MERHAB 2005: Project Summaries

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Rapid HAB Detection Instrument Development and Deployment

Institution: University of Maine

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Investigators: L.Connell and R. Smith


Demographic trends show strongly increasing numbers of people living in immediate proximity to the ocean increasing the risk of exposure to natural hazards. Paralytic shellfish poisoning (PSP) caused by consumption of shellfish that have fed on toxic algae remains a major health issue throughout North American coastal areas. The microalgae responsible for PSP are dinoflagellates, primarily Alexandrium ssp. These algae produce potent neurotoxins that comprise the paralytic shellfish toxins (PSTs). Alexandrium can be toxic at such low numbers that the cells are not easily visible as blooms and water discoloration is not evident, making detection at early stages very important. Extensive monitoring efforts in coastal areas target the toxic producing algae as early warning systems to trigger more costly mouse bioassay toxin monitoring. Development of rapid, inexpensive and easy-to-use algal detection and enumeration devices would be a great boon for coastal monitoring managers, especially those states with extensive coastlines such as Maine.

This project will focus on combining new molecular biology techniques with solid surfaces technologies to develop small, efficient instruments for use by water quality managers. These devices will be based on direct detection rather than chemical or enzymatic signal amplification.

This project will move detection of HAB organisms into a direct detection level that can more easily be either deployed on buoys or in hand held instruments for use by local groups. Synthetic DNA analogs will be used to enhance current technologies that are either impractical or inefficient using traditional DNA probes. The synthetic molecule, peptide nucleic acid (PNA), will be used as a capture probe for detection of Alexandrium . Several solid surface techniques will be explored for direct detection of the target organism, including surface plasma resonance (SPR), target mediated aggregation (TMA) and field effect transistor (FET)-based platforms. Hybridization time will be minimized using short low-voltage pulses within the hybridization chamber. The best of the platforms will be given to a coastal monitoring program for evaluation.

Direct detection of HAB organisms directly from field collected samples in a rapid (seconds), inexpensive (cents) and user-friendly format will represent a significant advance in our current HAB detection systems. The reduction of enzymes and other labile reagents will increase the shelf-life and further reduce costs. These platforms will allow non-scientists to monitor coastal waters in a cost effective manner and permit early warning systems to be eventually deployed onto buoys. Although this is primarily a proof-of concept project, successful completion will demonstrate utility of rapid platforms for non-scientists. These platforms will allow the addition of other organisms (both HAB and non-HAB) to the detectors through an electronic based microarray system.

Monitoring Toxic Alexandrium in Puget Sound using qPCR

Institution: Woods Hole Oceanographic Institution

Investigators: Sonya T. Dyhrman and Deana Erdner


Dinoflagellates of the genus Alexandrium can produce a suite of potent neurotoxins that cause paralytic shellfish poisoning (PSP) in humans, and can have serious deleterious impacts on public health and economic resources.Alexandrium and related PSP-toxicity is a problem of global scale. Within this genus, Alexandrium catenella is widespread in the northwestern part of North America, including the Puget Sound, and is responsible for seasonal harmful algal blooms in these regions. Even at low cell densities, A. catenella toxins can accumulate in shellfish and result in PSP. As a result, accurate measurements ofA. catenella distributions, particularly at low cell density, are critical to continued PSP monitoring and mitigation efforts. Towards this end a specific, sensitive, and high throughput real-time quantitative PCR (qPCR) method has recently been developed to assay the abundance of A. catenella . Laboratory validation indicates that the qPCR assay is sensitive enough to detect 10 cells per DNA extraction, and that it is very specific. This specificity is critical for work on harmful algal blooms (HAB), where toxic species are present in mixed communities of non-toxic phytoplankton. The overall goal of this work is to interface a proven, high-sensitivity detection method for A. catenellainto existing PSP monitoring efforts and to examine its efficacy in predicting or serving as an early warning of shellfish PSP toxicity. Specific objectives of the work plan are outlined in the project description, but key elements of the work plan are as follows:

  • Participate in high frequency seasonal sampling and qPCR analysis of water column samples from the 40 Sentinel Sites used for PSP testing by the Washington State Department of Health in the Puget Sound.
  • Map A. catenella abundance over two seasonal cycles (April - November) at the 40 different Sentinel Sites.
  • Compare A. catenella water column abundances at different sites with PSP Impact Category and the yearly estimate of PSP Impact Factor as defined by the Washington State Department of Health Office of Food Safety and Shellfish Programs to determine the extent to which qPCR may be used as a method for early warning of a PSP event.
  • Use the resulting data set as a teaching and research tool for undergraduates in the Harmful Algae Research Program funded through the NOAA Career 2004 Program.

This research directly relates to the overarching goal of the MERHAB program: to incorporate tools from harmful algal bloom (HAB) research programs into ongoing HAB monitoring programs. Specifically, this work will partner with existing monitoring efforts in the Puget Sound and it will result in a field-validated method for quantifying A. catenella that could benefit monitoring studies in the Puget Sound region and elsewhere. Furthermore, this research would provide a framework with which to teach and prepare the next generation of coastal ocean scientists and managers by partnering with our NOAA-funded career development program.

Identification and Monitoring of Nearshore Harmful Algal Blooms on the West Florida Shelf

Institution: Florida Environmental Research Institute

Investigators: W. Paul Bissett, Ph.D., David D.R. Kohler, Robert Steward, and Richard Stumpf ( NOAA Ocean Service Center for Coastal Monitoring and Assessment)


The project seeks to enhance the current operational NOAA HAB bulletin for the West Florida Shelf (WFS) by expanding its capabilities into the nearshore environment (defined as those waters <3 km from coast). The current HAB bulletin uses a satellite-based multispectral chlorophyll a anomaly approach, which includes a filter matrix of ecological parameters, to identify regions of large accumulations of Karenia brevis populations. These bulletins are issued to local, state, and federal resource managers, tourism officials, and business leaders in an effort to mitigate the health and economic impact of K. brevis blooms on the WFS. Over the last 4 years, the bulletins have demonstrated the ability (>80% success rate) to identify >1 m g chl/liter anomalies in offshore waters.

However, the greatest impacts on human and marine health exist in the nearshore waters, not the offshore waters. Unfortunately, the spatial and spectral limitations of the current suite of operational satellites preclude accurate retrieval of chlorophyll a anomalies in the nearshore coastal waters. The spatial limitations result from the approximately 1 km resolution of the satellites, the errors in exact geo-positioning of the coastline, and the contamination of nearshore pixels from reflection of light from the landward areas. The spectral limitation result from the number of spectral bands available for algorithms to estimate phytoplankton biomass in shallow water regions. The small number of spectral bands does not provide sufficient degrees of freedom to separate photons reflected off of the in-water optical constituents (e.g. phytoplankton) from those reflected off of the bottom.

Over the last 6 years, the Florida Environmental Research Institute (FERI) has demonstrated the capabilities to deploy, calibrate, geo-rectify, atmospherically-correct, and produce optical products of nearshore bathymetry, bottom reflectance, and in-water optical constituents from HyperSpectral Imaging (HSI) data. These high resolution geospatial technologies are able to map and monitor chlorophyll a anomalies in the nearshore regions, and this project seeks to demonstrate that capability. This project will further develop algorithms to reduce the false positives of the current HAB bulletins resulting from chlorophyll a anomalies cause by non-toxic phytoplankton species (e.g. diatoms andTrichodesmium spp.). Lastly, we will use the high resolution spatial and spectral imaging data to develop algorithms to specification identify K. brevis in nearshore waters.

This project will explicitly coordinate with the NOAA HAB Forecast System, since PI Stumpf is responsible for developing the improvements to this System. This improvement process involves semi-annual meetings with resource managers using the system, as well as community and business groups represented by START (Solutions to Avoid Red Tide). Project information and findings will be provided to the various communities through START and through the Red Tide Alliance, which coordinates dissemination of educational materials to the public.

Validating Remote Detection of Karenia brevis

Institution: The University of Texas at Austin

Investigators: Tracy Villareal and Richard Stumpf (NOAA Ocean Service Center for Coastal Monitoring and Assessment)


The proposed work will continue the testing of satellite-based monitoring program for the Gulf of Mexico to include the Texas coast (western Gulf). From 1935 to 1986, blooms of the toxic dinoflagellate, Karenia brevis, affected the region intermittently. The frequency of events has increased dramatically since the 1990's with over half the documented red tides occurring in the last decade. Texas has no large-scale monitoring program and the state agencies charged with recording fish mortality and closing shellfish beds respond to fish kills or fortuitous observations as tripwire indicators. There is little likelihood of a state-wide monitoring effort being implemented in the near future. Thus, satellite and modeling capabilities for routine remote detection and monitoring is the only practical means for covering the state's extensive offshore area. NOAA's now operational satellite-based harmful algal bloom program in Florida has been successfully tested in Texas waters during a previous MERHAB award. A key correction for benthic resuspended chlorophyll has been developed and applied, with the accuracy of positive detection of known blooms approaching that for Florida. However, the Texas coast has a complex, seasonal circulation that is unlike Florida's. Specifically, there are anomalous chlorophyll features that flag as blooms after the benthic correction. They are large and appear to be common features.

The proposed work will continue the focused 3-year monitoring program for model and algorithm verification. The field program uses a collaboration with Texas Parks and Wildlife Department (valued at >$) 120,000 to provide offshore (<9 nautical miles) samples at no cost to this program. Our proposed work will add monthly transects (1-2 days on local vessels) during the fall summer to characterize the optical and biological properties in these anomalous regions. In addition, limited sampling of the benthic boundary layer (nepheloid layer) common to these waters will be conducted to determine the characteristics of the resuspended particulates. The result will be a three-tiered system for testing the model results and developing algorithms to eliminate the major remaining false flags. These transect and event response sampling (cell counts, chlorophyll) will be based out of the Marine Science Institute (UT-Austin). Stumpf is collaborating at no charge to the project.

This work is a necessary and logical extension of the previous MERHAB project that will provide essential information to bring the satellite system into an operational mode for this region. The outcome of this project will be a near-real-time tool for detecting and predicting K. brevis events along the Texas coast. The product will be integrated into the NOAA HAB bulletins and the proposed Harmful Algal Bloom Observing System (HABSOS) program in order to provide a near-real time, web-accessible, HAB visualization product.

Development and Implementation of an Operational Harmful Algal Bloom Prediction System for Chesapeake Bay

Institutions: NOAA NESDIS, Chesapeake Research Consortium, University of Maryland Center for Environmental Science - Horn Point Lab, University of Illinois, Evansville, Maryland Department of Natural Resources

Investigators: C. Brown, T. Gross, R. Hood, D. Ramers P. Tango and B. Michael


Project Summary: Various noxious and toxic algal blooms afflict the Chesapeake Bay and other coastal U.S. waters, posing threats to human health and natural resources. The goal of this regional study is to develop and implement an operational system that will nowcast and forecast the likelihood of blooms of the following three harmful algal bloom (HAB) species in Chesapeake Bay and its tidal tributaries: the dinoflagellates Karlodinium micrum and Prorocentrum minimum and the cyanobacteria Microcystis aeruginosa. In addition, the feasibility of predicting other HAB species will be investigated and pursued. The method proposed involves using real-time and 3-day forecast data acquired and derived from a variety of sources and techniques to drive multi-variate empirical habitat models that predict the probability of blooms caused by these particular HAB species. The predictions, in the form of digital images, will be available via the World Wide Web to individuals and interested agencies to guide research, recreational and management activities. In particular, these nowcasts and forecasts will be employed by the Maryland Department of Natural Resources (MD DNR) to guide their response sampling efforts for HAB monitoring. This approach builds directly upon the system that the PIs have implemented for nowcasting the likelihood of encountering sea nettles (Chrysaora quinquecirrha) and relative abundance of Karlodinium micrum in Chesapeake Bay, and a new network of continuous in-situ monitors that have been deployed by MD DNR.

The operational HAB forecasting system will be constructed by 1) developing and implementing empirical habitat models for HAB species that predict the probability of a bloom as a function of each species preferred environmental conditions; 2) acquiring and forecasting the pertinent environmental variables in near-real time, using a combination of satellite remote sensing, real-time in situ measurement, and mechanistic 3-D modeling; 3) applying the habitat model of each species to the relevant environmental variables in order to nowcast and forecast the probability of their blooms throughout Chesapeake Bay and its tributaries; 4) validating the estimated environmental variables and bloom predictions using in situ data collected by MD DNR and other data sources; and 5) enhancing an existing webpage to disseminate these predictions of HAB bloom probability to managers, researchers, and the general public. The models, data, predictions and web site will be integrated into an operational forecasting system, built in accordance with NOAA / NOS forecast system standards, to routinely provide HAB predictions to the Maryland Department of Natural Resources -the agency that is responsible for protecting living resources and human health in the bay -and other users.

This multi-disciplinary project spans both the development and operationalization of HAB prediction in Chesapeake Bay and will 1) provide an improved understanding of HABs and the factors that give rise to them, 2) develop and implement a methodology to predict the probable occurrence of blooms of important HAB species in Chesapeake Bay, and 3) implement a robust and automated HAB forecast system, created with and for the MD Department of Natural Resources, to provide early warnings of these extreme natural events and aid in mitigating the deleterious effects of their presence on human and ecosystem health in the bay.

The Chesapeake Bay HAB web site is located at and presents current HAB nowcasts and related information.

Detection, Toxicity Characterization of Brevetoxins and Brevetoxin Metabolites and Validation of the ELISA as an Alternative to the Regulatory Mouse Bioassay for Shellfish Monitoring.

Institutions: Center for Marine Science-UNCW , Florida Fish and Wildlife Research Institute, Mote Marine Lab

Investigators: J. Naar, D.G. Baden, A. Bourdelais, CJ Wright, K.A. Steidinger, L. Flewelling, R. Pierce


In the Gulf of Mexico, blooms of the toxic dinoflagellate Karenia brevis cause ecological disasters, result in human respiratory distress and contaminated seafood. With support of a previously funded MERHAB project we had completed the development of a new enzyme immunoassay (ELISA) for brevetoxin analysis (1). This assay has been show to be very well-adapted for assessing human exposure to aerosolized toxins (2) (ref), diagnosing brevetoxin poisoning during mass mortalities of marine mammals (3), identifying new brevetoxin producing microalgae (4) as well as identifying some unexpected vectors of brevetoxin to higher trophic levels (3). This versatility is due to: 1) a sensitivity for brevetoxins in the nanomolar range, 2) a specificity for both brevetoxins and brevetoxin metabolites, and 3) a simplicity and absence of elevated matrix effects allowing analyses of both environmental (seawater, sea-spray, and air-filter) and biological (fish, bird and mammalian tissues and body fluids, shellfish extracts and homogenates). Since the early 197Os, the mouse bioassay has been the only FDA-approved method of shellfish monitoring. Because this assay is labor-intensive, requires the use of dangerous solvents and the destruction of many animals, analyses are restricted to very few laboratories with a low through-put. The development of a faster, more efficient technology to replace this assay has long been a goal of regulatory and scientific communities. The ELISA methodology does not require expensive facilities, the use of radioactive materials or dangerous solvents while providing better sensitivity and reducing the time required for analysis. Additionally, the ELISA can be performed on shellfish meat as well as extracts and, using different methods, parent brevetoxins and metabolites can be analyzed together or individually. A preliminary multi-laboratory evaluation (5) has shown that the ELISA appears to be a very good candidate to replace the mouse bioassay. The method was recommended in September of 2004 by the NSP subgroup of the AOAC task force to be evaluated as an alternative method to replace the mouse bioassay. Although members of the NSP subgroup agreed on the analytical method by itself, there is still a lot unknown regarding the toxins implicated in human poisonings, and the toxins that need to be monitored to ensure human safety. The ultimate objectives of this study are to: 1) identify in shellfish species of economical importance what compounds are implicated in the overall shellfish toxicity, 2) define what sample preparation is required to ensure an accurate evaluation of toxicity, 3) evaluate the performance of the ELISA in a selected area where shellfish will be monitored by both regulatory and alternative methods, 4) to prepare standardized material to perform an independent multi-laboratory evaluation of the assay.


  1. J. Naar, A. Bourdelais, C. Tomas, J. Kubanek, P.L. Whitney, et. Al. (2002) A competitive ELISA to detect brevetoxins from Karenia brevis (formerlyGymnodinium breve ) in seawater, shellfish, and mammalian body fluid. EHP110(2): 179-185.
  2. Cheng YS, Zhou Y, Irvin CM, Pierces RH, Naar J, Backer LC, Fleming LE, Kirkpatrick B, Baden DG. 2005. Characterization of Marine Aerosol for Assessment of Human Exposure to Brevetoxins. EHP 112:000-000.
  3. Flewelling L, Naar J, Abbott J, Baden DG. et al. Red tides and marine mammal mortalities, Nature 435: 755-756
  4. Bourdelais A., Tomas C.R., Naar J., Kubanek J., Baden D.G. (2002) New Fish-Killing Alga in Coastal Delaware Produces Neurotoxins. EHP 110: 465-470
  5. Dickey RW, Plakas SM, Jester ELE, ElSiad KR, Johannessen JN, et al. (2004) Multi-laboratory study of five methods for the determination of brevetoxins in shellfish tissue extracts. in Harmful Algae 2002 (Steidinger KA, Landsberg JH; Tomas CR and Vargo GA eds) St Petersburg Florida, USA 300:302

Shellfish HAB Sampling and Monitoring Project

Institution: Quinault Indian Nation (QIN)

Investigator: Joe Schumacker


Shellfish are extremely important to the economy and culture of the Quinault Indian Nation (QIN) Domoic acid continues to threaten QIN shellfish resources and more importantly the health of our tribal and surrounding communities. The project will expand shellfish sampling within the Washington State coastal area managed or co-managed by QIN (approximately 55 miles of coast) and incorporate the use of new technologies into sampling to build an independent testing ability, critical to the communities of the isolated Washington coastal area. The project expands and improves the Washington State funded shellfish monitoring effort known as the Olympic Region Harmful Algal Bloom program and supports QIN continued participation.

The Quinault Nation proposes to incorporate and test the feasibility of regular use of emerging technologies, specifically the MIST Rapid Assay test strip and Enzyme Linked Immuno-sorbent Assay (ELISA) to determine levels of domoic acid in seawater and razor clam samples. This is critical to forming a more independent, timely manner in which to assess threats to the health of coastal communities. QIN will expand established ORHAB sampling to include two new sites, test new technologies and make recommendations as to their usability, incorporate our findings into existing HAB management programs, make findings available to all interested co-managers and coastal co-managers, and continue seeking non MERHAB funding in order to extend our program beyond three years.

MERHAB-RAPDALERT - Rapid Analysis of Pseudo-nitzschia and Domoic Acid, Locating Events in near-Real Time.

Institution(s): University of Southern California, University of California, Los Angeles, University of California Santa Cruz, Southern California Water Research Project.

Investigators: David A. Caron, Burton H. Jones, Gaurav S. Sukhatme, Deborah Estrin, Peter Miller, and Stephen Weisberg.


The goal of this MERHAB project is to implement fine-scale HAB monitoring/sampling program coverage by incorporating (1) innovative in situsensor networking technology, (2) state-of-the-art remote sensing and (3) cutting-edge species identification and domoic acid quantification methods. This 3-pronged approach will establish a pilot project off the southern California coast in the Southern California Bight, where new technologies will be incorporated into an intensive monitoring program. This project will serve as a template for ultimately shifting much of the burden of HAB monitoring to an automated system that ensures early warning of impending blooms while minimizing unnecessary and expensive field-based sampling and lab-based testing. The resulting information should also advance our understanding and ability to predict HAB events in nature. Use of the in situ sensor and remote sensing data in conjunction with field sampling will enable tracking of the inception, proliferation, advection and decline of bloom events in real-time. In turn, this will provide managers with the necessary information to make informed decisions on when and where to direct their staff in the field to efficiently increase their efforts. The in situ sensor network (a network of 10 stationary nodes and an autonomous glider) will provide synoptic coverage of the study area, within-network data collection and communication, and ultimately sensor-actuated sampling and sample retrieval. Coupled with information from remote sensing, the network will also facilitate real-time data visualization, enabling a rapid response by agencies to emerging events. Integration of sensor information will provide unprecedented spatial and temporal resolution of pertinent parameters in the coastal ocean study site on temporal and spatial scales sufficient to resolve algal bloom dynamics. Transfer of emerging technologies for bloom monitoring, the identification of Pseudo-nitzschia species, and concentrations of domoic acid will be accomplished through the establishment of 'working partnerships' of scientists within the HAB research community and agencies charged with monitoring water quality. Stakeholder meetings will be held to assess the need for new approaches within agencies, and to facilitate the transfer of new technology into the hands of end-users where appropriate.

Last updated: July 11, 2016