Changes in persistent contaminant concentration and CYP1A1 protein expression in biopsy samples from northern bottlenose whales, Hyperoodon ampullatus, following the onset of nearby oil and gas development

Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Environmental Pollution 152 (2008): 205-216, doi:10.1016/j.envpol.2007.05.027.A small population of endangered northern bottlenose whales (Hyperoodon ampullatus) inhabits “The Gully” Marine Protected Area on the Scotian Shelf, eastern Canada. Amid concerns regarding nearby oil and gas development, we took 36 skin and blubber biopsy samples in 1996-97 (prior to major development) and 2002-03 (five years after development began), and 3 samples from a population in the Davis Strait, Labrador in 2003. These were analysed for cytochrome P4501A1 (CYP1A1) protein expression (n=36), and for persistent contaminants (n=23). CYP1A1 showed generally low expression in whales from The Gully, but higher levels during 2003, potentially co-incident with recorded oil spills, and higher levels in Davis Strait whales. A range of PCB congeners and organochlorine compounds were detected, with concentrations similar to other North Atlantic odontocetes. Concentrations were higher in whales from The Gully than from the Davis Strait, with significant increases in 4,4’-DDE and trans-nonachlor in 2002-03 relative to 1996-97.Research was funded by the Natural Sciences and Engineering Research Council (NSERC) of Canada, World Wildlife Fund Canada Endangered Species Recovery Fund, Fisheries and Oceans Canada, the National Geographic Society, the Canadian Federation of Humane Societies and two U.K. Royal Society International Collaborative Awards. S.K.H. was supported by a Canadian Commonwealth Scholarship and Royal Society Dorothy Hodgkin Research Fellowship. C.D.M. was awarded a Discovery grant from the Natural Sciences and Engineering Research Council (NSERC) of Canada. J.Y.W was supported by an NSERC PGS B fellowship and the Woods Hole Oceanographic Institution

Predicting the effects of polychlorinated biphenyls on cetacean populations through impacts on immunity and calf survival

This work was supported by funding from the International Whaling Commission's Pollution 2000+Program, the U.S. NOAA/NFMS Health and Stranding Response Program and the UK's Natural Environment Research Council (Grant Code SMRU 10001).The potential impact of exposure to polychlorinated biphenyls (PCBs) on the health and survival of cetaceans continues to be an issue for conservation and management, yet few quantitative approaches for estimating population level effects have been developed. An individual based model (IBM) for assessing effects on both calf survival and immunity was developed and tested. Three case study species (bottlenose dolphin, humpback whale and killer whale) in four populations were taken as examples and the impact of varying levels of PCB uptake on achievable population growth was assessed. The unique aspect of the model is its ability to evaluate likely effects of immunosuppression in addition to calf survival, enabling consequences of PCB exposure on immune function on all age-classes to be explored. By incorporating quantitative tissue concentration-response functions from laboratory animal model species into an IBM framework, population trajectories were generated. Model outputs included estimated concentrations of PCBs in the blubber of females by age, which were then compared to published empirical data. Achievable population growth rates were more affected by the inclusion of effects of PCBs on immunity than on calf survival, but the magnitude depended on the virulence of any subsequent encounter with a pathogen and the proportion of the population exposed. Since the starting population parameters were from historic studies, which may already be impacted by PCBs, the results should be interpreted on a relative rather than an absolute basis. The framework will assist in providing quantitative risk assessments for populations of concern.PostprintPostprintPeer reviewe

Population Estimate of the Humpback Whale (<i>Megaptera novaeangliae</i>) in the West Indies by Visual and Acoustic Techniques

Visual track census and a new method, acoustic counting, were used to estimate the humpback whale (Megaptera novaeangliae) population in the West Indies. Results produced by the two methods differed to some extent. The average or best estimate was 1018 whales with a range of 785–1157. Silver and Navidad banks, containing approximately 85% of the total population, are presently the major nursery grounds in the West Indies. The humpback whale population in the western North Atlantic has increased since the early part of the century. </jats:p

Chlorinated Hydrocarbons in Cetaceans

DDT, PCBs, chlordane, and dieldrin levels were measured in blubber of 18 cetaceans, including humpback, sperm, dense-beaked, Atlantic, and Pacific pilot whales, and five species of dolphins. All had significant residue levels, ranging from 1.1 to 1023 ppm ΣDDT (wet weight basis), and 0.7–147 ppm PCBs. These levels are high enough to justify efforts to reduce PCB contamination of the oceans and a continued ban on widespread use of DDT. </jats:p

An analysis of pilot whale vocalization activity using hidden Markov models

Popov V, Langrock R, DeRuiter SL, Visser F. An analysis of pilot whale vocalization activity using hidden Markov models. The Journal of the Acoustical Society of America. 2017;141(1):159-171

Differences in Acoustic Signals from Delphinids in the Western North Atlantic and Northern Gulf of Mexico

Whistle characteristics were quantitatively compared between both geographically separated and neighboring populations of Atlantic spotted dolphins (Stenella frontalis), bottlenose dolphins (Tursiops truncatus), and pilot whales (Globicephala spp.) in U.S. waters to evaluate if intraspecific acoustic differences exist between groups. We compared nine whistle characteristics between continental shelf and offshore Atlantic spotted dolphins in the western North Atlantic and between northern Gulf of Mexico and western North Atlantic bottlenose dolphins and pilot whales using discriminant analysis. Offshore Atlantic spotted dolphin whistles were significantly different (Hotelling\u27s T2,P= 0.0003) from continental shelf whistles in high frequency, bandwidth, duration, number of steps, and number of inflection points. Atlantic bottlenose dolphin whistles were significantly different (Hotelling\u27s T2, P \u3c 0.0001) from those in the Gulf of Mexico in duration, number of steps, and number of inflection points. There was no significant difference between pilot whale whistles in the two basins. The whistle differences indicate acoustic divergence between groups in different areas that may arise from geographic isolation or habitat separation between neighboring but genetically distinct populations of dolphins. This study supports the premise that acoustic differences can be a tool to evaluate the ecological separation between marine mammal groups in field studies