Dear Marmam and ECS-mailbase subscribers, Apologies to those of you who will receive duplicate emails due to cross-posting. The following are abstracts from the most recent issue (Volume 11, issue 2, 2010) of the Journal of Cetacean Research and Management. 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. 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 ************************************* *Heide-Jørgensen, M. P., L. Witting, K. L. Laidre, R. G. Hansen, and M. Rasmussen. 2010. Fully corrected estimates of common minke whale abundance in West Greenland in 2007. Journal of Cetacean Research and Management 11(2):75-82. *Contact email: mhj@ghsdk.dk A visual aerial line transect survey for common minke whales (Balaenoptera acutorostrata) was conducted off West Greenland in August and September 2007. A total of 8,670km of survey effort covered 11 strata in sea states <5 with a total stratum area of 213,807km2. The 27 sightings of common minke whales were all within a strip width of 300m and the average time from first detection to when the sighting passed abeam was 1.7 sec. Due to the uniform and narrow distribution of the detections, strip census methods were used to analyse the survey. Two methods were deployed to correct the strip census estimates for whales missed by the observers and whales that were submerged during the passage of the plane. Method 1 included all detections of common minke whales (n = 27) and correction for an instantaneous availability that included submergence of whales. Using data from sea states <3 (n = 22) the ‘at surface’ abundance of common minke whales was 1,866 (CV = 0.30) whales. A correction for whales missed by the observers with a simple mark-recapture estimator resulted in a corrected abundance of 1,904 (CV = 0.30) whales. Adjusting for the availability bias resulted in a fully corrected estimate of 16,609 (95% CI 7,172–38,461) common minke whales. Method 2 used only detections of common minke whales that were observed to break the surface (n = 19). Applying this method to effort data at sea state <3 (n = 14) resulted in an ‘at surface’ abundance of 1,174 (CV = 0.39) whales. A correction for whales missed by the observers increased the abundance to 1,198 (0.39) whales. Adjusting for the availability bias resulted in a fully corrected estimate of 22,952 (95% CI 7,815–67,403) common minke whales. ***************************** *Heide-Jørgensen, M. P., K. L. Laidre, M. Simon, M. L. Burt, D. L. Borchers, and M. Rasmussen. 2010. Abundance of fin whales in West Greenland in 2007. Journal of Cetacean Research and Management 11(2):83-88. *Contact email: mhj@ghsdk.dk An aerial line transect survey of fin whales (Balaenoptera physalus) conducted off West Greenland in 2007 was used to estimate the current abundance of fin whales on the summer feeding ground. A total of 24 sightings of fin whale groups were collected during 8,632km of survey effort in sea states <5. Based on conventional distance sampling techniques an abundance of 4,359 whales (95% CI 1,879–10,114) was estimated. The survey was conducted as a double platform survey and mark recapture distance sampling techniques were used to correct for perception bias which resulted in an estimate of 4,468 whales (95% CI 1,343–14,871). Both estimates are negatively biased because no corrections were applied for whales that were submerged during the passage of the survey plane. The abundance estimate furthermore only represents the coastal areas of West Greenland. The sightings at the westernmost border of the strata suggest that the entire Baffin Bay-Davis Strait summer abundance of fin whales could be considerably larger. Based on comparison with previous surveys in West Greenland in 1987/88 and 2005 it appears that the fin whale abundance in West Greenland has increased. ******************* *Koski, W. R., J. Zeh, J. Mocklin, A. R. Davis, D. J. Rugh, J. C. George, and R. Suydam. 2010. Abundance of Bering-Chukchi-Beaufort bowhead whales (Balaena mysticetus) in 2004 estimated from photo-identification data. Journal of Cetacean Research and Management 11(2):89-99. *Contact email: bkoski@lgl.com Ice-based surveys near Point Barrow, Alaska, have been used to obtain most estimates of abundance for the Bering-Chukchi-Beaufort (B-C-B) stock of bowhead whales, but global warming has raised concerns that ice-based surveys may not be practical in the future. Aerial photographic surveys provide an alternative method for obtaining abundance estimates and may replace ice-based surveys. Aerial photographic surveys were conducted near Point Barrow during the spring migrations of bowhead whales in 2003 and 2004 and, in 2005, in the northern Bering Sea in spring and near Barrow in fall. The 2003 survey was the most complete photographic survey of the population conducted to date. These surveys provided photo-identification data for use in capture-recapture analyses. A screening procedure was used to define which whales captured in 2003, 2004 and/or 2005 were marked and could be reidentified if photographed on another occasion. An estimate of the number of marked whales was obtained using a closed population model for capture-recapture data. Several models were investigated, including models that accounted for heterogeneity in capture probabilities, but a simple model with no covariates produced the most precise estimate. To account for unmarked whales, the estimate of marked whales was divided by an estimate of the proportion of the bowhead population that was marked based on the 1989-2004 spring photographic surveys near Point Barrow. Abundance of the B-C-B bowhead population in 2004 (excluding calves) was estimated to be 12,631 with CV 0.2442, 95% bootstrap percentile confidence interval (7,900; 19,700) and 5% lower limit 8,400. These results were compared with results that used approximate variance expressions for the estimates of the number of marked whales, the proportion of the population that was marked and population abundance instead of using the bootstrap. The estimates of abundance in 2004 computed for comparison included one based on a modified Petersen estimate of the number of marked whales that omitted the 2005 data as well as the estimate of 12,631 described above. The comparison estimates also included estimates of abundance in 1985 computed from 1984-87 photographic survey data using the same methods. All the abundance estimates computed from photographic data were consistent with expectations based on independent abundance and trend estimates from the ice-based surveys conducted from 1978 to 2001. ***************************** *Archer, F. I., K. K. Martien, B. L. Taylor, R. G. LeDuc, B. J. Ripley, G. H. Givens, and J. C. George. 2010. A simulation-based approach to evaluating population structure in non-equilibrial populations. Journal of Cetacean Research and Management 11(2):101-113. *Contact email: eric.archer@noaa.gov The standard null model of panmixia used to test for population subdivision is based on a set of assumptions that can be violated given recent events likely to result in non-equilibrial genetic composition coupled with the complex life histories of many species. Bowhead whales (Balaena mysticetus) represent such a species. Bowhead whales also have a well-documented history of severe commercial harvest in the recent past which would be expected to leave a population out of genetic equilibrium. They also have a very long life span, overlapping generations, and age and sex-structured migrations. In addition, samples come from whales killed in a hunt known to be non-random with respect to size at different whaling villages. Sampling of such a population could lead to erroneous conclusions regarding population structure, which could have real consequences for aboriginal whaling. To better interpret the results of standard population genetic analyses, an individual-based model of bowhead whale population dynamics and genetics was created using the R package rmetasim. The model re-created as closely as possible all aspects of the demography, genetics, and whaling history of bowhead whales. Simulated datasets were generated by sampling from the simulated population in a way that matched the age, sex and geographic distribution of empirically collected samples. The empirical bowhead datasets were compared to null distributions generated from the simulated datasets for a variety of genetic analyses. The analysis indicates that the empirical genetic data sampled from the Bering-Chukchi- Beaufort (BCB) stock of bowhead whales are more consistent with the model of a population with the same whaling history and demographic composition as BCB whales than they are with a single, randomly-mating population in genetic equilibrium under a standard Wright-Fisher model. Additionally, it was demonstrated that by failing to account for the unique features of the population dynamics of the species, standard tests of genetic differentiation based on panmixia may produce misleading results. The approach outlined will likely prove useful for evaluating population structure in other species likely to be out of equilibrium. ************** *Beekmans, B. W. P. M., J. Forcada, E. J. Murphy, H. J. W. De Baar, U. V. Bathmann, and A. H. Fleming. 2010. Generalised additive models to investigate environmental drivers of Antarctic minke whale (Balaenoptera bonaerensis) spatial density in austral summer. Journal of Cetacean Research and Management 11(2):115-129. *Contact email: bas.beekmans@wur.nl There is a need to characterise the physical environment associated with Antarctic minke whale density in order to understand long term changes in minke whale distribution and density in open waters of the Southern Ocean during austral summer months. To investigate environmental drivers of Antarctic minke whale density, generalised additive models (GAMs) were developed, based on line transect data collected for the International Decade of Cetacean Research (IDCR) and Southern Ocean Whale Ecosystem Research (SOWER) programmes. The GAMs were fitted independently by survey year. Explained deviances ranged from 14.9% to 35.1%. Most models included covariates related to transition zones, such as distances to the continental shelf break and sea ice edge, both of which showed a predominantly negative relationship with whale density. This study suggests high variability in the relationships between Antarctic minke whale density and the environment. None of the selected covariates had a consistent qualitative relationship with density at either the circumantarctic or the regional scale. This in part may be explained by the changing ice-related boundaries of the surveys between years and hence differences in survey region. Another possible reason is that in absence of better data, most of the covariates considered were derived from remote sensing data. More localised surveys with comparable survey area conducted across the Southern Ocean, where whale sightings data are collected simultaneously with in situ non-biotic and prey data, are likely to provide a better assessment of the environmental determinants of whale density. ***************************** Carrillo, M., and F. Ritter. 2010. Increasing numbers of ship strikes in the Canary Islands: Proposals for immediate action to reduce risk of vessel-whale collisions. Journal of Cetacean Research and Management 11(2):131-138. *Contact email: canariasconservacion@yahoo.es; info@m-e-e-r.de The Canary Islands, known for their extraordinarily high cetacean species diversity, have witnessed a rapid expansion in fast and high speed ferry traffic during the past few years. At the same time, ship strikes have been increasingly reported. 556 cetacean carcasses, found ashore, or reported, in the Canary Islands between 1991 and 2007, were examined. 59 strandings (10.6%) were found to involve vessel-whale collisions, the great majority of strandings (58%) occurred on Tenerife. Species most affected were sperm whales (Physeter macrocephalus, n = 24, 41%), pygmy sperm whales (Kogia breviceps, n = 10, 17%), Cuvier’s beaked whales (Ziphius cavirostris, n = 7, 12%), short-finned pilot whales (Globicephala macrorhynchus, n = 6, 10%) and at least three baleen whale species (n = 9, 15%). Twenty six animals (44%, n = 42) were either calves or juveniles, and one was a newborn. The temporal distribution of strandings indicates that lethal strikes have increased in recent years. Most ship strikes, assumingly by large and fast moving vessels, probably resulted in the death of the animals, as indicated by severe injuries such as huge slashes, cuts, broken vertebrae or animals separated into halves. Given these numbers and the widely accepted fact that only a portion of ship strikes will be recorded due to under-reporting and carcasses drifting away or sinking, ship strikes appear to be a major threat to cetaceans in the Canary Islands, especially to sperm whales. Moreover, the issue is a matter of human safety, as crew and passengers are at risk of being harmed, too. In this situation, a number of measures to mitigate the risk of ship strikes are recommended as a matter of high priority. These include the placement of dedicated look-outs on fast moving vessels, the shift of ferry transects where feasible, a speed limitation for local high-risk areas where cetacean abundance is notably high, the introduction of an obligatory reporting system of vessel-whale collisions and the conduction of detailed studies dealing with this pressing issue. ***************************** Ritter, F. 2010. Quantification of ferry traffic in the Canary Islands (Spain) and its implications for collisions with cetaceans. Journal of Cetacean Research and Management 11(2):139-146. *Contact email: info@m-e-e-r.de The Canary Islands, known for their high cetacean species diversity, have witnessed a rapid expansion of fast ferry traffic during the past few years. At the same time, ship strikes have been repeatedly documented. In this paper an overview of the inter-island ferry traffic in the archipelago is given. Ferry types in use (normal, fast and high speed vessels) are described, and the transects on which they operate are identified. To quantify the extent of the inter-island ferry traffic, three parameters were determined: (1) the actual transects from the different ports on the islands; (2) the number of journeys made per week on each transect; and (3) the length of each transect. Resulting numbers indicate that normal ferries travel approx. 66,000km, fast ferries travel approx. 570,000km and high speed ferries travel approx. 845,000km between islands each year. Fast and high speed ferry traffic is concentrated in the western islands. Areas of high risk for ship strikes within the archipelago are identified by comparing the location of transects with known areas of high cetacean abundance. It is argued that the Canary Islands are a hot spot for vessel-whale collisions and that a policy to counteract this situation is urgently needed. ****************** *Schaffar, A., C. Garrigue, and R. Constantine. 2010. Exposure of humpback whales to unregulated whalewatching activities in their main reproductive area in New Caledonia. Journal of Cetacean Research and Management 11(2):147-152. *Contact email: aline.schaffar@laposte.net Whale- and dolphin-watching activities are demonstrating a strong growth worldwide, raising concern of their potential impacts on cetacean populations and emphasising the need for management. Humpback whales recently have become the focus of an important tourism industry in the South Pacific, particularly in New Caledonia, where operators focus on a small population of humpback whales on their main breeding ground. Despite considerable growth since it began in 1995, the industry remains unregulated. Between 2005 and 2007, a study was conducted to assess the impact of whalewatching activities on the behaviour of humpback whales in New Caledonia. All data were collected from a land-based research station using a theodolite. Results show that 54% of all humpback whale groups sighted were exposed to whalewatching boats. Each group was watched simultaneously by an average of 2.5 boats. More than three boats were present within 300m of a group of whales 30% of the time. The length of time a group of whales was observed in the presence of boats each day was an average of one hour and 52 minutes but exceeded two hours 37% of the time. On average, each boat spent 52 minutes with the same group of whales. The closest point of approach was less than 100m for 86% of groups with a calf and 55% of non-calf groups. These results indicate that humpback whales are exposed to whalewatching boats in New Caledonia at a level exceeding the limits commonly recommended by management measures worldwide. Such exposure could be particularly problematic for mother-calf pairs, more vulnerable to threats. The strong site fidelity of individuals on this breeding ground raises concern of potential cumulative impacts. Management measures should be implemented to regulate whalewatching activities and ensure the conservation of this small, endangered population of humpback whales. *********************************** *Speakman, T. R., S. M. Lane, L. H. Schwacke, P. A. Fair, and E. S. Zolman. 2010. Mark-recapture estimates of seasonal abundance and survivorship for bottlenose dolphins (Tursiops truncatus) near Charleston, South Carolina, USA. Journal of Cetacean Research and Management 11(2):153-162. *Contact email: Todd.Speakman@noaa.gov The stock structure of western North Atlantic bottlenose dolphins (Tursiops truncatus) is complex, with seasonally migratory stocks often overlapping with year-round resident stocks. High rates of exchange between northernmost sites have been documented but movement and seasonal fluctuation in abundance among sites along the southern portion of the US Atlantic coast is not well understood. To better understand seasonal abundance, a three-year mark-recapture study of bottlenose dolphins in coastal and estuarine waters near Charleston, South Carolina, USA was conducted. A robust design was employed in order to minimise bias and more precisely determine seasonal estimates of abundance and concurrently examine temporary immigration/emigration and survivorship. Systematic boat-based surveys were carried out (n = 192) from January 2004 to December 2006. The entire study area was surveyed one week per month; an additional survey was conducted in the months in which seasonal abundance was estimated: January (winter), April (spring), July (summer) and October (autumn). Standard photo-identification techniques were used to accumulate sightings of 521 distinctively marked dolphins, 65% of which were sighted more than once. Pollock’s robust design was applied using MARK and the ensuing abundance estimates were adjusted for the seasonal proportion of unmarked dolphins (ranging from 0.27 to 0.40) in the population. Estimates ranged from 364 (95% CI = 305–442) in January 2004 to 910 (95% CI = 819–1018) in October 2006. Summer abundance estimates were consistently greater than those from winter months, although estimates varied considerably among years. The same model was used to calculate an annual survival rate estimate of 0.951 (95% CI = 0.882–1.00) for marked individuals within the population. A high degree of transience, demonstrated by seasonal influxes of single-sighted individuals, made it difficult to differentiate between mortality and permanent emigration. The results support the occurrence of three distinct dolphin groups found in Charleston waters: year-round residents; seasonal residents; and transients. Reporting abundance and survivorship estimates together is useful in explaining and validating results for populations in which transient individuals occur. These results provide important information for stock and viability assessment of coastal bottlenose dolphins in the western North Atlantic. ******* *Danil, K., S. J. Chivers, M. D. Henshaw, J. L. Thieleking, R. Daniels, and J. A. St. Leger. 2010. Cetacean strandings in San Diego County, California, USA: 1851-2008. Journal of Cetacean Research and Management 11(2):163-184. *Contact email: kerri.danil@noaa.gov There were 717 cetacean strandings recorded in San Diego County, California, USA between 1851 and 2008. These strandings comprised 18 odontocete and 6 mysticete species. Common dolphins (both the short-beaked (Delphinus delphis) and long-beaked common dolphin (D. capensis)) were the most commonly stranded cetacean species (43.2%), followed by bottlenose dolphins (Tursiops truncatus) (16.5%), gray whales (Eschrictius robustus) (11.0%), and Pacific white-sided dolphins (Lagenorhyncus obliquidens) (7.0%). A higher number of strandings was observed in the La Jolla and Coronado/Imperial Beach areas, which likely reflects the influence of coastal protrusions in those regions. Strandings of bottlenose dolphin neonates suggests their calving season extends from May to September. Strandings of common dolphin species peaked in the early- to mid-1970s and in the late-1990s to 2008, coincident with cool oceanographic regimes. In addition, extralimital strandings of harbour porpoises and temporal changes in stranding rates of Dall’s porpoises (Phocoenoides dalli) and short-finned pilot whales (Globicephala macrorhynchus) may have been associated with changes in oceanographic conditions. Evidence of human interaction in strandings included entanglements, boat strikes, shootings and harpooning. Overall, the stranding record largely reflected the species composition of the Southern California Bight and provided confirmation for presence of cryptic species not previously recorded by aerial and ship surveys. ******* Higdon, J. W. 2010. Commercial and subsistence harvests of bowhead whales (Balaena mysticetus) in eastern Canada and West Greenland. Journal of Cetacean Research and Management 11(2):185-216. *Contact email: jeff.higdon@dfo-mpo.gc.ca Commercial harvesting of bowhead whales (Balaena mysticetus) from the eastern Canada-West Greenland population started with Basque whalers in the Strait of Belle Isle ca 1530 AD. Subsistence harvests have an even longer history, and the first culture to be active bowhead whalers was the Thule, which replaced the Dorset culture in the central and eastern Arctic ca 1200 AD. Previous harvest compilations have been incomplete, and back-calculated population models have thus been negatively biased. In recent decades this population has shown significant recovery and is the subject of Inuit subsistence harvests in both Canada and West Greenland. A revised historic abundance estimate is needed to examine the level of recovery; this requires inter alia a revised and updated catch series. Available information from multiple anthropological, archaeological, historic and recent sources, and estimate commercial and subsistence harvests in eastern Canada and West Greenland is summarised. From 1530–1915, commercial whalers took an estimated 55,916–67,537 (median 61,537) bowhead whales (varying assumptions on the intensity of the Basque harvest), which is known to be incomplete. Inuit harvests before commercial whaling began (1200–1529 AD) were estimated at 11,435 whales, based on the abundance of whale bone at winter houses excavated by archaeologists. After 1500 AD, Inuit whaling declined, and the total estimated harvest between 1530 AD and the end of commercial whaling was 8,406 whales. Inuit whaling declined again after commercial whalers overharvested the population and only 65 whales are known to have been harvested (or struck and lost) from 1918–2009. The Inuit harvest statistics are based on scattered data and a number of assumptions, with some evidence that at least parts of the series are underestimated. Even if harvests were higher, they would have probably not been large enough to cause population declines. The long tradition of Inuit bowhead whaling was negatively impacted by commercial harvests. Combining all harvests from 1530–2009 AD results in a total estimated kill of some 70,000 whales (not including struck and lost whales and known gaps for some nations and eras), with most (88%) taken by commercial whalers. Data quality varies considerably by nation and era, and was assigned to a 3-point scale for reliability, with over half the harvest considered to be the least reliable. This is the most comprehensive summary and estimate of bowhead harvests for this region, but is still known to be incomplete and is based on a number of assumptions and disparate data sources.