Harmful Algal Blooms, Red Tide Aerosols, and Toxic Cyanobacteria¶

Harmful Algal Blooms (HABs) occur when colonies of microscopic marine dinoflagellates, diatoms, or freshwater cyanobacteria (blue-green algae) multiply explosively in warm, nutrient-rich water and produce potent biological cyanotoxins and marine biotoxins. Unlike ordinary green pond weeds, toxic cyanobacteria and marine red tides release chemical poisons, including microcystin, anatoxin-a ("Very Fast Death Factor"), saxitoxin, and brevetoxin, that are among the most lethal natural substances on Earth. In freshwater lakes, reservoirs, and rivers, a single mouthful of cyanobacteria surface scum can kill a swimming dog via respiratory paralysis or acute liver failure in 15 to 60 minutes, and when a toxic bloom enters a municipal water intake, boiling tap water does NOT destroy the toxin, it actually concentrates the poison by evaporating the water and bursting intact algal cells.

(Gulf of Mexico)

Yenza lokhu manje¶

1. Stay completely out of any lake, pond, river, or bay where the water looks like spilled green/blue latex paint, pea soup, cottage cheese curds, or reddish-brown streaks. Follow the CDC and EPA mandate: "When in Doubt, Stay Out." Never swim, wade, water-ski, jet-ski, or paddleboard through visible algal scum or discolored water, and never let children or dogs play in shoreline foam or dried crusty algal mats washed up on the beach (dried cyanobacteria mats retain lethal concentrations of neurotoxins for weeks on dry sand).
2. Wash dogs, children, and your own skin IMMEDIATELY with clean fresh tap water and soap if exposed to suspect water. Dogs are the number-one victims of fatal cyanobacteria poisoning because they swim through thick shoreline scum and then lick their contaminated fur dry on the beach, ingesting a massive dose of anatoxin-a or microcystin. Put on waterproof gloves, hose your dog down thoroughly with clean fresh water before allowing them to lick their coat or paws, wash your own skin and swimsuit with soap and clean water, and flush eyes with sterile saline or clean running water for 15 minutes.
3. (Gulf of Mexico) asthma attack first aid guide. Wearing a tight-fitting N95 / FFP2 particulate respirator mask on the beach filters out roughly 95 percent of airborne marine aerosol droplets if you must walk outdoors near the surf.
4. Never eat self-harvested clams, mussels, oysters, scallops, or reef fish during a coastal biotoxin closure, cooking and freezing do NOT destroy marine toxins. Marine shellfish filter-feed on toxic dinoflagellates and diatoms, concentrating saxitoxin (Paralytic Shellfish Poisoning), domoic acid (Amnesic Shellfish Poisoning), and brevetoxin (Neurotoxic Shellfish Poisoning) inside their meat without harming the shellfish itself. Boiling, steaming, frying, baking, marinating in lime juice, or freezing contaminated shellfish or ciguatera-toxic reef fish does NOT reduce the toxin by even 1 percent.
5. Seek emergency medical or veterinary care immediately if numbness around the lips/tongue, vomiting, muscle twitching, or difficulty breathing begins. Call your local emergency number (911 in the United States and Canada, 112 across the European Union, 999 in the United Kingdom, or see all izinombolo eziphuthumayo) or US Poison Control at 1-800-222-1222 (see our poisoning first aid guide). In human Paralytic Shellfish Poisoning (PSP), tingling and numbness of the lips and tongue within 15 to 60 minutes of eating shellfish can progress rapidly to complete diaphragm paralysis requiring mechanical ventilation.
6. Perform the 2-Minute "Stick Test" and 30-Minute "Glass Jar Test" before entering suspect freshwater. If you cannot tell whether green pond scum is harmless filamentous green algae ("frog hair") or lethal cyanobacteria, push a long stick under the mat and lift: if it hangs down like long, stringy green hair or wet cotton threads, it is usually harmless green filamentous algae; if it coats the stick like slimy liquid paint, disperses into tiny specks like green dust, or floats to the very top of a glass jar kept in the shade for 30 minutes, it is toxic cyanobacteria, stay out.

Harmful algal bloom, red tide, and shellfish poisoning decision flowchart¶

Use this clinical and environmental decision tree when encountering discolored water, airborne beach irritation, or acute post-exposure symptoms in humans or pets.

flowchart TD
    Start["Suspected Harmful Algal Bloom (HAB) Encounter:<br/>Discolored Lake/Ocean Water, Beach Coughing, or Shellfish Illness"] --> ExposureRoute{"What type of exposure or<br/>hazard occurred?"}

    ExposureRoute -->|"1. FRESHWATER LAKE / POND / RIVER BLOOM<br/>Spilled Paint, Pea Soup, Blue-Green Scum, or Crusty Shore Mats"| FreshBloom{"Did a person or dog already<br/>touch or swallow the water?"}

    FreshBloom -->|"NO Contact Yet"| StayOut["1. STAY OUT: Do not swim, wade, jet-ski, or let dogs near shore<br/>2. Never use lake water for camping dishes or showering<br/>   (Standard camp filters & boiling DO NOT remove cyanotoxins)"]

    FreshBloom -->|"YES: Skin Contact or Dog Swam in Water"| DeconNow["IMMEDIATE DECONTAMINATION:<br/>1. Prevent dog from licking fur (put on cone/muzzle or hold head)<br/>2. Rinse dog & human skin thoroughly with CLEAN fresh water + soap<br/>3. If dog drools, vomits, trembles, or stumbles: RUSH TO EMERGENCY VET<br/>   (Anatoxin-a neurotoxin can cause respiratory arrest in 15 to 60 mins)"]

    ExposureRoute -->|"2. COASTAL OCEAN RED TIDE / SEA SPRAY<br/>Sudden Dry Cough, Sneezing, Throat Tickle, or Dead Fish on Beach"| RedTideAction["MARINE BREVETOXIN AEROSOL PROTOCOL:<br/>1. Leave the beach & move >= 2 km inland or upwind from surf<br/>2. Go indoors, close windows, & set A/C to RECIRCULATE<br/>3. If asthma/COPD wheezing starts: Use Albuterol rescue inhaler<br/>4. Wear an N95 / FFP2 mask if forced to work outdoors near surf"]

    ExposureRoute -->|"3. MUNICIPAL TAP WATER ADVISORY<br/>City Issues Cyanotoxin 'Do Not Drink' Alert"| TapWater["TAP WATER CYANOTOXIN RULES:<br/>1. NEVER BOIL THE WATER (boiling bursts cells & concentrates toxin)<br/>2. Use ONLY bottled water for drinking, infant formula, ice, & pets<br/>3. Do not bathe infants or open wounds in tap water if Microcystin > 20 ug/L"]

    ExposureRoute -->|"4. ATE SHELLFISH OR REEF FISH<br/>Tingling Lips/Tongue, Reversed Hot-Cold Sensation, or Vomiting"| ShellfishER["ACUTE MARINE BIOTOXIN POISONING (PSP / Ciguatera / NSP):<br/>1. Call 911 / 112 / 999 IMMEDIATELY (PSP paralyzes breathing muscles)<br/>2. Prepare to give Rescue Breaths / CPR if breathing slows<br/>3. Save leftover shellfish/fish in freezer for hospital toxin testing"]

Comparing the 6 major freshwater and marine algal toxins¶

Freshwater cyanobacteria and marine dinoflagellates/diatoms produce chemically distinct toxins that attack either the liver (hepatotoxins) or the nervous system and respiratory muscles (neurotoxins).

I-Deep Dive 1: Ukuhlonza insimu ebonakalayo, "Ukuhlolwa Kwenduku" kanye "nokuhlolwa kweJar" kolwelwe lwamanzi ahlanzekile¶

Not all green algae in a lake is toxic. True green filamentous algae (Spirogyra, Cladophora) and duckweed (Lemna) are completely non-toxic to humans and dogs, whereas cyanobacteria (which are actually photosynthetic bacteria, not true algae) can be rapidly fatal. Before letting family members or dogs near a green pond or lake, use these two field tests endorsed by state environmental departments and the EPA:

(Gulf of Mexico)¶

(Gulf of Mexico)

Unlike freshwater cyanobacteria, which have tough cell walls and mostly stay inside the water, Karenia brevis is an unarmored ("naked") dinoflagellate with a fragile cell membrane. 1. How Surf Waves Turn Red Tide into an Airborne Poison Gas Cloud: - Uma amaseli e-Karenia brevis edilika ngaphakathi aphuka amagagasi okuseza ogwini noma enqunywa ophephela bezikebhe, izindonga zawo zamangqamuzana abuthakathaka ziyaphuka (lyse) futhi zichithe ama-brevetoxin emanzini olwandle. - Amabhamuza akhuphuka kumakepisi amhlophe aqhume endaweni yolwandle, ekhipha amaconsi amancanee-aerosol yasolwandle (\(2\text{ ukuya }ku-10\text{micrometers}\) ububanzi)* ambozwe nge-brevetoxin ngqo emoyeni. - An onshore sea breeze carries these brevetoxin aerosols 1.5 to 5 kilometers (1 to 3 miles) inland across beaches, boardwalks, coastal highways, and waterfront condos. 2. Immediate Physiological Effects of Inhaling Red Tide Aerosols: - Within 60 seconds of stepping onto the beach, brevetoxins bind to nerve endings in your nose, throat, and eyes, triggering immediate non-stop dry coughing, sneezing, rhinorrhea (runny nose), stinging watery eyes, and a scratchy throat. - In Healthy People: Leaving the beach and entering an air-conditioned building or driving 2 kilometers inland stops the coughing and eye irritation within 30 to 60 minutes without lasting damage. - (Gulf of Mexico) 3. How to Protect Your Coastal Home and Pets During a Red Tide Event: - Check daily NOAA HAB Operational Forecasts and the Mote Marine Laboratory Beach Conditions Reporting System before choosing which beach to visit; because wind direction controls aerosol drift, a beach with an offshore wind (blowing from land toward the sea) often has zero airborne irritation even when a beach 10 kilometers away with an onshore wind is uninhabitable. - Close windows and run home Air Conditioning with a MERV 13 or HEPA filter. - Keep beach dogs away from dead fish on the sand: Every dead mullet, pinfish, or catfish washed up on the tide line during a red tide has lethal concentrations of brevetoxin concentrated inside its organs; a dog that eats a single dead red-tide fish on the beach can develop severe Neurotoxic Shellfish Poisoning (ataxia, hind-limb paralysis, tremors, and vomiting).

Water treatment truth table: What removes cyanotoxins from drinking water?¶

If you are camping by a lake, living off a private lakeside well/intake, or under a municipal Cyanotoxin Advisory, you must know which water treatments work and which make the water more toxic:

Emergency veterinary and human first-aid checklist for HAB exposure¶

If your dog or child accidentally enters a cyanobacteria bloom or eats suspect marine shellfish:

• Step 1 (Pet Fur Decontamination): Physically restrain your dog from licking its fur or paws. Put on rubber/nitrile gloves, rinse the dog thoroughly with clean fresh tap water (use a garden hose or shower), lather with mild dish soap or dog shampoo, and rinse a second time.
• Step 2 (Save a Water or Scum Sample safely): If your dog is showing symptoms, scoop a small sample of the pond scum or vomitus into a sealed plastic bag/jar (wearing gloves) to bring to the veterinarian so they can identify whether it is hepatotoxic (Microcystis) or neurotoxic (Anatoxin-a).
• Step 3 (Emergency Vet / Hospital Transport): Do not wait to see if symptoms develop. Call the nearest 24-hour emergency veterinary clinic while driving there so they can prepare activated charcoal, intravenous fluids, atropine/anticonvulsants (for guanitoxin/anatoxin), and S-adenosylmethionine (SAMe) / N-acetylcysteine liver protectants.
• Step 4 (Human Marine Biotoxin Airway Monitoring): If a human exhibits tingling lips, numbness of the tongue, or slurred speech after eating clams, mussels, oysters, or tropical reef fish, call emergency services immediately and keep the person seated upright or in the recovery position, ready to perform rescue breathing / CPR if their diaphragm weakens.

Deep dive 3: US EPA and WHO drinking water action thresholds and livestock safety¶

When a municipal water reservoir experiences a cyanobacteria bloom, public water utilities monitor two primary toxins using enzyme-linked immunosorbent assays (ELISA) and liquid chromatography-mass spectrometry:

1. United States EPA 10-Day Drinking Water Health Advisory Thresholds:
2. For Bottle-Fed Infants and Pre-School Children (Under Age 6): The tap water is unsafe to drink if Microcystins exceed \(0.3\text{ micrograms per liter}\) (\(\mu\text{g/L}\), or parts per billion), OR if Cylindrospermopsin exceeds \(0.7\text{ micrograms per liter}\) (\(\mu\text{g/L}\)). Infants drink far more water per kilogram of body weight than adults, making their developing livers three to five times more vulnerable.
3. Ezinganeni Ezineminyaka Yesikole (Iminyaka Engu-6+) Nabantu Abadala: Amanzi okumpompi awaphephile ukuphuzwa uma Ama-Microcystin edlula u-\(1.6\umbhalo{ micrograms ilitha ngayinye}\) (\(\mu\text{g/L}\)), NOMA uma *I-Cylindrospermopsin idlula u-\(3.0\umbhalo{micrograms/L*\)g\(g**\) umbhalo ngamunye.
4. I-World Health Organization (WHO) Recreational Swimming Thresholds: I-WHO kanye ne-US EPA zixwayisa ngokubhukuda kokuzijabulisa noma ukugwedla uma ingqikithi yama-microcystin emanzini echibi idlula \(8\text{ ukuya }24\text{ micrograms ilitha ngalinye}\) (\(\mu\text{g/L}\)) noma ukuminyana kweseli le-cyanobacterial\0{0{0, kweqa ku- \(20{0} }100,000\text{ amaseli ngemililitha ngayinye}\).
5. Ingabe Ungadla Inhlanzi Yamanzi Ahlanzekile Ebanjwe Echibini Eliqhakaza I-Cyanobacteria?
6. Ungalokothi udle izitho zangaphakathi, isibindi, isikhumba, noma amafutha ezinhlanzi zasemanzini ahlanzekile (njenge-bass, i-walleye, i-perch, i-catfish, noma i-carp) ebanjwe phakathi noma phakathi namasonto amabili ngemva kokuqhakaza kwe-cyanobacteria, ngoba i-microcystin ne-cylindrospermopsin bioccumulate kakhulu ngaphakathi kwesibindi senhlanzi kanye ne-viscera.
7. Uma iziphathimandla zingakayivali ngokuphelele indawo yokudoba, umcuph wenyama yemisipha enciphile kuphela, gqoka amagilavu ​​ngenkathi ukhipha inhlanzi ukuze ungaqhubi umgudu oluhlaza wenyongo/isibindi kufillet, futhi geza izibopho eziluhlaza kahle ngaphansi kwamanzi kampompi agelezayo ahlanzekile ngaphambi kokupheka.
8. Ukuvikela Izinkomo, Amahhashi, Izimvu, Nezinkukhu Emachibini Asepulazini:
9. Phakathi nesomiso sasehlobo, umoya uvunguza ama-cyanobacteria antantayo agxumela ekhoneni eliphansi lamachibi emfuyo lapho izinkomo, amahhashi, nezimvu zingena khona zizophuza. Ngenxa yokuthi izinkomo namahhashi ziphuza amalitha angu-30 kuya kwangu-80 (amalitha angu-8 kuya kwangu-20) amanzi ngosuku, ukuqhakaza okukodwa okubangelwa umoya kungabulala umhlambi wonke ngamahora.
10. Biyela imfuyo kude namakhona echibi anomoya, pompa amanzi esitokwe epayipini* elicwilisiwe elicwiliswe emanzini elilengiswe amamitha angu-1 kuya ku-1.5 (amafidi angu-3 kuya kwangu-5) ngaphansi komhlaba** (njengoba I-Microcystis entantayo igxila emanzini angamasentimitha angu-30 phakathi namahora okukhanya kwelanga), futhi unikeze enye indawo yomthombo noma yamanzi emkhombeni ngokushesha nje uma kuvela upende oluhlaza.

Imibuzo ejwayelekile ukubuzwa¶

Kungani ngingakwazi ukubilisa amanzi kampompi noma amanzi echibi ukuze ngiwenze aphephe ngesikhathi sokuqhakaza kwe-algae enobuthi eluhlaza okwesibhakabhaka (i-cyanobacteria)?¶

Amanzi abilayo asebenza ngesikhathi sezimo eziphuthumayo zebhaktheriya noma indle ngoba u-$100^\circ\text{C}$ ($212^\circ\text{F}$) ukushisa kubulala ama-microorganisms aphilayo afana no-E. coli, Giardia, kanye ne-Cryptosporidium. Nokho, ingozi ekuqhakazeni kwe-cyanobacteria ivela kubuthi bamakhemikhali obubizwa ngokuthi i-cyanotoxins (njenge-microcystin, i-anatoxin-a, ne-cylindrospermopsin) ekhiqizwa amagciwane. Lawa ma-molecule wobuthi azinze ngendlela emangalisayo ekushiseni futhi adinga amazinga okushisa angaphezu kuka-$100^\circ\text{C}$ amahora ukuze aphuke. Lapho ubilisa amanzi ane-cyanobacteria esitofini sakho, uqhumisa amangqamuzana e-algal angaguquki (ukhiphe ubuthi obuningi nakakhulu embizeni), uhwamulise isitimu samanzi ahlanzekile (ugxilise ubuthi obusele), futhi ukhiphe ubuthi emoyeni wasekhishini lakho.

Ngingawubona kanjani umehluko phakathi kwe-poss yechibi eluhlaza engenangozi kanye ne-algae enobuthi obuluhlaza okwesibhakabhaka (i-cyanobacteria)?¶

Sebenzisa i-Stick Test yemizuzu emibili kanye ne-Jar Test yemizuzu engamashumi amathathu ngaphandle kokuthinta amanzi ngezandla zakho. Phusha induku eqinile kumata aluhlaza bese uyikhipha: uma into ilenga phezu kwenduku emicu emide, esindayo, efana nezinwele eziluhlaza noma imicu enjengokotini ephithene ("uboya bexoxo"), iwulwelwe oluluhlaza olungenabungozi. Ngakolunye uhlangothi, uma induku iphuma imbozwe ngoketshezi oluncane oluthambile olubukeka njengopende oluhlaza oluhlaza noma oluhlaza okotshani we-latex, isobho likaphizi, noma ama-cottage shizi ama-curd angenayo imicu enezintambo, noma uma imbiza yamanzi eshiywe emthunzini imizuzu engu-30 yakha ungqimba oluluhlaza oluntantayo phezulu kakhulu engilazini, iwubuthi obuyi-cyano kanye nezilwane ezifuywayo futhi kufanele ukhiphe ngokuphelele amanzi ezifuywayo.

Kungani abantu beqala ukukhwehlela nokuhefuza ogwini ngesikhathi se-Florida noma iGulf of Mexico Red Tide ngisho noma bengakaze bangene emanzini?¶

I-Gulf of Mexico i-red tides ibangelwa i-dinoflagellate yasolwandle encane encane ebizwa ngokuthi i-Karenia brevis, enolwelwesi lwangaphandle oluntekenteke kakhulu oluntula isivikelo se-cellulose. Lapho amagagasi olwandle ephahlazeka ogwini lolwandle, ukunyakaza ngokomzimba kuklebhula amaseli e-Karenia brevis futhi kuchitheke ubuthi bawo bangaphakathi (ama-brevetoxin) endaweni yokuseza. Njengoba amabhamuza omoya kuma-whitecaps ephuma phezulu, akhipha amaconsi amancane amancane anamanzi anosawoti ambozwe nge-brevetoxin emoyeni wasolwandle. Ukuhogela lawa ma-aerosols ahamba emoyeni kuthukuthelisa ama-receptors ezinzwa kumzila womoya ongaphezulu phakathi nemizuzwana, okubangela abantu abahamba ebhishi abanempilo ukuthi bakhwehlele futhi bathimula futhi kubangele i-bronchospasm eyingozi kubantu abanesifuba somoya noma i-COPD.

Ingabe ama-clam, izimbaza, ama-oyster, noma izinhlanzi zasolwandle ziwuqeda ngokuphelele ubuthi be-Paralytic Shellfish Poisoning (PSP) noma i-Ciguatera?¶

Cha. Yonke i-biotoxin yasolwandle eyinhloko, okuhlanganisa i-saxitoxin (Paralytic Shellfish Poisoning), i-domoic acid (i-Amnesic Shellfish Poisoning), i-brevetoxin (i-Neurotoxic Shellfish Poisoning), i-okadaic acid (i-Diarrhetic Shellfish Poisoning), ne-ciguatoxin (I-Ciguatera Fish Poisoning), ayishisi ngokuphelele, ayibandi futhi ayinaphunga. Ukubilisa, ukushisisa, ukuthosa, ukukosa, ukuzenzela, ukuqanda, noma ukuthulula ukudla kwasolwandle ngejusi kalamula akubhubhisi noma kwehlise lobu buthi sanhlobonhlobo, futhi i-shellfish engcolile noma inhlanzi ye-reef ibukeka, ihogela, futhi inambithe amaphesenti angu-100 evamile. Ngaso sonke isikhathi hlola amamephu we-biotoxin womnyango wezolimo wombuso wezolimo noma wezempilo ngaphambi kokuvuna izimbaza zasendle noma izimbaza.

Imithombo ihloliwe¶

• Izikhungo Zokulawula Nokuvimbela Izifo (CDC, United States): I-Algal Bloom Eyingozi (HAB)-Associated Illness Surveillance, Cyanobacteria Dog Poisoning Prevention, kanye nama-Marine Biotoxin Clinical Fact Sheets (PSP, NSP, ASP, ne-Ciguatera).
• I-United States Environmental Protection Agency (EPA): Izeluleko Zezempilo Zamanzi Okuphuza Ze-Cyanobacterial Toxins (Microcystins and Cylindrospermopsin, 10-Day Thresholds for Infants vs. Abadala) kanye Nemibandela Yamanzi Yokuzilibazisa.
• Izikhungo Zikazwelonke ZokuPhathwa Kwe-Oceanic and Atmospheric (NOAA, United States) Zikazwelonke Zesayensi Yolwandle Olusogwini (i-NCCOS): I-Gulf of Mexico ne-East Coast Harmful Algal Bloom Operational Forecast System (HAB-OFS) kanye ne-Karenia brevis Aerosol Dynamics.
• Inhlangano Yezempilo Yomhlaba (WHO): I-Cyanobacteria Enobuthi Emanzini: Umhlahlandlela Wemiphumela Yawo Yezempilo Yomphakathi, Ukuqapha, Nokuphatha.
• Isikhungo Sokulawula Ubuthi Bezilwane I-ASPCA kanye Nemanuwali Yezilwane Ze-Merck: I-Acute Anatoxin-a kanye ne-Microcystin Toxicosis Ezinjeni: Ukukhipha Ukungcola kanye Nokuqiniswa Kwezilwane Eziphuthumayo.

Iziqondiso ezihlobene¶

• Ukuphepha kwamanzi, ukuhlanzwa, kanye nezaziso zamanzi abilayo
• Usizo lokuqala olunobuthi nokungenwa ubuthi
• I-asthma attack usizo lokuqala oluphuthumayo
• Izilwane ezifuywayo ezimweni eziphuthumayo: ukuphuma nokunakekelwa kwengozi
• I-CPR: izinyathelo zokuvuselela i-cardiopulmonary