Harmful algal blooms and eutrophication : examining linkages from selected coastal regions of the United States

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.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.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)

The use of operational harmful algal bloom monitoring systems in South Africa to assess long term changes to bloom occurrence & impacts for aquaculture

The south coast of South Africa is a very dynamic, productive, high energy environment and is considered to be a generally challenging setting for in-water aquaculture. One of the largest environmental threats to aquaculture are harmful algal blooms (HABs), a natural ecological phenomenon often accompanied by severe impacts on coastal resources and local economies. There is a wide variety of potentially harmful blooming species in the region, with impacts resulting from both toxicity and the negative effects associated with high biomass. While HABs are fairly well documented around the southern Benguela area, the primary concern is the lack of long-term data showing if blooms are becoming more frequent, persistent or are having greater impact over the last decades, consistent with environmental change experienced in the region. For this study, high-resolution satellite remote sensing observations from 16 years of MODIS-Aqua (1 km) and one month of Sentinel-3 OLCI (300 m), using regionally optimised blended algorithms, were used to investigate the spatial distribution and temporal variability of chlorophyll-a (Chl-a) along the south coast of South Africa. A Chl-a threshold of 27 mg m−3 was used as an analytic to identify the occurrence of high biomass blooms in the remote sensing data. Phytoplankton count data from aquaculture farms are used to provide information corresponding to changes in phytoplankton community structure, and to investigate the distribution and seasonal trends of HABs along the south coast. To further explore the spatial and temporal distribution, phytoplankton species considered harmful for this study were identified and classified to their seasonal occurrence: some species were consistently present throughout the years, however each region showed contrasting seasonality. A second interest of this study is linked to assessing the capacity of the aquaculture industry to make profitable use of existing observational and early warning tools. The impact of HABs on the environment or in aquaculture facilities can be potentially mitigated by increasing the industry awareness and early warnings of HAB development. In this regard, the Fisheries and Aquaculture Decision Support Tool (DeST) was used in order to develop short term alerts on HAB development. The EO analyses conducted here specifically use the same methods used by this DeST to demonstrate the use of this tool for historical analysis in addition to real time alerting. In order to evaluate the effectiveness of the tool and how the aquaculture farmers use the ABSTRACT information provided on the DeST, an online user feedback was generated, and distributed to all stakeholders via emai

Marine harmful algal blooms (HABs) in the united states: history, current status and future trends

© 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.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.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

Zooplankton Population Dynamics in Relation to the Red Tide Dinoflagellate Karenia brevis on the West Florida Shelf of the Gulf of Mexico

Blooms of the toxin producing dinoflagellate Karenia brevis are common in the Gulf of Mexico, and while several studies have investigated nutrient sources and bloom processes, there has been less research in regards to zooplankton population dynamics within these blooms. Zooplankton community structure and copepod species composition were analyzed from samples collected on the West Florida Shelf during October 2007-2010. Copepods constituted the most important zooplankton group, averaging 60% of total abundance. In 2009 there was a significant difference between the abundance of zooplankton at stations within a K. brevis bloom. As the K. brevis bloom progressed, total zooplankton abundance decreased. Additionally, the role of zooplankton within Karenia brevis blooms was investigated as both grazers of primary productivity and potential sources of regenerated nutrients

Marine harmful algal blooms (HABs) in the United States: History, current status and future trends

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. (...

Assessing risks and mitigating impacts of harmful algal blooms on mariculture and marine fisheries

Aquaculture is the fastest growing food sector globally and protein provisioning from aquaculture now exceeds that from wild capture fisheries. There is clear potential for the further expansion of marine aquaculture (mariculture), but there are associated risks. Some naturally occurring algae can proliferate under certain environmental conditions, causing deoxygenation of seawater, or releasing toxic compounds (phycotoxins), which can harm wild and cultured finfish and shellfish, and also human consumers. The impacts of these so‐called harmful algal blooms (HABs) amount to approximately 8 $billion/yr globally, due to mass mortalities in finfish, harvesting bans preventing the sale of shellfish that have accumulated unsafe levels of HAB phycotoxins and unavoided human health costs. Here, we provide a critical review and analysis of HAB impacts on mariculture (and wild capture fisheries) and recommend research to identify ways to minimise their impacts to the industry. We examine causal factors for HAB development in inshore versus offshore locations and consider how mariculture itself, in its various forms, may exacerbate or mitigate HAB risk. From a management perspective, there is considerable scope for strategic siting of offshore mariculture and holistic Environmental Approaches for Aquaculture, such as offsetting nutrient outputs from finfish farming, via the co‐location of extractive shellfish and macroalgae. Such pre‐emptive, ecosystem‐based approaches are preferable to reactive physical, chemical or microbiological control measures aiming to remove or neutralise HABs and their phycotxins. To facilitate mariculture expansion and long‐term sustainability, it is also essential to evaluate HAB risk in conjunction with climate change

Anthropogenic nutrients and harmful algae in coastal waters

© The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Environmental Management 146 (2014): 206-216, doi:10.1016/j.jenvman.2014.07.002.Harmful algal blooms (HABs) are thought to be increasing in coastal waters worldwide. Anthropogenic nutrient enrichment has been proposed as a principal causative factor of this increase through elevated inorganic and/or organic nutrient concentrations and modified nutrient ratios. We assess: 1) the level of understanding of the link between the amount, form and ratio of anthropogenic nutrients and HABs; 2) the evidence for a link between anthropogenically generated HABs and negative impacts on human health; and 3) the economic implications of anthropogenic nutrient/HAB interactions. We demonstrate that an anthropogenic nutrient-HAB link is far from universal, and where it has been demonstrated, it is most frequently associated with high biomass rather than low biomass (biotoxin producing) HABs. While organic nutrients have been shown to support the growth of a range of HAB species, insufficient evidence exists to clearly establish if these nutrients specifically promote the growth of harmful species in preference to benign ones, or if/how they influence toxicity of harmful species. We conclude that the role of anthropogenic nutrients in promoting HABs is site-specific, with hydrodynamic processes often determining whether blooms occur. We also find a lack of evidence of widespread significant adverse health impacts from anthropogenic nutrient-generated HABs, although this may be partly due to a lack of human/animal health and HAB monitoring. Detailed economic evaluation and cost/benefit analysis of the impact of anthropogenically generated HABs, or nutrient reduction schemes to alleviate them, is also frequently lacking.The work described here is based in part on a project ‘Harmful Algae, Nuisance Blooms and Anthropogenic Nutrient Enrichment’ funded by the UK Department for Environment, Food and Rural Affairs (contract ME2208). In addition KD was supported by the FP7 project Asimuth and funding from the NERC Shelf Seas Biogeochemistry and PURE Associates programmes. PJH was supported by University Grants Council of Hong Kong AoE project (AoE/P-04/0401). PH and LEF were funded by the US National Science Foundation (NSF) Award 1009106; LEF was funded in part by the European Regional Development Fund and European Social Fund (University of Exeter, Truro, Cornwall, UK). GM was supported by a NERC PhD studentship

Remotely Sensed Assessment of the Preferred Habitat of Alexandrium catenella in the Gulf of Maine and the Bay of Fundy

Harmful Algal Blooms (HABs) of the toxic dinoflagellate Alexandrium catenella are an annually recurring problem in the Gulf of Maine (GoM), resulting in risks to human health and substantial economic losses due to shellfish harvesting closures. The monitoring approaches in the region are restricted to real-time identification of the HABs events, when they are clearly underway and already causing deleterious effects to the environment. To fully function as an early warning system rather than an immediate response, monitoring strategies need to be focused on environmental conditions preceding A. catenella HABs. However, the current understanding of the preferred habitat for A. catenella in the GoM is still scarce due to the complex interactions between this organism and the environment. My dissertation research contributes to the solution of these problems by determining the preferred thermal habitat for A. catenella, contrasting environmental conditions for two extremes in A. catenella concentration, and exploring the benefits of using high resolution spectral data to characterize the GoM surface waters. This dissertation is focused on the application of current and future remote sensing technology to the measurement and management of GoM HABs. Chapter 1 briefly introduces the problematic of HABs, monitoring efforts and the study species. Chapter 2 characterizes the interannual variability in the thermal habitat and bloom phenology of A. catenella in the Bay of Fundy, identifying the environmental conditions associated with this variability and its responses to climate change. Chapter 3 contrasts the optical and thermal conditions associated with two extremes in A. catenella concentration over multiple years and areas in the GoM and establishes a set of typical water types for each concentration category. Chapter 4 characterizes the spatial and temporal variability of hyperspectral reflectance of surface waters in the GoM and determines the advantage of hyperspectral resolution over multispectral to identify important spatial patterns and regions. Chapter 5 will conclude with a discussion on the implications of these results to monitoring efforts in the GoM, implications of climate change, and discusses future directives to further explore habitat suitability approaches in monitoring efforts

Harmful Algal Blooms (HAB) in a changing world : the case of S and W Iberian Bays

This thesis aimed to investigate, in two wide-open sheltered bays (Lisbon and Lagos) influenced by upwelling, how the meteorological and oceanographic (MetOc) setting may affect phytoplankton communities. Results of a 9-year time series data showed a high interannual variability of phytoplankton biomass, estimated as chlorophyll a (Chl-a). Nevertheless, the Chl-a sinusoidal model showed different temporal variability patterns in each bay: a uni-modal pattern with a short peak and low Chl-a concentrations in Lagos, and a weak bi-modal pattern with a long period of high Chl-a concentrations in Lisbon. Cross-correlation analyses performed for Chl-a and different MetOc variables indicated that PAR contributed most to Chl-a in winter/early-spring, while upwelling and SST were the main drivers in late-spring/summer. Analysis performed during 1-year showed significant spatial differences in phytoplankton assemblages between the bays. On a temporal scale, significant differences were observed on phytoplankton communities in both bays in the 4-meteorological seasons. However, results from a nearshore station studied in Lagos only indicated the occurrence of 3-biological seasons, with no significant differences between summer and autumn communities. This study suggests that Lagos region has a higher probability for the occurrence of HABs (in higher cell concentrations and persistence). The ecology of the benthic genus Ostreopsis was studied based on 7-years of water samples. Two species were identified reaching maximum cell densities in late-summer/early-autumn: Ostreopsis cf. ovata restricted to the south coast and Ostreopsis cf. siamensis present in both Portuguese coasts. Ostreopsis was much more abundant in Lagos (nearshore) and maxima concentrations were related to positive SST anomalies. High densities in the plankton were often recorded after a period of more than 2-weeks of low sea state, followed by short-time events of onshore wind and moderate waves. In Lisbon, O. cf. siamensis was seldom recorded in the plankton and no clear relationship could be established with the studied MetOc drivers. The recent records of Ostreopsis in this bay are interpreted as an early colonization stage of an invasion process. The present work highlights the relevance of the peculiarities of regional setting in determining phytoplankton dynamics in wide-open coastal bays influenced by upwelling, even at short latitudinal distance.Instituto Português do Mar e da Atmosfera (MAR2020-P02M01-1490P)Centro de Ciências do Mar e do Ambiente da Faculdade de Ciências da Universidade de Lisboa (UIDB/04292/2020)Centro de Ciências do Mar da Universidade do Algarve (UID/Multi/04326/2020