Effects of a dredging operation on the movement and dive behaviour of marine turtles during breeding

2017 ◽  
Vol 206 ◽  
pp. 190-200 ◽  
Author(s):  
Paul A. Whittock ◽  
Kellie L. Pendoley ◽  
Renae Larsen ◽  
Mark Hamann
2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.


2019 ◽  
Vol 18 (2) ◽  
pp. 249 ◽  
Author(s):  
Edson Soares da Silva-Júnior ◽  
Daniel Solon Dias de Farias ◽  
Aline da Costa Bomfim ◽  
Augusto Carlos da Boaviagem Freire ◽  
Rafael Ângelo Revorêdo ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam G. Clause ◽  
Aaron J. Celestian ◽  
Gregory B. Pauly

AbstractPlastic pollution, and especially plastic ingestion by animals, is a serious global issue. This problem is well documented in marine systems, but it is relatively understudied in freshwater systems. For turtles, it is unknown how plastic ingestion compares between marine and non-marine species. We review the relevant turtle dietary literature, and find that plastic ingestion is reported for all 7 marine turtle species, but only 5 of 352 non-marine turtle species. In the last 10 years, despite marine turtles representing just 2% of all turtle species, almost 50% of relevant turtle dietary studies involved only marine turtles. These results suggest that the potential threat of plastic ingestion is poorly studied in non-marine turtles. We also examine plastic ingestion frequency in a freshwater turtle population, finding that 7.7% of 65 turtles had ingested plastic. However, plastic-resembling organic material would have inflated our frequency results up to 40% higher were it not for verification using Raman spectroscopy. Additionally, we showcase how non-native turtles can be used as a proxy for understanding the potential for plastic ingestion by co-occurring native turtles of conservation concern. We conclude with recommendations for how scientists studying non-marine turtles can improve the implementation, quality, and discoverability of plastic ingestion research.


2014 ◽  
Vol 29 (1) ◽  
pp. 198-206 ◽  
Author(s):  
Chris Wilcox ◽  
Grace Heathcote ◽  
Jennifer Goldberg ◽  
Riki Gunn ◽  
David Peel ◽  
...  

1986 ◽  
Vol 34 (2) ◽  
pp. 241 ◽  
Author(s):  
D Blair

A revision of the subfamily Microscaphidiinae Looss, 1900 is presented and characters of taxonomic significance discussed. The genus Microscaphidium Looss, 1900, contains M. reticulare (van Beneden, 1859) Looss, 1901 (synonyms M. japonicum Oguro, 1941; M. caballeroi Groschaft, 1977); M. aberrans Looss, 1902 (synonym M. reticulare in part); and M, warui, sp. nov. Confusion in the literature over the identities of M. reticulare and M. aberrans is discussed. A neotype is selected for the former species and a lectotype for the latter. Polyangium linguatula (Looss, 1899) Looss, 1902 (synonyms P. miyajimai Kobayashi, 1921; P. colymbi Poche, 1925; P. longiseminale Chattopadhyaya, 1972) is the sole species in Polyangium Looss, 1902. The genus Angiodictyum Looss, 1902 contains A. parallelum (Looss, 1901) Looss, 1902; A. posterovitellatum Chattopadhyaya, 1972; A. longum, sp, nov.; A. glossoides, sp. nov. Polygorgyra, gen. nov., is proposed for P. cholados, sp. nov. Microscaphidium chelonei Chattopadhyaya, 1972 nec Mehrotra, 1973 and Angiodictyum anteroporum Chattopadhyaya, 1972 are regarded as species inquirendae. Microscaphidium chelonei Mehrotra, 1973 nec Chattopadhyaya, 1972 is a nomen nudum. The following species are recorded for the first time from the green turtle, Chelonia mydas (L.) in Australian waters: Microscaphidium reticulare; M. aberrans; M. warui; Angiodictyum posterovitellatum; A. longum; Polygorgyra cholados.


Phytotaxa ◽  
2015 ◽  
Vol 233 (3) ◽  
pp. 236 ◽  
Author(s):  
Roksana Majewska ◽  
J. P. Kociolek ◽  
Evan W. Thomas ◽  
Mario De Stefano ◽  
Mario Santoro ◽  
...  

Marine mammals such as whales and dolphins have been known for a long time to host a very specific epizoic community on their skin. Less known however is the presence of a similar community on the carapaces of sea turtles. The present study is the first describing new taxa inhabiting sea turtle carapaces. Samples, collected from nesting olive ridley sea turtles (Lepidochelys olivacea) on Ostional Beach (Costa Rica), were studied using light and scanning electron microscopy. Two unknown small-celled gomphonemoid taxa were analysed in more detail and are described as two new genera, closely related to other gomphonemoid genera with septate girdle bands, such as Tripterion, Cuneolus and Gomphoseptatum. Chelonicola Majewska, De Stefano & Van de Vijver gen. nov. has a flat valve face, uniseriate striae composed of more than three areolae, simple external raphe endings, internally a siliceous flap over the proximal raphe endings and lives on mucilaginous stalks. Poulinea Majewska, De Stefano & Van de Vijver gen. nov. has at least one concave valve, uniseriate striae composed of only two elongated areolae, external distal raphe endings covered by thickened siliceous flaps and lives attached to the substrate by a mucilaginous pad. Chelonicola costaricensis Majewska, De Stefano & Van de Vijver sp. nov. and Poulinea lepidochelicola Majewska, De Stefano & Van de Vijver sp. nov. can be separated based on stria structure, girdle structure composed of more than 10 copulae, raphe structure and general valve outline. A cladistics analysis of putative members of the Rhoicospheniaceae indicates that the family is polyphyletic. Chelonicola and Poulinea are sister taxa, and form a monophyletic group with Cuneolus and Tripterion, but are not closely related to Rhoicosphenia, or other genera previously assigned to this family. Features used to help diagnose the family such as symmetry and presence of septa and pseudosepta are homoplastic across the raphid diatom tree of life.


2003 ◽  
Vol 18 (2) ◽  
pp. 215-240

AbstractThis article explains the provisions of the Convention for the Conservation of Migratory Species of Wild Animals (CMS) and its subsidiary marine wildlife instruments as they relate to bycatch management. The CMS was primarily developed with the purpose of protecting and conserving migratory species and their habitats. The Convention was initially regarded as little more than a paper accord. Since its inception the CMS has undergone gradual significant changes not only in its scope but also in its geographical coverage. There are ten subsidiary instruments currently in force under the CMS which include regional accords on a wide range of marine species such as cetaceans, marine turtles and pinnipeds. These agreements have considerable potential for regulating the incidental capture of marine wildlife in fisheries. Issues of interest in regard to these agreements include the use of non-binding instruments, and mechanisms for coordination between accords. This article examines the CMS and its subsidiary instruments; it identifies challenges facing the Convention, and provides options for the development of more comprehensive approaches to the management of bycatch.


2004 ◽  
Vol 118 (1) ◽  
pp. 72 ◽  
Author(s):  
Donald F. McAlpine ◽  
Stan A. Orchard ◽  
Kelly A. Sendall ◽  
Rod Palm

Marine turtles in British Columbia have previously been considered off course stragglers. Here we document 20 new reports for Green Turtles, Chelonia mydas, and Leatherback Turtles, Dermochelys coriacea, for the province. Until recently there had been no concerted effort to acquire data on marine turtle abundance or frequency off British Columbia. Observations presented here allow a reassessment of marine turtle status in British Columbia waters. We suggest Green Turtles and Leatherbacks should be considered rare vagrants and uncommon seasonal residents, respectively, off British Columbia and that they are a natural part of the British Columbia marine environment.


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