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Olympia, WA, United States

Potvin J.,Saint Louis University | Goldbogen J.A.,Cascadia Research Collective | Shadwick R.E.,University of British Columbia
PLoS ONE | Year: 2012

Bulk-filter feeding is an energetically efficient strategy for resource acquisition and assimilation, and facilitates the maintenance of extreme body size as exemplified by baleen whales (Mysticeti) and multiple lineages of bony and cartilaginous fishes. Among mysticetes, rorqual whales (Balaenopteridae) exhibit an intermittent ram filter feeding mode, lunge feeding, which requires the abandonment of body-streamlining in favor of a high-drag, mouth-open configuration aimed at engulfing a very large amount of prey-laden water. Particularly while lunge feeding on krill (the most widespread prey preference among rorquals), the effort required during engulfment involve short bouts of high-intensity muscle activity that demand high metabolic output. We used computational modeling together with morphological and kinematic data on humpback (Megaptera noveaangliae), fin (Balaenoptera physalus), blue (Balaenoptera musculus) and minke (Balaenoptera acutorostrata) whales to estimate engulfment power output in comparison with standard metrics of metabolic rate. The simulations reveal that engulfment metabolism increases across the full body size of the larger rorqual species to nearly 50 times the basal metabolic rate of terrestrial mammals of the same body mass. Moreover, they suggest that the metabolism of the largest body sizes runs with significant oxygen deficits during mouth opening, namely, 20% over maximum VO2at the size of the largest blue whales, thus requiring significant contributions from anaerobic catabolism during a lunge and significant recovery after a lunge. Our analyses show that engulfment metabolism is also significantly lower for smaller adults, typically one-tenth to one-half VO2/max. These results not only point to a physiological limit on maximum body size in this lineage, but also have major implications for the ontogeny of extant rorquals as well as the evolutionary pathways used by ancestral toothed whales to transition from hunting individual prey items to filter feeding on prey aggregations. © 2012 Potvin et al. Source


Williams R.,University of British Columbia | Gero S.,Dalhousie University | Bejder L.,Murdoch University | Calambokidis J.,Cascadia Research Collective | And 4 more authors.
Conservation Letters | Year: 2011

Evaluating impacts of human activities on marine ecosystems is difficult when effects occur out of plain sight. Oil spill severity is often measured by the number of marine birds and mammals killed, but only a small fraction of carcasses are recovered. The Deepwater Horizon/BP oil spill in the Gulf of Mexico was the largest in the U.S. history, but some reports implied modest environmental impacts, in part because of a relatively low number (101) of observed marine mammal mortalities. We estimate historical carcass-detection rates for 14 cetacean species in the northern Gulf of Mexico that have estimates of abundance, survival rates, and stranding records. This preliminary analysis suggests that carcasses are recovered, on an average, from only 2% (range: 0-6.2%) of cetacean deaths. Thus, the true death toll could be 50 times the number of carcasses recovered, given no additional information. We discuss caveats to this estimate, but present it as a counterpoint to illustrate the magnitude of misrepresentation implicit in presenting observed carcass counts without similar qualification. We urge methodological development to develop appropriate multipliers. Analytical methods are required to account explicitly for low probability of carcass recovery from cryptic mortality events (e.g., oil spills, ship strikes, bycatch in unmonitored fisheries and acoustic trauma). © 2011 Wiley Periodicals, Inc. Source


In response to initial customer and developer feedback, Apple has investigated reports concerning data loss and corruption and in response has made improvements to Drive Setup and provided updates to correct other customer issues. Mac OS 8.5.1 Update fixes a memory leak in AppleScript, a memory problem in the file system (asynchronous File I/O error, as reported by FileMaker Pro users), and a Mac OS Extended format corruption issue, re-enables the use of many third party ADB devices, and provides some improved communication through Internet proxy firewalls for Sherlock. In addition, Apple has developed a number of additional Sherlock plug-ins that are included in this update. Watch for new plug-ins on the Sherlock Plug-in Directory. Previous versions of Drive Setup can overwrite small portions of the Mac OS Standard format partition if the partitions on the target drive are not as expected. This is an extremely rare occurrence, but could cause drive repair utilities to report that block 0 of that volume is bad or cause the drive not to show up on the desktop. Volumes initialized or updated with previous versions of Drive Setup also may not always have the needed patches installed on the hard drive. These patches are now installed on all drives.


Courbis S.,Portland State University | Baird R.W.,Cascadia Research Collective | Cipriano F.,San Francisco State University | Duffield D.,Portland State University
Journal of Heredity | Year: 2014

Understanding gene flow and dispersal patterns is important for predicting effects of natural events and anthropogenic activities on animal populations. In Hawaii, most species of odontocetes are managed as single populations. Recent exceptions include false killer whales, spinner dolphins, and common bottlenose dolphins, for which studies have shown fidelity to individual islands or groups of islands. Our study focused on pantropical spotted dolphins. We analyzed mitochondrial control region and 11 microsatellite loci from 101 individuals from 4 areas: Hawaii, Maui/Lanai, Oahu, and Kauai/Niihau. We examined F ST, F'ST, RST, Jost's D, and φST and used TESS to estimate number of populations and assignment probabilities. Our results support genetic differentiation among Hawaii, Maui/Lanai, and Oahu and suggest that pantropical spotted dolphins near Kauai/Niihau are likely transient and in low numbers. Between island regions, FST for microsatellites ranged from 0.016 to 0.045 and for mtDNA, from 0.011 to 0.282. F'ST, ranged from 0.098 to 0.262 for microsatellites and 0.019 to 0.415 for mtDNA. RST and φST showed similar results to FST for microsatellites and mtDNA respectively, and Jost's D fell between FST and F'ST. TESS supported 3 populations, and greatest mean assignment probability by island region ranged from 0.50 to 0.72. The private alleles method indicated migration rates among regions from 1.49 to 3.45, and effective population size of the island of Hawaii was estimated to be 220. There was no strong evidence to support sex-biased dispersal or group fidelity. Considering this study in the larger context of other odontocete population studies and studies of connectivity, we suggest genetic differentiation may be mediated by behavior adapted to differing habitat types and niches. © The American Genetic Association 2014. All rights reserved. Source


Goldbogen J.A.,Cascadia Research Collective
Proceedings. Biological sciences / The Royal Society | Year: 2013

Mid-frequency military (1-10 kHz) sonars have been associated with lethal mass strandings of deep-diving toothed whales, but the effects on endangered baleen whale species are virtually unknown. Here, we used controlled exposure experiments with simulated military sonar and other mid-frequency sounds to measure behavioural responses of tagged blue whales (Balaenoptera musculus) in feeding areas within the Southern California Bight. Despite using source levels orders of magnitude below some operational military systems, our results demonstrate that mid-frequency sound can significantly affect blue whale behaviour, especially during deep feeding modes. When a response occurred, behavioural changes varied widely from cessation of deep feeding to increased swimming speed and directed travel away from the sound source. The variability of these behavioural responses was largely influenced by a complex interaction of behavioural state, the type of mid-frequency sound and received sound level. Sonar-induced disruption of feeding and displacement from high-quality prey patches could have significant and previously undocumented impacts on baleen whale foraging ecology, individual fitness and population health. Source

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