165 research outputs found

    Underwater Passive Acoustic Monitoring Around Kauai, Hawaii

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    Ph.D. Thesis. University of Hawaiʻi at Mānoa 2018

    Molecular characterization and morphology of Cochlodinium strangulatum, the type species of Cochlodinium, and Margalefidinium gen. nov. for C. polykrikoides and allied species (Gymnodiniales, Dinophyceae)

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    © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Harmful Algae 63 (2017): 32-44, doi:10.1016/j.hal.2017.01.008.Photosynthetic species of the dinoflagellate genus Cochlodinium such as C. polykrikoides, one of the most harmful bloom-forming dinoflagellates, have been extensively investigated. Little is known about the heterotrophic forms of Cochlodinium, such as its type species, Cochlodinium strangulatum. This is an uncommon, large (~200 μm long), solitary, and phagotrophic species, with numerous refractile bodies, a central nucleus enclosed in a distinct perinuclear capsule, and a cell surface with fine longitudinal striae and a circular apical groove. The morphology of C. polykrikoides and allied species is different from the generic type. It is a bloom-forming species with single, two or four-celled chains, small cell size (25–40 μm long) with elongated chloroplasts arranged longitudinally and in parallel, anterior nucleus, eye-spot in the anterior dorsal side, and a cell surface smooth with U-shaped apical groove. Phylogenetic analysis based on LSU rDNA sequences revealed that C. strangulatum and C. polykrikoides/C. fulvescens formed two distally related, independent lineages. Based on morphological and phylogenetic analyses, the diagnosis of Cochlodinium is emended and C. miniatum is proposed as synonym of C. strangulatum. The new genus Margalefidinium gen. nov., and new combinations for C. catenatum, C. citron, C. flavum, C. fulvescens and C. polykrikoides are proposed.F.G. was supported by the Brazilian Conselho Nacional de Desenvolvimento Científico e Tecnológico [grant number BJT 370646/2013–14]. Support for M.L.R. and D.M.A. was provided through the Woods Hole Center for Oceans and Human Health, National Science Foundation [grant number OCE–1314642] and National Institute of Environmental Health Sciences [grant number 1–P01–ES021923–01]

    Characterization and comparison of toxin-producing isolates of Dinophysis acuminata from New England and Canada

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    Following the identification of the first toxic isolate of Dinophysis acuminata from the northwestern Atlantic, we conducted detailed investigations into the morphology, phylogeny, physiology, and toxigenicity of three isolates from three sites within the northeastern U.S./Canada region: Eel Pond and Martha\u27s Vineyard, Massachusetts, and the Bay of Fundy. Another isolate, collected from the Gulf of Mexico, was grown under the same light, temperature, and prey conditions for comparison. Despite observed phenotypic heterogeneity, morphometrics and molecular evidence classified the three northwestern Atlantic isolates as D. acuminata Claparede & Lachmann, whereas the isolate from the Gulf of Mexico was morphologically identified as D. cf. ovum. Physiological and toxin analyses supported these classifications, with the three northwestern Atlantic isolates being more similar to each other with respect to growth rate, toxin profile, and diarrhetic shellfish poisoning (DSP) toxin content (okadaic acid + dinophysistoxin 1/cell) than they were to the isolate from the Gulf of Mexico, which had toxin profiles similar to those published for D. cf. ovum F. Schutt. The DSP toxin content, 0.01-1.8 pg okadaic acid (OA) + dinophysistoxin (DTX1) per cell, of the three northwestern Atlantic isolates was low relative to other D. acuminata strains from elsewhere in the world, consistent with the relative scarcity of shellfish harvesting closures due to DSP toxins in the northeastern U. S. and Canada. If this pattern is repeated with the analyses of more geographically and temporally dispersed isolates from the region, it would appear that the risk of significant DSP toxin outbreaks in the northwestern Atlantic is low to moderate. Finally, the morphological, physiological, and toxicological variability within D. acuminata may reflect spatial (and/or temporal) population structure, and suggests that sub-specific resolution may be helpful in characterizing bloom dynamics and predicting toxicity

    Impact of sea-ice dynamics on the spatial distribution of diatom resting stages in sediments of the Pacific Arctic region

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    Author Posting. © American Geophysical Union, 2021. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 126(7), (2021): e2021JC017223, https://doi.org/10.1029/2021JC017223.The Pacific Arctic region is characterized by seasonal sea-ice, the spatial extent and duration of which varies considerably. In this region, diatoms are the dominant phytoplankton group during spring and summer. To facilitate survival during periods that are less favorable for growth, many diatom species produce resting stages that settle to the seafloor and can serve as a potential inoculum for subsequent blooms. Since diatom assemblage composition is closely related to sea-ice dynamics, detailed studies of biophysical interactions are fundamental to understanding the lower trophic levels of ecosystems in the Pacific Arctic. One way to explore this relationship is by comparing the distribution and abundance of diatom resting stages with patterns of sea-ice coverage. In this study, we quantified viable diatom resting stages in sediments collected during summer and autumn 2018 and explored their relationship to sea-ice extent during the previous winter and spring. Diatom assemblages were clearly dependent on the variable timing of the sea-ice retreat and accompanying light conditions. In areas where sea-ice retreated earlier, open-water species such as Chaetoceros spp. and Thalassiosira spp. were abundant. In contrast, proportional abundances of Attheya spp. and pennate diatom species that are commonly observed in sea-ice were higher in areas where diatoms experienced higher light levels and longer day length in/under the sea-ice. This study demonstrates that sea-ice dynamics are an important determinant of diatom species composition and distribution in the Pacific Arctic region.This work was conducted by the Arctic Challenge for Sustainability (ArCS) project, Arctic Challenge for Sustainability II (ArCSII) project and ArCS program for overseas visits by young researchers. In addition, this work was partly supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number JP20J20410 and JP21H02263. We thank Anderson laboratory members for their support of our study at WHOI, and also thank Robert Pickart, Leah McRaven, and Jacqueline Grebmeier for their support and assistance on the Healy cruises. Funding for DA, EF, and MR was provided by the NOAA Arctic Research Program through the Cooperative Institute for the North Atlantic Region (CINAR Award NA14OAR4320158), by the NOAA ECOHAB Program (NA20NOS4780195) and by the National Science Foundation Office of Polar Programs (OPP-1823002). This is ECOHAB contribution number ECO986.2021-12-1

    Asynchrony of Gambierdiscus spp. abundance and toxicity in the U.S. Virgin Islands: implications for monitoring and management of Ciguatera

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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 Liefer, J. D., Richlen, M. L., Smith, T. B., DeBose, J. L., Xu, Y., Anderson, D. M., & Robertson, A. Asynchrony of Gambierdiscus spp. abundance and toxicity in the U.S. Virgin Islands: implications for monitoring and management of Ciguatera. Toxins, 13(6), (2021): 413, https://doi.org/10.3390/toxins13060413.Ciguatera poisoning (CP) poses a significant threat to ecosystem services and fishery resources in coastal communities. The CP-causative ciguatoxins (CTXs) are produced by benthic dinoflagellates including Gambierdiscus and Fukuyoa spp., and enter reef food webs via grazing on macroalgal substrates. In this study, we report on a 3-year monthly time series in St. Thomas, US Virgin Islands where Gambierdiscus spp. abundance and Caribbean-CTX toxicity in benthic samples were compared to key environmental factors, including temperature, salinity, nutrients, benthic cover, and physical data. We found that peak Gambierdiscus abundance occurred in summer while CTX-specific toxicity peaked in cooler months (February–May) when the mean water temperatures were approximately 26–28 °C. These trends were most evident at deeper offshore sites where macroalgal cover was highest year-round. Other environmental parameters were not correlated with the CTX variability observed over time. The asynchrony between Gambierdiscus spp. abundance and toxicity reflects potential differences in toxin cell quotas among Gambierdiscus species with concomitant variability in their abundances throughout the year. These results have significant implications for monitoring and management of benthic harmful algal blooms and highlights potential seasonal and highly-localized pulses in reef toxin loads that may be transferred to higher trophic levels.This work was funded in part by the National Oceanic and Atmospheric Administration, Ecology and Oceanography of Harmful Algal Blooms Program (ECOHAB publication number 984) through the CiguaHAB project (NA11NOS4780028), and also contributes to CIGUATOX (NA17NOS4780181) granted to coauthors AR, TBS, DMA, and MLR. Additional support was provided by NSF Partnerships in International Research and Education (1743802), and the Greater Caribbean Center for Ciguatera Research (NIH 1P01ES028949-01 and NSF 1841811). Financial support of YX was from the National Natural Science Foundation of China (41976155), the Natural Science Foundation of Guangxi Province (2020GXNSFDA297001)

    A strategic framework for community engagement in oceans and human health

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    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Carson, M., Doberneck, D., Hart, Z., Kelsey, H., Pierce, J., Porter, D., Richlen, M., Schandera, L., & Triezenberg, H. A strategic framework for community engagement in oceans and human health, Community Science, 1(1), (2022): e2022CSJ000001, https://doi.org/10.1029/2022csj000001.Over the past two decades, scientific research on the connections between the health and resilience of marine ecosystems and human health, well-being, and community prosperity has expanded and evolved into a distinct “metadiscipline” known as Oceans and Human Health (OHH), recognized by the scientific community as well as policy makers. OHH goals are diverse and seek to improve public health outcomes, promote sustainable use of aquatic systems and resources, and strengthen community resilience. OHH research has historically included some level of community outreach and partner involvement; however, the increasing disruption of aquatic environments and urgency of public health impacts calls for a more systematic approach to effectively identify and engage with community partners to achieve project goals and outcomes. Herein, we present a strategic framework developed collaboratively by community engagement personnel from the four recently established U.S. Centers for Oceans and Human Health (COHH). This framework supports researchers in defining levels of community engagement and in aligning partners, purpose, activities, and approaches intentionally in their community engagement efforts. Specifically, we describe: (a) a framework for a range of outreach and engagement approaches; (b) the need for identifying partners, purpose, activities, and approaches; and (c) the importance of making intentional alignment among them. Misalignment across these dimensions may lead to wasting time or resources, eroding public trust, or failing to achieve intended outcomes. We illustrate the framework with examples from current COHH case studies and conclude with future directions for strategic community engagement in OHH and other environmental health contexts.This publication was prepared by Heather Triezenberg and the team under award NA180AR4170102 from the National Oceanic and Atmospheric Administration, U.S. Department of Commerce through the Regents of the University of Michigan, and supported by funding from the NIH (1P01ES028939-01) and the NSF (1840715) to the Bowling Green State University Great Lakes Center for Fresh Waters and Human Health. Funding for M. L. Richlen was provided by the NSF (OCE1840381) and NIH (1P01-ES028938-01) through the Woods Hole Center for Oceans and Human Health. Research at the Center for Oceans and Human Health and Climate Change Interactions (OHHC2I) at the University of South Carolina is supported by the NIH Award Number P01ES028942, granted to Principal Investigators Geoffrey Scott and Paul Sandifer. M. A. Carson, Z. Hart, H. Kelsey, D. E. Porter, and L. Schandera are Community Engagement Core investigators at this Center. Funding for J. Pierce is provided by the NSF (grant number OCE-1841811) and the NIH (P01ES028949) through the Greater Caribbean Center for Ciguatera Research at the Florida Gulf Coast University

    LSU rDNA based RFLP assays for the routine identification of Gambierdiscus species

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    © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Harmful Algae 66 (2017): 20-28, doi:10.1016/j.hal.2017.04.009.Gambierdiscus is a genus of benthic dinoflagellates commonly associated with ciguatera fish poisoning (CFP), which is generally found in tropical or sub-tropical regions around the world. Morphologically similar species within the genus can vary in toxicity; however, species identifications are difficult or sometimes impossible using light microscopy. DNA sequencing of ribosomal RNA genes (rDNA) is thus often used to identify and describe Gambierdiscus species and ribotypes, but the expense and time can be prohibitive for routine culture screening and/or large-scale monitoring programs. This study describes a restriction fragment length polymorphism (RFLP) typing method based on analysis of the large subunit ribosomal RNA gene (rDNA) that can successfully identify at least nine of the described Gambierdiscus species and two Fukuyoa species. The software programs DNAMAN 6.0 and Restriction Enzyme Picker were used to identify a set of restriction enzymes (SpeI, HpyCH4IV, and TaqαI) capable of distinguishing most of the known Gambierdiscus species for which DNA sequences were available. This assay was tested using in silico analysis and cultured isolates, and species identifications of isolates assigned by RFLP typing were confirmed by DNA sequencing. To verify the assay and assess intra-specific heterogeneity in RFLP patterns, identifications of 63 Gambierdiscus isolates comprising ten Gambierdiscus species, one ribotype, and two Fukuyoa species were confirmed using RFLP typing, and this method was subsequently employed in the routine identification of isolates collected from the Caribbean Sea. The RFLP assay presented here reduces the time and cost associated with morphological identification via scanning electron microscopy and/or DNA sequencing, and provides a phylogenetically sensitive method for routine Gambierdiscus species assignment.Funding for this study was provided by the U.S. National Oceanic and Atmospheric Administration ECOHAB program (CiguaHAB; Cooperative Agreement NA11NOS4780060, NA11NOS4780028), the China Scholarship Council and Natural Science Foundation of China (No. 41606137, 41606136), and the Guangxi Natural Science Foundation (2015GXNSFCA139003, 2016GXNSFBA380037)

    Understanding interannual, decadal level variability in paralytic shellfish poisoning toxicity in the Gulf of Maine : the HAB Index

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    Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 103 (2014): 264-276, doi:10.1016/j.dsr2.2013.09.018.A major goal in harmful algal bloom (HAB) research has been to identify mechanisms underlying interannual variability in bloom magnitude and impact. Here the focus is on variability in Alexandrium fundyense blooms and paralytic shellfish poisoning (PSP) toxicity in Maine, USA, over 34 years (1978 – 2011). The Maine coastline was divided into two regions - eastern and western Maine, and within those two regions, three measures of PSP toxicity (the percent of stations showing detectable toxicity over the year, the cumulative amount of toxicity per station measured in all shellfish (mussel) samples during that year, and the duration of measurable toxicity) were examined for each year in the time series. These metrics were combined into a simple HAB Index that provides a single measure of annual toxin severity across each region. The three toxin metrics, as well as the HAB Index that integrates them, reveal significant variability in overall toxicity between individual years as well as long-term, decadal patterns or regimes. Based on different conceptual models of the system, we considered three trend formulations to characterize the long-term patterns in the Index – a three-phase (mean-shift) model, a linear two-phase model, and a pulse-decline model. The first represents a “regime shift” or multiple equilibria formulation as might occur with alternating periods of sustained high and low cyst abundance or favorable and unfavorable growth conditions, the second depicts a scenario of more gradual transitions in cyst abundance or growth conditions of vegetative cells, and the third characterizes a ”sawtooth” pattern in which upward shifts in toxicity are associated with major cyst recruitment events, followed by a gradual but continuous decline until the next pulse. The fitted models were compared using both residual sum of squares and Akaike’s Information Criterion. There were some differences between model fits, but none consistently gave a better fit than the others. This statistical underpinning can guide efforts to identify physical and/or biological mechanisms underlying the patterns revealed by the HAB Index. Although A. fundyense cyst survey data (limited to 9 years) do not span the entire interval of the shellfish toxicity records, this analysis leads us to hypothesize that major changes in the abundance of A. fundyense cysts may be a primary factor contributing to the decadal trends in shellfish toxicity in this region. The HAB Index approach taken here is simple but represents a novel and potentially useful tool for resource managers in many areas of the world subject to toxic HABs.Research support provided through the Woods Hole Center for Oceans and Human Health, National Science Foundation (NSF) Grants OCE- 1128041 and OCE-1314642; and National Institute of Environmental Health Sciences (NIEHS) Grant 1-P50-ES021923-01, the ECOHAB Grant program through NOAA Grants NA06NOS4780245 and NA09NOS4780193, the MERHAB Grant program through NOAA Grant NA11NOS4780025, the PCMHAB Grant program through NOAA Grant NA11NOS4780023, and funding through the states of ME, NH, and MA. Funding for J.L. Martin was provided by Fisheries and Oceans Canada

    Harmful algal blooms in the Alaskan Arctic: an emerging threat as the ocean warms

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    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Anderson, D., Fachon, E., Hubbard, K., Lefebvre, K., Lin, P., Pickart, R., Richlen, M., Sheffield, G., & Van Hemert, C. Harmful algal blooms in the Alaskan Arctic: an emerging threat as the ocean warms. Oceanography, 35(2), (2022), https://doi.org/10.5670/oceanog.2022.121.Harmful algal blooms (HABs) present an emerging threat to human and ecosystem health in the Alaskan Arctic. Two HAB toxins are of concern in the region: saxitoxins (STXs), a family of compounds produced by the dinoflagellate Alexandrium catenella, and domoic acid (DA), produced by multiple species in the diatom genus Pseudo-nitzschia. These potent neurotoxins cause paralytic and amnesic shellfish poisoning, respectively, in humans, and can accumulate in marine organisms through food web transfer, causing illness and mortality among a suite of wildlife species. With pronounced warming in the Arctic, along with enhanced transport of cells from southern waters, there is significant potential for more frequent and larger HABs of both types. STXs and DA have been detected in the tissues of a range of marine organisms in the region, many of which are important food resources for local residents. The unique nature of the Alaskan Arctic, including difficult logistical access, lack of response infrastructure, and reliance of coastal populations on the noncommercial acquisition of marine resources for nutritional, cultural, and economic well-being, poses urgent and significant challenges as this region warms and the potential for impacts from HABs expands.The authors acknowledge that the Alaskan Arctic as described here includes the lands and waters of the Inupiaq, Saint Lawrence Island Yupik, and Central Yupik peoples. Funding for DMA, RSP, EF, PL, and MLR was provided by grants from NSF Office of Polar Programs (OPP-1823002 and OPP-1733564) and NOAA’s Arctic Research program (through the Cooperative Institute for the North Atlantic Region [CINAR]; NA14OAR4320158 and NA19OAR4320074), and for DMA, KH, and KAL through NOAA’s Center for Coastal and Ocean Studies ECOHAB Program (NA20NOS4780195). Additional support was provided for DMA, MLR, and EF by the US National Park Service Shared Beringian Heritage Program (P21AC12214-00). We also thank Natalie Renier (WHOI Graphic Services) and Emily Bowers (Northwest Fisheries Science Center) for creating figures. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the US Government. This is ECOHAB Contribution number 1007

    The Change of Prevalence of Xerophthalmia on Lombok, September 1977 - September 1983

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    Berdasarkan data "Survei Prevalensi Kebutaan Gizi" tahun 1977, Lombok, Nusa Tenggara Barat, dinyatakan sebagai wilayah tinggi prevalensi xeroftalmia. Sebagai suatu wilayah dengan prevalensi xeroftalmia paling tinggi di Indonesia, banyak faktor risiko yang diidentifikasi bagi daerah ini, termasuk kejadian kecacingan, kekurangan frekuensi pemberian ASI pada anak yang masih menyusu; kekurangan "kamar cuci" di dalam rumah; variasi diet yang terbatas, tidak ada variasi konsumsi bahan pokok selain beras; dan kecilnya konsumsi sumber-sumber protein. Faktor risiko khusus xeroftalmi-korneal berkaitan dengan riwayat penyakit yang baru diderita si anak (campak dan infestasi berat kecacingan) dan kurang kalori protein berat. Sejak tahun 1978, Pemerintah Indonesia telah mengembangkan berbagai macam pendekatan untuk mengawasi (kontrol) xeroftalmia; sampai tahun 1982 telah mencapai 80% sasaran (anak Balita) dan telah menghasilkan penurunan prevalensi xeroftalmia di wilayah ini. Penurunan prevalensi ini dicapai tanpa penurunan secara proporsional faktor-faktor risiko terkait
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