Dear Marmam subscribers, The following are abstracts from one of the most recent issues (Volume 13, issue 2, 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 [email protected]. 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 Sumich, J.L., S.A. Blokhin, and P.A. Tiupeleyev. 2013. Revised estimates of foetal and post-natal growth in young gray whales (Eschrichtius robustus). Journal of Cetacean Research and Management 13(2):89-96. Contact e-mail: [email protected] Patterns of gray whale growth in body length and weight with age are evaluated using published values of foetal and post-natal body dimensions at reported ages, supplemented with previously unpublished measured lengths of 88 mid-gestation foetuses, 82 first-summer calves and 30 secondsummer whales taken in the summer/autumn Chukotkan native subsistence fishery. Gompertz growth models are fitted to foetal and post-natal lengths at age, predicting mean lengths at birth in mid-January of 4.7m, 7.9m at weaning and 8.7m at one year. The late foetal diapause in growth of length is not supported by the available data. Two equations were derived for estimating body weights from the linear body dimensions of length nd maximum girth. For biomass estimates, two equations based on length alone and on both girth and length are derived. A multiple least squares regression equation fit to 14 measurements of the same whale over 14 months of captive rehabilitation predicts mean body weights at birth of 1,100–1,200kg, 5,100–5,200kg at six months (weaning), and 6,700–6,800kg at one year of age. ****** D’Intino, A.M., J.D. Darling, J. Urbán R., and T.R. Frasier. 2013. Lack of nuclear differentiation suggests reproductive connectivity between the ‘southern feeding group’ and the larger population of eastern North Pacific gray whales, despite previous detection of mitochondrial differences. Journal of Cetacean Research and Management 13(2):97-104. Contact e-mail: [email protected] During winter, eastern North Pacific gray whales migrate south to calving grounds in the lagoons of Baja California, and in spring they migrate north to their summer feeding grounds in the Chukchi and Beaufort Seas. Although the majority of the population makes this migration, a small subset of the population known as the ‘southern feeding group’ ends their northward migration early, spending summers feeding in waters ranging from northern California to southern Alaska. Previous analyses based on photo-ID and mtDNA data indicate that this seasonal substructuring results from maternally-directed site fidelity to different feeding grounds, and that this site fidelity and feeding ground preference is passed from mothers to their offspring. It is currently assumed, but not known, that the individuals of the southern feeding group mate with the rest of the population, and therefore that the eastern North Pacific gray whale represents one interbreeding population. Testing this assumption and understanding how these whales are related to the rest of the population, is key to making appropriate management decisions, which are particularly relevant given the recent increase in potential removals, or threats in the area such as the proposed resumption of aboriginal whaling, and increased oil pipeline development and subsequent vessel traffic. This paper analyses 15 nuclear microsatellite loci in 59 individuals from the southern feeding group and 40 individuals from the calving lagoons (representative of the larger population) to test the hypothesis that the eastern North Pacific gray whale represents one interbreeding population. No indication of population substructuring was found based on these nuclear loci, suggesting that all sampled whales do indeed represent one interbreeding population. Combined, these data from mitochondrial and nuclear markers therefore suggest one interbreeding population that is seasonally subdivided based on maternally-directed site fidelity to different feeding areas. **** Coughran, D.K., N.J. Gales, and H.C. Smith. 2013. A note on the spike in recorded mortality of humpback whales (Megaptera novaeangliae) in Western Australia. Journal of Cetacean Research and Management 13(2):105-108. Contact e-mail: [email protected] An unprecedented number of humpback whales (n = 46) from Breeding Stock D (BSD) were found dead or dying on Western Australian beaches in 2009. This compares to an average of less than four stranded humpback whales in each year in the period between 1989 and 2008. The recorded number of humpback whales on beaches in the year preceding this peak (2008, n = 13) and the two years following the peak (2010, n = 16; 2011, n = 17) were also above the long term average. In 2012 (n = 7), the numbers of stranded whales was closer to the longer term average. The majority of stranded individuals were either calves (44%) or juveniles/sub-adults (49%), with only 7% classified as adults. Most whales appeared emaciated. There were insufficient data to determine cause of death. Three possible hypotheses to explain this spike in mortality are proposed: (1) the increase in mortality of BSD was an artefact of increased detection and reporting; (2) the increase was temporary and transitory; and (3) the spike in mortality represents the start of an increasing trend in mortality as the population approaches carrying capacity. We suggest that hypothesis two is the most plausible but on-going monitoring will be required to test this. ***** Rankin, R.W., D. Maldini, and G. Kaufman. 2013. Bayesian estimate of Australian humpback calving interval under sparse resighting rates: 1987-2009. Journal of Cetacean Research and Management 13(1):109-121. Contact e-mail: [email protected] This study estimates a calving interval for humpback whales from a longterm photo-ID catalogue of 2,973 individuals resighted in Hervey Bay, East Australia. The study proposes a modification of two existing methods to handle partial identification of sex and age-classes of whales from visual surveys. One method truncates the data to just breeding females and discards all resighting events prior to the first observed breeding event. The second method utilises the multi-stage mark recapture (MSMR) framework and multi-event extension to include all resighted individuals and their entire encounter history. The performance of each method is assessed and the conditioning required to handle ambiguity of sex and age-classes is detailed, which is subtly different from most other mark-recapture methods. Both truncation and the multi-event methods led to similar estimates of calving intervals: 2.98 years (95% CI: 2.27–3.51) and 2.78 years (95% CI: 2.23–3.68) respectively. More importantly, estimates were more sensitive to the exact specification of resighting probabilities among age and sex classes than to the type of conditioning. However, the multi-event framework resulted in more precise estimates of other important life-history parameters such as apparent survival, and included a wider constituency of age and sex classes. ***** Hakamada, T., K. Matsuoka, S. Nishiwaki, and T. Kitakado. 2013. Abundance estimates and trends for Antarctic minke whales (Balaenoptera bonaerensis) in Antarctic Areas IV and V for the period 1989/90-2004/05. Journal of Cetacean Research and Management 13(2):123-151. Contact e-mail:[email protected] The Japanese Whale Research Programme under Special Permit in the Antarctic (JARPA) conducted sighting surveys during the 1989/90 to 2004/05 austral summer seasons (mainly in January and February), alternating between IWC management Areas IV (70°E–130°E) and V (130°E–170°W), both south of 60°S each (split-)year. These data are analysed to obtain abundance estimates for Antarctic minke whales (Balaenoptera bonaerensis) in these Areas. The estimates are calculated by standard line transect analysis methods using the program DISTANCE under the assumption that g(0) = 1. Annual rates of increase in abundance are estimated using log-linear models. The analyses take several recommendations from the 2006 JARPA Review Meeting into consideration. Those addressed here aim to: (a) improve the point estimates of abundance and their precision; and (b) evaluate (through sensitivity tests) the effect of different factors associated with the JARPA survey on the estimates of abundance and trend. GLM models are used to adjust for different strata being surveyed at different times of year over the duration of JARPA, with model selection being based on AICc. Abundance estimates for Area IV range from 16,562 (CV = 0.542) in 1997/98 to 44,945 (CV = 0.338) in 1999/00, while those for Area V range from 74,144 (CV = 0.329) in 2004/05 to 151,828 (CV = 0.322) in 2002/03. Estimates of the annual rates of increase in abundance are 1.8% with a 95% CI of [–2.5%, 6.0%] for Area IV and 1.9% with a 95% CI of [–3.0%, 6.9%] for Area V. Estimates of these trends are robust to the effects of changes in survey timing, the shapes of the shoulders of detection functions, portions of survey tracklines following the ice edge, parts of the Areas in which no survey took place and poor coverage within some strata. Adjustments to allow for the g(0) being less than 1 are made by the application of a regression model, developed from the results of the Okamura-Kitakado (OK) method estimate of minke whale abundance from the IDCR-SOWER surveys, which provides estimates of g(0) from the statistics of the minke whale school size distribution in a stratum. With this adjustment, abundance estimates increase by an average of 32,333 (106%) for Area IV and 89,245 (86%) for Area V, while the estimates of annual rates of increase and their 95% CIs change slightly to 2.6% [–1.5%,6.9%] for Area IV and 1.6% [ 3.4%,6.7%] for Area V. ***** Murase, H., I. Temoai, T. Kirata, S. Finkaso, G. Yasunaga, and L.A. Pastene. 2013. A note on cetaceans off Kiribati and Tuvalu from a research cruise in October 2010. Journal of Cetacean Research and Management 13(2):153-158. Contact e-mail: [email protected] This paper summarises the results of a sighting survey conducted around the Gilbert Islands (Kiribati) and Tuvalu Islands (Tuvalu) in the central Pacific Ocean between 3 and 17 October 2010. This was the first systematic collection of cetacean sighting data in this region. The main objective of the survey was to investigate the occurrence and distribution of cetaceans around Kiribati and Tuvalu. In addition biopsy samples were obtained to investigate the species identity of Bryde’s-whale-like baleen whales through genetic analyses and to assess feeding ecology of cetaceans in the survey area through the examination of fatty acids. The survey was carried out using a sighting survey vessel, which covered a total of 1,012 n.miles (≈1,875km). A total of 24 schools (640 individuals) of cetaceans was sighted: three schools (five individuals) of Bryde’s-whale-like baleen whales, one school (nine individuals) of sperm whales (Physeter macrocephalus), one school (six individuals) of killer whales (Orcinus orca), one school (14 individuals) of short finned pilot whales (Globicephala macrorhynchus), one school (two individuals) of false killer whales (Pseudorca crassidens), eight schools (483 individuals) of spinner dolphins (Stenella longirostris), and one school (70 individuals) of striped dolphins (Stenella coeruleoalba). Mitochondrial DNA (mtDNA) analyses based on the biopsy samples identified two of the Bryde’s-whale-like whales sighted, as of the putative species Balaenoptera brydei. Compositions of fatty acids of Bryde’s and killer whales are presented. The survey provided new information on the distribution and fatty-acid composition of cetaceans around Kiribati and Tuvalu. ***** Stevick, P.T., J.M. Allen, M.H. Engel, F. Félix, B. Haase, and M.C. Neves. 2013. Inter-oceanic movement of an adult female humpback whale between Pacific and Atlantic breeding grounds off South America. Journal of Cetacean Research and Management 13(2):159-162. Contact e-mail: [email protected] We report the first documented movement of an individual humpback whale between the eastern South Pacific stock off Ecuador and the western South Atlantic stock off Brazil. This constitutes the first record of a humpback whale in both the Atlantic and Pacific breeding grounds off South America, and one of a small number of inter-oceanic movements documented to date. It is possible that, even at quite low levels, this movement of individuals between breeding grounds contributes to the current high level of mtDNA diversity in these once-depleted Southern Hemisphere populations. When first sighted, the whale was accompanied by a young calf, and is therefore identified as an adult female. This movement to a different and distant breeding ground is the first reported by a reproductively mature female, and shows that extreme long-distance travellers among humpback whales are not restricted to young males. ***** Iriarte, V., and M. Marmontel. 2013. Insights on the use of dolphins (boto, Inia geoffrensis and tucuxi, Sotalia fluviatilis) for bait in the piracatinga (Calophysus macropterus) fishery in the western Brazilian Amazon. Journal of Cetacean Research and Management 13(2):163-173. Contact e-mail: [email protected] In the Amazon Basin, the use of the pink dolphin or boto (Inia geoffrensis) for bait in the piracatinga (Calophysus macropterus) fishery was first detected in the year 2000. Since then, this artisanal fishery has become more prevalent as it requires only a few hours of work per night and provides immediate cash earnings. It is thus an attractive addition to (or replacement for) traditional fishing. Previous reports have noted the use of botos as bait, but stated that the most common bait used are caimans (Melanosuchus niger, Caiman crocodilus). Estimates of the number of dolphins killed based on fish landings have been proposed and an apparent decrease in sighting/survival of an artificially-marked boto population was observed. Although stocks/population estimates, trends and actual numbers of hunted dolphins are unknown, the conservation impacts of this activity are of concern. Between October 2010 and November 2011, research was conducted within an area with serious conflicts between dolphins and fishermen as well as intense fishing for piracatinga, i.e. in the lower Japurá River, on the border with the Mamirauá and Amanã Sustainable Development Reserves, where both boto and tucuxi (Sotalia fluviatilis) are used for bait. One-hundred and fifty-seven monitoring surveys were carried out in eight key communities, confirming 114 piracatinga fishing events through direct monitoring and incognito surveys of fishing gear (gaiolas). Empirical evidence of the activity in gaiolas comprised pieces of bait, carcass remains, piracatinga provoked vomits and dolphin fished carcasses. Of those, 31.2% (n = 35) involved cetacean bait (91.4% I. geoffrensis, 8.58% S. fluviatilis), 68.7% (n = 77) caiman bait (96% M. niger, 4% C. crocodilus), and two fishing events used both types. These percentages may be higher/lower in other areas within and outside the Reserves. Given the increasing trend of the piracatinga fishery, the authors believe that precautionary measures for the conservation of Amazonian dolphins are urgently needed. Development of practical short-term solutions (e.g. offal-baited fish traps) and multispecies management together with law enforcement, incentives and educational programmes could allow the future transition of riverine communities from the piracatinga fishery to sustainable, higher income activities. ***** Ryan, C., D. Craig, P. López-Suárez, J.V. Perez, I. O’Connor, and S.D. Berrow. 2013. Breeding habitat of poorly studied humpback whales (Megaptera novaeangliae) in Boa Vista, Cape Verde. Journal of Cetacean Research and Management 13(2):175-180. Contact e-mail address: [email protected] The waters surrounding Cape Verde comprise one of two known breeding grounds for humpback whales in the North Atlantic. The population remains very small and has apparently failed to recover since the cessation of whaling there. During the breeding seasons of 2011 and 2012, sighting surveys were carried out for humpback whales off Boa Vista, the easternmost island of the Cape Verde Island archipelago. The distribution and relative abundance of humpback whales and mother-calf pairs was investigated by plotting effort-corrected sightings using a 2km2 grid-square. The study area, a 206km2 region from the coastline up to 8km offshore, covered the western half of Boa Vista where whales have previously been regularly recorded. Following 1,954km of search effort, 117 sightings of humpback whales were made. An encounter rate of 0.11 whales per km was recorded for both years. It is hoped that these data may assist in implementing conservation measures to protect humpback whales and the habitat of Baia Sal Rei, which appears to be the single most important bay for winter breeding, calving and nursing humpback whales in the eastern North Atlantic.
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