[MARMAM] Abstracts - Journal of Cetacean Research & Management 13(3)

Dagmar Fertl dagmar_fertl at hotmail.com
Tue Jan 27 07:42:59 PST 2015


Dear Marmam subscribers,
 
The following are abstracts from the most recent issue (Volume 13, issue 3, 2013) of the Journal of Cetacean Research and Management. The following is posted on behalf of the IWC and the journal editor.
 
The International Whaling Commission (IWC) publishes the Journal of Cetacean Research and Management thrice yearly (Spring, Autumn, and Winter), with at least one supplement that will contain the full report of the IWC Scientific Committee. 
This is one of the final issues of JCRM to be published in hard copy format. The IWC is delighted to inform you that the Journal of Cetacean Research and Management will be available free of charge online from Volume 14 (https://iwc.int/jcrm). Back copies will also be available free of charge on the IWC website. Some back copies of the Journal of Cetacean Research and Management are available in hard copy format, and these are available for the cost of postage only. For further details, please contact secretariat at iwc.int.
 
Contact information is provided for the corresponding author for each article. Please do not contact the listserve editors or me for pdfs or copies of the articles. Thank you for your continued interest in the journal and abstract postings. 
 
A guide for authors is included at the website.
 
With regards,
 

Dagmar Fertl
Kitakado, T., C. Lockyer, and A.E. Punt. 2013. A statistical model for quantifying age-reading errors and its application to the Antarctic minke whales. Journal of Cetacean Research and Management 13(3):181-190.
 
Contact e-mail: kitakado at kaiyodai.ac.jp
 
A statistical method for quantifying age-reading error, i.e. the extent of bias and inter-reader variability among readers, is introduced. The method assumes the availability of an independent ‘control reader’ who produces reference ages for age-reading structures which are also read by additional readers. This control reader is assumed to provide unbiased or consistently biased age estimates so that the additional readers’ age-reading outcomes can be standardised. Linear structures in bias and variance are incorporated in a conditional probability matrix representing the stochastic nature of age-determination for each reader. A joint likelihood function for the parameters related to age-reading bias, variance and nuisance parameters is defined based on observed age-reading outcomes from both the control and additional readers. The method is applied to data for Antarctic minke whales taken during Japanese commercial (1971/72–1986/87) and scientific (JARPA: 1987/88–2004/05, JARPA II: 2005/06–2010/11) whaling. A total of 250 earplugs selected according to a predetermined protocol were used in the analyses to estimate the inter-reader variation for four Japanese readers. One of the authors acted as the control reader. The Japanese readers and the control reader differed in terms of both the expected age given the true age, and variance in age-estimates. The expected age and random uncertainty in age estimates differed among the Japanese readers, although the two readers in charge of age-reading for samples taken during Japanese scientific whaling (JARPA and JARPA II) provided quite similar agereading outcomes. These results contribute to analyses using catch-at-age data for this species. It should also be noted that the model and approach in this paper can be applied to populations other than the Antarctic minke whales, if a control reader is available, even retrospectively.
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Félix, F., and B. Haase. 2013. A note on the northernmost record of the Antarctic minke whale (Balaenoptera bonaerensis) in the Eastern Pacific. Journal of Cetacean Research and Management 13(3):191-194.
 
Contact e-mail: fefelix90 at hotmail.com
 
In this study the first record of the Antarctic minke whale (Balaenoptera bonaerensis) in Ecuador (2°7.35’S, 80°45.7’W) is presented. It was a single stranding of a calf of 3.43m in length. The species was identified based on morphological characteristics such as the number and colour of baleen plates, the number and extension of ventral grooves, lack of white flipper patch and the waved greyish light colouration pattern on the flanks, among others. Although only a handful of records exist of this species in the Eastern Pacific, it confirms that the breeding area of this species at least reaches the equator in this region.
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Koh, H.S., J.E. Jo, N.H. Ahn, J.J. Lee, K.S. Kim, and C.W. Jin. 2013. Preliminary study on genetic differences between two species of finless porpoises, genus Neophocaena, with lack of genetic divergence between two subspecies of the narrow-ridged finless porpoise, N. asiaeorientalis: cytochrome b sequence analyses. Journal of Cetacean Research and Management 13(3):195-199.
 
Contact e-mail: syskoss at chungbuk.ac.kr
 
Using samples from bycaught finless porpoises, cytochrome b sequences were analysed and phylogenetic trees were constructed. The aims were to: (1) determine genetic divergences within the genus Neophocaena; (2) examine interspecific divergences between N. asiaeorientalis and N. phocaenoides; and (3) examine intraspecific divergence between N.a. asiaeorientalis and N.a. sunameri. For this purpose, complete cytochrome b sequences for 12 N.a. sunameri specimens, collected from fishery markets at Pohang in southeastern Korea, were obtained, and these sequences were compared to the corresponding partial (402bp) and complete (1,140bp) sequences of Neophocaena, obtained from GenBank. From a maximum likelihood tree with the partial sequences of the two Neophocaena species, two clades were detected, corresponding to the two species, with average genetic distance of 1.64%, four fixed site differences (1.00%), and a Gst value of 0.64, although we did not examine the specimens from Southeast Asia and contiguous South China Sea. Furthermore, from the complete sequences, we recognised a lack of genetic divergence between the two subspecies of N. asiaeorientalis, with a Gst value of 0.06 and two pairs of identical sequences between them, indicating that our results do not support current subspecies classification. Thus, we newly found that our cytochrome b sequencing results are useful for the examination of interspecific and intraspecific divergences in Neohpocaena, although further genetic analyses with additional specimens of Neophocaena across its distributional range are necessary to confirm the findings in this study.
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Pitchford, J.L., B.J.S. Serafin, D. Shannon, A.T.  Coleman, and M. Solangi. 2013. An analysis of historical bottlenose dolphin (Tursiops truncatus) strandings in the Mississippi Sound, USA using classification and regression trees (CART). Journal of Cetacean Research and Management 13(3):201-209.
 
Contact e-mail: jpitchford at imms.org
 
Trends in bottlenose dolphin (Tursiops truncatus) strandings can be used to examine several factors associated with mortality and life history and are essential for detecting unusual mortality events (UMEs). This study characterised stranding trends in the Mississippi Sound (MS) region of the northern Gulf of Mexico (GoM) from 1996–2009 using kernel density estimation (KDE) and classification and regression tree (CART) analysis. An annual mean of 26.1 strandings (n = 14), SD = 13.7, 95% CI [18.2, 34.0] and a peak in strandings during spring (March–May) were evident from our analyses. Neonates stranded almost exclusively in spring indicating that this is the dominant breeding and calving season in this area. Spatial distributions revealed that the majority of dolphins stranded along central and western portions of the MS Sound near Gulfport, MS and on Ship Island during the spring and summer months, but were more often found in the eastern MS Sound during winter and autumn. Our CART analyses indicated that 1996, which contained a declared UME, was anomalous from other years as the number of adult, sub-adult and juvenile strandings was relatively high during the autumn and winter. Further, our analyses showed that the location of those strandings on Ship Island in autumn and winter was unique from all other years in the historical record. These results represent historical conditions that can be used as a baseline for future studies of the effects of environmental disturbances, including UMEs, in MS. This research also demonstrates the versatility and usefulness of CART for describing historical trends, detecting departures from the norm and explaining UMEs within the framework of a single analysis. This approach represents an objective assessment tool that could be used to assist governmental agencies with determining the onset of a UME and could help support or refute the cause of these events.
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Benmessaoud, R., M. Cherif, and N. Bejaoui. 2013. Baseline data on abundance, site fidelity and association patterns of common bottlenose dolphins (Tursiops truncatus) off the northeastern Tunisian coast (Mediterranean Sea). Journal of Cetacean Research and Management 13(3):211-219.
 
Contact e-mail: benmessaoud_rimel at yahoo.fr
 
The common bottlenose dolphin has been studied intensively in numerous locations around the world but very little is known about this species along the South Mediterranean Basin. In this study, the temporal distribution of dolphins, group dynamics, site fidelity and association patterns of common bottlenose dolphins along the northeastern coastal waters of Tunisia was assessed through mark recapture photo-identification techniques. Prior to this study, no research has focused on bottlenose dolphins within these waters, despite the potential for human impacts on this species. A total of 718h of boat-based observations, spanning 284 days, were spent at sea between August 2008 and July 2010. During this period, 253h were spent in direct observation of 317 groups of common bottlenose dolphins. Bottlenose dolphins were observed in all seasons, although seasonality was evident, with more encounters during the summer. Photo-identification studies show that 43 individuals used the northeastern coast of Tunisia on a regular basis, while others were present less often. Based on a social structure analysis it was possible to discriminate different communities related with the spatial distribution of the sightings (Zembra island, Hammamet, Kelibia and Galite island).
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Towers, J.R., C.J. McMillan, M. Malleson, J. Hildering, J.K.B. Ford, and G.M. Ellis. 2013. Seasonal movements and ecological markers as evidence for migration of common minke whales photo-identified in the eastern North Pacific. Journal of Cetacean Research and Management 13(3):221-229.
 
Contact e-mail: jrtowers at gmail.com
 
In the eastern North Pacific Ocean, common minke whales (Balaenoptera acutorostrata) are widespread but encountered relatively infrequently. It is generally believed that they make annual migrations between higher latitudes in the summer and lower latitudes in the winter; however, in some temperate coastal regions where common minke whales have been sighted year-round they have been referred to as resident. To determine movement patterns of common minke whales found in coastal waters of British Columbia and Washington we examined photo-identification data that were collected opportunistically from 2005–12. These data were from four non-overlapping areas between 48°N and 53°N. Despite year-round search efforts, common minke whales were only encountered between April and October. Most of the 44 unique individuals identified in 405 encounters displayed fidelity to areas both within and among years. Five of these whales made relatively large-scale intra-annual movements between areas on six occasions. They were documented to move up to 424km in a northerly direction in spring and up to 398km in a southerly direction in autumn. The seasonal patterns of these movements provide new insights into the foraging ranges and migrations of the individuals. Ecological markers provide evidence that the common minke whales photographed undertake annual long distance migrations. Scars believed to be from cookiecutter shark (Isistius brasiliensis) bites were observed on 43 individuals and the majority of whales documented with good quality images each year had acquired new scars since the previous year. Furthermore, the commensal barnacle Xenobalanus globicipitis was observed on three individuals. Since these sharks and barnacles are from relatively warm waters, it can be inferred that they interacted with the common minke whales at lower latitudes. These findings may have important implications for the definition and management of common minke whale stocks and/or populations in the eastern North Pacific.
 
 		 	   		  
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