149 research outputs found

    Photoenergy transduction in halobacterium halobium

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    The structure and function of a rhodopsin-like pigment bacteriorhodopsin, discovered and isolated from the membranes of the halophile Halobacterium halobium, were studied. Intermediatesm appearing in the cyclic photoreaction that drives the proton translocation, were spectroscopically characterized. The charge translocation in membrane monolayers and mulitlayers placed between electrodes were kinetically resolved. A model was developed for the proton translocation process, in which the isomerization of the retinal Schiff base decreases its pK to drive the proton off and simultaneaouly changes the connectivity from the cytoplasmic surface to the external surface. The stoichiometry of proton pumping in intact cells and the effect of the light generated electrochemical potential on the kinetics of the photoreaction cycle and the synthesis of ATP were investigated

    Gulf of Maine seals - populations, problems and priorities

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    Meeting held: May 28th – 29th 2009, WHOI, Quissett Campus, Sponsored by the Marine Mammal Center at WHOIAs pinniped populations shift and change along the northeast U.S. and Canadian coastline, so too do the interests and issues of regional residents, scientists and stakeholders. In May 2009 the Woods Hole Oceanographic Institution (WHOI) sponsored a meeting resulting in recommendations in three key areas regarding pinnipeds: population dynamics, human interaction and disease/health. The population group recommended: developing long-term surveys over all seasons and geographic ranges, coordinating sampling efforts for dietary research, refining correction factors for survey results, increasing documentation of fishery interactions and developing means of funding. The human interactions group recommended: addressing marine debris, developing survey, reporting and retrieval protocols for discarded fishing gear, studying impact of and expanding education and outreach for commercial seal watching, researching methods to deter depredation from fishing gear, streamlining the permitting processes for acoustic deterrent and gear modification research, and increasing cooperative research and outreach to the fishing community. The health and disease working group recommended: establishing baseline health indicators, addressing priority disease concerns, creating a pool of resources for standardized analysis of normal and unusual health event monitoring, determining standard health baselines for release, establishing a health consortium, improving communication along the coastline and establishing long term funding and ongoing collaboration.Funding was provided by the Woods Hole Oceanographic Institution Marine Mammal Cente

    Seals and ecosystem health : meeting report of the Northwest Atlantic Seal Research Consortium

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    On May 1 and 2, 2015, over 75 people attended the Northwest Atlantic Seal Research Consortium's first official biennial two day scientific meeting, "Seals and Ecosystem Health", at Salem State University in Salem, Massachusetts. The focus of the meeting was addressed by two keynote presentations: "Seals and Ecosystem Health" and "Marine mammals and ecosystem functioning: what can recovering seal populations teach us?" The first day of the meeting featured 16 oral and two poster presentations, covering a diverse range of topics highlighting the important underlying concepts, data gaps and future directions. Following the theme of the meeting, attendees discussed the nature of ecosystems, acknowledging the complex and often cryptic interactions between components, with cumulative and synergistic effects on animals and their environment. As our understanding of the ecological role of seals in the Northwest Atlantic grows, the cumulative interactions increase our recognition of seals as sentinels of ecosystem health. Meeting presentations highlighted the value of existing data and ongoing research efforts, including long-term population monitoring, tagging and photo-identification, stranding response, and rehabilitation facilities. The importance of observational effort was recognized as a critical component in detecting mortality events, documenting population processes in remote locations and cryptic species interactions. Research priorities identified included development of molecular tools for study of diet and disease, population dynamics studies (demographics and trends), telemetry-based investigations of spatiotemporal distribution, and model- and field-based ecosystem-level studies. Several of the presentations and the panel discussion, "Addressing Perception vs. Reality: How data (or lack of data) affects public perceptions and management decisions," highlighted the diverse and evolving perspectives with which society views seals, perspectives that are often biased by the backgrounds of individual humans. Diverse opinions necessitate engagement of stakeholders and the public, and societal objectives need to be defined in order to effect science-based natural resource management at an ecosystem level. At the closing of the meeting, recommendations from the panel discussion and for the overall goals of NASRC were discussed.Funding was provided by the Woods Hole Oceanographic Institution Marine Mammal Center and the US Marine Mammal Commissio

    Development of a one-step duplex RT-qPCR for the quantification of phocine distemper virus

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    Author Posting. © Wildlife Disease Association, 2015. This article is posted here by permission of Wildlife Disease Association for personal use, not for redistribution. The definitive version was published in Journal of Wildlife Diseases 51 (2015): 454-465, doi:10.7589/2014-05-142.Worldwide, stranded marine mammals and the network personnel who respond to marine mammal mortality have provided much of the information regarding marine morbillivirus infections. An assay to determine the amount of virus present in tissue samples would be useful to assist in routine surveying of animal health and for monitoring large-scale die-off events. False negatives from poor-quality samples prevent determination of the true extent of infection, while only small amounts of tissue samples or archived RNA may be available at the time of collection for future retrospective analysis. We developed a one-step duplex real-time reverse transcriptase-quantitative-PCR assay (RT-qPCR) based on Taqman probe technology to quantify phocine distemper virus (PDV) isolated from an outbreak in harbor (Phoca vitulina concolor) and gray seals (Halichoerus grypus) along the northeast US coast in 2006. The glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) gene was selected to assess RNA quality. This duplex assay is specific for PDV and sensitive through a range of 100 to 109 copies ds-plasmid DNA. For the GAPDH target, the reaction in duplex amplified 100 to 109 copies of ds-plasmid DNA and was detectable in multiple seal species. This assay reduced the likelihood of false negative results due to degradation of tissues and well-to-well variability while providing sensitive and specific detection of PDV, which would be applicable in molecular epidemiologic studies and pathogen detection in field and laboratory investigations involving a variety of seal species.This project was possible thanks to the John H. Prescott Marine Mammal Rescue Assistance Grant Program (Grant NA10NMF4390260) and with support from the National Oceanographic and Atmospheric Administration/University of Connecticut Oceans and Human Health I-RICH Fellowship.2016-04-0

    Gulf of Maine seals - fisheries interactions and integrated research : final report

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    Meeting held: October 28, 2011, Provincetown Center for Coastal Studies, Provincetown, MA. Sponsored by the Marine Mammal Center at the Woods Hole Oceanographic Institution and the Provincetown Center for Coastal StudiesThe 2011 meeting, “Gulf of Maine Seals: Fisheries Interactions and Integrated Research”, held at the Provincetown Center for Coastal Studies (PCCS), featured posters and oral presentations as well as a series of discussion groups. This meeting was a follow up to the 2009 meeting, “Gulf of Maine Seals - Populations, Problems and Priorities”, held at the Woods Hole Oceanographic Institution (WHOI) (Bogomolni et al. 2010). At the conclusion of the 2009 meeting, attendees emphasized the need to improve communication, to obtain funding for long term research, to continue meeting on a regular basis, to increase data and data sharing, and to support cross cutting research between the meeting’s three primary topic areas: disease and health; human and fishery interactions; and population biology. The overarching goals of the 2011 meeting were to discuss and share work to date, present some of the tools developed since the 2009 meeting, and outline goals for future integrated research. One of the tools presented within the framework of cross-cutting research areas and integrative research was the development of a sightings database and website for uniquely identifiable (unique pelage, scars, lesions, tagged, branded, marked, etc.) animals. The practicality of this tool as a means to increase communication was discussed. Additionally, seal/fisheries interactions throughout the Gulf of Maine, Cape Cod and waters off of the northeast U.S. have continued to concern stakeholders since the 2009 meeting. The urgency of documenting, understanding and mitigating these interactions has become more apparent. Therefore, the focus of the 2011 Provincetown meeting was on fisheries interaction and related topics raised at the last 2009 workshop and in the meetings with Cape Cod fishermen described below. For the purposes of this report, 'fisheries interaction' can be direct/operational (e.g. depredation, when seals remove fish from gear; or entanglement/bycatch, when seals are unintentionally captured), or indirect/ecological (competition, displacement or other large-scale interactions between seals and fisheries). Stakeholder concerns about fisheries interactions and recent increases in local seal abundance were rising prior to the 2009 meeting. In December of 2006, the Chatham-based Cape Cod Commercial Hook Fishermen’s Association (CCCHFA) took the lead in organizing a meeting entitled, “Structuring a Novel Research Team to Define and Assess the Impact of Human/Seal Interactions on Cape Cod/Gulf of Maine through Ecosystem-Based Analysis”. Participants included fishermen, policy makers, environmental organizations and researchers aiming to develop a unique partnership to study the New England seal population. The goal of this meeting was to create a research team that would define the ecological role of seals in Cape Cod waters by studying population dynamics, behavior, and health. This meeting resulted in a successful partnership, financially aided by the International Fund for Animal Welfare (IFAW), between fishermen and seal researchers. A cost-effective cooperative research agreement was reached whereby seal researchers were provided boat transport around the Chatham and Monomoy areas by local fishermen. This agreement allowed students and researchers to gain access to areas off of Chatham that would otherwise not have been accessible. It also supported a collaborative effort to increase understanding and communication between stakeholders. In addition to the CCCHFA-led meeting in 2006, a series of informal meetings have been held on Cape Cod between commercial and recreational fishermen and marine scientists. This work was initially funded by the Cape Cod Five Cents Savings Bank Charitable Foundation. Owen Nichols and Lisa Sette (PCCS) have held individual meetings with commercial fishermen in Chatham, Orleans, and Provincetown, and recreational fishermen, outfitters, and associations throughout the Outer Cape. These individual meetings were followed by larger group meetings in Eastham and Chatham in 2010 and 2011, and more are planned for 2012. Attendees included commercial and recreational fishermen and scientists, and discussion topics included observed seal/fishery interactions and potential collaborative research projects. The goal of the meetings is to develop a working group composed of members of the fishing and scientific communities with expertise in marine mammal and fisheries ecology. The above meetings laid the foundation for the 2011 meeting, during which members of the scientific and fishing communities gathered to focus on fisheries interactions and integrated research techniques to quantify and mitigate interactions. Several invited presentations were given, some of which were scheduled (Appendix A) with selected abstracts provided (Appendix B), and some of which were delivered on an ad hoc basis upon request from organizers or attendees (see Appendix F for edited transcripts of presentations). In order to ensure that the fishing community had a distinct voice, a forum was included in the agenda, during which fishermen were encouraged to share their observations, experiences and concerns. Separately, moderated discussion groups focused specifically on fisheries interactions, tagging and tracking, and management issues. All four sessions, despite their specific foci, shared common themes such as the need for collaborative research involving both the scientific and fishing communities. Recommendations from the discussion groups and summaries from each session are listed on the following pages.Funding was provided by the Woods Hole Oceanographic Institution Marine Mammal Center and the Provincetown Center for Coastal Studie

    Discrimination between bycatch and other causes of cetacean and pinniped stranding

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    © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Diseases of Aquatic Organisms 127 (2018): 83-95, doi:10.3354/dao03189.The challenge of identifying cause of death in discarded bycaught marine mammals stems from a combination of the non-specific nature of the lesions of drowning, the complex physiologic adaptations unique to breath-holding marine mammals, lack of case histories, and the diverse nature of fishing gear. While no pathognomonic lesions are recognized, signs of acute external entanglement, bulging or reddened eyes, recently ingested gastric contents, pulmonary changes, and decompression-associated gas bubbles have been identified in the condition of peracute underwater entrapment (PUE) syndrome in previous studies of marine mammals. We reviewed the gross necropsy and histopathology reports of 36 cetaceans and pinnipeds including 20 directly observed bycaught and 16 live stranded animals that were euthanized between 2005 and 2011 for lesions consistent with PUE. We identified 5 criteria which present at significantly higher rates in bycaught marine mammals: external signs of acute entanglement, red or bulging eyes, recently ingested gastric contents, multi-organ congestion, and disseminated gas bubbles detected grossly during the necropsy and histologically. In contrast, froth in the trachea or primary bronchi, and lung changes (i.e. wet, heavy, froth, edema, congestion, and hemorrhage) were poor indicators of PUE. This is the first study that provides insight into the different published parameters for PUE in bycatch. For regions frequently confronted by stranded marine mammals with non-specific lesions, this could potentially aid in the investigation and quantification of marine fisheries interactions.This work was supported by the Nat - ional Oceanic and Atmospheric Administration (NOAA) John H. Prescott Program NA12NMF4390144. The WHOI Marine Mammal Center, Wick and Sloan Simmons, and the University of Las Palmas de Gran Canaria provided postdoctoral funding for Y.B.Q

    An assessment of temporal, spatial and taxonomic trends in harmful algal toxin exposure in stranded marine mammals from the US New England coast

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    © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Fire, S. E., Bogomolni, A., DiGiovanni, R. A., Jr., Early, G., Leighfield, T. A., Matassa, K., Miller, G. A., Moore, K. M. T., Moore, M., Niemeyer, M., Pugliares, K., Wang, Z., & Wenzel, F. W. An assessment of temporal, spatial and taxonomic trends in harmful algal toxin exposure in stranded marine mammals from the US New England coast. Plos One, 16(1),(2021): e0243570, https://doi.org/10.1371/journal.pone.0243570.Despite a long-documented history of severe harmful algal blooms (HABs) in New England coastal waters, corresponding HAB-associated marine mammal mortality events in this region are far less frequent or severe relative to other regions where HABs are common. This long-term survey of the HAB toxins saxitoxin (STX) and domoic acid (DA) demonstrates significant and widespread exposure of these toxins in New England marine mammals, across multiple geographic, temporal and taxonomic groups. Overall, 19% of the 458 animals tested positive for one or more toxins, with 15% and 7% testing positive for STX and DA, respectively. 74% of the 23 different species analyzed demonstrated evidence of toxin exposure. STX was most prevalent in Maine coastal waters, most frequently detected in common dolphins (Delphinus delphis), and most often detected during July and October. DA was most prevalent in animals sampled in offshore locations and in bycaught animals, and most frequently detected in mysticetes, with humpback whales (Megaptera novaeangliae) testing positive at the highest rates. Feces and urine appeared to be the sample matrices most useful for determining the presence of toxins in an exposed animal, with feces samples having the highest concentrations of STX or DA. No relationship was found between the bloom season of toxin-producing phytoplankton and toxin detection rates, however STX was more likely to be present in July and October. No relationship between marine mammal dietary preference and frequency of toxin detection was observed. These findings are an important part of a framework for assessing future marine mammal morbidity and mortality events, as well as monitoring ecosystem health using marine mammals as sentinel organisms for predicting coastal ocean changes.S.F. - NOAA John H. Prescott Marine Mammal Rescue Assistance Grant Program #NA16NMF4390151 S.F. - NOAA John H. Prescott Marine Mammal Rescue Assistance Grant Program #NA17NMF4390082 S.F. - Florida Tech Department of Biological Sciences S.F. - Florida Tech John H. Evans Library Open Access Subvention Fund. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Marine mammal skin microbiotas are influenced by host phylogeny

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Apprill, A., Miller, C. A., Van Cise, A. M., U'Ren, J. M., Leslie, M. S., Weber, L., Baird, R. W., Robbins, J., Landry, S., Bogomolni, A., & Waring, G. Marine mammal skin microbiotas are influenced by host phylogeny. Royal Society Open Science, 7(5), (2020): 192046, doi:10.1098/rsos.192046.Skin-associated microorganisms have been shown to play a role in immune function and disease of humans, but are understudied in marine mammals, a diverse animal group that serve as sentinels of ocean health. We examined the microbiota associated with 75 epidermal samples opportunistically collected from nine species within four marine mammal families, including: Balaenopteridae (sei and fin whales), Phocidae (harbour seal), Physeteridae (sperm whales) and Delphinidae (bottlenose dolphins, pantropical spotted dolphins, rough-toothed dolphins, short-finned pilot whales and melon-headed whales). The skin was sampled from free-ranging animals in Hawai‘i (Pacific Ocean) and off the east coast of the United States (Atlantic Ocean), and the composition of the bacterial community was examined using the sequencing of partial small subunit (SSU) ribosomal RNA genes. Skin microbiotas were significantly different among host species and taxonomic families, and microbial community distance was positively correlated with mitochondrial-based host genetic divergence. The oceanic location could play a role in skin microbiota variation, but skin from species sampled in both locations is necessary to determine this influence. These data suggest that a phylosymbiotic relationship may exist between microbiota and their marine mammal hosts, potentially providing specific health and immune-related functions that contribute to the success of these animals in diverse ocean ecosystems.Funding provided by the Earth Microbiome Project, WHOI Marine Mammal Center, WHOI Ocean Life Institute and WHOI's Andrew W. Mellon Foundation Endowed Fund for Innovative Research to A.A. Hawai‘i sampling was undertaken during field projects funded by grants from ONR (N000141310648 to R.W.B, N000141110612 to T.A. Mooney and N00014101686 to R.D. Andrews) and NMFS (NA13OAR4540212 to R.W.B)

    Attractant and Repellent Signaling Conformers of Sensory Rhodopsin−Transducer Complexes†

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    ABSTRACT: Attractant and repellent signaling conformers of the dual-signaling phototaxis receptor sensory rhodopsin I and its transducer subunit (SRI-HtrI) have recently been distinguished experimentally by the opposite connection of their retinylidene protonated Schiff bases to the outwardly located periplasmic side and inwardly located cytoplasmic side. Here we show that the pKa of the outwardly located Asp76 counterion in the outwardly connected conformer is lowered by ∼1.5 units from that of the inwardly connected conformer. The pK a difference enables quantitative determination of the relative amounts of the two conformers in wild-type cells and behavioral mutants prior to photoexcitation, comparison of their absorption spectra, and determination of their relative signaling efficiency. We have shown that the onephoton excitation of the SRI-HtrI attractant conformer causes a Schiff base connectivity switch from inwardly connected to outwardly connected states in the attractant signaling photoreaction. Conversely, a second near-UV photon drives the complex back to the inwardly connected conformer in the repellent signaling photoreaction. The results suggest a model of the color-discriminating dual-signaling mechanism in which phototaxis responses (his-kinase modulation) result from the photointerconversion of the two oppositely connected SRI-HtrI conformers by one-photon and two-photon activation. Furthermore, we find that the related repellent phototaxis SRII-HtrII receptor complex has an outwardly connecte
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