Humpback Whale Song and Foraging Behavior on an Antarctic Feeding Ground

The article of record as published may be located at http://dx.doi.org/10.1371/journal.pone.0051214Reports of humpback whale (Megaptera novaeangliae) song chorusing occuring outside the breeding grounds are becoming more common, but song structure and underwater behavior of individual singers on feeding grounds and migration routes remain unknown. Here, ten humpback whales in the Western Antarctic Peninsula were tagged in May 2010 with non-invasive, suction-cup attached tags to study foraging ecology and acoustic behavior. Background song was identified on all ten records, but additionally, acoustic records of two whales showed intense and continuous singing, with a level of organization and structure approaching that of typical breeding ground song. The songs, produced either by the tagged animalsor close associates, shared phrase types and theme structure with one another, and some song bouts lasted close to an hour. Dive behavior of tagged animals during the time of sound production showed song occurring during periods of active diving, sometimes to depths greater than 100 m. One tag record also contained song in the presence of feeding lunges identified from the behavioral sensors, indicating that mating displays occur in areas worthy of foraging. These data show behavioral flexibility as the humpbacks manage competing needs to continue to feed and prepare for the breeding season during late fall. This may also signify an ability to engage in breeding activities outside of the traditional, warm water breeding ground locations.This material is based upon work supported by the National Science Foundation under Grant No. ANT-07-39483. The authors also greatefully acknowledge funding support from the F.V. Hunt Fellowship of the Acoustical Society of America

Swimming kinematics and efficiency of entangled North Atlantic right whales

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Endangered Species Research 32 (2017): 1-17, doi:10.3354/esr00781.Marine mammals are streamlined for efficient movement in their relatively viscous fluid environment and are able to alter their kinematics (i.e. fluke stroke frequency, amplitude, or both) in response to changes in force balance. Entanglement in fishing gear adds significant drag and buoyant forces that can impact swimming behaviors across a range of timescales. We deployed biologging tags during the disentanglement of 2 North Atlantic right whales Eubalaena glacialis to (1) examine how their kinematics changed in response to drag and buoyancy from entanglement in fishing gear, and (2) calculate resultant changes in swimming efficiency for one individual. We observed variable responses in dive behavior, but neither whale appeared to exploit added buoyancy to reduce energy expenditure. While some of the observed changes in behavior were individually specific, some swimming kinematics were consistently modulated in response to high drag and buoyancy associated with entangling gear, affecting thrust production. In high drag and buoyancy conditions, fluke strokes were significantly shorter and more variable in shape, and gliding was less frequent. Thrust and efficiency significantly differed among dive phases. Disentanglement reduced thrust coefficients ~4-fold, leading to 1.2 to 1.8-fold lower power (W). Ideal propulsive efficiency was significantly lower when entangled, though we detected no difference in observed propulsive efficiency between the conditions. Similar to carrying heavy objects or changing shoes, we present another condition where animals perceive unique movement constraints over seconds to minutes and develop compensatory strategies, altering their movement accordingly.J.M.v.d.H was supported by a postgraduate scholarship from the Natural Sciences and Engineering Research Council of Canada, the MIT Martin Family for Sustainability Fellowship, the Herrington Fitch Family Foundation, a NOAA Award #NA14OAR4320158 to The Cooperative Institute for the North Atlantic Region, and a WHOI-Duke Fellowship through the WHOI Marine Mammal Center

Marine seismic surveys and ocean noise : time for coordinated and prudent planning

Marine seismic surveys use intense (eg >= 230 decibel [dB] root mean square [RMS]) sound impulses to explore the ocean bottom for hydrocarbon deposits, conduct geophysical research, and establish resource claims under the United Nations Convention on the Law of the Sea. The expansion of seismic surveys necessitates greater regional and international dialogue, partnerships, and planning to manage potential environmental risks. Data indicate several reasons for concern about the negative impacts of anthropogenic noise on numerous marine species, including habitat displacement, disruption of biologically important behaviors, masking of communication signals, chronic stress, and potential auditory damage. The sound impulses from seismic surveys - spanning temporal and spatial scales broader than those typically considered in environmental assessments - may have acute, cumulative, and chronic effects on marine organisms. Given the international and transboundary nature of noise from marine seismic surveys, we suggest the creation of an international regulatory instrument, potentially an annex to the existing International Convention on the Prevention of Pollution from Ships, to address the issue.Publisher PDFPeer reviewe

North Atlantic right whales (Eubalaena glacialis) ignore ships but respond to alerting stimuli

Author Posting. © Royal Society, 2004. This article is posted here by permission of Royal Society for personal use, not for redistribution. The definitive version was published in Proceedings of the Royal Society of London B 271 (2004): 227-231, doi:10.1098/rspb.2003.2570.North Atlantic right whales were extensively hunted during the whaling era and have not recovered. One of the primary factors inhibiting their recovery is anthropogenic mortality caused by ship strikes. To assess risk factors involved in ship strikes, we used a multi-sensor acoustic recording tag to measure the responses of whales to passing ships and experimentally tested their responses to controlled sound exposures, which included recordings of ship noise, the social sounds of conspecifics and a signal designed to alert the whales. The whales reacted strongly to the alert signal, they reacted mildly to the social sounds of conspecifics, but they showed no such responses to the sounds of approaching vessels as well as actual vessels. Whales responded to the alert by swimming strongly to the surface, a response likely to increase rather than decrease the risk of collision.Funding for this work was provided by the Fisheries Service of the US National Oceanic and Atmospheric Administration (contract no. NA87RJ0445), and was conducted under NOAA Fisheries permit to conduct scientific research no. 1014 issued to Dr Scott Kraus and Canadian Department of Fisheries and Oceans permits 2001-559 and 2002-568

Comparative manufacture and cell-based delivery of antiretroviral nanoformulations

Nanoformulations of crystalline indinavir, ritonavir, atazanavir, and efavirenz were manufactured by wet milling, homogenization or sonication with a variety of excipients. The chemical, biological, immune, virological, and toxicological properties of these formulations were compared using an established monocyte-derived macrophage scoring indicator system. Measurements of drug uptake, retention, release, and antiretroviral activity demonstrated differences amongst preparation methods. Interestingly, for drug cell targeting and antiretroviral responses the most significant difference among the particles was the drug itself. We posit that the choice of drug and formulation composition may ultimately affect clinical utility

Effects of vessel traffic on relative abundance and behaviour of cetaceans : the case of the bottlenose dolphins in the Archipelago de La Maddalena, north-western Mediterranean sea

Acknowledgements This study was part of the Tursiops Project of the Dolphin Research Centre of Caprera, La Maddalena. Financial and logistical support was provided by the Centro Turistico Studentesco (CTS) and by the National Park of the Archipelago de La Maddalena. We thank the Natural Reserve of Bocche di Bonifacio for the support provided during data collection. The authors thank the numerous volunteers of the Caprera Dolphin Research Centre and especially Marco Ferraro, Mirko Ugo, Angela Pira and Maurizio Piras whose assistance during field observation and skills as a boat driver were invaluable.Peer reviewedPostprin

Long-acting antituberculous therapeutic nanoparticles target macrophage endosomes.

Eradication of Mycobacterium tuberculosis (MTB) infection requires daily administration of combinations of rifampin (RIF), isoniazid [isonicotinylhydrazine (INH)], pyrazinamide, and ethambutol, among other drug therapies. To facilitate and optimize MTB therapeutic selections, a mononuclear phagocyte (MP; monocyte, macrophage, and dendritic cell)-targeted drug delivery strategy was developed. Long-acting nanoformulations of RIF and an INH derivative, pentenyl-INH (INHP), were prepared, and their physicochemical properties were evaluated. This included the evaluation of MP particle uptake and retention, cell viability, and antimicrobial efficacy. Drug levels reached 6 μg/10(6) cells in human monocyte-derived macrophages (MDMs) for nanoparticle treatments compared with 0.1 μg/10(6) cells for native drugs. High RIF and INHP levels were retained in MDM for \u3e15 d following nanoparticle loading. Rapid loss of native drugs was observed in cells and culture fluids within 24 h. Antimicrobial activities were determined against Mycobacterium smegmatis (M. smegmatis). Coadministration of nanoformulated RIF and INHP provided a 6-fold increase in therapeutic efficacy compared with equivalent concentrations of native drugs. Notably, nanoformulated RIF and INHP were found to be localized in recycling and late MDM endosomal compartments. These were the same compartments that contained the pathogen. Our results demonstrate the potential of antimicrobial nanomedicines to simplify MTB drug regimens

Selective reactions to different killer whale call categories in two delphinid species

This research was supported by award RC-2154 from the Strategic Environmental Research and Development Program and funding from the Naval Facilities Engineering Command Atlantic and National Oceanic and Atmospheric Administration Fisheries, Southeast Region.The risk of predation is often invoked as an important factor influencing the evolution of social organization in cetaceans, but little direct information is available about how these aquatic mammals respond to predators or other perceived threats. We used controlled playback experiments to examine the behavioral responses of short-finned pilot whales (Globicephala macrorhynchus) off Cape Hatteras, NC, USA, and Risso's dolphins (Grampus griseus) off the coast of Southern California, USA, to the calls of a potential predator, mammal-eating killer whales. We transmitted calls of mammal-eating killer whales, conspecifics and baleen whales to 10 pilot whales and four Risso's dolphins equipped with multi-sensor archival acoustic recording tags (DTAGs). Only playbacks of killer whale calls resulted in significant changes in tagged animal heading. The strong responses observed in both species occurred only following exposure to a subset of killer whale calls, all of which contained multiple non-linear properties. This finding suggests that these structural features of killer whale calls convey information about predatory risk to pilot whales and Risso's dolphins. The observed responses differed between the two species; pilot whales approached the sound source while Risso's dolphins fled following playbacks. These divergent responses likely reflect differences in anti-predator response mediated by the social structure of the two species.Publisher PDFPeer reviewe

Why whales are big but not bigger : physiological drivers and ecological limits in the age of ocean giants

This research was funded in part by grants from the National Science Foundation (IOS-1656676, IOS-1656656; OPP-1644209 and 07-39483), the Office of Naval Research (N000141612477), and a Terman Fellowship from Stanford University. All procedures in USA were conducted under approval of the National Marine Fisheries Service (Permits 781-1824, 16163, 14809, 16111, 19116, 15271, 20430), Canada DFO SARA/MML 2010-01/SARA-106B, National Marine Sanctuaries (MULTI-2017-007), Antarctic Conservation Act (2009-014, 2015-011) and institutional IACUC committee protocols. Fieldwork, data collection and data processing for M. densirostris were funded by the Office of Naval Research grants N00014-07-10988, N00014-07-11023, N00014-08-10990, N00014-18-1-2062, and 00014-15-1-2553, and the U.S. Strategic Environmental Research and Development Program Grant SI-1539. PLT gratefully acknowledges funding from funding the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland). MASTS is funded by the Scottish Funding Council (HR09011) and contributing institutions.The largest animals are marine filter feeders, but the underlying mechanism of their large size remains unexplained. We measured feeding performance and prey quality to demonstrate how whale gigantism is driven by the interplay of prey abundance and harvesting mechanisms that increase prey capture rates and energy intake. The foraging efficiency of toothed whales that feed on single prey is constrained by the abundance of large prey, whereas filter-feeding baleen whales seasonally exploit vast swarms of small prey at high efficiencies. Given temporally and spatially aggregated prey, filter feeding provides an evolutionary pathway to extremes in body size that are not available to lineages that must feed on one prey at a time. Maximum size in filter feeders is likely constrained by prey availability across space and time.PostprintPeer reviewe