Beschreibung: Author Posting. © The Author(s), 2012. 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 Deep Sea Research Part II: Topical Studies in Oceanography 103 (2014): 163-173, doi:10.1016/j.dsr2.2012.11.002.

Beschreibung: A series of oceanographic surveys on Georges Bank document variability of populations of the toxic dinoflagellate Alexandrium fundyense on time scales ranging from synoptic to seasonal to interannual. Blooms of A. fundyense on Georges Bank can reach concentrations on the order of 104 cells l-1, and are generally bank-wide in extent. Georges Bank populations of A. fundyense appear to be quasi-independent of those in the adjacent coastal Gulf of Maine, insofar as they occupy a hydrographic niche that is colder and saltier than their coastal counterparts. In contrast to coastal populations that rely on abundant resting cysts for bloom initiation, very few cysts are present in the sediments on Georges Bank. Bloom dynamics must therefore be largely controlled by the balance between growth and mortality processes, which are at present largely unknown for this population. Based on correlations between cell abundance and nutrient distributions, ammonium appears to be an important source of nitrogen for A. fundyense blooms on Georges Bank.

Beschreibung: We appreciate financial support of the National Oceanic Atmospheric Administration (grant NA06NOS4780245 for the Gulf of Maine Toxicity (GOMTOX) program) and the Woods Hole Center for Oceans and Human Health through National Science Foundation grants OCE-0430724 and OCE-0911031 and National Institute of Environmental Health Sciences grant 1P50-ES01274201.

Beschreibung: Author Posting. © The Authors, 2005. 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 Deep Sea Research Part II: Topical Studies in Oceanography 52 (2005): 2698-2714, doi:10.1016/j.dsr2.2005.06.021.

Beschreibung: Observations of Alexandrium fundyense in the Gulf of Maine indicate several salient characteristics of the vegetative cell distributions: patterns of abundance are gulf-wide in geographic scope; their main features occur in association with the Maine Coastal Current; and the center of mass of the distribution shifts upstream from west to east during the growing season from April to August. The mechanisms underlying these aspects are investigated using coupled physical-biological simulations that represent the population dynamics of A. fundyense within the seasonal mean flow. A model that includes germination, growth, mortality, and nutrient limitation is qualitatively consistent with the observations. Germination from resting cysts appears to be a key aspect of the population dynamics that confines the cell distribution near the coastal margin, as simulations based on a uniform initial inoculum of vegetative cells across the Gulf of Maine produces blooms that are broader in geographic extent than is observed. In general, cells germinated from the major cyst beds (in the Bay of Fundy and near Penobscot and Casco Bays) are advected in the alongshore direction from east to west in the coastal current. Growth of the vegetative cells is limited primarily by temperature from April through June throughout the gulf, whereas nutrient limitation occurs in July and August in the western gulf. Thus the seasonal shift in the center of mass of cells from west to east can be explained by changing growth conditions: growth is more rapid in the western gulf early in the season due to warmer temperatures, whereas growth is more rapid in the eastern gulf later in the season due to severe nutrient limitation in the western gulf during that time period. A simple model of encystment based on nutrient limitation predicts deposition of new cysts in the vicinity of the observed cyst bed offshore of Casco and Penobscot Bays, suggesting a pathway of re-seeding the bed from cells advected downstream in the coastal current. A retentive gyre at the mouth of the Bay of Fundy tends to favor re-seeding that cyst bed from local populations.

Beschreibung: We gratefully acknowledge the support of the US ECOHAB Program, sponsored by NOAA, NSF, EPA, NASA, and ONR.

Beschreibung: This paper is not subject to U.S. copyright. The definitive version was published in Journal of Phycology 52 (2016): 230–238, doi:10.1111/jpy.12386.

Beschreibung: Toxin-producing blooms of dinoflagellates in the genus Alexandrium have plagued the inhabitants of the Salish Sea for centuries. Yet the environmental conditions that promote accelerated growth of this organism, a producer of paralytic shellfish toxins, is lacking. This study quantitatively determined the growth response of two Alexandrium isolates to a range of temperatures and salinities, factors that will strongly respond to future climate change scenarios. An empirical equation, derived from observed growth rates describing the temperature and salinity dependence of growth, was used to hindcast bloom risk. Hindcasting was achieved by comparing predicted growth rates, calculated from in situ temperature and salinity data from Quartermaster Harbor, with corresponding Alexandrium cell counts and shellfish toxin data. The greatest bloom risk, defined at μ 〉0.25 d−1, generally occurred from April through November annually; however, growth rates rarely fell below 0.10 d−1. Except for a few occasions, Alexandrium cells were only observed during the periods of highest bloom risk and paralytic shellfish toxins above the regulatory limit always fell within the periods of predicted bloom occurrence. While acknowledging that Alexandrium growth rates are affected by other abiotic and biotic factors, such as grazing pressure and nutrient availability, the use of this empirical growth function to predict higher risk time frames for blooms and toxic shellfish within the Salish Sea provides the groundwork for a more comprehensive biological model of Alexandrium bloom dynamics in the region and will enhance our ability to forecast blooms in the Salish Sea under future climate change scenarios.

Beschreibung: NOAA Ecology and Oceanography of Harmful Algal Bloom (ECOHAB) Program; Woods Hole Center for Oceans and Human Health; National Science Foundation Grant Number: OCE-1314642; National Institute of Environmental Health Sciences Grant Number: 1-P01-ES021923-01

Beschreibung: Author Posting. EHP is a publication of the United States government. Publication of EHP lies in the public domain and is therefore without copyright. The definitive version was published in Environmental Health Perspectives 109 Supplement 5 (2001): 695-698.

Beschreibung: Public and political concerns about Pfiesteria from 1997 to the present vastly exceed the attention given to other harmful algal bloom (HAB) issues in the United States. To some extent, the intense focus on Pfiesteria has served to increase attention on HABs in general. Given the strong and continuing public, political, and research interests in Pfiesteria piscicida Steidinger & Burkholder and related organisms, there is a clear need for information and resources of many different types. This article provides information on Pfiesteria-related educational products and information resources available to the general public, health officials, and researchers. These resources are compiled into five categories: reports; website resources; state outreach and communication programs; fact sheets; and training manuals and documentaries. Over the last few years there has been rapid expansion in the amount of Pfiesteria-related information available, particularly on the Internet, and it is scattered among many different sources.

Beschreibung: This research was supported by the following grants to D.M. Anderson: National Oceanic & Atmospheric Administration grant NA97OA0355 and U.S. Environmental Protection Agency grant X-82838701-0.

Beschreibung: Author Posting. © The Author(s), 2011. 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 Harmful Algae 14 (2012): 10-35, doi:10.1016/j.hal.2011.10.012.

Beschreibung: The dinoflagellate genus Alexandrium is one of the major harmful algal bloom (HAB) genera with respect to the diversity, magnitude and consequences of blooms. The ability of Alexandrium to colonize multiple habitats and to persist over large regions through time is testimony to the adaptability and resilience of this group of species. Three different families of toxins, as well as an as yet incompletely characterized suite of allelochemicals are produced among Alexandrium species. Nutritional strategies are equally diverse, including the ability to utilize a range of inorganic and organic nutrient sources, and feeding by ingestion of other organisms. Many Alexandrium species have complex life histories that include sexuality and often, but not always, cyst formation, which is characteristic of a meroplanktonic life strategy and offers considerable ecological advantages. Due to the public health and ecosystem impacts of Alexandrium blooms, the genus has been extensively studied, and there exists a broad knowledge base that ranges from taxonomy and phylogeny through genomics and toxin biosynthesis to bloom dynamics and modeling. Here we present a review of the genus Alexandrium, focusing on the major toxic and otherwise harmful species.

Beschreibung: Support to DMA was provided by the National Institute of Environmental Health Sciences (1-P50-ES012742) and the National Science Foundation through the Woods Hole Center for Oceans and Human Health (OCE-0430724), and by NOAA Grants NA09NOS4780193, NA06OAR4170021 and NA06NOS4780245. Research funding to ADC and previously to TJA was furnished under the PACES Programme (Coast WP2) from the Helmholtz Society initiative Earth and Environment. Support to TJA was obtained by the research funding program LOEWE (Landes-Offensive zur Entwicklung Wissenschaftlich-ökonomischer Exzellenz) of Hesse’s Ministry of Higher Education, Research, and the Arts. Support to EM and YC was provided by grants from the French National Programme “Ecosphère Continentale et Côtière-EC2CO and from the “Fondation pour la Recherche sur la Biodiversité-INVALEX project (AAP-IN-2009- 036).

Beschreibung: Virtually every coastal country in the world is affected by harmful algal blooms (HABs, commonly called “red tides”). This diverse array of phenomena includes blooms of toxic, microscopic algae that lead to illness and death in humans, fish, seabirds, marine mammals, and other oceanic life. There are also non-toxic HABs that cause damage to ecosystems, fisheries resources, and recreational facilities, often due to the sheer biomass of the accumulated algae. The term “HAB” also applies to non-toxic macroalgae (seaweeds), which can cause major ecological impacts such as the displacement of indigenous species, habitat alteration and oxygen depletion in bottom waters. The frequency, spatial extent, and economic impact of HABs have all expanded in recent decades, in parallel with, and sometimes a result of, the world’s increasing exploitation on the coastal zone for shelter, food, recreation, and commerce. HABs are complex oceanographic phenomena that require multidisciplinary study ranging from molecular and cell biology to large-scale field surveys, numerical modelling, and remote sensing from space. Multi-lateral international programmes and bilateral initiatives are bringing scientists together from different countries and disciplines in a concerted attack on this complex and multi-faceted issue. Our understanding of these phenomena is increasing dramatically, and with this understanding come technologies and management tools that can reduce HAB incidence and impact. More effective HAB management is sure to be one major outcome of the growing investment in the Global Ocean Observing System. HABs will always be with us, and in the next few decades at least, are likely to continue to expand in geographic extent and frequency. Nevertheless, scientifically based management should permit full exploitation of fisheries, recreational, and commercial resources, despite the recurrent and diverse threat that HABs pose. This series of lectures is dedicated to the memory of the noted Danish oceanographer and first chairman of the Commission, Dr Anton Frederick Bruun. The "Anton Bruun Memorial Lectures" were established in accordance with Resolution 19 of the Sixth Session of the IOC Assembly, in which the Commission proposed that important inter-session developments be summarized by speakers in the fields of solid earth studies, physical and chemical oceanography and meteorology, and marine biology.

Beschreibung: Published

Beschreibung: Refereed

Beschreibung: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Anderson, D. M., Fachon, E., Pickart, R. S., Lin, P., Fischer, A. D., Richlen, M. L., Uva, V., Brosnahan, M. L., McRaven, L., Bahr, F., Lefebvre, K., Grebmeier, J. M., Danielson, S. L., Lyu, Y., & Fukai, Y. Evidence for massive and recurrent toxic blooms of Alexandrium catenella in the Alaskan Arctic. Proceedings of the National Academy of Sciences of the United States of America, 118(41) (2021): e2107387118, https://doi.org/10.1073/pnas.2107387118.

Beschreibung: Among the organisms that spread into and flourish in Arctic waters with rising temperatures and sea ice loss are toxic algae, a group of harmful algal bloom species that produce potent biotoxins. Alexandrium catenella, a cyst-forming dinoflagellate that causes paralytic shellfish poisoning worldwide, has been a significant threat to human health in southeastern Alaska for centuries. It is known to be transported into Arctic regions in waters transiting northward through the Bering Strait, yet there is little recognition of this organism as a human health concern north of the Strait. Here, we describe an exceptionally large A. catenella benthic cyst bed and hydrographic conditions across the Chukchi Sea that support germination and development of recurrent, locally originating and self-seeding blooms. Two prominent cyst accumulation zones result from deposition promoted by weak circulation. Cyst concentrations are among the highest reported globally for this species, and the cyst bed is at least 6× larger in area than any other. These extraordinary accumulations are attributed to repeated inputs from advected southern blooms and to localized cyst formation and deposition. Over the past two decades, warming has likely increased the magnitude of the germination flux twofold and advanced the timing of cell inoculation into the euphotic zone by 20 d. Conditions are also now favorable for bloom development in surface waters. The region is poised to support annually recurrent A. catenella blooms that are massive in scale, posing a significant and worrisome threat to public and ecosystem health in Alaskan Arctic communities where economies are subsistence based.

Beschreibung: Funding for D.M.A., R.S.P., E.F., P.L., A.D.F., V.U., M.L.B., L.M., F.B., and M.L.R. was provided by grants from the NSF Office of Polar Programs (Grants OPP-1823002 and OPP-1733564) and the National Ocanic and Atmospheric Administration (NOAA) Arctic Research program (through the Cooperative Institute for the North Atlantic Region [CINAR; Grants NA14OAR4320158 and NA19OAR4320074]), for J.M.G. through CINAR 22309.07 UMCES (University of Maryland Center for Environmental Science), and for D.M.A. and K.L. through NOAA’s Center for Coastal and Ocean Studies Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) Program (NA20NOS4780195). Funding for D.M.A., M.L.R., M.L.B., E.F., V.U., and A.D.F. was also provided by NSF (Grant OCE-1840381) and NIH (Grant 1P01-ES028938-01) through the Woods Hole Center for Oceans and Human Health. S.L.D. was supported by North Pacific Research Board IERP Grants A91-99a and A91-00a. This is IERP publication ArcticIERP-41 and ECOHAB Contribution No. ECO983.

Beschreibung: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Anderson, D. M., Fensin, E., Gobler, C. J., Hoeglund, A. E., Hubbard, K. A., Kulis, D. M., Landsberg, J. H., Lefebvre, K. A., Provoost, P., Richlen, M. L., Smith, J. L., Solow, A. R., & Trainer, V. L. Marine harmful algal blooms (HABs) in the united states: history, current status and future trends. Harmful Algae, 102, (2021): 101975, https://doi.org/10.1016/j.hal.2021.101975.

Beschreibung: Harmful algal blooms (HABs) are diverse phenomena involving multiple. species and classes of algae that occupy a broad range of habitats from lakes to oceans and produce a multiplicity of toxins or bioactive compounds that impact many different resources. Here, a review of the status of this complex array of marine HAB problems in the U.S. is presented, providing historical information and trends as well as future perspectives. The study relies on thirty years (1990–2019) of data in HAEDAT - the IOC-ICES-PICES Harmful Algal Event database, but also includes many other reports. At a qualitative level, the U.S. national HAB problem is far more extensive than was the case decades ago, with more toxic species and toxins to monitor, as well as a larger range of impacted resources and areas affected. Quantitatively, no significant trend is seen for paralytic shellfish toxin (PST) events over the study interval, though there is clear evidence of the expansion of the problem into new regions and the emergence of a species that produces PSTs in Florida – Pyrodinium bahamense. Amnesic shellfish toxin (AST) events have significantly increased in the U.S., with an overall pattern of frequent outbreaks on the West Coast, emerging, recurring outbreaks on the East Coast, and sporadic incidents in the Gulf of Mexico. Despite the long historical record of neurotoxic shellfish toxin (NST) events, no significant trend is observed over the past 30 years. The recent emergence of diarrhetic shellfish toxins (DSTs) in the U.S. began along the Gulf Coast in 2008 and expanded to the West and East Coasts, though no significant trend through time is seen since then. Ciguatoxin (CTX) events caused by Gambierdiscus dinoflagellates have long impacted tropical and subtropical locations in the U.S., but due to a lack of monitoring programs as well as under-reporting of illnesses, data on these events are not available for time series analysis. Geographic expansion of Gambierdiscus into temperate and non-endemic areas (e.g., northern Gulf of Mexico) is apparent, and fostered by ocean warming. HAB-related marine wildlife morbidity and mortality events appear to be increasing, with statistically significant increasing trends observed in marine mammal poisonings caused by ASTs along the coast of California and NSTs in Florida. Since their first occurrence in 1985 in New York, brown tides resulting from high-density blooms of Aureococcus have spread south to Delaware, Maryland, and Virginia, while those caused by Aureoumbra have spread from the Gulf Coast to the east coast of Florida. Blooms of Margalefidinium polykrikoides occurred in four locations in the U.S. from 1921–2001 but have appeared in more than 15  U.S. estuaries since then, with ocean warming implicated as a causative factor. Numerous blooms of toxic cyanobacteria have been documented in all 50  U.S. states and the transport of cyanotoxins from freshwater systems into marine coastal waters is a recently identified and potentially significant threat to public and ecosystem health. Taken together, there is a significant increasing trend in all HAB events in HAEDAT over the 30-year study interval. Part of this observed HAB expansion simply reflects a better realization of the true or historic scale of the problem, long obscured by inadequate monitoring. Other contributing factors include the dispersion of species to new areas, the discovery of new HAB poisoning syndromes or impacts, and the stimulatory effects of human activities like nutrient pollution, aquaculture expansion, and ocean warming, among others. One result of this multifaceted expansion is that many regions of the U.S. now face a daunting diversity of species and toxins, representing a significant and growing challenge to resource managers and public health officials in terms of toxins, regions, and time intervals to monitor, and necessitating new approaches to monitoring and management. Mobilization of funding and resources for research, monitoring and management of HABs requires accurate information on the scale and nature of the national problem. HAEDAT and other databases can be of great value in this regard but efforts are needed to expand and sustain the collection of data regionally and nationally.

Beschreibung: Support for DMA, MLR, and DMK was provided through the Woods Hole Center for Oceans and Human Health (National Science Foundation grant OCE-1840381 and National Institutes of Health grants NIEHS‐1P01-ES028938–01) and the U.S. National Office for Harmful Algal Blooms with funding from NOAA's National Centers for Coastal Ocean Science (NCCOS) through the Cooperative Institute for the North Atlantic Region (CINAR) (NA14OAR4320158, NA19OAR4320074). Funding for KAL and DMA was provided by the National Oceanic and Atmospheric Administration National Centers for Coastal Ocean Science Competitive Research Program under award NA20NOS4780195 to the Woods Hole Oceanographic Institution and NOAA's Northwest Fisheries Science Center. We also acknowledge support for A.H. from the National Oceanic and Atmospheric Administration [NOAA] Office of Ocean and Coastal Resource Management Award NA19NOS4780183, C.J.G from NOAA-MERHAB (NA19NOS4780186) and (NA16NOS4780189) for VLT Support was also received for JLS, CJG, and VLT from NOAA-NCCOS-ECOHAB under awards NA17NOS4780184 and NA19NOS4780182. This is ECOHAB publication number ECO972.

Beschreibung: Author Posting. © The Authors, 2005. 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 Aquatic Toxicology 72 (2005): 351-360, doi:10.1016/j.aquatox.2005.01.007.

Beschreibung: Chattonella marina, a harmful algal bloom (HAB) causative species, was used to study the mortality, physiology, and pathology of a marine stenohaline fish, goldlined seabream exposed to the toxic alga. The median lethal time (LT50) was 3 h upon exposure to 8000 cells/ml of C. marina. Significant induction of filamental chloride cells (CCs) [i.e. increases in CC fractional area and in the volume density of CCs], concomitant with significant reduction of blood osmolality, were found in C. marina treated fish. To verify whether the toxicity of C. marina was mediated through oxidative stress, a hydrogen peroxide exposure experiment was carried out and the toxicity as well as cytological and physiological changes were compared with the C. marina treatment. Hydrogen peroxide at a concentration of 500 μM H2O2, (i.e. 25 times higher than that produced by 8000 cells/ml of C. marina (20 μM H2O2)) was unable to induce similar CC alterations and osmoregulatory impairment in fish as observed in the C. marina treatment. Non-specific membrane damage such as severe loss of microvilli projections on the CC apical opening and rupture of epithelial membranes in the lamellae were observed. The LT50 was 6 h, two times longer than that with 8000 cells/ml of C. marina. Based on the cytological and physiological evidence and toxicity data, the mechanism by which C. marina kills fish appears to be very different from that caused by H2O2/ROS. Osmoregulatory distress is the major cause of fish death upon exposure to C. marina.

Beschreibung: The work described in this paper was supported by a grant from the Research Grants Council (Project No. 9040547 CityU 1105/00M) and a grant from the University Grants Committee (Project No. AoE/P-04/04) of the Hong Kong Special Administrative Region, China. Support for D. Anderson was also provided by the US National Science Foundation through grant no. OCE-0136861.

Beschreibung: 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): 174-184, doi:10.1016/j.dsr2.2013.05.011.

Beschreibung: In early July 2009, an unusually high concentration of the toxic dinoflagellate Alexandrium fundyense occurred in the western Gulf of Maine, causing surface waters to appear reddish brown to the human eye. The discolored water appeared to be the southern terminus of a large-scale event that caused shellfish toxicity along the entire coast of Maine to the Canadian border. Rapid-response shipboard sampling efforts together with satellite data suggest the water discoloration in the western Gulf of Maine was a highly ephemeral feature of less than two weeks in duration. Flow cytometric analysis of surface samples from the red water indicated the population was undergoing sexual reproduction. Cyst fluxes downstream of the discolored water were the highest ever measured in the Gulf of Maine, and a large deposit of new cysts was observed that fall. Although the mechanisms causing this event remain unknown, its timing coincided with an anomalous period of downwelling-favorable winds that could have played a role in aggregating upward-swimming cells. Regardless of the underlying causes, this event highlights the importance of short-term episodic phenomena on regional population dynamics of A. fundyense.

Beschreibung: The R/V Tioga sampling effort was facilitated by event response funding from the National Oceanic Atmospheric Administration (NOAA), National Ocean Service, Center for Sponsored Coastal Ocean Research, through NOAA Cooperative Agreement NA17RJ1223. Additional support for follow-up analysis and synthesis was provided by NOAA grant NA06NOS4780245 for the Gulf of Maine Toxicity (GOMTOX) program and the Woods Hole Center for Oceans and Human Health through National Science Foundation grants OCE- 0430724 and OCE-0911031 and National Institute of Environmental Health Sciences grant 1P50-ES01274201.