from tissues dried at 60°C. Therefore, the stable isotope ratios obtained from the leatherback epidermis tissue preserved in 70% ethanol from the first portion of my thesis should be reliable. However, I also found that samples preserved in DMSO were significantly altered from the dried samples. Samples that have been preserved using DMSO are not ideal for use in stable isotope analysis. The freezing preservation only showed a significant change in isotopic ratios at 60 days. I believe this difference was due to the use of a frost-free freezer in this experiment and that the effects seen in this study could be corrected by using a different type of freezer.
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 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 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 Migratory Connectivity and Carry over Effects in Northwest Atlantic Loggerhead Turtles Caretta Caretta L written by Simona A. Ceriani and published by . This book was released on 2014 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Migration is a widespread and complex phenomenon in nature that has fascinated humans for centuries. Connectivity among populations influences their demographics, genetic structure and response to environmental change. Here, I used the loggerhead turtle (Caretta caretta, L.) as a study organism to address questions related to migratory connectivity and carry-over effects using satellite telemetry, stable isotope analysis and GIS interpolation methods. Telemetry identified foraging areas previously overlooked for loggerheads nesting in Florida. Next, I validated and evaluated the efficacy of intrinsic markers as a complementary and low cost tool to assign loggerhead foraging regions in the Northwest Atlantic Ocean (NWA), using both a spatially implicit and spatially explicit (isoscapes) approach. I then focused on the nesting beaches and developed a common currency for isotopic studies based on unhatched eggs, which provide a non-invasive and non-destructive method for more extensive sampling to elucidate isotopic patterns across broader spatiotemporal scales. Lastly, I found that intra-population variations in foraging strategies affect annual and long-term reproductive output of loggerheads nesting in Florida. Understanding geospatial linkages is critical to the fostering of appropriate management and conservation strategies for migratory species. My multi-faceted approach contributes to the growing body of literature exploring migratory connectivity and carry-over effects.
Download or read book Jellyfish Blooms New Problems and Solutions written by Jennifer E. Purcell and published by Springer. This book was released on 2014-11-06 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides an identification key for the ephyrae of 18 common scyphozoan species, documents the Mediterranean-wide bloom of the invasive ctenophore Mnemiopsis leidyi, and addresses the direct effects of ocean acidification on jellyfish.
Download or read book Development and Extinction of Food Preferences in the Loggerhead Sea Turtle Caretta Caretta written by Mark Allen Grassman and published by . This book was released on 1982 with total page 969 pages. Available in PDF, EPUB and Kindle. Book excerpt:
