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May 2009

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Abstracts - Journal of Cetacean Research and Management, vol 10(2), 2008
by Dagmar Fertl 01 May '09

01 May '09

Dear Marmam and ECS-mailbase subscribers, Apologies to those of you who will receive duplicate emails due to cross-posting. 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. The following is posted on behalf of the IWC and the journal editor Dr. Greg Donovan. Further information can be found at: http://www.iwcoffice.org/publications/JCRM.htm. A guide for authors is included in the first volume of each issue and on the IWC website: http://www.iwcoffice.org/publications/authorsguide.htm. 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. With regards, Dagmar Fertl Ziphius EcoServices http://www.ziphiusecoservices.com **************************** LeDuc, R. G., K. K. Martien, P. A. Morin, N. Hedrick, K. M. Robertson, B. L. Taylor, N. S. Mugue, R. G. Borodin, D. A. Zelenina, D. Litovka, and J. C. George. 2008. Mitochondrial genetic variation in bowhead whales in the western Arctic. Journal of Cetacean Research and Management 10 (2):93-97. Contact email: Barbara.Taylor(a)noaa.gov Bowhead whales in the Western Arctic are managed as a single stock by the International Whaling Commission (IWC). In response to recent concerns about the potential existence of multiple stocks in the region, we examined genetic variation in the mitochondrial control region among various spatial, temporal and age-related strata. Sequences from 382 samples were used in the comparisons. No significant differences were detected in spatial comparisons or in temporal comparisons along Alaska’s North Slope. However the cc2 analysis showed evidence of genetic heterogeneity between some of the age cohorts, specifically between animals born prior to 1918 (n=8) and those born after 1979 (n=34) (p=0.030), between those born 1918-1949 (n=13) and those born after 1979 (p=0.050), and between the two aforementioned older cohorts and those born after 1979 (p=0.009). There was also a significant Fst difference between autumn (n=13) and spring (n=11) whales from St. Lawrence Island (p=0.049). The age data were insufficient to determine if this seasonal difference was due in part to the difference between age cohorts. *************************** Koski, W. R., J. Zeh, and J. C. George. 2008. A calf index for monitoring reproductive success in the Bering-Chukchi-Beaufort Seas bowhead whale (Balaena mysticetus) population. Journal of Cetacean Research and Management 10 (2):99-106. Contact email: bkoski(a)lgl.com The percentage of calves in a whale population can provide information on whether a population is increasing, stable or decreasing and is an input to population models. In this paper a method for estimating the percentage of calves in the Bering-Chukchi-Beaufort Seas (B-CB) bowhead whale population in any given year by obtaining information on the percentage of calves passing Point Barrow, Alaska, during the last three weeks of the spring migration is presented. The method incorporates information on the timing of the migration with the percentage of calves detected during calf index surveys conducted during weekly periods from 14 May to early June. Historic data provide the different proportions of the migration during the weekly periods during low, medium and high calf years. The index is adjusted to allow for calves passing before 14 May and calves that are born after their mothers pass Point Barrow. The calf index was calculated for eight years using data from aerial photographic surveys near Point Barrow from 1985 to 2004 and the mean percentage of calves in the sampled years was 6.1%. Power analyses indicate that nine years of calf index data are required following a decline to detect a 60% reduction in the calf index. Additional calf index surveys prior to a decline would increase the power to detect a decline. This method can provide a robust estimate of the percentage of calves in the population each year with a modest aerial survey or photographic effort at Point Barrow. The data would be valuable in evaluating whether calving rates are within the range tested for the purpose of reviewing the B-C-B bowhead whale Strike Limit Algorithm. ******************************************** O'Hara, T. M., C. Hanns, V. M. Woshner, J. Zeh, G. Bratton, and R. Taylor. 2008. Essential and non-essential elements in the bowhead whale: Epidermis-based predictions of blubber, kidney, liver and muscle tissue concentrations. Journal of Cetacean Research and Management 10 (2):107-117. Contact contact email: fftmo(a)uaf.edu Assessment of element concentrations in wildlife must address both nutritional and toxicological considerations. The liver, epidermis, muscle and kidney of the bowhead whale are rich in some essential and non-essential elements. Blubber tends to have lower concentrations of these elements. Various cetaceans have been evaluated for these elements using a variety of sample sources (live and dead stranded whales, bycaught animals, remote and capture-release biopsy techniques, hunter killed whales etc). One constant shared by these approaches is the sampling of epidermis and adjacent dermis (blubber). In this study, the ability of elemental concentrations in bowhead whale epidermal samples to predict the corresponding elemental concentrations in blubber, kidney, liver and muscle is investigated. Epidermal concentrations had no predictive value for copper (Cu), manganese (Mn), lead (Pb), selenium (Se) or zinc (Zn) in any of the other tissues evaluated, except that the epidermal measurement provided an upper bound for blubber concentration of Cu, Mn, Se and Zn. Epidermal concentrations of the four other elements considered were predictive for some other tissues. Arsenic (As) concentrations could be predicted in kidney, liver and muscle but not blubber, although the preponderance of samples with concentrations below the minimum level reported (MLR, also known as ‘detection limit’) and the small sample sizes that resulted from their omission suggest that these data should be interpreted with caution. Epidermal concentrations of cadmium (Cd) were strongly predictive for blubber and weakly predictive for muscle concentrations. Epidermal concentrations of mercury (Hg) were weakly predictive of blubber, liver and muscle concentrations. Epidermal concentrations of magnesium (Mg) were strongly predictive in blubber, kidney and liver but only weakly predictive in muscle. Thus epidermal biopsy cannot predict elemental concentrations in four key tissues in bowhead whales in most cases. Cobalt (Co) and molybdenum (Mo) were not detected in any epidermal samples. This inability of epidermal element concentrations to reflect concentrations in internal tissues is likely true for other mysticetes and perhaps for cetaceans in general. At a minimum, before using epidermal biopsies to predict internal tissue concentrations of elements, researchers must establish that a sound scientific basis exists for doing so. Such proof must be specific to the elements, species and tissues in question as well as based upon statistically adequate sample sizes. ***************************************** Heide-Jørgensen, M. P., D. L. Borchers, L. Witting, K. L. Laidre, M. J. Simon, A. Rosing-Asvid, and D. G. Pike. 2008. Estimates of large whale abundance in West Greenland waters from an aerial survey in 2005. Journal of Cetacean Research and Management 10 (2):119-129. contact email: mjh(a)ghsdk.dk An aerial line transect and cue counting survey of large whales in West Greenland was conducted in August and September 2005. The survey covered the area between Cape Farewell and Disko Island on the West Greenland coast out to the 200m depth contour. The surveyed area covered 163,574km2 and a total of 246 sightings of 9 cetacean species were obtained. Abundance estimates were developed for humpback whales, Megaptera novaeangliae (21 sightings), fin whales, Balaenoptera physalus (78 sightings) and common minke whales, B. acutorostrata (42 sightings). The mean group size of humpback whales was 3.30 but groups as large as 95 animals were seen off effort. The mean group size of fin whales was 2.96 with groups as large as 50 seen. Common minke whale group size was 1.1 with only one sighting of a group of two whales. Humpback whales were found both in offshore and coastal areas of West Greenland with the exception of Store Hellefiske Bank and the Cape Farewell offshore area. The line transect abundance estimate of humpback whales was 1,218 (CV=0.56), uncorrected for submerged whales (availability bias) and whales that were available to be seen but were missed by the observers (perception bias). Fin whales were observed in all areas of the survey and the uncorrected line transect estimate was 1,660 (CV=0.38). When corrected for perception bias the estimates increases to 3,234 fin whales (CV=0.44). Common minke whales were found in almost equal densities in all strata except for the Cape Farewell offshore area, where none were seen. The cue-counting abundance estimate of common minke whales was 4,856 (CV=0.49) for West Greenland using a cue rate of 46.3 cues per hour (CV=0.11). If the estimate is corrected for perception bias the common minke whale abundance is estimated to be 10,792 whales (CV=0.59). Low coverage was attained in the northern area of West Greenland and this should cause an especially large negative bias for the estimates of fin whale and humpback whale abundance because this area is believed to have particularly large densities of these whales. ******************************************* Pace D.S., A. Miragliuolo, and B. Mussi. 2008. Behaviour of a social unit of sperm whales (Physeter macrocephalus) entangled in a driftnet off Capo Palinuro (southern Tyrrhenian Sea, Italy). Journal of Cetacean Research and Management 10 (2):131–135. Contact email: danielasilvia.pace(a)gmail.com Driftnet fishing is notorious for being the major source of fatal entanglement of cetaceans and for its devastating impact on some pelagic species of the Mediterranean fauna. Of all the large cetaceans, the sperm whale (Physeter macrocephalus) is most affected by this fishing technique. On 9 August 2004, a group of five sperm whales, two adult females and three juvenile individuals, was found trapped in a driftnet 40 miles southwest off Capo Palinuro (Italy). Their tails were totally immobilised by the net and one animal was completely entangled. All the animals showed numerous lesions on their bodies. The group was freed by the Italian Coast Guard scuba-diving team during a two-day rescue operation. This exceptional case of sperm whale disentanglement was a unique opportunity to study the group’s acoustic and general behavior during a particularly stressful event. Out of a total video/acoustic recording of 110 minutes, 91 were examined. During the rescue procedures, the whales’ behaviour was described as open mouthed, sideways roll, agitation of fluke and pectoral fins, head rubbing, fluke contact (with head, flippers and back by the liberated animals) and defecation. As expected, the entangled individuals produced different patterns of clicks, identified as ‘usual clicks’, ‘codas’ and ‘creaks’. Each pattern was associated with specific behaviour. Despite international and national regulation banning fishing with driftnets in the Mediterranean Sea, driftnets continue to be used illegally in this sperm whale habitat, posing a constant threat to the species’ survival in the region. ***************************************** Waring, G. T., L. Nøttestad, E. Olsen, H. Skov, and G. Vikingsson. 2008. Distribution and density estimates of cetaceans along the mid-Atlantic Ridge during summer 2004. Journal of Cetacean Research and Management 10 (2):137-146. Contact email: Gordon.Waring(a)noaa.gov During 4 June-2 July 2004, the Norwegian R/V G.O. Sars conducted a multi-disciplinary survey along the mid-Atlantic Ridge (MAR) from the Reykjanes Ridge to north of the Azores. This provided the first systematic survey information on MAR cetacean populations. Using naked eye or 7x50 hand-held binoculars, observers searched in a 140 degree arc centred along the ships' heading. Eleven cetacean species and 10 other taxonomic groups were identified along 2,312km of transect effort. The sei whale (Balaenoptera borealis) and sperm whale (Physeter macrocephalus) were the most commonly sighted species (53 and 48 sightings, respectively). There were 12 sightings of the fin whale (B. physalus). There were 26, 13 and 12 sightings, respectively of the common dolphin (Delphinus delphis), pilot whale (Globicephala sp.) and striped dolphin (Stenella coeruleoalba). Density estimates of species ranged from 0.018 to 0.238 animals km^-2. The precision of the estimates (CV) was low, ranging from 40% to 61%. Species distribution varied north to south; the highest aggregations of baleen whales were sighted in the Charles Gibbs Fracture Zone (CGFZ). Sperm whales were also observed at the CGFZ as well as north of this area. Pilot whales and Atlantic white-sided dolphins (Lagenorhynchus acutus) were sighted mainly in the cold (5-16 degrees C) and less saline (34.6-35.8 ppt) water masses along the Reykjanes Ridge. Conversely, common dolphins and striped dolphins were most commonly sighted south of the CGFZ in areas with warmer (12-22 degrees C) and more saline (34.8-36.7 ppt) surface water temperatures. **************** Koschinski, S., A. Diederichs, and M. Amundin. 2008. Click train patterns of free-ranging harbour porpoises acquired using T-PODs may be useful as indicators of their behaviour. Journal of Cetacean Research and Management 10 (2):147-155. Contact email: marine-zoology(a)t-online.de Harbour porpoise signals consist of directional, high frequency stereotypic clicks which can be logged using T-PODs. Variation in interclick intervals (ICs) can be used to distinguish different acoustic behaviours. So far, studies on ICI variation are mostly descriptive and the behavioural context in which certain click train patterns are emitted is poorly understood. In this study, the behaviour of free-ranging porpoises was quantified by using typical ICI patterns known from the literature. These were recordered using two T-PODS deployed at a wind farm site (Nysted, Denmark) between 14 June and 12 July 2005 and during the entanglement of a porpoise calf in a gillnet (Clayoquot Sound Canada). It was possible to distinguish between feeding, approach behaviour and communication and known ICI patterns associated with those behaviours were used to categorise acoustic dta. During feeding typical click trains start with long ICIs (30-70ms) and end with ICIs down to about 2 ms. In a transition phase ICIs rapidly decreasing. Click trains attributed to feeding were found in the wind farm data at a rate of 6.3d^-1 (n=174) with a patchy distribution. We found 20 to 74s long click train sequences with ICIs gradually decreasing from a median of 72ms (range 34 to 124ms) down to 5 ms at a rate of 1.6day^-1 (n=45). This was interpreted as approach behaviour, in which the animal was acoustically 'locked on' to a reflective structure. Communication signals are built up of click trians with very short ICIs (<7.7ms). During the entanglement of a porpoise calf, three differentcall types were determined at a rate of 8.9min^-1 (n=89). One call with variable duration (100 to 890ms) and relatively stable ICIs as a low as 3.6ms resembled 'distress calls' described by Amundin (1991b). Another call type with durations form 780 to 830ms and ICIs ranging from 3.0 to 10 ms and thus different with respect to ICI curve progression was found only three times. These had a U-shaped ICI curve, similar to an 'alarm' or 'fright' call described by Busnel and Dziedzic (1966). A third and previously unreported call is characterized by a long call duration (up to 1,270ms) and sometimes oscillating ICIs with an initial decrease from about 9ms to around 7ms and an increase towards the end. The data presented suggest that the T-POD is a promising tool for behavioural studies. It is possible to recognise certain acoustic behavioural categories described in the literature, but it is important to look at the temporal context with other vocalisations in T-POD data, such as ICIs of preceding click trains. ********************* Balmer, B. C., R. S. Wells, S. M. Nowacek, D. P. Nowacek, L. H. Schwacke, W. A. McLellan, F. S. Scharf, T. K. Rowles, L. J. Hansen, T. R. Spradlin, and D. A. Pabst. 2008. Seasonal abundance and distribution patterns of common bottlenose dolphins (Tursiops truncatus) near St. Joseph Bay, Florida, USA. Journal of Cetacean Research and Management 10 (2):157-167. Contact email: bpalmer(a)mote.org Three unusual mortalities events involving bottlenose dolphins (Tursiops truncatus Montagu 1821) occurred along Florida’s northern Gulf of Mexico coast between 1999 and 2006. The causes of these events, in which over 300 bottlenose dolphins are known to have died, are still under investigation. The impact of these mortality events cannot be fully evaluated, because little prior information on bottlenose dolphin abundance and distribution patterns exist in this region. Thus, the goals of this study were to estimate seasonal abundance, develop site-fidelity indices, and describe distribution patterns of bottlenose dolphins in St. Joseph Bay, Gulf County, Florida, USA. This study site was chosen because it was impacted by all three unusual mortality events and was the geographic focus of the 2004 event. Mark-recapture photo-identification surveys were conducted across multiple seasons from February 2005 through July 2007. Site-fidelity indices were calculated for each identifiable dolphin based upon all photo-ID efforts undertaken in the area. Distribution patterns were investigated by short-term (12-94 days) radio-tracking of tagged individuals across seasons (April-July, n=9; July-October, n=15). Mark-recapture closed and robust abundance estimates, as well as site-fidelity indices suggest that St. Joseph Bay supports a resident community of 78-152 bottlenose dolphins. During spring and autumn, this region experiences an influx of dolphins, as demonstrated by closed and robust abundance estimates of 313-410 and 237-340, respectively. These results are supported by the distribution patterns of radio-tagged individuals. Individuals tagged in summer tended to stay within or near St. Joseph Bay, whereas two individuals tagged in spring ranged more than 40km from the study site. This study provides the first detailed examination of bottlenose dolphin abundance and distribution patterns for this region of the northern Gulf coast of Florida. These results suggest that unusual mortality events probably had, and will in the future have, seasonally variable effects on bottlenose dolphins in St. Joseph Bay. Future mortality events that occur during the summer and winter in St. Joseph Bay may predominantly affect resident individuals, while those that occur during the spring and autumn will probably affect both residents and seasonal visitors. ******************* Larese, J. P., and S. J. Chivers. 2008. Age estimates for female eastern and whitebelly spinner dolphins (Stenella longirostris) incidentally killed in the eastern tropical Pacific tuna purse-seine fishery from 1973-82. Journal of Cetacean Research and Management 10 (2):169-177. Contact email: susan.chivers(a)noaa.gov Age was estimated from teeth for 1,267 female eastern spinner dolphins (Stenella longirostris orientalis) and 1,071 female whitebelly spinner dolphins (S. longirostris) incidentally killed in the eastern tropical Pacific yellowfin tuna purse-seine fishery between 1973 and 1982. The final age assigned to each specimen was the mean of two readers’ age estimates made independently and without knowledge of the corresponding biological data for each specimen. The oldest eastern spinner dolphin was estimated to be 24.5 years and the oldest whitebelly spinner dolphin was 26 years. Age bias plots revealed nonlinear systematic bias between readers while a measure of overall precision, coefficient of variation (CV), indicated equivalent difficulty in estimating age for each population. The age frequency distributions generated in this study document the age structure of dolphins sampled from the observed incidental kill, which will facilitate further assessments of the impact of the fishery on these dolphins. *********** Avila, I. C., C. García, and J. C. Bastidas. 2008. A note on the use of dolphins as bait in the artisanal fisheries off Bahía Solano, Chocó, Colombia. Journal of Cetacean Research and Management 10 (2):179-182. Contact email: Isabel_c_avila(a)yahoo.com Dolphin hunting for fishing bait in Bahía Solano, Chocó, Colombia, was evaluated during eight months, between July 2005 and April 2006. Interviews were conducted with 122 fishermen (18.2% of the registered fishermen in the zone), who cover at most 890km2 when fishing (approximately 2.3% of the Pacific Territorial Sea of Colombia), and data obtained from landings at a fishing company. Only fishermen using longlines (37.3%) confirmed using dolphins as bait. It was not possible to obtain additional information about date, specific location or dolphin species, but the most probable captured species were common bottlenose dolphin and pantropical spotted dolphin. Nine dolphins were killed during the study period (1.1 dolphins/month) and extrapolating these numbers to all fishermen using longlines in the region (250), 24 dolphins might have been taken during the study period (3 dolphins/month). Fish species caught using dolphin bait include Pacific bearded brotula, groupers and smooth-hound. _________________________________________________________________ Rediscover Hotmail®: Get quick friend updates right in your inbox. http://windowslive.com/RediscoverHotmail?ocid=TXT_TAGLM_WL_HM_Rediscover_Up…

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FW: Postdoctoral fellowship available
by Kit Kovacs 01 May '09

01 May '09

The Norwegian Polar Institute (NPI) is seeking a well qualified spatial analyst/marine mammal ecologist for a 3-year postdoctoral (PDF) position to work within a study entitled "The population biology and ecology of the world's northernmost harbour seals in a changing Arctic". The position is to be held at the institute's head office in Tromsø; field work will be conducted in Svalbard. The precise starting date is negotiable, but, the successful candidate must be in place by 01 09 2009. The successful applicant must have an educational background in biology, ideally including some marine mammal biology, and have strong analytical skills, particularly in the area of spatial analyses and habitat assessment. Documented experience in dealing with statistical treatment of data from Satellite-Relay-Data-Loggers (e.g. mixed models, first-passage times, Argos filters etc., etc. ) is an essential job skill for this PDF. Field experience from Polar Regions is desirable but is not a prerequisite. Similarly, experience with CTD-SRDL data bases and an interest in polar marine systems and climate change are seen as desirable. A strong publication record will be viewed favourably. The application deadline is 10 June 2009. Qualifications: We are looking for a candidate who holds a Ph.D. degree and has some experience with publishing in good quality, refereed journals. The successful candidate must be able to work well in a small team, both in the field and in the office. The salary will be at pay level 57-60, depending on qualifications. (NOK 435,700 - 459, 900 (66,000- 69,500 US)). Further inquiries about the position can be directed to the Biodiversity Research Programme Leader Dr. Kit M. Kovacs, e-mail: kit(a)npolar.no<mailto:kit@npolar.no> phone: +47 77750526; or Dr. Christian Lydersen, Christian(a)npolar.no<mailto:Christian@npolar.no>, phone: +47 77750523; or Personnel Officer Harald R. Lind, e-mail job(a)npolar.no<mailto:job@npolar.no>, phone: +47 77750630. The application deadline is 10 June 2009. The application should include a CV that includes a list of publications, names of at least two references and details of your relevant qualifications and experience. NPI prefers electronic applications, submitted at www.jobbnorge.no<http://www.jobbnorge.no/>. If this is not feasible, printed applications may be sent to the attention of Dr. Kit M. Kovacs, Norwegian Polar Institute, Polar Environmental Centre, NO-9296 Tromsø, Norway or emailed as PDF documents to (kit(a)npolar.no<mailto:kit@npolar.no>). All applications can be handled confidentially until the application deadline. Thereafter, a public list of applicants will be prepared. Applicants who wish to reserve their applications from the public list must give reasons for this in their applications. In accordance with new public information laws, information about an applicant can be made public even if the applicant has requested not be included from the public list of applicants, cf. Freedom of Information Act, Section 25, 2nd paragraph. Kit M. Kovacs Biodiversity Programme Leader Norwegian Polar Institute 9296 Tromsø Norway Kit M. Kovacs Biodiversity Programme Leader Norwegian Polar Institute 9296 Tromsø Norway

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