Ten thousand and increasing: Is the western Arctic population of bowhead whale endangered?

Based on a series of 11 abundance estimates over 23 years, the western Arctic population of bowhead whale (WABW) has recovered substantially since it was listed under the US Endangered Species Act. We evaluate extinction risk for WABW to determine if this population should be considered for reclassification under the ESA. Given the uncertainty associated with distinguishing process error and observation error, we consider three scenarios reflecting different assumptions for process error. We applied the quantitative criteria for recovery and delisting using the approach proposed by [Gerber, L.R., DeMaster, D.P., 1999. An approach to endangered species act classification of North Pacific humpback whales. Conservation Biology, 13, 1203-1214] for large whales. To further examine the monitoring process and make recommendations for future data needs, we then re-ran the model using progressively smaller sub-samples of the census data. As longer time series of data were considered, the fraction of outcomes consistent with a “delisting” decision increased. For the 10 and 11-census year subsets, data unequivocally support a decision to delist this population for the 3 scenarios. Furthermore, the IUCN criteria for endangered and vulnerable are not met for this population of bowhead whale under any of our scenarios. Results from the population projections and application of the risk classification criteria are consistent with a determination that the risk of extinction for this population is insignificant in the foreseeable future.     

凝胶渗透色谱-气相-质谱测定鲸皮脂中的多氯联苯

建立了一种测定鲸皮脂中多氯联苯(PCBs)前处理的改良方法,即将皮脂样品分别经超声波萃取、GPC净化和浓缩等处理后,用GC-MS测定.结果显示,该方法加标回收率为73%～118%,精密度为4.1%～9.7%,检出限在0.19～1.07 ng · g-1之间.该方法操作简单,净化效果好、准确性高、重复性强,适合鲸皮脂中PCBs含量的分析测定.     

Haematological findings in captive dolphins and whales

Objective To examine haematological features in five species of healthy, captive marine mammals.
Animals Twenty bottlenose dolphins ( Tursips truncatus ), seven Pacific white-sided dolphins ( Lagenorhynchus obliquidens ), five Risso dolphins ( Grampus griseus ) and five false killer whales ( Pseudorca crassidens ).
Results and conclusion The red blood cell count was 4.21 × 10¹²/L in bottlenose dolphins, 5.32 × 10¹²/L in Pacific white-sided dolphins, 4.35 × 10¹²/L in Risso dolphins and 4.43 × 10¹²/L in false killer whales. The haemoglobin concentration was 1.51 g/L and packed cell volume 44.7% in bottlenose dolphins; the corresponding values were 1.71 g/L and 48.9% in Pacific white-sided dolphins, 1.72 g/L and 49.4% in Risso dolphins, and 1.52 g/L and 47.8% in false killer whales. The white blood cell count was 7.097 × 10⁹/L in bottlenose dolphins, 5.928 × 10⁹/L in Pacific white-sided dolphins, 5.001 × 10⁹/L in Risso dolphins and 7.921 × 10⁹/L in false killer whales. There were no significant differences in these values among bottlenose dolphins and Pacific white-sided dolphins. The proportion of eosinophils in the differential leukocyte count ranged from 10.3% to 11.5% in bottlenose dolphins, Pacific white-sided dolphins and false killer whales, but was only 0.4% in Risso dolphins. The eosinophilic granules were larger in Risso dolphins and false killer whales than in bottlenose and Pacific white-sided dolphins.     

中国大陆海域须鲸科的新纪录

首次记述了采自浙江省玉环县沿海的大村鲸Balaenoptera omurai Wada，Oishi＆Yamada，2003，并对其外部形态和骨骼特征作简要描述。     

Accuracy and precision of archival tag data: a multiple-tagging study conducted on a whale shark (Rhincodon typus) in the Indian Ocean

Pop‐up satellite archival tags (PSATs) are now widely used to document the geographic and vertical movements of large pelagic fishes. These instruments record measurements of ambient light, depth and temperature at regular intervals and the light data are used to compute daily estimates of latitude and longitude. Several methods have been developed to improve those estimates, including the application of Kalman filter models and matching sea surface temperatures (SST) from tags with remotely sensed SSTs. Despite their widespread use, few studies have evaluated the accuracy of raw estimates of location from PSATs or quantified the improvements that may result from refinement techniques. To assess the accuracy of raw and refined estimates of locations from PSATs, we attached two PSATs and one Argos satellite‐linked transmitter (SAT tag) to one whale shark (Rhincodon typus) at Ningaloo Reef, Western Australia. The root mean square error (RMSE) in raw estimates of location provided by the PSATs was 5.16° latitude and 2.00° longitude. Estimates were more accurate after processing the data with a Kalman filter (RMSE = 2.97° latitude and 0.78° longitude) and most accurate after processing with a Kalman filter model that integrates SST measurements (RMSE = 1.84° latitude and 0.78° longitude). We also assessed the precision of the PSAT‐derived locations, and depth and temperature measurements by comparing the data from the two PSATs. Our findings support the use of archival tag data to reconstruct the large‐scale movements of marine animals and demonstrate the significant improvements that may result from two refinement techniques.     

Fisheries induced shift in sea snake community assemblages along the Konkan coast,India

1. The impacts of fisheries on several charismatic marine fauna have been a subject of global concern. Sea snakes share the same habitats as many commercially important fish species and often end up as fisheries bycatch.
2. Previous studies of bycatch from India have been limited to individual reports of mortality, with little information on the regional community structure of sea snakes. This study was carried out along the Konkan coast, off the central west coast of India, between 2016 and 2018, to determine trends in the bycatch of sea snakes in coastal fisheries.
3. In this study, 922 sea snakes were encountered in 916.57 gillnet haul hours and 449.16 trawlers haul hours of fishing, comprising largely of two species: beaked sea snake (Hydrophis schistosus) and spine-bellied sea snake (Hydrophis curtus) (83.05 and 16.94% respectively) which was in stark contrast to a similar study conducted in 2002–03, which recorded a dominance of H. curtus (84%) followed by H. schistosus (14%) in the same region. Both studies, however, indicated higher mortality in H. curtus than in H. schistosus in trawl nets.
4. This study highlights the significant impact of non-selective fishing practices on regional assemblages of other marine organisms such as sea snakes from South Asia, which has been relatively understudied, and the potential consequences for local ecosystems.

     

Seasonal acoustic occurrence of blue,fin, and North Atlantic right whales in the New York Bight

相似文献   

Assessing the impacts of tourism on the world's largest fish Rhincodon typus at Panaon Island,Southern Leyte,Philippines

相似文献   

Perception of a cetacean mass stranding in Italy: the emergence of compassion

• 1 The view that whales are malicious monsters has been pervasive throughout history. Conversely, the idea that these animals experience suffering has emerged only recently. One way of investigating perceptual, as well as behavioural, shifts is assessing general public reactions to mortality events involving wild, rare and charismatic animals.
• 2 Here, the responses of 118 individuals to questions regarding the mass stranding of seven sperm whales (Physeter macrocephalus) along the Adriatic Sea coast of Italy in December 2009 are reported through interviews taken at the stranding site and in the direct proximity of the dead animals.
• 3 When asked why the whales were stranded, 44.1% of the respondents suggested anthropogenic causes and 21.2% non‐anthropogenic. The remaining 34.7% mentioned a generic ‘disorientation’ or stated they did not know. When asked how they felt about the whales, 68.6% expressed feelings of compassion or care towards the animals. Clearly non‐compassionate attitudes accounted for only 4.1% of the sample. Finally, 21.2% expressed feelings that were ambiguous in terms of being suggestive of compassionate or non‐compassionate attitudes, including 11.9% amazement, 4.2% deprecation and 5.1% powerlessness.
• 4 These results are in stark contrast with information obtained from accounts of similar events that have occurred in historical times, up until the first half of the 20th century. For centuries, responses to cetacean live strandings—typically including killing and harming of the animals—were either utilitarian or characterized by feelings including fear and a desire to ‘subjugate the beast’, with no apparent concern for their suffering and death.
• 5 It is concluded that attitudes towards whales—today strikingly revolving around sadness, compassion and a sense of loss—have changed dramatically over time, with a steep turnaround in the 1970/1980s. Full appreciation of the ongoing evolution in public perception can channel marine conservation efforts and assist in the design of response strategies to marine mammal strandings. Copyright © 2010 John Wiley & Sons, Ltd.