Download or read book Interpreting Sea Turtle Trophic Ecology Through Stable Isotope Analysis written by Hannah Vander Zanden and published by . This book was released on 2012 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: Together, this research aids in understanding the trophic ecology of these species. Information on where and what sea turtles eat is critical to protecting the areas they use most and for assessing the risk of encountering anthropogenic threats such incidental capture in fisheries or oil spills.
Download or read book Stable Isotope Ecology written by Brian Fry and published by Springer Science & Business Media. This book was released on 2007-01-15 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: A solid introduction to stable isotopes that can also be used as an instructive review for more experienced researchers and professionals. The book approaches the use of isotopes from the perspective of ecological and biological research, but its concepts can be applied within other disciplines. A novel, step-by-step spreadsheet modeling approach is also presented for circulating tracers in any ecological system, including any favorite system an ecologist might dream up while sitting at a computer. The author’s humorous and lighthearted style painlessly imparts the principles of isotope ecology. The online material contains color illustrations, spreadsheet models, technical appendices, and problems and answers.
Download or read book Temporal Variability in the Stable Carbon and Nitrogen Isotope Values from Common Mid trophic Level Species in the Bering Sea written by Andrea Kelsey Liu and published by . This book was released on 2017 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analyzing stable isotope values from the tissues of marine consumers is useful for reconstructing animal trophic ecology and movement patterns. However, interpretation of isotopic values from predators can be confounded by variability in the stable isotope values of their prey species, which differ spatially and temporally. Some factors affecting stable isotope values include environmental conditions, nitrogen cycling, primary production at the base of the food web, and trophic interactions. Understanding the potential for isotopic variation in common prey species for top predators is necessary for the best use of stable isotope analysis in marine systems and for tracing energy through food webs. In this study, I measured the stable carbon ([delta]13C) and nitrogen ([delta]15N) isotope values in muscle tissue from common mid-trophic level fish and squid species in the eastern Bering Sea over two years to compare values across years and size/age classes. I found interannual changes in the [delta]15N and [delta]13C values between 2014 and 2016 in atka mackerel, Pacific herring, sockeye salmon, squid, and walleye pollock, and variation in the [delta]13C and [delta]15N values across age/size classes in Pacific herring, sockeye salmon, and walleye pollock. I compared my data to those collected from the same size class fish in the Bering Sea in 1997 and found increases in the [delta]15N and decreases in the [delta]13C values consistent with expectations from higher ocean temperatures in 2016 and continued increased inputs of anthropogenic, isotopically light carbon.
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 Foraging Ecology of Green Turtles Chelonia Mydas on the Texas Coast as Determined by Stable Isotope Analysis written by Catherine Concetta Theresa Gorga and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The green turtle, Chelonia mydas, is a circumglobal species that exhibits several important developmental or ontogenetic shifts throughout its life history. The first major shift occurs when juvenile turtles migrate from pelagic habitat, where they forage as omnivores, to coastal neritic habitat, where they become primarily herbivores, foraging on algae and seagrass. Anecdotal evidence and gut-content analyses suggest that juvenile green turtles in south Texas bays, such as the lower Laguna Madre and Aransas Bay, undergo an additional ontogenetic shift during this important life history stage. Evidence from stable isotope analysis (SIA) of scute tissues of green turtles from Texas' lower Laguna Madre and Aransas Bay supports an intermediate stage between this species' shift from pelagic waters to seagrass beds in neritic waters; this additional shift comprises an initial recruitment of post-pelagic juveniles to jetty habitat located on the channel passes Gulf-ward of adjacent bays before subsequently recruiting to seagrass beds in these bays. Examination of stable carbon ([delta]13C) and nitrogen ([delta]15N) isotopes in microlayers of scute tissue from several size classes of green turtles from the lower Laguna Madre and Aransas Bay was used to confirm the occurrence of two ontogenetic shifts. Smaller green turtles (35 cm SCL) exhibited more depleted [delta]13C signatures and more enriched [delta]15N signatures, consistent with jetty habitat, compared to those of larger counterparts ( 45 cm SCL) that displayed enriched [delta]13C signatures and depleted 15N signatures, consistent with seagrass habitat. Changes in the isotopic composition between these size classes indicate distinct shifts in diet. Post-pelagic juveniles first recruit to jetty habitat and forage primarily on algae, before subsequently shifting to seagrass beds and foraging primarily on seagrass. These findings indicate the use of a characteristic sequence of distinct habitats by multiple life history stages of green turtles in Texas bays, a conclusion with broad management implications for this endangered species.
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 The Biology of Sea Turtles written by Jeanette Wyneken and published by CRC Press. This book was released on 2013-03-25 with total page 479 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 not exist even a decade ago. The book assembles the foremost experts in each topic to provide the most up-to-date and comprehensive book on sea turtles available today. New areas covered include in vivo imaging of structure, spatial distributions of marine turtles at sea, epibiosis, imprinting, parasitology, and climatic effects. Life history is explored in three chapters covering age determination, predator-prey interactions, and mortality from bycatch. The Biology of Sea Turtles, Volume III will inspire scientists and students to explore and expand their understanding of these intriguing animals. The book provides clear baseline summaries, thoughtful syntheses, and effective presentation of the most fundamental topics spanning form and function, health, distributions, behavior, genetics, evolution, and ecology. Its scope and depth make it the definitive go-to reference in the field.
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 Diet Characterization in Immature Neritic Green Turtles Chelonia Mydas Using Gut Contents and Stable Isotope Analyses written by Natalie Christine Williams and published by . This book was released on 2012 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent developments in open water research have refined our understanding of green turtle, Chelonia mydas, foraging ecology, but diet characterization among populations remains understudied. Previous hypotheses state that once young green turtles recruit to shallow water habitat they shift rapidly from an omnivorous to herbivorous diet. Supporting evidence has primarily been derived from traditional gut content analysis that only provides a small window in time to perceive the diet of an animal. In contrast, stable isotope analysis explore show a consumer uses its resources over a broad temporal scale. We tested the dietary shift hypothesis using gut content and stable isotope analyses to assess the nutritional ecology of a juvenile green turtle aggregation in the northern Gulf of Mexico. We examined the gut contents of 65 green turtles collected from 2008 and 2011 hypothermic stunning events in St. Joseph Bay, Florida. Gut contents were evaluated using volume, dry mass, percent frequency of occurrence, and index of relative importance (IRI). Juvenile green turtles showed omnivorous feeding behavior, feeding on a variety of animal and vegetal items with a bias towards seagrass and tunicates. In addition, we evaluated feeding consistency by stable isotope patterns from epidermis tissue. We measured the stable carbon (delta13C)and nitrogen (delta15N)isotope values in epidermis of 43 green turtles, ranging from 22.5 to 72.7cm in curved carapace length (CCLmin), and eight known prey items (e.g., algae, seagrasses, invertebrates) collected in 2011. Our study provides a foundation for characterizing the foraging ecology of green turtles in St. Joseph Bay and highlights the value of utilizing isotopic ecology for further foraging studies.
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 Advances in the Biology and Conservation of Marine Turtles written by Sara M. Maxwell and published by Frontiers Media SA. This book was released on 2019-05-15 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Twenty eighth Annual Symposium on Sea Turtle Biology and Conservation written by and published by . This book was released on 2010 with total page 316 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 Tracking Animal Migration with Stable Isotopes written by and published by Academic Press. This book was released on 2008-04-09 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tracking Animal Migration with Stable Isotopes provides a consolidated overview of the current knowledge of stable isotopes in terrestrial migration research questions. It offers ecologists and conservation biologists provide a practical handbook for those considering using stable isotopes in their migration research. - Presents information for readers to understand how to apply isotopic methods for tracking - Critical information on areas for future research - Practical guidelines and discussions of sample collection, sample preparation, and data analysis - Enhanced understanding of data and statistical analysis in isotope-based studies of migratory animals
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 Stable Isotope Approach to Trophic Ecology written by Jaclyn Marie Hill and published by . This book was released on 2007 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment of Sea Turtle Status and Trends written by National Research Council and published by National Academies Press. This book was released on 2010-10-07 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: All six species of sea turtles found in U.S. waters are listed as endangered or threatened, but the exact population sizes of these species are unknown due to a lack of key information regarding birth and survival rates. The U.S. Endangered Species Act prohibits the hunting of sea turtles and reduces incidental losses from activities such as shrimp trawling and development on beaches used for nesting. However, current monitoring does not provide enough information on sea turtle populations to evaluate the effectiveness of these protective measures. Sea Turtle Status and Trends reviews current methods for assessing sea turtle populations and finds that although counts of sea turtles are essential, more detailed information on sea turtle biology, such as survival rates and breeding patterns, is needed to predict and understand changes in populations in order to develop successful management and conservation plans.
