Harmful Algal Bloom Events Research Articles

Pelagic harmful algal blooms and climate change: Lessons from nature’s experiments with extremes

Time series now have sufficient duration to determine harmful algal bloom (HAB) responses to changing climate conditions, including warming, stratification intensity, freshwater inputs and natural patterns of climate variability, such as the El Niño Southern Oscillation and Pacific Decadal Oscillation. Against the context of time series, such as those available from phytoplankton monitoring, dinoflagellate cyst records, the Continuous Plankton Recorder surveys, and shellfish toxin records, it is possible to identify extreme events that are significant departures from long-term means. Extreme weather events can mimic future climate conditions and provide a “dress rehearsal” for understanding future frequency, intensity and geographic extent of HABs. Three case studies of extreme HAB events are described in detail to explore the drivers and impacts of these oceanic outliers that may become more common in the future. One example is the chain-forming diatom of the genus Pseudo-nitzschia in the U.S. Pacific Northwest and its response to the 2014-16 northeast Pacific marine heat wave. The other two case studies are pelagic flagellates. Highly potent Alexandrium catenella group 1 dinoflagellate blooms (up to 150 mg/kg PST in mussels; 4 human poisonings) during 2012-17 created havoc for the seafood industry in Tasmania, south-eastern Australia, in a poorly monitored area where such problems were previously unknown. Early evidence suggests that changes in water column stratification during the cold winter-spring season are driving new blooms caused by a previously cryptic species. An expansion of Pseudochattonella cf. verruculosa to the south and A. catenella to the north over the past several years resulted in the convergence of both species to cause the most catastrophic event in the history of the Chilean aquaculture in the austral summer of 2016. Together, these two massive blooms were colloquially known as the “Godzilla-Red tide event”, resulting in the largest fish farm mortality ever recorded worldwide, equivalent to an export loss of USD$800 million which when combined with shellfish toxicity, resulted in major social unrest and rioting. Both blooms were linked to the strong El Niño event and the positive phase of the Southern Annular Mode, the latter an indicator of anthropogenic climate change in the southeastern Pacific region. For each of these three examples, representing recent catastrophic events in geographically distinct regions, additional targeted monitoring was employed to improve the understanding of the climate drivers and mechanisms that gave rise to the event and to document the societal response. Scientists must be poised to study future extreme HAB events as these natural experiments provide unique opportunities to define and test multifactorial drivers of blooms.

Integrated observing systems: An approach to studying harmful algal blooms in south Florida

ABSTRACTThe Indian River Lagoon (IRL) is a large and complex barrier island estuary on Florida’s East coast. The system is also one of the nation’s most biologically diverse, a major spawning and nursery ground for numerous species of fish and shellfish, and home to significant populations of dolphins and manatees. Ocean observing systems can play an integral role in evaluating the effects of both natural (e.g. climate change) and anthropogenic impacts (e.g. nutrient pollution) on such a complex system. In this paper we present an integrated multidisciplinary approach to studying the recurrent large-scale harmful algal bloom (HAB) events that have threatened both the ecological and economic stability of the IRL and represent a significant public health hazard. Due to the complex biological, chemical and physical interactions associated with IRL HABs, the integration of classical observing methodology, such as phytoplankton surveys, with real-time water quality monitoring, innovative technology, and biological sentinels, is essential. The open sharing of data for research, education and public engagement is another key component of our approach. There are multiple stakeholders and end users that rely on these efforts to understand HAB dynamics in a unique marine system.

MULTI-TEMPORAL MODIS FOR DETECTION AND PUBLISHED LITERATURES FOR VALIDATION OF PHYTOPLANKTON BLOOMS IN SABAH AND SARAWAK, MALAYSIA

The coastal region of Sabah, Malaysia is mostly affected by harmful algal blooms (HABs) that often cause massive fish kills, and sometimes human casualties. Lack of a well-agreed, transparent and reproducible method, aperiodic nature and limited (technical) ability to monitor HAB at large regional scale, have all led to reinforced methodological improvement for bloom prediction, scientific management of coastal water resources, and regulatory attention. MODerate Resolution Imaging Spectroradiometer (MODIS), one of the well validated ocean colour sensors, enables acquiring high spectral resolution images, with short revisit time, freely accessible, and bay-wide coverage. Yet, the relative efficiency of MODIS-derived Chl-a (Chlorophyll-a), ABI (Algal Bloom Index), and nFLH (normalized Fluorescence Line Height) have not been compared in coastal regions of Malaysia. Fifteen MODIS Level 2 images acquired between 2005 and 2013 were considered as time series data that matched HAB events mentioned in previous studies. As historical real time in-situ data collection is often difficult (inaccessible), and thus unavailable; this project had to validate results obtained from literature, assuming that in-situ, would indicate HAB location at least during MODIS acquisition dates. Variations of HAB affected areas with temporal and spatial scales derived from bloom indices are shown in colour maps. Reliability of bloom information was measured by subjectively comparing HAB results provided by indices, and previously published in-situ results. ABI outperformed Chl-a and nFLH indices based on comparisons in both normal and HAB conditions occurring in the coastal waters of Sabah and Sarawak. The configuration and reliability retrieved from MODIS-ABI allowed their application in different likely tropical region as automated HAB monitoring systems and coastal water management programmes.

Historical Occurrence of Algal Blooms in the Northern Beibu Gulf of China and Implications for Future Trends.

Large-scale harmful algal blooms (HABs) occur in the coastal waters of the northern Beibu Gulf, China, and have deleterious effects on the marine ecosystem. The frequency, duration, and extent of HAB events in this region have increased over the last 30 years. However, the underlying causes of HABs and their likely future trends are unclear. To investigate, we evaluated historical data for temporal trends of HABs in the Beibu Gulf, and association with environmental factors as possible drivers. The results confirmed that HAB events had increased in frequency, from 6 reported events during the period 1985–2000, to 13 during 2001–2010, and 20 during 2011–2017. We also found that the geographic scale of algal blooms had increased from tens of km2 to hundreds of km2. There were temporal changes in HAB trigger species: prior to 2000, the cyanobacteria Microcystis aeruginosa was the dominant species, while during the period 2001–2010, blooms of cyanobacteria, dinoflagellates, and diatoms co-occurred, and during 2011–2017, the haptophyte Phaeocystis globosa became the dominant algal bloom species. Principal component analysis and variation partitioning analysis indicated that nutrient discharge, industrial development, and human activities were the key drivers of HAB events, and redundancy analysis showed that variation in the algal community tended to be driven by nutrient structure. Other factors, such as shipping activities and mariculture, also contributed to HAB events and algal succession, especially to P. globosa blooms. We speculated that the increasing severity of algal blooms in the northern Beibu Gulf reflects a more complex aquatic environment and highlights the damaging effects of anthropogenic inputs, urbanization development, and an expanding industrial marine-economy on the marine ecosystem. This research provides more insight into the increase of HABs and will aid their management in the Beibu Gulf.

Oceanography of Harmful Algal Blooms on the Ecuadorian Coast (1997–2017): Integrating Remote Sensing and Biological Data

Ocean climate drivers and phytoplankton life strategies interact in a complex dynamic to produce harmful algal blooms (HABs). This study aims to integrate historical biological data collected during “red tide” events along the Ecuadorian coast between 1997 and 2017 in relation to five ocean variables derived from satellite remote sensing data to explain the seasonal drivers of coastal processes associated with HABs dynamics. Seasonality of the occurrence of HABs was assessed in relation to oceanographic variables by applying multiple correspondence analysis (MCA) to the Ecuadorian central coast (Zone 1) and at the outer and inner Gulf of Guayaquil (Zone 2). Sixty-seven HABs events were registered between 1997 and 2017. From a total of 40 species of phytoplankton identified, 28 were identified as non-toxic and the remaining 12 are well known to produce toxins. Dinoflagellates were the taxonomic group most highly associated with potential HABs events along the entire Ecuadorian coast. HABs appear to be constrained by the Humboldt coastal upwelling, high precipitation, and associated coastal runoff, with higher biomass abundance in the Gulf of Guayaquil than in the central coast. Results from the MCA reveal that in the central Ecuadorian coast (oligotrophic system), toxic HABs occurred with low abundance of dinoflagellates, while in the Gulf of Guayaquil (eutrophic system), toxic HABs corresponded to a high abundance of dinoflagellates. In both cases, high values were found for sea surface temperature, precipitation, and irradiance—characteristic of wet seasons or El Nino years. Non-toxic HABs occurred with a high abundance of dinoflagellates, ciliates, and centric diatoms, corresponding to colder waters and low levels of precipitation and irradiance. These findings confirm that dinoflagellates display several strategies that enhance their productive capacity when ocean conditions are warmer, allowing them to produce toxins at high or at low concentrations. Considering that the Gulf of Guayaquil is essential to tourism, the shrimp industry, fisheries, and international shipping, these findings strongly suggest the need to establish an ecosystem health research program to monitor HABs and the development of a preventive policy for tourism and public health in Ecuador.

Integration of GIS and a Lagrangian Particle-Tracking Model for Harmful Algal Bloom Trajectories Prediction

Harmful algal bloom (HAB) is a major environmental problem in coastal waters around the world. The technologies and approaches for short-term forecasting of the HABs trajectories have obtained increasing attention from researchers. In this paper, we present a straightforward physical-based model based on a non-Fickian Lagrangian particle-tracking scheme for understanding the movement of detected HABs. The model adopts the fractional Brownian motion (fBm) technology, and is coupled with the Delft3D and WRF models and GIS. The fBm based Lagrangian particle-tracking model can flexibly control the scale of the particle clouds diffusion through Hurst value, which can be used to account for uncertainties and adjust for better representing the trajectories of HABs. Simulation results demonstrate that the presented model can successfully predict the trends and the main features of red tide drifting. The developed simulation tool enables users to create the model configuration, manage data inputs, run the model, and generate model maps and animations within a GIS environment. It is believed that the model and the tool outlined herein can be very useful for rapidly evaluating potential areas at risk from the HABs events.

Significantly decreasing harmful algal blooms in China seas in the early 21st century

Harmful algal blooms (HABs) are one of primary worldwide environmental problems with severe consequences for aquatic ecosystems, human health, marine fisheries and local economy. During the past few decades, coastal waters of China Seas have experienced a significant increase in the occurrence of the HAB events, which is common across the vast majority of coastal waters of the world. Here we report the absence of the widespread increase over the early 21st century in China Seas. Both frequency and coverage area of annual HAB events have decreased at statistically significant rates for the 2000–2017 period. Despite the multiple factors determining the outbreak of HABs, the improvement of water quality in the marginal sea off China and changes in the sea surface temperature in the early 21st century may play an important role in the decrease in the HABs.

Harmful algal blooms (red tide): a review of causes, impacts and approaches to monitoring and prediction

Red tide, an impermanent natural phenomenon including harmful algal blooms, causes changing the color of the sea generally to red or almost brown, and has a serious impact on environment along the coast and aquatic ecosystem. Due to recent extensive steady harmful algal blooms events that cause adverse impacts on human healthsome, aquaculture and tourism industry, and the entire economy of the coastal region, the need of society for realizing these phenomena is much greater than the past. In the recent decades, consideration of algal blooms and determination of bloom-former species and fundamental researches about dynamics of blooms are increased worldwide. Development in technology has increased our abilities in monitoring oceans and has provided new opportunities for blooms identification as well as defining the biological, physical and chemical parameters that lead to algae beginning, expansion and disappearance. In spite of these rapidly developing observational capabilities, harmful algal blooms’ proceedings will carry on to be undersampled for the foreseeable future, due to their spacious spaced and temporal coverage. Therefore, reliance on models to help interpreting observations is necessary. To watch red tides, there are different methods: field observation and using sampling data, satellite-based studies, laboratory studies, modeling. (This item includes complex numerical models, conceptual models, simple analytic formula, semi-empirical models and aggregated box models or zero-dimensional models.) This paper proposes different observation and prediction methods ever used worldwide.

Scope for growth of Texas Bay scallop Argopecten irradians amplicostatus

ABSTRACTBivalves have exceptional potential as sentinel organisms because their sedentary benthic lifestyle and ability to pump large volumes of water in short periods of time results in bioaccumulation of pollutants and toxins present in the water column. Scope for Growth (SFG) is an instantaneous measure of production that ranges from maximum positive values under optimal conditions to negative valves when the organism is stressed and utilizing its body reserves for maintenance. We determined baseline SFG for the Texas bay scallop Argopecten irradians amplicostatus so that this species might be used to determine sublethal effects of toxins, contaminants, or other environmental stressors in light of recent harmful algal bloom events in the Gulf of Mexico. We also quantified the effects of different diets (phytoplankton, zooplankton, mixed phytoplankton/zooplankton) on Texas bay scallop SFG. SFG of starved animals was negative, indicating that body reserves were used for maintenance. SFG varied significantly (P < 0.001) by diet, with rotifers yielding the highest value (mean = 14.88 Joules hr−1g dry weight, SE = 0.72). We determined that the Texas bay scallop has presently unrecognized potential as sentinel organisms to define effects of various environmental and anthropogenic perturbations.

Spatio-temporal variations of Harmful algal blooms along the coast of Guangdong, Southern China during 1980–2016

Harmful algal blooms (HAB) have become a recurring problem, posing severe impacts on marine ecosystems, fisheries, mariculture industry, and even public health. In this study, the geographic information system (GIS) was utilized to determine spatial and temporal characteristics of HAB events in the coastal waters of Guangdong from 1980–2016. We analyzed distribution patterns and characteristics of HABs by dividing the coast of Guangdong into well-known bays, estuary and coastal waters. Results showed that there were a total of 337 HABs recorded in Guangdong coastal waters. Spatial and temporal distributions varied among different regions. Most HABs occurred in the Mirs Bay, followed by the west coast of Daya Bay, while a few occurred in the west and east coasts of Guangdong but with an increasing trend in the past two decades. HABs occurred mostly in warmer months of March to May in the western coast of Guangdong, March and April in Mirs Bay, April in Zhujiang (Pearl) River estuary, November in eastern coast of Guangdong. For Daya Bay, most HABs were reported between March and September. The most frequently occurring HABs species were Noctiluca scintillans, P haeocystis globosa, Skeletonema costatum and Scrippsiella trochoidea, occurring mostly in Mirs Bay, western Guangdong coast area, eastern Guangdong coast area and Zhujiang River estuary and Daya Bay, respectively. Ichthyotoxic blooms were more common than toxic blooms, and Heterosigma akashiwo, Chattonella marina, Karenia mikimotoi and P haeocystis globosa were the most common ichthyotoxic species. Our results provide baseline information useful for policy making and management of HABs in the region.

Is Submarine Groundwater Discharge (SGD) Important for the Historical Fish Kills and Harmful Algal Bloom Events of Mobile Bay?

Large-scale fish and crustacean kills, locally known as Jubilees, and harmful algal blooms (HABs) have been occurring in Mobile Bay (Alabama) for more than a century. In fact, the first record describing a Jubilee event in Mobile Bay during 1867 was the first ever-documented case of mass mortalities of marine animals caused by hypoxia. To evaluate the importance of submarine groundwater discharge (SGD) in the occurrence of Jubilees and HABs in Mobile Bay, a 3-year study was conducted using a multi-method approach. Significant spatial and temporal variations of SGD were revealed in the bay only by applying a combination of geochemical and shallow geophysical techniques. The development of seasonal hypoxia observed in bay waters in areas impacted by Jubilees was the result of anoxic SGD inputs, which magnitude and spatial distribution were controlled by shallow lithological heterogeneities created during the modern development of the bay. Although when compared to the river discharge SGD contributed between 0.2 (wet season) and 5% (dry season) of the total freshwater inputs to Mobile Bay, 80% of the total SGD in the bay occurred in areas ecologically impacted by hypoxia and Jubilees. In these areas, SGD comprised up to 37% of the total water inputs during the dry season, coinciding with the time of the year when Jubilees and HABs occur. In conclusion, while SGD might not be a significant source of fresh water to Mobile Bay or other estuaries worldwide, enhanced SGD caused by site-specific lithological heterogeneities can have a critical role in the development of hypoxia and ecological issues in nearshore waters.

Economic and sociocultural impacts of fisheries closures in two fishing-dependent communities following the massive 2015 U.S. West Coast harmful algal bloom

In the spring of 2015, a massive harmful algal bloom (HAB) of the toxin-producing diatom Pseudo-nitzschia occurred on the U.S. West Coast, resulting in the largest recorded outbreak of the toxin domoic acid and causing fisheries closures. Closures extended into 2016 and generated an economic shock for coastal fishing communities. This study examines the economic and sociocultural impacts of the Dungeness crab and razor clam fisheries closures on two fishing-dependent communities. Semi-structured interviews were conducted with 36 community members from two communities impacted by the event – Crescent City, California and Long Beach, Washington. Interviewees included those involved in the fishing, hospitality, and retail industries, local government officials, recreational harvesters, and others. Interviews probed aspects of resilience in economic, social, institutional, and physical domains, based on the contention that community resilience will influence the communities’ ability to withstand HAB events. Dimensions of vulnerability were also explored, encompassing sensitivity of the communities to HAB events and their adaptive capacity. Common themes that emerged from the interview responses indicate that economic hardships extended beyond fishing-related operations and permeated through other sectors, particularly the hospitality industry. Significant barriers to accessing financial and employment assistance during extended fisheries closures were identified, particularly for fishers. Long-held traditions surrounding crab and shellfish harvest and consumption were disrupted, threatening the cultural identities of the affected communities. Community members expressed a desire for clearer, more thorough, and more rapid dissemination of information regarding the management of fisheries closures and the health risks associated with HAB toxins. The likelihood of intensifying HABs under climate change heightens the need for actions to increase the resilience of fishing communities to the economic and sociocultural impacts caused by HAB-related fisheries closures.

Proposal of an integrated system for forecasting Harmful Algal Blooms (HAB) in Chile

Harmful Algal Blooms (HAB), are natural phenomena that are produced by the proliferation of phytoplankton potentially harmful to humans and for some ecosystem services ( e.g ., good water quality for use in aquaculture, availability of natural resources). In Chile, HAB events of Pseudo-nitzschia spp. and Alexandrium catenella are particularly relevant due to their potential toxicity. Although there are studies of the negative impact of these events, both the prediction of the occurrence of these phenomena and the associated risks are limited in the country. The proliferations have been attributed to the action of various oceanographic forcings ( e.g ., vertical stratification, irradiation, availability of nutrients). A research has been made about the factors and processes that have been associated with the appearance, permanence and toxicity of HAB and about the methodological efforts made to study and generate HAB forecasts in other countries. Based on a compilation of the information of occurrences and localities affected by these events, the seasonal, interannual and spatial variability of the events or occurrences of HAB in Chile was constructed. Subsequently, the current monitoring system is described, as well as future prediction efforts. Finally, the configuration of a monitoring system with observations and integrated prediction for the occurrence of Pseudo-nitzschia spp. and Alexandrium catenella is suggested.

Cuando la conservación no puede seguir el ritmo del desarrollo: Estado de salud de los ecosistemas coralinos del Pacífico Norte de Costa Rica

Abstract: When conservation can keep up with development´s pace: Health status of coral ecosystems in the North Pacific of Costa Rica. Coral reefs are diverse and productive ecosystems, despite this, they are being threatened by human activities that enhance the detrimental impact of the natural phenomenon’s like Harmful Algal Blooms (HAB). The north Pacific of Costa Rica has been characterized as one of the best regions for the coral reefs development in the country. However, many of these ecosystems are being lost as a result of eutrophication, overfishing, invasive species and others impacts that affect the region. In the present study, live coral cover in the north Pacific was 5.0 ± 10.4(s.d.) %, with a domination in the ecosystems by turf algae. Twenty-six invertebrate taxa were registered in the region with the predominance of the sea urchin Diadema mexicanum. Ninety-four species of reef fish were identified. Snappers and some planktivores species were the groups with the highest frequency and abundance. The localities previously studied in the 1990 decade, presented a mean live coral cover between 40-50 %, whereby the actual state of the reef reflect a significant deterioration. This decline in coral cover is due to natural events like the El Niño, as well as the decrease in water quality in the region. In recent years, proliferations of the invasive seaweed Caulerpa sertularioides and high densities of bioerosive sea urchins have been reported, mainly associated with HAB events. Likewise, fish communities have low biomass, especially in the vicinity of fishing villages. The state of the reefs in the North Pacific is worrying and requires actions for its recovery and conservation, for which there must be better planning of the development of projects and activities on the coast. Rev. Biol. Trop. 66(Suppl. 1): S280-S308. Epub 2018 April 01.

Time series models of decadal trends in the harmful algal species Karlodinium veneficum in Chesapeake Bay

The harmful dinoflagellate, Karlodnium veneficum, has been implicated in fish-kill and other toxic, harmful algal bloom (HAB) events in waters worldwide. Blooms of K. veneficum are known to be related to coastal nutrient enrichment but the relationship is complex because this HAB taxon relies not only on dissolved nutrients but also particulate prey, both of which have also changed over time. Here, applying cross-correlations of climate-related physical factors, nutrients and prey, with abundance of K. veneficum over a 10-year (2002–2011) period, a synthesis of the interactive effects of multiple factors on this species was developed for Chesapeake Bay, where blooms of the HAB have been increasing. Significant upward trends in the time series of K. veneficum were observed in the mesohaline stations of the Bay, but not in oligohaline tributary stations. For the mesohaline regions, riverine sources of nutrients with seasonal lags, together with particulate prey with zero lag, explained 15%–46% of the variation in the K. veneficum time series. For the oligohaline regions, nutrients and particulate prey generally showed significant decreasing trends with time, likely a reflection of nutrient reduction efforts. A conceptual model of mid-Bay blooms is presented, in which K. veneficum, derived from the oceanic end member of the Bay, may experience enhanced growth if it encounters prey originating from the tributaries with different patterns of nutrient loading and which are enriched in nitrogen. For all correlation models developed herein, prey abundance was a primary factor in predicting K. veneficum abundance.

Thermal acclimation affects growth and lipophilic toxin production in a strain of cosmopolitan harmful alga Dinophysis acuminata

Species of the harmful algal bloom (HAB) genera Dinophysis are causative of one of the most widespread and expanding HAB events associated with the human intoxication, diarrheic shellfish poisoning (DSP). The effects of warming temperature on the physiology and toxinology of these mixotrophic species remain intractable due to their low biomass in nature and difficulties in establishing and maintaining them in culture. Hence, the present study investigated the influence of warming temperature, encompassing present and predicted climate scenarios, on growth and toxin production in a strain of the most cosmopolitan DSP-causative species, Dinophysis acuminata. The strain was isolated from western Japan, acclimated, and cultured over extended time spans.The specific growth and toxin production rates were highest at 20–26 °C and 17–29 °C, respectively, and had significant linear relationships during exponential phase. The cellular toxin production of okadaic acid and pectenotoxin-2 were highest during early exponential growth phase at temperatures ≤17 °C but highest during late stationary phase at temperatures ≥20 °C. The cellular toxin production of Dinophysistoxin-1, however, increased from early exponential to late stationary growth phase independently from temperature. The net toxin productions were not affected by acclimation temperature but significantly affected by growth and were highest during early exponential growth phase. Warming water temperatures increase growth and promote toxin production of D. acuminata, potentially increasing incidence of diarrheic shellfish poisoning events and closures of shellfish production. It is likely that D. acuminata is more toxic at low cell densities during bloom initiation in winter, and at high cell densities during bloom termination in spring-autumn. The results of the present research are also of importance for the mass production of D. acuminata for subsequent studies of the toxicological and pharmacological bioactivities of DSTs and PTX2, and the fate of these toxins in the natural environment and the vectoring shellfish molluscs.

Correlation of cyanobacterial harmful bloom monitoring parameters: A case study on western Lake Erie

Occurrence of cyanobacterial harmful blooms (CHBs) in water has caused serious concern to environmental and health authorities because of their potential to produce and release lethal biological toxins. Among many toxins, microcystins (MCs) are of particular interest. There have been significant efforts to observe the harmful algal bloom events and cyanotoxin levels, including: (i) manual field sampling followed by lab analysis to directly measure MCs, (ii) remote sensing based on satellite image analysis to estimate cyanobacterial index (CI), and (iii) in-situ sensing of proxy parameters to cyanobacterial blooms such as phycocyanin. This study compared the observation systems in western Lake Erie to find any potential correlations among these CHB monitoring parameters based on the Pearson Product-Moment equation. We found the relationships among the parameters to be site-specific and so we compared geographical, ecological, meteorological, and analytical factors specific to the locations to explain the observed correlations and variations. The CHB observing parameters (MCs, CI, and phycocyanin) were generally well correlated because they inherently represented the same phenomenon. In particular, we found the measured biological toxin concentration (MCs) to be strongly correlated with the cyanobacterial bloom activity (CI) estimated by satellite image analysis. The phycocyanin concentration also had a strong correlation with CI, implying that measuring an easy-to-detect proxy parameter in-situ and in real-time is effective for monitoring CHBs. The results support the notion that key environmental management parameters such as CHB toxicity can be inferred from remotely-sensed ocean color through proxy variables such as CI.

Potential Photochemical Interactions of UV Filter Molecules with Multichlorinated Structure of Prymnesins in Harmful Algal Bloom Events

Potential Photochemical Interactions of UV Filter Molecules with Multichlorinated Structure of Prymnesins in Harmful Algal Bloom Events

HARMFUL ALGAL BLOOM 2012 EVENT VERIFICATION IN LAMPUNG BAY USING RED TIDE DETECTION ON SPOT 4 IMAGE

In mid-December 2012, harmful algal bloom phenomenon occurred in Lampung Bay. Harmful Algal Bloom (HAB) is blooming of algae in aquatic ecosystems. It has negative impact on living organism, due to its toxic. This study was applied Red Tide (RT) detection algorithm on SPOT 4 images and verified the distribution of HAB 2012 event in Lampung Bay. The HAB event in 2012 in Lampung Bay can be detected by using RT algorithm on SPOT 4 images quantitatively and qualitatively. According to field measurement, the phytoplankton blooming which happen at Lampung Bay in 2012 were Cochlodinium sp. Image analysis showed that Cochlodinium sp has specific pattern of RT with values, digitally, were 13 to 41 and threshold value of red band SPOT 4 image was 57. The total area of RT distribution, which are found in Lampung Bay, was 11,545.3 Ha. Based on the RT classification of RT images and field data measurement, the RT which is caused many fishes died on the western coastal of Lampung Bay spread out from Bandar Lampung City to Batumenyan village. By using confusion matrix, the accuracy of this this method was 74.05 %. This method was expected to be used as early warning system for HAB monitoring in Lampung Bay and perhaps in another coastal region of Indonesia.

Ocean warming since 1982 has expanded the niche of toxic algal blooms in the North Atlantic and North Pacific oceans

Global ocean temperatures are rising, yet the impacts of such changes on harmful algal blooms (HABs) are not fully understood. Here we used high-resolution sea-surface temperature records (1982 to 2016) and temperature-dependent growth rates of two algae that produce potent biotoxins, Alexandrium fundyense and Dinophysis acuminata, to evaluate recent changes in these HABs. For both species, potential mean annual growth rates and duration of bloom seasons significantly increased within many coastal Atlantic regions between 40°N and 60°N, where incidents of these HABs have emerged and expanded in recent decades. Widespread trends were less evident across the North Pacific, although regions were identified across the Salish Sea and along the Alaskan coastline where blooms have recently emerged, and there have been significant increases in the potential growth rates and duration of these HAB events. We conclude that increasing ocean temperature is an important factor facilitating the intensification of these, and likely other, HABs and thus contributes to an expanding human health threat.