scholarly journals Driftnets Catch Leatherback Turtles

Oryx ◽  
1982 ◽  
Vol 16 (5) ◽  
pp. 428-430 ◽  
Author(s):  
George H. Balazs
Keyword(s):  
North Pacific ◽  
Hawaiian Islands ◽  
Dermochelys Coriacea ◽  
Migration Routes ◽  
Leatherback Turtles ◽  
North West ◽  
Fishing Vessels ◽  
And Migration ◽  
Monofilament Mesh ◽  
Feeding Grounds

In 1979 Japanese fishing vessels began using monofilament mesh driftnets to catch squid in international waters north-west of the Hawaiian Islands, between 35° and 45° N. This new fishery threatens the survival of leatherback turtles Dermochelys coriacea in their North Pacific feeding grounds and migration routes. It is only recently that the existence of leatherbacks in this remote oceanic area has been discovered and made known.

Sex differences in site fidelity and migration of humpback whales (Megaptera novaeangliae) to the Hawaiian Islands

1997 ◽  
Vol 75 (11) ◽  
pp. 1923-1933 ◽  
Author(s):  
Alison S. Craig ◽  
Louis M. Herman
Keyword(s):  
Site Fidelity ◽  
Hawaiian Islands ◽  
High Energy ◽  
Megaptera Novaeangliae ◽  
Humpback Whales ◽  
Low Latitude ◽  
Wintering Area ◽  
The Mean ◽  
And Migration ◽  
Feeding Grounds

Humpback whales (Megaptera novaeangliae) perform extensive seasonal migrations between high-latitude summer feeding grounds and low-latitude winter reproductive grounds. To investigate gender-related site fidelity to the Hawaiian Islands, an important wintering area for North Pacific humpback whales, photographically based resight histories of 224 females and 416 males observed in Hawai'i from 1976 through 1991 were compiled. Results indicated that the mean number of years in which they were seen was higher for males than for females, that the probability of an individual being resighted across years was higher for males than for females, and that more males than females were seen in consecutive years. Potential sources of bias favoring the photographic capture of males were considered, but none were judged to be significant contributors to the results obtained. It was proposed instead that not all females undertake or complete the migration to the winter grounds each year. Because of the high energy costs of migration and reproduction, some females may overwinter in high latitudes, while others may become pregnant en route to the area traditionally associated with breeding and return to the feeding grounds before arriving at the terminal winter destination.

A risk assessment for Pacific leatherback turtles (Dermochelys coriacea)

2005 ◽  
Vol 62 (8) ◽  
pp. 1710-1719 ◽  
Author(s):  
I C Kaplan
Keyword(s):  
Risk Assessment ◽  
Mortality Rate ◽  
Dermochelys Coriacea ◽  
Point Estimate ◽  
Central Pacific ◽  
Leatherback Turtles ◽  
Fishing Vessels ◽  
Catch Rates ◽  
Simple Logistic ◽  
Annual Mortality

Leatherback turtles (Dermochelys coriacea) are critically endangered in the eastern and western Pacific Ocean. Here, I estimate the magnitude of two likely causes of their decline: (i) bycatch by longline fishing vessels and (ii) coastal sources of mortality. I calculate point estimates of longline bycatch based on turtle catch rates from the US Hawaii-based fleet and effort data for the international Pacific longline fleet. I estimate the intrinsic growth rate of the population and the magnitude of coastal mortality by fitting a simple logistic model. In the western and central Pacific, coastal sources lead to a 13% annual mortality rate, compared with a point estimate of 12% from longlining. In the eastern Pacific, coastal sources account for a 28% annual mortality rate, compared with a point estimate of only 5% from longlining. A Bayesian risk assessment reveals the importance of reducing coastal sources of mortality, as well as longline bycatch, if the populations are to avoid extinction. International efforts to protect the leatherback should expand beyond focusing solely on longline bycatch and should attempt to reduce coastal harvest of adult females and eggs, as well as reduce bycatch by inshore gears such as gillnets.

scholarly journals Cryptic speciation in the Warbling Vireo (Vireo gilvus)

The Auk ◽  
2021 ◽  
Author(s):  
Scott F Lovell ◽  
M Ross Lein ◽  
Sean M Rogers
Keyword(s):  
Contact Zone ◽  
Nuclear Dna ◽  
Biological Species ◽  
Valid Species ◽  
Migration Routes ◽  
Dna Evidence ◽  
Show Evidence ◽  
And Migration ◽  
Surrounding Areas ◽  
Taxonomic Groups

Abstract Eastern (Vireo gilvus gilvus) and western (V. g. swainsoni) forms of the Warbling Vireo have essentially allopatric breeding ranges across north-central North America, but come into contact in central Alberta, Canada. In 1986, Jon Barlow presented preliminary morphological and song evidence suggesting that the Warbling Vireo complex might comprise more than one valid species. However, to date, Barlow’s suggestion is supported by only limited DNA evidence, demonstration of molt and migration differences between the taxa, and anecdotal accounts of differences in song, morphology, plumage, and ecology. We analyzed variation in both mitochondrial and nuclear DNA in birds from Alberta and surrounding areas to determine the levels of genetic differentiation and hybridization occurring in the contact zone, and whether the two taxa warrant recognition as separate biological species. Our analyses reveal that Warbling Vireos in Alberta and the surrounding areas are separated into two well-defined, genetically differentiated, and monophyletic clades corresponding to previously recognized taxonomic groups. The two taxa come into contact in a narrow (~85 km) zone in Barrhead County, northwest of Edmonton, Alberta. They show evidence of limited hybridization. The distinct genetic differences are maintained in the contact zone, where individuals of the two taxa may occupy neighboring territories. Differences in spring arrival dates, molt schedules, and migration routes indicate that a migratory divide may play an important role in reproductive isolation. We suggest that the two taxa are distinct cryptic species: an eastern form, Vireo gilvus, and a western form, Vireo swainsoni.

Evaluation of the larval distribution and migration of the Japanese eel in the western North Pacific

2010 ◽  
Vol 21 (3) ◽  
pp. 591-611 ◽  
Author(s):  
Akira Shinoda ◽  
Jun Aoyama ◽  
Michael J. Miller ◽  
Tsuguo Otake ◽  
Noritaka Mochioka ◽  
...  
Keyword(s):  
North Pacific ◽  
Western North Pacific ◽  
Japanese Eel ◽  
Larval Distribution ◽  
And Migration

scholarly journals Large-scale movements and high-use areas of western Pacific leatherback turtles,Dermochelys coriacea

Ecosphere ◽  
2011 ◽  
Vol 2 (7) ◽  
pp. art84 ◽  
Author(s):  
Scott R. Benson ◽  
Tomoharu Eguchi ◽  
Dave G. Foley ◽  
Karin A. Forney ◽  
Helen Bailey ◽  
...  
Keyword(s):  
Large Scale ◽  
Western Pacific ◽  
Dermochelys Coriacea ◽  
Leatherback Turtles

scholarly journals Revised distribution and phytosociological data of Orobanche coerulescens Stephan in Willd. (Orobanchaceae): Poland in relation to Central Europe

2012 ◽  
Vol 26 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Renata Piwowarczyk
Keyword(s):  
Eastern Europe ◽  
Central Europe ◽  
Plant Communities ◽  
Field Research ◽  
Range Limits ◽  
Migration Routes ◽  
Original Field ◽  
Critical Revision ◽  
And Migration ◽  
North Western

Abstract Orobanche coerulescens has a Eurasian distribution. The species is classified as extinct at most of its localities at the western limit of its range. Its populations are very scarce and critically endangered in Central Europe. This work presents the current distribution of O.coerulescens in Poland, based on a critical revision of herbarium and literature data as well as results of original field research, and reviews its distribution in Central Europe (partly in Eastern Europe). Habitats, plant communities, and migration routes of O.coerulescens in Central Europe are discussed. The species was initially known in Poland from now historical localities in Pomerania and the valley of the lower Vistula. In 2000-2011 it was recorded at 9 localities in Podlasie, the Małopolska Upland (Wyżyna Małopolska), and the Łódź Hills (Wzniesienia Łódzkie). Its abundance at the localities ranged from a few to over 1000 shoots. These are the largest populations of O.coerulescens at its western and north-western range limits.

scholarly journals Status of Marine Turtles in British Columbia Waters: A Reassessment

2004 ◽  
Vol 118 (1) ◽  
pp. 72 ◽  
Author(s):  
Donald F. McAlpine ◽  
Stan A. Orchard ◽  
Kelly A. Sendall ◽  
Rod Palm
Keyword(s):  
British Columbia ◽  
Marine Environment ◽  
Chelonia Mydas ◽  
Marine Turtle ◽  
Dermochelys Coriacea ◽  
Concerted Effort ◽  
Leatherback Turtles ◽  
Marine Turtles ◽  
Green Turtles

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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