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 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 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 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 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 Diet tissue Stable Isotope delta13C and Delta15N Discrimination Factors for Multiple Tissues from Terrestrial Reptiles rock Iguanas Cyclura Species written by Ronnie Steinitz and published by . This book was released on 2015 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trophic interactions can drive community structure; therefore, studying food webs is key in understanding ecological communities. Stable isotope analysis is a powerful tool for reconstructing foraging patterns. However, stable isotope discrimination factors (delta13C and delta15N) are needed to best use this tool. We determined the first delta13C and delta15N values for Rock Iguanas (Cyclura spp.) to better understand isotope fractionation patterns in reptiles and estimate wild reptile diets. We analyzed delta13C and delta15N values between skin, blood, and scat from juvenile and adult iguanas held for over a year on a known diet and their food. We determined relationships between size/age and discrimination factors and compared isotope values from lipid- and non-lipid-extracted tissues and from scats that were treated/untreated with HCl. The delta13C and delta15N values ranged from -2.9 to +6.20/00 and from +1.7 to +7.00/00, respectively, with some differences among tissues and between juveniles and adults. The delta13C values from blood and skin differed among species, but not delta15N values. The delta13C values from blood and skin and delta15N values from blood were positively correlated with size/age. The delta13C values from scat were negatively correlated with size (not age). Treatment with HCl (scat) and lipid extraction (skin) did not affect isotope values. Our results aid in the understanding of processes driving stable carbon and nitrogen isotope discrimination factors in reptiles. We provided estimates of delta13C and delta15N values and linear relationships between iguana size/age and discrimination factors for the best application of these values for interpreting wild reptile foraging ecology.
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 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 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 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 Blood Biochemistry and Hematology of Migrating Loggerhead Turtles Caretta Caretta in the Northwest Atlantic written by Tiffany Yang and published by . This book was released on 2018 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Blood Biochemistry of Loggerhead Sea Turtles Caretta Caretta Entangled in Longline Fishing Gear in the Western Mediterranean written by Anna Tommerdahl and published by . This book was released on 2010 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment of Organohalogen Contaminants in Benthic Juvenile Loggerhead Sea Turtles Caretta Caretta from Coastal North Carolina Including Method Development Blood Compartment Partitioning and Temporal Analysis with Emphasis on Polybrominated Diphenyl Ethers written by Brianna K. R. Carlson and published by . This book was released on 2006 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Biomarkers to Assess the Migratory Ecology and Reproduction of the Florida Green Turtle Chelonia Mydas written by Ryan Maddox Chabot and published by . This book was released on 2017 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: Migratory connectivity between breeding and foraging areas is a vital component of the ecology of a diverse collection of marine vertebrates. Habitat quality, composition, and resource availability at these locations have direct ramifications for individual fitness. The green turtle (Chelonia mydas) is a long-lived, highly migratory species of conservation concern. Important green turtle nesting habitat in Florida is protected, but more information is needed to identify foraging habitats and the influence these habitats have on reproduction. Here, I used stable isotope analysis of [delta]13C, [delta]15N, and [delta]34S and satellite telemetry validation to determine the number of putative foraging areas used by the breeding aggregation at the Archie Carr National Wildlife Refuge (ACNWR), and the relative contribution of each foraging area. I evaluated the influence of foraging area and other variables on egg size, clutch size, hatching success, and emerging success using model selection frameworks. Isotopic values of skin and eggs were used to build conversion equations between the two tissue types. Results suggest strong migratory connectivity between the ACNWR and the Florida Keys/Florida Bay complex. I found that the influences of foraging area are likely to be more detectable when evaluating female-centric fitness metrics like clutch size and egg size; these influences are more muted in hatching and emerging success, which are strongly influenced by nest incubation conditions. These are the first green turtle-specific tissue conversion equations for [delta]13C and [delta]15N, and the first [delta]34S equation for any marine turtle species. These will allow researchers to have a “common currency” between frequently collected samples to better compare results.
Download or read book Hazardous Chemicals Associated with Plastics in the Marine Environment written by Hideshige Takada and published by Springer. This book was released on 2018-10-13 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume consists of 15 chapters and focuses on hazardous chemicals, how they are associated with plastics, and their environmental risks. It includes background information on plastics and additives chemistry, and their observed or potential effects on living organisms as well as the oceanographic aspects of marine debris dispersion. The respective chapters provide insights into the sorption/desorption of chemicals in and out of plastics, the mechanisms and kinetics, but also the scale of the concentrations of chemicals found in marine debris, particularly in microplastics. The occurrence of the various chemicals is analyzed, as well as the distribution profiles of the chemicals in microplastics throughout the world’s oceans. The implications of the fact that plastics carry within them several chemicals are discussed in detail. In closing, new research topics that warrant further attention are identified. The book will appeal to all scientists who are already working or interested in starting to work on the topic of marine debris, as well as policymakers, NGOs and the broader informed public.
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.
