scholarly journals Population recovery changes population composition at a major southern Caribbean juvenile developmental habitat for the green turtle, Chelonia mydas

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jurjan P. van der Zee ◽  
Marjolijn J. A. Christianen ◽  
Mabel Nava ◽  
Ximena Velez-Zuazo ◽  
Wensi Hao ◽  
...  
Keyword(s):  
Green Turtle ◽  
Chelonia Mydas ◽  
Caribbean Region ◽  
Population Composition ◽  
Temporal Shift ◽  
The North ◽  
Southern Caribbean ◽  
Western Caribbean ◽  
Eastern Caribbean ◽  
North Western

Abstract Understanding the population composition and dynamics of migratory megafauna at key developmental habitats is critical for conservation and management. The present study investigated whether differential recovery of Caribbean green turtle (Chelonia mydas) rookeries influenced population composition at a major juvenile feeding ground in the southern Caribbean (Lac Bay, Bonaire, Caribbean Netherlands) using genetic and demographic analyses. Genetic divergence indicated a strong temporal shift in population composition between 2006–2007 and 2015–2016 (ϕST = 0.101, P < 0.001). Juvenile recruitment (<75.0 cm straight carapace length; SCL) from the north-western Caribbean increased from 12% to 38% while recruitment from the eastern Caribbean region decreased from 46% to 20% between 2006–2007 and 2015–2016. Furthermore, the product of the population growth rate and adult female abundance was a significant predictor for population composition in 2015–2016. Our results may reflect early warning signals of declining reproductive output at eastern Caribbean rookeries, potential displacement effects of smaller rookeries by larger rookeries, and advocate for genetic monitoring as a useful method for monitoring trends in juvenile megafauna. Furthermore, these findings underline the need for adequate conservation of juvenile developmental habitats and a deeper understanding of the interactions between megafaunal population dynamics in different habitats.

Assessing the geodynamics of strongly arcuate subduction zones in the eastern Caribbean subduction setting

2020 ◽  
Author(s):  
Menno Fraters ◽  
Wim Spakman ◽  
Cedric Thieulot ◽  
Douwe Van Hinsbergen
Keyword(s):  
Stress Field ◽  
Subduction Zones ◽  
Focal Mechanisms ◽  
North American Plate ◽  
Plate Motion ◽  
Caribbean Region ◽  
The North ◽  
Eastern Caribbean ◽  
Subduction Setting ◽  
Subduction System

&lt;p&gt;The eastern Caribbean Lesser-Antilles subduction system is a strongly arcuate subduction system. We have investigated the dynamics of this system through numerical modelling, demonstrating the developed capabilities and computational feasibility for assessing the 3D complexity and geodynamics of natural subductionsystems and applied this to the eastern Caribbean region. We show the geodynamic feasibility of westward directed trench-parallel slab transport through the mantle, i.e. slab dragging, on the northern segment of the slab, while the eastern segment of the slab is subducting by a mantle-stationary trench. The resistance of the mantle against slab dragging by the North American plate motion, as well as the deformation associated with the arcuate geometry of the slab, creates a complex 3D stress field in the slab that deviates strongly from the classical view of slab-dip aligned orientation of slab stress. More generally this means that the process of slab dragging may reveal itself in the focal mechanisms of intermediate and deep earthquakes. The characteristics of the arcuate subduction such as slab dragging and a complex 3D stress field as studied in the Caribbean region can be more generically applied to other arcuate subduction systems as well, such as the Izu-Bonin-Marianas or the Aleutians-Alaskasystems, where anomalous focal mechanisms of slabs are observed.&lt;/p&gt;

Green turtles (Chelonia mydas) of the north-western Arabian Gulf, Kuwait: the need for conservation

2013 ◽  
Vol 24 (2) ◽  
pp. 166-178 ◽  
Author(s):  
Salim Y. Al-Mohanna ◽  
Amani S. Y. Al-Zaidan ◽  
Preeta George
Keyword(s):  
Arabian Gulf ◽  
Chelonia Mydas ◽  
Green Turtles ◽  
The North ◽  
North Western

Redescription of Eunice sebastiani and recognition of E. riojai (Polychaeta: Eunicidae)

2008 ◽  
Vol 88 (3) ◽  
pp. 503-507
Author(s):  
Luis F. Carrera-Parra ◽  
Alexandra E. Rizzo ◽  
Sergio I. Salazar-Vallejo
Keyword(s):  
Caribbean Sea ◽  
Morphological Features ◽  
Type Locality ◽  
Geographical Range ◽  
The North ◽  
Western Caribbean ◽  
Morphological Differences ◽  
Recent Monograph ◽  
North Western

In a series of studies on eunicids, there were explicit or implicit indications that Eunice riojai described from the north-western Caribbean Sea, and Eunice sebastiani described from south-east Brazil, were synonyms. This was based upon a then recent monograph on the genus, and on the fact that some specimens were found in drifting wood which would explain the large geographical range. The study of some large specimens of E. sebastiani, collected at the type locality, shows that there are several relevant morphological differences between the two species and thus both species names must be regarded as distinct. In fact, E. sebastiani is unique in the genus because their maxillae V are bidentate. Furthermore, herein we re-describe these two species and re-evaluate some morphological features described in previous studies.

Population structure and aspects of the reproductive biology of the blackmouth catshark, Galeus melastomus Rafinesque, 1810 (Chondrichthyes: Scyliorhinidae) caught accidentally off the Greek coasts

2016 ◽  
Vol 98 (4) ◽  
pp. 909-925
Author(s):  
Christoforos Panicos Metochis ◽  
Greta Carmona-Antoñanzas ◽  
Vasiliki Kousteni ◽  
Dimitrios Damalas ◽  
Persefoni Megalofonou
Keyword(s):  
Logistic Regression ◽  
Population Structure ◽  
Reproductive Biology ◽  
Eastern Mediterranean ◽  
Maturity Stage ◽  
Population Composition ◽  
Egg Capsules ◽  
The North ◽  
Different Seasons ◽  
North Western

The population composition and aspects of the reproductive biology of 452 blackmouth catsharks, Galeus melastomus were investigated. The sharks were incidentally caught off the North-Western Aegean, the Eastern Corinthian and Northern Euboean Gulfs by commercial bottom trawlers and longlines at depths between 200 and 500 m. The overall sex ratio (1:1.1 females:males) was not different from the theoretical unit (1:1). No differences in the sex ratios were detected among seasons, areas or depth strata. Significant differences in the population structure regarding different maturity stage proportions at different seasons, fishing areas and depths, were observed. The sampled population mainly consisted of immature catsharks (77%), predominantly trawled off the NW Aegean and Corinthian Gulf during winter and autumn. Fifteen per cent of the samples, mainly captured in spring and summer off the N Euboean Gulf, were mature. Eight per cent of the specimens was found to be maturing. Higher frequencies of heavier female individuals were observed. Based on the maturation ogives and the total lengths (TL) for each sex, using logistic regression which presented sex-related differences, male Galeus melastomus achieved maturity at 433.6 mm while females at 483.5 mm. The number of egg capsules in the oviducts spanned from 1–12 per female with sizes varying from 38 × 14 mm to 55 × 20 mm. This is the first study investigating the demography and aspects of Galeus melastomus reproduction in the Eastern Mediterranean.

Condition assessment of coral reefs of two marine protected areas under different regimes of use in the north-western Caribbean

2016 ◽  
Vol 127 ◽  
pp. 16-25 ◽  
Author(s):  
Susana Perera-Valderrama ◽  
Héctor Hernández-Arana ◽  
Miguel-Ángel Ruiz-Zárate ◽  
Pedro M. Alcolado ◽  
Hansel Caballero-Aragón ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Protected Areas ◽  
Marine Protected Areas ◽  
Condition Assessment ◽  
The North ◽  
Western Caribbean ◽  
North Western
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