Description: Author Posting. © The Author(s), 2014. 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 34 (2014): 56–68, doi:10.1016/j.hal.2014.02.007.

Description: Ciguatera is a serious seafood poisoning syndrome caused by the consumption of ciguatoxin-contaminated finfish from tropical and subtropical regions. This study examined the community structure of ciguatera-associated dinoflagellates and the distribution pattern, taxonomy and toxicity of Gambierdiscus spp. from a high-risk area of Marakei, Republic of Kiribati. The genera Gambierdiscus, Prorocentrum, Ostreopsis, Amphidinium and Coolia were present, and generally the former three dominated the dinoflagellate assemblage. Among these three, Gambierdiscus was the most abundant dinoflagellate genus observed at three of the four sites sampled, two of which (Sites 1 and 2) were on the northern half of the island and two (Sites 3 and 4) on the southern half. The following patterns of abundance were observed among sites: (1) Average Gambierdiscus spp. abundance at the northern sites exceeded the southern sites by a factor of 19-54; and (2) Gambierdiscus spp. abundance at shallow sites (2-3 m) exceeded deeper sites (10-15 m). The distribution of Gambierdiscus spp. at Marakei corresponded with previously observed patterns of fish toxicity, with fish from southern locations being much less toxic than fish sampled north of the central channel. DNA sequencing identified three Gambierdiscus species (G. carpenteri, G. belizeanus, G. pacificus) and three previously unreported ribotypes (Gambierdiscus sp. type 4, Gambierdiscus sp. type 5, Gambierdiscus sp. type 6) in the samples; Gambierdiscus sp. type 4 may represent a Pacific clade of Gambierdiscus sp. ribotype 1. Toxicity analyses determined that Gambierdiscus sp. type 4 isolates were more toxic than the Gambierdiscus sp. type 5 and G. pacificus isolates, with toxin contents of 2.6-6.0 (mean: 4.3± 1.4), 0.010 and 0.011 fg P-CTX-1 eq cell-1, respectively. Despite low densities of Gambierdiscus spp. observed at Marakei relative to other studies in other parts of the world, the presence of low and moderately toxic populations may be sufficient to render the western coast of Marakei a high-risk area for ciguatera. The long history of toxicity along the western side of Marakei suggests that large-scale oceanographic forcings that regulate the distribution of Gambierdiscus spp. along the western side of Marakei may have remained relatively stable over that time. Chronic as well as acute exposure to ciguatoxins may therefore pose an important human health impact to the residents of Marakei.

Description: Funding for this work was provided by the Centers for Disease Control and Prevention (U01 EH000421), USFDA (F223201000060C), NOAA NOS (Cooperative Agreement NA11NOS4780060, NA11NOS4780028), National Program on Key Basic Research Project of China (973 Program, 2013CB956503), the Nonprofit Research Project for the State Oceanic Administration (China, 201005006-01), and the National Natural Science Foundation of China (41276110).

Description: Blooms of toxic or harmful microalgae, commonly called "red tides," represent a significant and expanding threat to human health and fisheries resources throughout the United States and the world. Ecological, aesthetic, and public health impacts include: mass mortalities of wild and farmed fish and shellfish, human intoxication and death from the consumption of contaminated shellfish or fish, alterations of marine food webs through adverse effects on larvae and other life history stages of commercial fish species, the noxious smell and appearance of algae accumulated in nearshore waters or deposited on beaches, and mass mortalities of marine mammals, seabirds, and other animals. In this report, we provide an estimate of the economic impacts of HABs in the United States from events where such impacts were measurable with a fair degree of confidence during the interval 1987-92. The total economic impact averaged $49 million per year, with public health impacts representing the largest component (45 percent). Commercial fisheries impacts were the next largest (37 percent of the total), while recreation/tourism accounted for 13 percent, and monitoring/management impacts 4 percent. These estimates are highly conservative, as many economic costs or impacts from HABs could not be estimated.

Description: Funding was provided by the National Oceanic and Atmospheric Administration under Grants No. NA46RG0470 and NA90AA-D-SG480, the National Science Foundation under Grant No. OCE-9321244, and the Johnson Endowment of the Marine Policy Center.

Description: © 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.

Description: 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.

Description: 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].

Description: Author Posting. © Elsevier B.V., 2008. 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 Harmful Algae 8 (2008): 39-53, doi:10.1016/j.hal.2008.08.017.

Description: Coastal waters of the United States (U.S.) are subject to many of the major harmful algal bloom (HAB) poisoning syndromes and impacts. These include paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), ciguatera fish poisoning (CFP) and various other HAB phenomena such as fish kills, loss of submerged vegetation, shellfish mortalities, and widespread marine mammal mortalities. Here, the occurrences of selected HABs in a selected set of regions are described in terms of their relationship to eutrophication, illustrating a range of responses. Evidence suggestive of changes in the frequency, extent or magnitude of HABs in these areas is explored in the context of the nutrient sources underlying those blooms, both natural and anthropogenic. In some regions of the U.S., the linkages between HABs and eutrophication are clear and well documented, whereas in others, information is limited, thereby highlighting important areas for further research.

Description: Support was provided through the Woods Hole Center for Oceans and Human Health (to DMA), National Science Foundation (NSF) grants OCE-9808173 and OCE-0430724 (to DMA), OCE-0234587 (to WPC), OCE04-32479 (to MLP), OCE-0138544 (to RMK), OCE-9981617 (to PMG); National Institute of Environmental Health Sciences (NIEHS) grants P50ES012742-01 (to DMA) and P50ES012740 (to MLP); NOAA Grants NA96OP0099 (to DMA), NA16OP1450 (to VLT), NA96P00084 (to GAV and CAH), NA160C2936 and NA108H-C (to RMK), NA860P0493 and NA04NOS4780241 (to PMG), NA04NOS4780239-02 (to RMK), NA06NOS4780245 (to DWT). Support was also provided from the West Coast Center for Oceans and Human Health (to VLT and WPC), USEPA Grant CR826792-01-0 (to GAV and CAH), and the State of Florida Grant S7701617826 (to GAV and CAH).

Description: On May 8 and 9, 1989, a consultation of experts was convened at the Woods Hole Oceanographic Institution to discuss the possible link between natural biotoxins and recent mass mortalities of humpback whales and bottlenose dolphins along the eastern coast of the United States. The focus was on the possible role of dinoflagellate toxins in these events. The objectives of the meeting were to review and assess the existing evidence and to recommend research priorities and needs.

Description: Funding was provided by NOAA, National Marine Fisheries Service, Woods Hole Oceanographic Institution Coastal Research Center through a grant from the Andrew W. Mellon Foundation and the Woods Hole Oceanographic Institution Sea Grant Program under Grant NA86-D-SW90 (Project R/B - 92 and M/O-2).

Description: Author Posting. © The Author(s), 2011. 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 I: Oceanographic Research Papers 58 (2011): 1130-1146, doi:10.1016/j.dsr.2011.08.009.

Description: Observations and numerical modeling indicate that a mesoscale anti-cyclonic eddy formed south of Cape Ann at the northern entrance of Massachusetts Bay (MB) during May 2005, when large river discharges in the western Gulf of Maine and two strong Nor’easters passing through the regions led to an unprecedented toxic Alexandrium fundyense bloom (red tide). Both model results and field measurements suggest that the western Maine coastal current separated from Cape Ann around May 7-8, and the eddy formed on around May 10. The eddy was trapped at the formation location for about a week before detaching from the coastline and moving slowly southward on May 17. Both model results and theoretical analysis suggest that the separation of the coastal current from the coast and subsequent eddy formation were initiated at the subsurface by an adverse pressure gradient between Cape Ann and MB due to the higher sea level set up by onshore Ekman transport and higher density in downstream MB. After the formation, the eddy was maintained by the input of vorticity transported by the coastal current from the north, and local vorticity generation around the cape by the horizontal gradients of wind-driven currents, bottom stress, and water density induced by the Merrimack River plume. Observations and model results indicate that the anti-cyclonic eddy significantly changed the pathway of nutrient and biota transport into the coastal areas and enhanced phytoplankton including Alexandrium abundances around the perimeter of the eddy and in the western coast of MB.

Description: MJ was partially supported by the MWRA for this work. Support for DMA and many of the cruise observations was provided by the GOMTOX project through NOAA Grant NA06NOS4780245. Additional cruise support came from NSF grant OCE-0430724, DMS-0417769 and NIEHS grant 1P50-ES01274201 (Woods Hole Center for Oceans and Human Health) and through NOAA ECOHAB Grant NA09NOS4780193.

Description: 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): 277-287, doi:10.1016/j.dsr2.2013.03.027.

Description: Development of forecasting systems for harmful algal blooms (HABs) has been a long-standing research and management goal. Significant progress has been made in the Gulf of Maine, where seasonal bloom forecasts are now being issued annually using Alexandrium fundyense cyst abundance maps and a population dynamics model developed for that organism. Thus far these forecasts have used terms such as “significant”, “moderately large” or “moderate” to convey the extent of forecasted paralytic shellfish poisoning (PSP) outbreaks. In this study, historical shellfish harvesting closure data along the coast of the Gulf of Maine were used to derive a series of bloom severity levels that are analogous to those used to define major storms like hurricanes or tornados. Thirty-four years of PSP-related shellfish closure data for Maine, Massachusetts and New Hampshire were collected and mapped to depict the extent of coastline closure in each year. Due to fractal considerations, different methods were explored for measuring length of coastline closed. Ultimately, a simple procedure was developed using arbitrary straight-line segments to represent specific sections of the coastline. This method was consistently applied to each year’s PSP toxicity closure map to calculate the total length of coastline closed. Maps were then clustered together statistically to yield distinct groups of years with similar characteristics. A series of categories or levels was defined (“Level 1: Limited”, “Level 2: Moderate”, and “Level 3: Extensive”) each with an associated range of expected coastline closed, which can now be used instead of vague descriptors in future forecasts. This will provide scientifically consistent and simply defined information to the public as well as resource managers who make decisions on the basis of the forecasts.

Description: Research support provided through the Woods Hole Center for Oceans and Human Health, National Science Foundation (NSF) Grants OCE-0430724, and OCE-0911031; and National Institute of Environmental Health Sciences (NIEHS) Grant 1-P50-ES012742-01, the ECOHAB Grant program through NOAA Grant NA06NOS4780245, and the PCM HAB Grant program through NOAA Grant NA11NOS4780023.

Description: © 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.

Description: 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.

Description: 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.

Description: Author Posting. © The Author(s), 2011. 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 Desalination 293 (2012): 1-6, doi:10.1016/j.desal.2012.02.014.

Description: Over the last several decades, countries throughout the world have experienced an escalating and worrisome trend in the incidence of harmful algal blooms (HABs). A concern is that highly potent algal toxins might be retained in the treated water, posing a threat to human health. Seawater contaminated with saxitoxins, domoic acid, okadaic acid, and brevetoxins was desalinated using small (〈100 mL capacity) reverse osmosis and distillation equipment. Analyses of desalinated water samples indicated efficient removal of the four toxins to greater than 99%, except brevetoxins for which some carryover was observed during distillation. Hypochlorite concentrations of 4 ppm or higher were sufficient to react with all of the saxitoxins, domoic acid and okadaic acid in the samples that contained initial toxin concentrations up to 1,250 ng.mL-1 . Brevetoxins appeared to be unaffected in experiments in which the toxins were exposed to up to 30 ppm hypochlorite in seawater at 35 °C for 60 min. These results and their implications in terms of desalination plant design and operation are discussed.

Description: This work was also supported in part by the Woods Hole Center for Oceans and Human Health (NSF Grants OCE-0430724 and OCE-0911031; NIEHS Grant P50ES012742-01) and Effects of Inhaled Florida Red Tide Brevetoxins (NIH Grant P01 ES010594-09).

Description: 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): 6-26, doi:10.1016/j.dsr2.2013.10.002.

Description: Here we document Alexandrium fundyense cyst abundance and distribution patterns over nine years (1997 and 2004-2011) in the coastal waters of the Gulf of Maine (GOM) and identify linkages between those patterns and several metrics of the severity or magnitude of blooms occurring before and after each autumn cyst survey. We also explore the relative utility of two measures of cyst abundance and demonstrate that GOM cyst counts can be normalized to sediment volume, revealing meaningful patterns equivalent to those determined with dry weight normalization.Cyst concentrations were highly variable spatially. Two distinct 1 seedbeds (defined here as accumulation zones with 〉 300 cysts cm-3) are evident, one in the Bay of Fundy (BOF) and one in mid-coast Maine. Overall, seedbed locations remained relatively constant through time, but their area varied 3-4 fold, and total cyst abundance more than 10 fold among years. A major expansion of the mid-coast Maine seedbed occurred in 2009 following an unusually intense A. fundyense bloom with visible red-water conditions, but that feature disappeared by late 2010. The regional system thus has only two seedbeds with the bathymetry, sediment characteristics, currents, biology, and environmental conditions necessary to persist for decades or longer. Strong positive correlations were confirmed between the abundance of cysts in both the 0-1 and the 0-3 cm layers of sediments in autumn and geographic measures of the extent of the bloom that occurred the next year (i.e., cysts → blooms), such as the length of coastline closed due to shellfish toxicity or the southernmost latitude of shellfish closures. In general, these metrics of bloom geographic extent did not correlate with the number of cysts in sediments following the blooms (blooms → cysts). There are, however, significant positive correlations between 0-3 cm cyst abundances and metrics of the preceding bloom that are indicative of bloom intensity or vegetative cell abundance (e.g., cumulative shellfish toxicity, duration of detectable toxicity in shellfish, and bloom termination date). These data suggest that it may be possible to use cyst abundance to empirically forecast the geographic extent of the forthcoming bloom and, conversely, to use other metrics from bloom and toxicity events to forecast the size of the subsequent cyst population as the inoculum for the next year’s bloom. This is an important step towards understanding the excystment/encystment cycle in A. fundyense bloom dynamics while also augmenting our predictive capability for this HAB-forming species in the GOM.

Description: Research support provided by the ECOHAB Grant program through NOAA Grants NA06NOS4780245 and NA09NOS4780193, and through the Woods Hole Center for Oceans and Human Health, National 1 Science Foundation (NSF) Grants OCE-0430724, OCE-0911031, and OCE-1314642; and National Institute of Environmental Health Sciences (NIEHS) Grants 1-P50-ES012742-01 and 1-P01-ES021923-01, and funding through the states of ME, NH, and MA. We are also grateful for event response funding provided for many of the cruises. Funding for J.L. Martin was provided by Fisheries and Oceans Canada.