Plastic flipper tags are inadequate for long-term identification of the flatback sea turtle (Natator depressus)

2003 ◽  
Vol 30 (5) ◽  
pp. 519 ◽  
Author(s):  
C. J. Parmenter
Keyword(s):  
Sea Turtles ◽  
Sea Turtle ◽  
Wild Duck ◽  
Pit Tagging ◽  
Natator Depressus ◽  
Term Identification ◽  
Nesting Season

Two styles of plastic tags were used on flatback sea turtles (Natator depressus). In parallel with conventional metal flipper tagging, and internal PIT tagging methodologies, a total of 476 plastic tags were applied to 428 individual females in the 1991, 1992, 1993 and 1998 nesting seasons at Wild Duck Island, Queensland. Data are reported up to and including the 2000 nesting season demonstrating that plastic tags are inadequate for the long-term identification of these turtles, with failures of approximately 80% within three years of application.

A preliminary evaluation of the performance of passive integrated transponders and metal tags in apopulation study of the flatback sea turtle, Nataor depressus

1993 ◽  
Vol 20 (3) ◽  
pp. 375 ◽  
Author(s):  
CJ Parmeter
Keyword(s):  
Failure Rate ◽  
Sea Turtle ◽  
Loss Probability ◽  
Preliminary Evaluation ◽  
Wild Duck ◽  
Probability Estimates ◽  
Short Period ◽  
Passive Integrated Transponders ◽  
Natator Depressus

Marking of nesting female Natator depressus with passive integrated transponders (PITs) at the major eastern Australian rookery of Wild Duck I. was initiated in 1989. The failure rate of PITs after two years was calculated and compared with loss probability estimates calculated for conventional metal tags on the basis of 1979-91 data. PITs compared favourably in the short period of evaluation with an 8% loss of identification after two years (n=37). Loss of metal tags was variable between metals and tagging positions, with titanium tags applied to the axillary position of the front flippers being the most effective in the long term. Factors peculiar to this species that affect loss of metal tags and prospects of PIT performance in the long term are discussed.

scholarly journals Behavioural inference from signal processing using animal-borne multi-sensor loggers: a novel solution to extend the knowledge of sea turtle ecology

2020 ◽  
Vol 7 (5) ◽  
pp. 200139 ◽  
Author(s):  
Lorène Jeantet ◽  
Víctor Planas-Bielsa ◽  
Simon Benhamou ◽  
Sebastien Geiger ◽  
Jordan Martin ◽  
...  
Keyword(s):  
Sea Turtles ◽  
Time Budget ◽  
Natural Habitat ◽  
Sea Turtle ◽  
Automatic Identification ◽  
Detailed Knowledge ◽  
Supervised Learning Algorithms ◽  
Conservation Of Endangered Species ◽  
Free Ranging

The identification of sea turtle behaviours is a prerequisite to predicting the activities and time-budget of these animals in their natural habitat over the long term. However, this is hampered by a lack of reliable methods that enable the detection and monitoring of certain key behaviours such as feeding. This study proposes a combined approach that automatically identifies the different behaviours of free-ranging sea turtles through the use of animal-borne multi-sensor recorders (accelerometer, gyroscope and time-depth recorder), validated by animal-borne video-recorder data. We show here that the combination of supervised learning algorithms and multi-signal analysis tools can provide accurate inferences of the behaviours expressed, including feeding and scratching behaviours that are of crucial ecological interest for sea turtles. Our procedure uses multi-sensor miniaturized loggers that can be deployed on free-ranging animals with minimal disturbance. It provides an easily adaptable and replicable approach for the long-term automatic identification of the different activities and determination of time-budgets in sea turtles. This approach should also be applicable to a broad range of other species and could significantly contribute to the conservation of endangered species by providing detailed knowledge of key animal activities such as feeding, travelling and resting.

scholarly journals Influence of short-term temperature drops on sex-determination in sea turtles

2021 ◽  
Author(s):  
Ellen Porter ◽  
David T Booth ◽  
Col J Limpus
Keyword(s):  
Sex Determination ◽  
Heavy Rainfall ◽  
Incubation Temperature ◽  
Sea Turtles ◽  
Sex Ratios ◽  
Temperature Drop ◽  
Sea Turtle ◽  
Short Term ◽  
Sand Temperature

All sea turtles exhibit temperature-dependent sex-determination, where warmer temperatures produce mostly females and cooler temperatures produce mostly males. As global temperatures continue to rise, sea turtle sex-ratios have become increasingly female-biased, threatening the long-term viability of many populations. Nest temperatures are dependent on sand temperature, and heavy rainfall events reduce sand temperatures for a brief period. However, it is unknown whether these short-term temperature drops are large and long enough to produce male hatchlings. To discover if short-term temperature drops within the sex-determining period can lead to male hatchling production, we exposed green and loggerhead turtle eggs to short-term temperature drops conducted in constant temperature rooms. We dropped incubation temperature at four different times during the sex-determining period for a duration of either 3 or 7 days to mimic short-term drops in temperature caused by heavy rainfall in nature. Some male hatchlings were produced when exposed to temperature drops for as little as 3 days, but the majority of male production occurred when eggs were exposed to 7 days of lowered temperature. More male hatchlings were produced when the temperature drop occurred during the middle of the sex-determining period in green turtles, and the beginning and end of the sex-determining period in loggerhead turtles. Inter-clutch variation was evident in the proportion of male hatchlings produced, indicating that maternal and or genetic factors influence male hatchling production. Our findings have management implications for the long-term preservation of sea turtles on beaches that exhibit strongly female-biased hatchling sex-ratios.

scholarly journals Insights into the successful breeding of Hawksbill sea turtles (Eretmochelys imbricata) from a long-term captive breeding program

2020 ◽  
Author(s):  
Ruth Maggeni ◽  
William E Feeney
Keyword(s):  
Captive Breeding ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Breeding Program ◽  
Evidence Based ◽  
Trial And Error ◽  
Eretmochelys Imbricata ◽  
Captive Breeding Program ◽  
Marine Park

AbstractSea turtle populations are declining and evidence-based methods for supporting their populations are required. Captive breeding and release programs can be effective, offering the opportunity to supplement nature populations; however, sea turtles require specific conditions to successfully breed. Here, we present insights gained from a 16 year Hawksbill sea turtle (Eretmochelys imbricata) captive breeding program that was conducted at the Underwater Observatory Marine Park, Eilat, Israel, between 1982-1997. As the first program of its kind for the Hawksbill sea turtle, insights were gained largely through trial-and-error and word of mouth advice. The key insight gained during this program was the critical importance of pre-breeding separation of the sexes; turtles did not breed prior to pre-breeding separation being implemented, but it became predictably regular once it was. Over the course of the program, 161 two-three years old hatchlings were introduced to the Red Sea, which was enabled largely as a result of pre-breeding separation being implemented.

Parasitic isopods associated with sea turtles nesting in Brazil

2014 ◽  
Vol 95 (5) ◽  
pp. 973-981 ◽  
Author(s):  
José C. Rocha Júnior ◽  
Joseph B. Pfaller ◽  
Ricardo Corbetta ◽  
Luciana Veríssimo
Keyword(s):  
Sea Turtles ◽  
Sea Turtle ◽  
Olive Ridley ◽  
Quantitative Survey ◽  
Recent Emergence ◽  
Parasitic Isopods ◽  
Biological Impacts ◽  
Basic Biology ◽  
Hawksbill Turtles ◽  
Nesting Season

Studies of sea turtle epibiosis have focused on the diversity and ecology of facultative commensalisms and less attention has been given to parasitic associations, in which the epibiont species derives nutrients from the tissue of the host turtle. We present the first description and quantitative survey of the parasitic isopods Excorallana costata, Excorallana bicornis and Excorallana oculata on loggerhead (N = 79) and hawksbill turtles (N = 23), and E. costata on olive ridley turtles (N = 9), nesting on Praia do Forte, Bahia, Brazil during the 2009–2010 season. Excorallana costata was the most common isopod species (N = 651), followed by E. bicornis (N = 77) and E. oculata (N = 20). Patterns include: (1) E. costata exhibited a higher frequency and intensity of parasitism than E. bicornis and E. oculata and (2) loggerheads hosted parasitic isopods at a higher frequency and intensity than hawksbills and olive ridleys. We also detected temporal shifts in the occurrence and intensity of parasitism across the nesting season, which strongly suggests that turtles were parasitized by all three isopod species during their internesting periods. Because parasitic isopods were observed only rarely prior to the 2009–2010 turtle-nesting season and have continued to be common in subsequent seasons, it is important to gain a better understanding of the basic biology of these interactions, the reasons for their recent emergence, and the potential biological impacts on turtle, as well as isopod, populations.

scholarly journals First satellite tracks of neonate sea turtles redefine the ‘lost years’ oceanic niche

2014 ◽  
Vol 281 (1781) ◽  
pp. 20133039 ◽  
Author(s):  
Katherine L. Mansfield ◽  
Jeanette Wyneken ◽  
Warren P. Porter ◽  
Jiangang Luo
Keyword(s):  
North Atlantic ◽  
Sea Turtles ◽  
Life Stage ◽  
Sea Turtle ◽  
Sea Surface ◽  
The North ◽  
Satellite Transmitters ◽  
The North Atlantic ◽  
Solar Powered

Few at-sea behavioural data exist for oceanic-stage neonate sea turtles, a life-stage commonly referred to as the sea turtle ‘lost years’. Historically, the long-term tracking of small, fast-growing organisms in the open ocean was logistically or technologically impossible. Here, we provide the first long-term satellite tracks of neonate sea turtles. Loggerheads ( Caretta caretta ) were remotely tracked in the Atlantic Ocean using small solar-powered satellite transmitters. We show that oceanic-stage turtles (i) rarely travel in Continental Shelf waters, (ii) frequently depart the currents associated with the North Atlantic Subtropical Gyre, (iii) travel quickly when in Gyre currents, and (iv) select sea surface habitats that are likely to provide a thermal benefit or refuge to young sea turtles, supporting growth, foraging and survival. Our satellite tracks help define Atlantic loggerhead nursery grounds and early loggerhead habitat use, allowing us to re-examine sea turtle ‘lost years’ paradigms.

scholarly journals Vulnerability of sea turtles and fishes in response to two catastrophic Caribbean hurricanes, Irma and Maria

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
J. K. Matley ◽  
S. Eanes ◽  
R. S. Nemeth ◽  
P. D. Jobsis
Keyword(s):  
Prey Availability ◽  
Sea Turtles ◽  
Space Use ◽  
Sea Turtle ◽  
Virgin Islands ◽  
Extreme Weather Events ◽  
Short Term ◽  
Eretmochelys Imbricata ◽  
Us Virgin Islands

Abstract Extreme weather events (e.g., cyclones, floods, droughts) are capable of changing ecosystems and altering how animals obtain resources. Understanding the behavioural responses of animals being impacted by these natural events can help initiate and ameliorate conservation or management programs. This study investigated short- and long-term space-use of the critically endangered hawksbill sea turtle (Eretmochelys imbricata), as well as five species of fishes and stingrays, in response to two of the most destructive Caribbean hurricanes in known history – Irma and Maria, which were at their peak intensity when they passed the US Virgin Islands in September of 2017. Using passive acoustic telemetry in St. Thomas, US Virgin Islands, we show a variety of short-term behavioural patterns initiated across species to reduce exposure to the strong environmental conditions, such as moving to deeper habitats within the study area. Although short-term expansion of activity space was evident for several sea turtles, long-term impacts on space-use and body condition were limited. In contrast, southern stingrays (Hypanus americanus) left the study area shortly after the hurricanes, suggesting vulnerability stemming from altered habitat, prey availability, or temperature/oxygen profiles. This study shows the strong spatial resilience of several nearshore species despite exposure to two consecutive category 5 hurricanes.

scholarly journals Redescription of the skull of the Australian flatback sea turtle, Natator depressus, provides new morphological evidence for phylogenetic relationships among sea turtles (Chelonioidea)

2020 ◽  
Author(s):  
Ray M Chatterji ◽  
Mark N Hutchinson ◽  
Marc E H Jones
Keyword(s):  
Phylogenetic Relationships ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Molecular Data ◽  
Morphological Data ◽  
Morphological Evidence ◽  
Molecular Evidence ◽  
Crown Group ◽  
Extant Species ◽  
Natator Depressus

Abstract Chelonioidea (sea turtles) are a group where available morphological evidence for crown-group relationships are incongruent with those established using molecular data. However, morphological surveys of crown-group taxa tend to focus on a recurring subset of the extant species. The Australian flatback sea turtle, Natator depressus, is often excluded from comparisons and it is the most poorly known of the seven extant species of Chelonioidea. Previous descriptions of its skull morphology are limited and conflict. Here we describe three skulls of adult N. depressus and re-examine the phylogenetic relationships according to morphological character data. Using X-ray micro Computed Tomography we describe internal structures of the braincase and identify new phylogenetically informative characters not previously reported. Phylogenetic analysis using a Bayesian approach strongly supports a sister-group relationship between Chelonia mydas and N. depressus, a topology that was not supported by previous analyses of morphological data but one that matches the topology supported by analysis of molecular data. Our results highlight the general need to sample the morphological anatomy of crown-group taxa more thoroughly before concluding that morphological and molecular evidence are incongruous.

scholarly journals Heavy metals contaminants in the eggs and temperatures of nesting beaches of sea turtles in Kaimana, West Papua, Indonesia

2020 ◽  
Vol 21 (10) ◽  
Author(s):  
Ricardo F Tapilatu ◽  
Hengki Wona ◽  
Rima Siburian ◽  
SEFRIANTO T. SALEDA
Keyword(s):  
Heavy Metals ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Marine Turtle ◽  
Turtle Species ◽  
Turtle Conservation ◽  
West Papua ◽  
Nesting Beaches ◽  
Nesting Season

Abstract. Tapilatu RF, Wona H, Siburian RHS, Saleda ST. 2020. Heavy metals contaminants in the eggs and temperatures of nesting beaches of sea turtles in Kaimana, West Papua, Indonesia. Biodiversitas 21: 4582-4590. Etna Bay and Venu Island in Kaimana, West Papua, Indonesia are two of many areas that sea turtles use during the nesting season. Here, we report data on heavy metals contaminants from a sample of eggs of green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles collected from a subset of two nests during the 2016 nesting season at Venu Island, Kaimana, West Papua, Indonesia. Three heavy metals contaminants (i.e. mercury, cadmium, arsenic) found in eggs exceeded the established safety limits for human consumption. Other contaminants such as lead, zinc, manganese, iron, and copper were found below the established safety standards. There is an implication of the containment of heavy metals in sea turtle eggs to human health in Kaimana when it is consumed. It is highly recommended that the harvesting of turtle eggs and adults of all of sea turtles at Kaimana be totally prohibited. In addition, overall, beach temperatures in Lakahia fluctuated at a larger range between 26.5o and 33.8oC than at Venu island that fluctuated between 25.9o and 30.2oC. Mean daily temperatures of in-situ nests during the middle third of the incubation period were above the pivotal temperature of 29.0oC for temperature-dependent sex determination suggesting a female bias may already exist. The chemical contamination found in the eggs of C. mydas and E. imbricata at Venu Island is thought to assist sea turtle conservation initiatives in the area. The conservation program at the prime nesting habitat for green and hawksbill turtles on the small islands west of Kaimana such as Venu Island should be intensified to reverse the decline and increase population size of nesting sea turtle species. It is recommended that education and outreach be implemented in surrounding communities in Kaimana to raise awareness about marine turtle conservation.

scholarly journals Meiofauna Life on Loggerhead Sea Turtles-Diversely Structured Abundance and Biodiversity Hotspots That Challenge the Meiofauna Paradox

Diversity ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 203
Author(s):  
Jeroen Ingels ◽  
Yirina Valdes ◽  
Letícia P. Pontes ◽  
Alexsandra C. Silva ◽  
Patrícia F. Neres ◽  
...  
Keyword(s):  
Large Scale ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Loggerhead Sea Turtles ◽  
Geographic Ranges ◽  
Naked Eye ◽  
Higher Taxa ◽  
Nematode Diversity ◽  
Abundance And Diversity ◽  
Nesting Season

Sea turtles migrate thousands of miles annually between foraging and breeding areas, carrying dozens of epibiont species with them on their journeys. Most sea turtle epibiont studies have focused on large-sized organisms, those visible to the naked eye. Here, we report previously undocumented levels of epibiont abundance and biodiversity for loggerhead sea turtles (Caretta caretta), by focusing on the microscopic meiofauna. During the peak of the 2018 loggerhead nesting season at St. George Island, Florida, USA, we sampled all epibionts from 24 carapaces. From the subsamples, we identified 38,874 meiofauna individuals belonging to 20 higher taxa. This means 810,753 individuals were recovered in our survey, with an average of 33,781 individuals per carapace. Of 6992 identified nematodes, 111 different genera were observed. To our knowledge, such levels of sea turtle epibiont abundance and diversity have never been recorded. Loggerhead carapaces are without doubt hotspots of meiofaunal and nematode diversity, especially compared to other non-sedimentary substrates. The posterior carapace sections harbored higher diversity and evenness compared to the anterior and middle sections, suggesting increased colonization and potentially facilitation favoring posterior carapace epibiosis, or increased disturbance on the anterior and middle carapace sections. Our findings also shed new light on the meiofauna paradox: “How do small, benthic meiofauna organisms become cosmopolitan over large geographic ranges?” Considering high loggerhead epibiont colonization, the large distances loggerheads migrate for reproduction and feeding, and the evolutionary age and sheer numbers of sea turtles worldwide, potentially large-scale exchange and dispersal for meiofauna through phoresis is implied. We distinguished different groups of loggerhead carapaces based on divergent epibiont communities, suggesting distinct epibiont colonization processes. These epibiont observations hold potential for investigating loggerhead movements and, hence, their conservation.

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