The Southern Oscillation Regulates the Annual Numbers of Green Turtles (Chelonia-Mydas) Breeding Around Northern Australia

1988 ◽  
Vol 15 (2) ◽  
pp. 157 ◽  
Author(s):  
CJ Limpus ◽  
N Nicholls
Keyword(s):  
Southern Oscillation ◽  
Chelonia Mydas ◽  
Northern Australia ◽  
Biological Impact ◽  
Turtle Species ◽  
Green Turtles ◽  
Interannual Fluctuations ◽  
The Impact ◽  
The Relationship ◽  
The Tropical Pacific

The green turtle (Chelonia mydas) is one of six turtle species which breeds around northern Australia and Indonesia. The number of green turtles observed nesting varies substantially from year to year. The interannual fluctuations in the number of nesting turtles are in phase at widely separated rookeries. They are also correlated with an index of the Southern Oscillation, a coherent pattern of atmospheric pressure, temperature and rainfall fluctuations which dominates the interannual variability of the climate of the tropical Pacific. Major fluctuations in the numbers of turtles breeding occur two years after major fluctuations in the Southern Oscillation. The relationship is strong enough to be useful in predicting, two years in advance, the numbers of green turtles breeding in Great Barrier Reef rookeries. This is the first study to report a biological impact of the Southern Oscillation that allows such a long-range prediction of the impact.

scholarly journals Dietary analysis of two sympatric marine turtle species in the eastern Mediterranean

2021 ◽  
Vol 168 (6) ◽  
Author(s):  
Josie L. Palmer ◽  
Damla Beton ◽  
Burak A. Çiçek ◽  
Sophie Davey ◽  
Emily M. Duncan ◽  
...  
Keyword(s):  
Green Turtle ◽  
Eastern Mediterranean ◽  
Chelonia Mydas ◽  
Marine Turtle ◽  
Dietary Analysis ◽  
Low Frequencies ◽  
Turtle Species ◽  
Dietary Shift ◽  
Green Turtles ◽  
Loggerhead Turtles

AbstractDietary studies provide key insights into threats and changes within ecosystems and subsequent impacts on focal species. Diet is particularly challenging to study within marine environments and therefore is often poorly understood. Here, we examined the diet of stranded and bycaught loggerhead (Caretta caretta) and green turtles (Chelonia mydas) in North Cyprus (35.33° N, 33.47° E) between 2011 and 2019. A total of 129 taxa were recorded in the diet of loggerhead turtles (n = 45), which were predominantly carnivorous (on average 72.1% of dietary biomass), foraging on a large variety of invertebrates, macroalgae, seagrasses and bony fish in low frequencies. Despite this opportunistic foraging strategy, one species was particularly dominant, the sponge Chondrosia reniformis (21.5%). Consumption of this sponge decreased with increasing turtle size. A greater degree of herbivory was found in green turtles (n = 40) which predominantly consumed seagrasses and macroalgae (88.8%) with a total of 101 taxa recorded. The most dominant species was a Lessepsian invasive seagrass, Halophila stipulacea (31.1%). This is the highest percentage recorded for this species in green turtle diet in the Mediterranean thus far. With increasing turtle size, the percentage of seagrass consumed increased with a concomitant decrease in macroalgae. Seagrass was consumed year-round. Omnivory occurred in all green turtle size classes but reduced in larger turtles (> 75 cm CCL) suggesting a slow ontogenetic dietary shift. Macroplastic ingestion was more common in green (31.6% of individuals) than loggerhead turtles (5.7%). This study provides the most complete dietary list for marine turtles in the eastern Mediterranean.

The impact of fibropapillomatosis on clinical characteristics, blood gas, plasma biochemistry, and hematological profiles in juvenile green turtles ( Chelonia mydas)

2020 ◽  
Vol 96 (4) ◽  
pp. 723-734
Author(s):  
Tsung-Hsien Li ◽  
Chao-Chin Chang
Keyword(s):  
White Blood Cells ◽  
Extracellular Fluid ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Total Carbon ◽  
Blood Gas ◽  
Green Turtles ◽  
Cell Counts ◽  
Significant Difference ◽  
The Impact

Fibropapillomatosis (FP) is a tumor- forming disease that afflicts all marine turtles and is the most common in green turtles (Chelonia mydas). In this study, the morphometric characteristics, blood gas, biochemistry, and hematological profiles of 28 (6 FP-positive and 22 FP-negative) green turtles from the coast of Taiwan were investigated. The results indicated that body weight ( P < 0.001) and curved carapace length (CCL; P < 0.001) in green turtles with FP were significantly higher than in turtles without FP. Furthermore, green turtles with FP had a significantly lower value of hemoglobin (HB; P = 0.010) and packed cell volume (PCV; P = 0.005) than turtles without FP. Blood cell counts of white blood cells (WBC; P = 0.008) and lymphocytes ( P = 0.022) were observed with significant difference; green turtles with FP had lower counts than turtles without FP. In addition, turtles with FP had significantly higher pH ( P = 0.036), base excess in extracellular fluid (BEecf; P = 0.012), bicarbonate (HCO3– ; P = 0.008), and total carbon dioxide (TCO2 ; P = 0.025) values than turtles without FP. The findings of this study provide valuable clinical parameters for the medical care of the species in sea turtle rehabilitation centers and help us to understand the physiological response of green turtles to different tumor-forming conditions.

scholarly journals The nesting success of green turtles on beaches at Kazanli, Turkey

Oryx ◽  
1992 ◽  
Vol 26 (3) ◽  
pp. 165-171 ◽  
Author(s):  
Stephanie J. Coley ◽  
Andrew C. Smart
Keyword(s):  
Nest Site ◽  
Chelonia Mydas ◽  
Nesting Success ◽  
Beach Erosion ◽  
Marine Turtle ◽  
Chemical Pollution ◽  
Turtle Species ◽  
Green Turtles ◽  
Nesting Beaches ◽  
Turkish Society

The green turtle Chelonia mydas is one of two marine turtle species to nest in Turkey. Its three main nesting beaches are in eastern Turkey, with possibly the densest congregation of nesting turtles in the Mediterranean being found at Kazanli. However, beach erosion, hatchling predation, agricultural encroachment and chemical pollution mean that the future of the Kazanli nest site is uncertain. The Turkish Society for the Protection of Nature (Dogal Hayati Koruma Dernegi) is making valiant efforts to protect all the turtle nesting beaches in Turkey but lacks detailed information on the numbers of nesting turtles on many beaches. This paper describes a short study of nesting turtles at Kazanli during 1990 and makes recommendations for the conservation of the nesting beach.

Sea Turtle Navigation and the Detection of Geomagnetic Field Features

1998 ◽  
Vol 51 (1) ◽  
pp. 10-22 ◽  
Author(s):  
Kenneth J. Lohmann ◽  
Catherine M. F. Lohmann
Keyword(s):  
Chelonia Mydas ◽  
Sea Turtle ◽  
Ocean Basin ◽  
Open Ocean ◽  
Continuous Series ◽  
Turtle Species ◽  
Green Turtles ◽  
Open Sea ◽  
Circular Current ◽  
Distant Target

The lives of sea turtles consist of a continuous series of migrations. As hatchlings, the turtles swim from their natal beaches into the open sea, often taking refuge in circular current systems (gyres) that serve as moving, open-ocean nursery grounds. The juveniles of many populations subsequently take up residence in coastal feeding areas that are located hundreds or thousands of kilometres from the beaches on which the turtles hatched; some juveniles also migrate between summer and winter habitats. As adults, turtles periodically leave their feeding grounds and migrate to breeding and nesting regions, after which many return to their own specific feeding sites. The itinerant lifestyle characteristic of most sea turtle species is thus inextricably linked to an ability to orient and navigate accurately across large expanses of seemingly featureless ocean.In some sea turtle populations, migratory performance reaches extremes. The total distances certain green turtles (Chelonia mydas) and loggerheads (Caretta caretta) traverse over the span of their lifetimes exceed tens of thousands of kilometres, several times the diameter of the turtle's home ocean basin. Adult migrations between feeding and nesting habitats can require continuous swimming for periods of several weeks. In addition, the paths of migrating turtles often lead almost straight across the open ocean and directly to the destination, leaving little doubt that turtles can navigate to distant target sites with remarkable efficiency.

scholarly journals Modulation of hydroxyl variability by ENSO in the absence of external forcing

2018 ◽  
Vol 115 (36) ◽  
pp. 8931-8936 ◽  
Author(s):  
Alexander J. Turner ◽  
Inez Fung ◽  
Vaishali Naik ◽  
Larry W. Horowitz ◽  
Ronald C. Cohen
Keyword(s):  
Climate Model ◽  
Southern Oscillation ◽  
Function Analysis ◽  
Oxidative Capacity ◽  
Dominant Mode ◽  
External Forcing ◽  
External Forcings ◽  
Methane Budget ◽  
Interannual Fluctuations ◽  
The Impact

The hydroxyl radical (OH) is the primary oxidant in the troposphere, and the impact of its fluctuations on the methane budget has been disputed in recent years, however measurements of OH are insufficient to characterize global interannual fluctuations relevant for methane. Here, we use a 6,000-y control simulation of preindustrial conditions with a chemistry-climate model to quantify the natural variability in OH and internal feedbacks governing that variability. We find that, even in the absence of external forcing, maximum OH changes are 3.8 ± 0.8% over a decade, which is large in the context of the recent methane growth from 2007–2017. We show that the OH variability is not a white-noise process. A wavelet analysis indicates that OH variability exhibits significant feedbacks with the same periodicity as the El Niño–Southern Oscillation (ENSO). We find intrinsically generated modulation of the OH variability, suggesting that OH may show periods of rapid or no change in future decades that are solely due to the internal climate dynamics (as opposed to external forcings). An empirical orthogonal function analysis further indicates that ENSO is the dominant mode of OH variability, with the modulation of OH occurring primarily through lightningNOx. La Niña is associated with an increase in convection in the Tropical Pacific, which increases the simulated occurrence of lightning and allows for more OH production. Understanding this link between OH and ENSO may improve the predictability of the oxidative capacity of the troposphere and assist in elucidating the causes of current and historical trends in methane.

scholarly journals Impact of Equatorial Atlantic Variability on ENSO Predictive Skill

2021 ◽  
Author(s):  
Eleftheria Exarchou ◽  
Pablo Ortega ◽  
Maria Belén Rodrıguez de Fonseca ◽  
Teresa Losada Doval ◽  
Irene Polo Sanchez ◽  
...  
Keyword(s):  
Climate Models ◽  
Southern Oscillation ◽  
Sensitivity Study ◽  
Tropical Pacific ◽  
Climate Impacts ◽  
Equatorial Atlantic ◽  
Predictive Capacity ◽  
Predictive Skill ◽  
The Impact ◽  
The Tropical Pacific

&lt;p&gt;El Ni&amp;#241;o&amp;#8211;Southern Oscillation (ENSO) is a key mode of climate variability with worldwide climate impacts. Recent studies have highlighted the impact of other tropical oceans on its variability. In particular, observations have demonstrated that summer Atlantic Ni&amp;#241;os (Ni&amp;#241;as) favor the development of Pacific Ni&amp;#241;as (Ni&amp;#241;os) the following winter, but it is unclear how well climate models capture this teleconnection and its role in defining the seasonal predictive skill of ENSO. Here we use an ensemble of seasonal forecast systems to demonstrate that a better representation of equatorial Atlantic variability in summer and its lagged teleconnection mechanism with the Pacific relates to enhanced predictive capacity of autumn/winter ENSO. An additional sensitivity study further shows that correcting SST variability in equatorial Atlantic improves different aspects of forecast skill in the Tropical Pacific, boosting ENSO skill. This study thus emphasizes that new efforts to improve the representation of equatorial Atlantic variability, a region with long standing systematic model biases, can foster predictive skill in the region, the Tropical Pacific and beyond, through the global impacts of ENSO.&lt;/p&gt;

scholarly journals Quantifying Illegal Extraction of Sea Turtles in Costa Rica

2021 ◽  
Vol 2 ◽  
Author(s):  
Helen Pheasey ◽  
George Glen ◽  
Nicole L. Allison ◽  
Luis G. Fonseca ◽  
Didiher Chacón ◽  
...  
Keyword(s):  
Costa Rica ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Wildlife Trade ◽  
Caribbean Coast ◽  
Turtle Species ◽  
Illegal Wildlife Trade ◽  
The Caribbean ◽  
The Impact

Estimates of illegal wildlife trade vary significantly and are often based on incomplete datasets, inferences from CITES permits or customs seizures. As a result, annual global estimates of illegal wildlife trade can vary by several billions of US dollars. Translating these figures into species extraction rates is equally challenging, and estimating illegal take accurately is not achievable for many species. Due to their nesting strategies that allow for census data collection, sea turtles offer an exception. On the Caribbean coast of Costa Rica, three sea turtle species (leatherback, Dermochelys coriacea; green, Chelonia mydas; and hawksbill, Eretmochelys imbricata) are exploited by poachers. Despite the consumption of turtle eggs and meat being illegal, they are consumed as a cultural food source and seasonal treat. Conservation programmes monitor nesting beaches, collect abundance data and record poaching events. Despite the availability of robust long-term datasets, quantifying the rate of poaching has yet to be undertaken. Using data from the globally important nesting beach, Tortuguero, as well as beaches Playa Norte and Pacuare on the Caribbean coast of Costa Rica, we modelled the spatial and temporal distribution of poaching of the three sea turtle species. Here, we present data from 2006 to 2019 on a stretch of coastline covering c.37 km. We identified poaching hotspots that correlated with populated areas. While the poaching hotspots persisted over time, we found poaching is declining at each of our sites. However, we urge caution when interpreting this result as the impact of poaching varies between species. Given their low abundance on these beaches, the poaching pressure on leatherback and hawksbill turtles is far greater than the impact on the abundant green turtles. We attribute the decline in poaching to supply-side conservation interventions in place at these beaches. Finally, we highlight the value of data sharing and collaborations between conservation NGOs.

Intake and excretion of arsenicals in green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata)

2011 ◽  
Vol 8 (1) ◽  
pp. 19 ◽  
Author(s):  
Tetsuro Agusa ◽  
Kozue Takagi ◽  
Todd W. Miller ◽  
Reiji Kubota ◽  
Yasumi Anan ◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
Chelonia Mydas ◽  
Water Soluble ◽  
Marine Animals ◽  
Eretmochelys Imbricata ◽  
Accumulation Pattern ◽  
Turtle Species ◽  
Green Turtles ◽  
Hawksbill Turtles ◽  
Prey Items

Environmental context Although among higher marine animals, relatively high concentration of arsenic and unique distribution of arsenic compounds are found in green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata), the accumulation mechanism remains unknown. We examined the accumulation of arsenicals in two turtles from the standpoint of short- and long-term intake and excretion and found that prey items might be important for the arsenic accumulation. This study can provide useful information on the accumulation pattern of arsenic speciation in sea turtles. Abstract We analysed arsenic (As) compounds in the stomach and intestine contents, bile and urine of green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) to understand As accumulation through intake and excretion. Stable isotopes of δ15N and δ13C were also measured for understanding the feeding behaviour dependent accumulation of As. Major As species in gastrointestinal contents were unknown water-soluble As, followed by unextracted As. Concentrations of AB and DMA in the tissues were higher than those in the stomach contents (prey items), indicating high bioaccumulation of these arsenicals. In green turtles, AB concentration was high in bile and increased throughout the gastrointestinal tract, suggesting significant biliary excretion of AB. δ15N was positively correlated with AB level in green turtles, whereas a negative relationship between residual As and δ15N was observed in hawksbill turtles. This study indicates feeding behaviour-dependent accumulation of As compounds in both turtle species for the first time.

scholarly journals Atmospheric teleconnection patterns and eddy kinetic energy content: wavelet analysis

2004 ◽  
Vol 11 (3) ◽  
pp. 295-301 ◽  
Author(s):  
V. N. Khokhlov ◽  
A. V. Glushkov ◽  
I. A. Tsenenko
Keyword(s):  
Kinetic Energy ◽  
North Atlantic ◽  
Energy Content ◽  
Southern Oscillation ◽  
Eddy Kinetic Energy ◽  
The North ◽  
The North Atlantic ◽  
The Impact ◽  
The Relationship

Abstract. In this paper, we employ a non-decimated wavelet decomposition to analyse long-term variations of the teleconnection pattern monthly indices (the North Atlantic Oscillation and the Southern Oscillation) and the relationship of these variations with eddy kinetic energy contents (KE) in the atmosphere of mid-latitudes and tropics. Major advantage of using this tool is to isolate short- and long-term components of fluctuations. Such analysis allows revealing basic periodic behaviours for the North Atlantic Oscillations (NAO) indices such as the 4-8-year and the natural change of dominant phase. The main results can be posed as follows. First, if the phases of North Atlantic and Southern Oscillations vary synchronously with the 4-8-year period then the relationship between the variations of the NAO indices and the KE contents is the most appreciable. Second, if the NAO phase tends to abrupt changes then the impact of these variations on the eddy kinetic energy contents in both mid-latitudes and tropics is more significant than for the durational dominance of certain phase.

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