Public posting warning of toxic shellfish

A new study published in the American Chemical Society journal: Chemical Research in Toxicology shows that in animals the brevetoxin cysteine conjugate eliminates quickly from the blood, whereas the highly toxic brevetoxin lipid conjugate eliminates slowly.   The study reveals the types of changes to the toxin molecule that increase or decrease toxicity and provides the first toxicokinetic parameters for the red tide toxin that describes and models the rate it enters the body, how long it stays, and how long it takes to be eliminated: factors that change the outcome of neurotoxic shellfish poisoning (NSP).

Red tides in the Gulf of Mexico affect humans, wildlife, fisheries and the regional tourist-related economy.  They are caused by the harmful algae Karenia brevis, which release a powerful a neurotoxin called brevetoxin.  Research shows that brevetoxin is highly reactive and attaches to proteins and lipids, leading to hybrid “conjugate” molecules that are hard to detect and  threaten human and animal health.

Collaborating with researchers in New Zealand, NCCOS scientists used chemical synthesis to prepare brevetoxin conjugates that pose the greatest risk to Gulf of Mexico shellfish consumers, to test how they may affect humans and animals.  Initial studies showed that the common shellfish brevetoxin which is attached to the amino acid cysteine had little effect on its toxicity or on the ability of test methods to safely reopen shellfish harvests.  By contrast another shellfish metabolite, brevetoxin attached to a lipid, greatly increases its toxic potency and escapes existing test methods.

Chemical structure of the neurotoxin called brevetoxin and the cysteine conjugate

Expanding the knowledge of the toxic properties of brevetoxins will help refine strategies to reduce its risk to humans, improve resiliency of local fishing industries and mitigate economic impacts. For more information, contact John.Ramsdell@noaa.gov.

Related Links:

Red Tide Algae Bloom Closes All Oyster Harvesting In Texas

Texas Oyster Industry Hurt as Red Tide Sweeps Coast

Red tide kills fish along South Sarasota County, Charlotte County beaches

Florida Monitors Massive Red Tide with NOAA’s Help

Blood Monitoring Aids Response and Rehabilitation of Algae-poisoned Seabirds

NOAA Harmful Algal Bloom Operational Forecast System

Where is all the Brevetoxin in Florida Dolphins?

2008 Noctiluca bloom in Ketchican, AK, repeated in 2009 and 2010

For the sixth summer in a row an orange discoloration has appeared in Alaskan coastal waters.  NCCOS scientists provided “coastal intelligence” to officials that these “orange tides” differ; Some result from water borne harmful algal cells, others by air-driven terrestrial fungal spores.

In 2008, NCCOS scientists determined an orange tide in Ketchican came from a bloom of harmful algae, Noctiluca scintillians. Researchers have linked this alga with fish mortality events worldwide, but its toxic compounds do not affect humans. Blooms of Noctiluca repeated the next two summers in Ketchican.

2011 Chrysomyxa spore dispersal in Kivalina, AK repeated in 2012 in Kachemak, AK

In May 2013, U.S. Fish and Wildlife Service Wildlife biologists from the Izembek National Wildlife Refuge observed an orange water discoloration visually similar to the other Alaskan events.  NCCOS scientists announced this Alaskan orange tide as a Noctiluca algal bloom not hazardous to coastal residents.

In 2011, an unusual orange tide appeared in the coastal waters of Kivalina, a remote Inupiaq village along Alaska’s northwest coast.  Though visually similar to Noctiluca blooms, NCCOS scientists identified it as terrestrial fungal spores driven by wind into coastal waters. Based upon NOAA electron micrographs, U.S. and Canadian Forest Service scientists confirmed the spores as spruce needle rust (Chrysomyxa ledicola).  ‘Rust’ infects only plants, not people; however, high densities of fungal spores could cause respiratory effects.  An orange tide of fungal spore repeated the following summer in the Kachemak Bay National Estuarine Research Reserve.

Discolored waters from  harmful algal blooms alarm coastal residents and can quickly threaten their health and the environment. Alaska coastal waters, with many unique ecosystems and 34,000 miles of tidal shoreline, pose unparalleled challenges for coastal preparedness and response.  As part of the NOS coastal intelligence network, NCCOS Event Response Program scientists provide actionable information for local decision making. For more information, contact Steve.Morton@noaa.gov.

Related Links

Alaska “Orange Goo” Rust Spores Confirmed

Alaskan “Orange Goo” Determined to be Fungal Spores

Mysterious “Orange Goo” Washes Ashore in Northwest Alaska in Early August -National Ocean Service

Mystery goo in Alaska now called fungal spores -Reuters

Orange Goo at Alaska Village Was Fungal Spores -Huffington Post

Mystery of Alaskan “Goo” Rust Solved at Last | The Artful Amoeba, Scientific American Blog Network

The RBA for PSP toxins is a rapid, cost-effective test that measures algal toxins to protect consumers from exposure to contaminated shellfish, and has been accepted as an Official Method of Analysis by the Association of Official Analytical Chemists (AOAC) following a rigorous, international inter-laboratory validation trial.  The technique is a candidate for replacing the current approach for regulatory testing of shellfish, which requires injecting shellfish fluids into mice and timing how long it takes for them to die. 

RAI LLC provides consulting and laboratory testing for marine biotoxins for governments, universities, researchers, and industry.  Transfer of this NCCOS-developed technology to private-sector enterprises avails greater monitoring capabilities to coastal managers and enhances the ability of our partners to protect public health while realizing the economic benefits of expanding shellfish harvests.

For more information, contact Fran.VanDolah@noaa.gov.

Related Links

• NOAA Technology Provides Regulatory Method to Safeguard Fisheries and Promote International Trade
• NOAA Test Method to be Demonstrated to International Shellfish Authorities
• International Analytical Agency Greenlights Shellfish Toxin Detection Method
• Transfer Deal with International Organization Promotes Global Shellfish Safety
• Alaska to Use NCCOS Designed Phytoplankton Monitoring for Proactive Response to Red Tide Event

NCCOS’s primary role in this effort is to develop sensors that can be deployed on the ESP to detect seafood toxins produced by harmful algae. The commercially available, second generation ESP is designed primarily for use underwater on stationary moorings. Work is underway on a third generation instrument that will adopt a miniaturized sensor technology to allow deployment on a long-range autonomous underwater vehicle (AUV).

The AUV-mounted ESP, if successfully completed, will be able to track and interrogate the composition and toxicity of harmful algal blooms, providing coastal managers with a uniquely powerful tool for detecting and monitoring these events in near-real time.

For more information, contact Greg.Docuette@noaa.gov.

Related Links

• NCCOS and Partners Experiment with First Underwater Robot that Will Remotely Detect Red Tide Toxins in Gulf of Maine
• Underwater Ocean Observing Robots Sniff Out Signs of Toxic Algae
• California HAB Forecasting Highlighted by Major Ocean Research Organization, Online News Service
• Sensor Monitors Gulf of Maine Algae for Signs of Approaching Red Tides
• Algae Sensor for NOAA Integrated Ocean Observing System’s Underwater Vehicles Nears Completion

Vibrio vulnificus is a water-borne pathogen responsible for 95% of food-borne illness deaths from seafood consumption. Vibrio parahaemolyticus is another water-borne human pathogen that causes gastrointestinal infections. A multiple antibiotic resistance assay was developed to test resistance of these species to ten antibiotics. Isolates from around the Southeastern United States were examined, including clinical (blood, wound) and environmental (oyster, water, sediment).

Results showed blood and water had the most diverse resistance profiles for sample matrixes tested. There were low amounts of resistance in Vibrio spp. in both clinical and environmental isolates, and no resistance to current antibiotics used to treat V. vulnificus infections. Further research is necessary on antibiotic resistance in Vibrio spp. to determine overall public health risk, however, current risks of becoming infected by a strain resistant to current therapies appears to be low.  For more information, contact Marie.DeLorenzo@noaa.gov.

Nearly 600 visitors came to learn about the Laboratory and its mission to bring together the unique combination of science, response, and management capabilities to improve and protect the ecological health of the Chesapeake Bay and provide science for ecosystem management relevant to ecosystems worldwide.

Visitor activities included interactions with scientists and rare Chesapeake Bay fish species, as well as hands-on experience building remote control underwater vessels, seining, touching and seeing bay critters up close, making T-shirt prints of local marine species, and learning about the health of the Chesapeake Bay. For more information contact: Gretchen.Messick@noaa.gov.

Since bloom toxicity can fluctuate substantially and, in turn, influence toxin levels in shellfish, the addition of a PST sensor to ESP deployments represents a significant step towards assessing the potential of a bloom to cause shellfish toxicity.  This year’s toxin information will be included to the regular updates for scientists, coastal managers, and public health officials in the region to support decisions on shellfish harvesting closures.

NCCOS in-house research that adds toxin detection to the ESP’s capabilities complements external NOAA’s externally-funded partner efforts overseen by an NCCOS Monitoring and Event Response for Harmful Algal Bloom (MERHAB) pilot, which supports deployments of ESPs with integrated PST sensors and design of an optimum ESP deployment array as part of the Northeast Regional Association of Coastal & Ocean Observing Systems (NERACOOS).

An NCCOS Prevention Control and Mitigation of Harmful Algal Blooms (PCMHAB) project is transitioning predictive models into the NOAA HAB Operational Forecast System. ESP data, including PST levels, and will improve the accuracy of future HAB forecasts. These NCCOS HAB research investments are leading to enhanced NOAA observing and forecasting capabilities that will benefit the Gulf of Maine.

See Also:

• Scientists Report First Remote, Underwater Detection of Harmful Algae, Toxins

The scientists used blood collection cards to help evaluate live stranded birds along the central west coast of Florida.  The data showed that during a recent bloom of Karenia brevis, a brevetoxin-producing dinoflagellate, 82% of seabirds upon admission tested positive for brevetoxin and, of those, 64% died afterwards due to brevetoxicosis. Daily monitoring of blood levels of brevetoxin guided rehabilitation and release of the surviving birds by enabling a proper diagnosis and appropriate treatment.

Double-crested Cormorants (Phalacrocorax auritus) were the most commonly poisoned by brevetoxin, along with the Brown Pelican (Pelecanus occidentalis), Great Blue Heron (Ardea herodias) and Laughing Gulls (Larus atricilla). However, 19% of birds also tested positive when a toxic bloom or ‘red tide’ was not occurring, which shows that there can be long term health risks to seabirds in this area, and points to a need for monitoring of brevetoxin levels.

The double crested cormorant and laughing gull are two of the most common birds poisoned by brevetoxins in the Gulf of Mexico.

The use of blood collection cards, a Center for Disease Control (CDC) method for blood collection and sample archiving, was developed by NCCOS for biomonitoring brevetoxin exposure in humans and wildlife species, including sea birds, sea turtles, manatees and dolphins. The blood card method used as part of this study could be a reliable means of monitoring brevetoxin levels to assess wildlife mortality events in the Gulf of Mexico, as well as to establish “baseline” levels during non-bloom periods.

Contributing partners in this study include Mote Marine Laboratory, Florida Fish and Wildlife Conservation Commission, Pelican Man’s Bird Sanctuary, the University of Illinois Zoological Pathology Program and the Wildlife Health Center of University of California, Davis. The Morris Animal Foundation funded this research.

Publications

Blood Collection cards provide a validated method to store blood for chemical analysis

• See also: Biomonitoring Brevetoxin Exposure in Mammals Using Blood Collection Cards and Optimization of Blood Collection Card Method/Enzyme-Linked Immunoassay for Monitoring Exposure of Bottlenose Dolphin to Brevetoxin-Producing Red Tides.

Presentation

• NOAA Library Powerpoint Presentation by Dr. Fauquier, Lead Author and 2012 Knauss Sea Grant Fellow.
• Deep background:  Karenia brevis red tides and brevetoxin-contaminated fish: a high risk factor for Florida’s scavenging shorebirds?

 Products

• Blood Cards: NOAA scientists develop blood collection cards that provide new on site technology for harmful algal bloom rapid response
• Toxin Test Kit: The detection of brevetoxin from the blood collection cards used in this study was accomplished by an enzyme linked immunosorbant assay, developed by NCCOS and AgResearch (New Zealand), and which is available commercially as a test kit by Abraxis (Warminster, PA).  This ELISA has been used to successfully detect brevetoxins from a wide variety of wildlife including seabirds, turtles, dolphins and other marine mammals.

The study area for the March 2013 ECOHAB experiment. The left shows selected tracks of ships, AUVs, and underwater gliders. The right depicts the same area overlain by a satellite-derived map of chlorophyll, an indicator of marine algae near the sea surface (dark red = highest chlorophyll levels). Credit: MBARI / ECOHAB (Base map from Google maps).

NCCOS researchers and their colleagues from the Monterey Bay Aquarium Research Institute (MBARI), the University of California Santa Cruz (UCSC), and several other institutions are using the Controlled, Agile, and Novel Observing Network, also known as CANON. This network is an array of sensors measuring the physics, chemistry, and biology of the ocean to investigate the complex physical and chemical interactions responsible for toxic Pseudo-nitzschia blooms and blooms of other harmful algae along the California coast.

Understanding these interactions will help the team create more accurate forecast models and to establish an early warning system for HABs in this region. Moreover, it will demonstrate the utility of an integrated observing system for harmful algae as part of a Regional Coastal Ocean Observing System under the U.S. IOOS Program.

This work is funded by NOAA’s Ecology & Oceanography of Harmful Algal Blooms program (also called ECOHAB) through a regional project led by UCSC. Other participants include University of Southern California, Moss Landing Marine Laboratory, University of California Los Angeles, and Southern California Coastal Water Research Project, as well as MBARI and NOAA. These partners are contributing a number of new and proven sensor technologies to provide data on Pseudo-nitzschia bloom dynamics and the environmental conditions that promote their development or cause their decline.

An NCCOS scientist leads a training session on using a paralytic shellfish toxin detection method for scientists who test seafood.

A NOAA method to test for paralytic shellfish toxins will be demonstrated to scientists, regulators, policymakers, and industry representatives in Sydney, Australia from March 18-22. The technique, which was recently accepted as an Official Method of Analysis by the Association of Official Analytical Chemists, is a candidate for replacing the current approach for regulatory testing of shellfish.

This methodology simplifies the current practice that requires injecting shellfish fluids into mice and timing how long it takes for them to die. The U.S. Food and Drug Administration is working with NOAA to support this effort, undertaken by researchers from the National Centers for Coastal Ocean Science.

The demonstration will take place at the International Conference on Molluscan Shellfish Sanitation, a world venue for shellfish safety and commerce funded by the International Atomic Energy Agency. Transferring this technology will strengthen the ability of coastal managers around the world to protect public health while realizing the economic benefits of expanding shellfish harvests.

Hawaiian monk seal and her pup. Photo courtesy of the Pacific Islands Fisheries Science Center

A single-celled plant known as Gambierdiscus is responsible for the most common cause of harmful algae poisoning worldwide: ciguatera.  The algae’s potent neurotoxin–called ciguatoxin–is found in over 400 species of fish and is conservatively estimated to sicken more than 50,000 people every year. Two years ago, researchers from NOAA’s National Centers for Coastal Ocean Science and Pacific Islands Fisheries Science Center found the toxin in the blood of wild Hawaiian monk seals. The endangered mammals are recognized as a key species in the Papahānaumokuākea Marine National Monument, yet its population of 1100-1200 continues to dwindle at four percent annually. A NOAA press release called for future steps “to understand more clearly how widespread (ciguatoxin) exposure is and, more importantly, what role it may be playing in the decline of the species.”

Because human and monk seal testing is often limited to individual blood samples, we use what are called toxicokinetic models in laboratory animals to better understand what happens to the toxin once it is in the body. Toxicokinetics describes the rate a chemical enters the body, how long it stays, and how long it takes to be eliminated–more recognizable as nutrients in our food, but in this case it’s a poison. Our scientists determined ciguatoxin’s toxicokinetic parameters for the first time and published the findings for three exposure routes in rats (two links below).

39% of the ciguatoxin is absorbed from the intestines into the bloodstream within 6 minutes, where it travels to the brain and liver and lingers for as long as 36 hours in the body until it is filtered out and eliminated in feces. Understanding this timeline helps the scientists make models that can compare experimental results in laboratory animals with corresponding environmental exposures in humans or other animals.

NCCOS scientists are measuring ciguatoxin in Hawaiian monk seals from an archive of blood cards collected over the last decade in response to the Monument’s Natural Resource Science Plan, which calls for scientific examination of “biocontaminants in blood and other tissues to determine presence and load of these chemicals and assess their impacts to monk seals.”

NCCOS scientists are now conducting similar toxicokinetic studies in fish, measuring blood and tissue levels of ciguatoxin as they feed on the poisonous algae. These new parameters will be helpful for models to predict how changes in coral reef ecosystems impact human health and the recovery of endangered species such as the Hawaiian monk seal.

See also:

Bioavailability and intravenous toxicokinetic parameters for Pacific ciguatoxin P-CTX-1 in rats;  and  Toxicokinetics of the ciguatoxin P-CTX-1 in rats after intraperitoneal or oral administration.

See also: Identification of ciguatoxins in Hawaiian monk seals Monachus schauinslandi from the Northwestern and Main Hawaiian Islands.

Further Interest:  Hawaiian Monk Seal Research

Deep background:  Predictive Ecotoxicology in the 21st Century

“The study suggests that marine protected areas should be as large and diverse as possible,” Peter Etnoyer, a marine biologist at the US National Oceanic and Atmospheric Administration (NOAA), said in a statement Thursday.

Etnoyer, who co-authored the study published by open access peer-reviewed scientific journal PLoS ONE, stressed that providing more protected marine space made it possible to “include more species, more habitats, and more genetic diversity to offer species the best chance of adapting to sea temperature and other environmental changes.”

The Coral Triangle covers a triangular area stretching across the Philippines, eastern Sabah, eastern Indonesia, East Timor, Papua New Guinea and the Solomon Islands.

via Ocean scientists find how size of Coral Triangle matters in biodiversity | SciTech | GMA News Online.

See also: Secrets of world’s richest marine area revealed

During the upcoming meeting, Advisory Committee members will receive updates on regional technology transfer projects with NCCOS from representatives of African, Asia-Pacific, Gulf of Oman/Persian Gulf, and Latin America regions, as well as a summary of capacity building efforts in Latin America through the UN Intergovernmental Oceanographic Commission.

Discussions will also focus on managing algal blooms in a changing environment and the potential impacts of ocean acidification, the socioeconomic effects of toxic algae, and how best to incorporate the use of nuclear technologies to understand how global climate change will affect this phenomenon.

The outcome of these discussions is expected to provide a roadmap for the IAEA’s future technical cooperation activities to assist with and strengthen sustainable use and management of marine ecosystems that are threatened on a global scale by harmful algal blooms.

Neurons damaged by domoic acid appear black. A close up of the blue boxed area, below, shows blackened granule cells and their extended dendrites. Damage changes information processing and activates seizure-sensitive brain regions, which include the olfactory cortex and hippocampus.

NOAA researchers discovered how a harmful algal toxin called domoic acid targets the brain to induce seizures. Using a rat epilepsy model for the California sea lion, a species susceptible to poisoning by the toxin, they showed that it causes extensive damage to the olfactory bulb, a specialized brain region responsible for the perception of odors.

It alters the normal processing of odor, which can trigger a ‘domino effect’ of further damage  along the neuronal pathways that leads to seizures in regions of the brain important for short-term memory. These seizures can eventually progress to a permanent disease state, similar to epilepsy in humans.

Microscopic analysis using special staining techniques revealed damage localized to olfactory granule cells found in the olfactory bulb. These cells send a ‘map’ of smell to the olfactory cortex of the brain. Together with the hippocampus that stores similar ‘maps’ of spatial information, these two regions provide the foundation for short-term memory.

The same researchers from NOAA’s National Centers for Coastal Ocean Science are now investigating how olfactory pathway damage may be sufficient to progress to a chronic state of epileptic disease observed long after domoic acid is eliminated from the body. It’s similar to symptoms of chronic neurological disease in some California sea lions. The paper is slated for physical release in the February 2013 issue of Toxicologic Pathology.

Read the article online: A Cupric Silver Histochemical Analysis of Domoic Acid Damage to Olfactory Pathways Following Status Epilepticus in a Rat Model for Chronic Recurrent Spontaneous Seizures and Aggressive Behavior

See also: Toxic Algal Blooms May Cause Seizures in California Sea Lions

Deep background: Sniff Sniff: Smelling Led to Smarter Mammals

Watch: Sea Lion Sickness, Usoceangov Ocean Today kiosk video

Fact sheet: Pseudo-nitzschia