Phycotoxins Marine Marine Marine algal blooms Ocean warming

Phycotoxins

Marine

Marine • Marine algal blooms • Ocean warming has combined with nutrient enrichment to create larger, more frequent algal blooms around the world. • Other environmental stresses that encourage blooms include over-harvesting of fish that feed on plankton.

ü Marine algal blooms affect: v commercial and recreational shellfish and fish harvesting, v recreational swimming and diving, v fish and wildlife food chain.

Toxic effects on humans

Common human health problems caused by harmful marine algae consists of the following syndromes Ø Amnesic Shellfish Poisoning (ASP) Ø Diarrhetic Shellfish Poisoning (DSP) Ø Neurotoxic Shellfish Poisoning (NSP) Ø Paralytic Shellfish Poisoning (PSP) Ø Ciguatera Fish Poisoning (CFP) ü Each of these syndromes are caused by different species of toxic algae

Amnesic Shellfish Poisoning (ASP) • causative organisms: Pseudo-nitzschia australis, Pseudo-nitzschia pungens • toxin produced: Domoic Acid ü ASP is characterized by gastrointestinal and neurological disorders including loss of shortterm memory.

üGastrointestinal symptoms q Gastroenteritis ﺇﻟﺘﻬﺎﺏ ﺍﻟﻤﻌﺪﺓ ﻭﺍﻻﻣﻌﺎﺀ usually develops within 24 hours of the consumption of toxic shellfish and symptoms include: Ø nausea ﻏﺜﻴﺎﻥ Ø vomiting ﻗﻴﺀ Ø abdominal cramps ﻣﻐﺺ Ø diarrhea ﺇﺳﻬﺎﻝ

üNeurological symptoms • Neurological symptoms also appear, usually within 48 hours of toxic shellfish consumption. v These symptoms include: q dizziness ﺩﻭﺧﺔ q headache q seizures ﺻﺮﻉ q disorientation ﺍﺭﺗﺒﺎﻙ q lethargy ﻛﺴﻞ ﻭﻧﻌﺎﺱ q short-term memory loss q respiratory difficulty and coma.

Diarrhetic Shellfish Poisoning (DSP) • causative organisms: Dinophysis, Prorocentrum, Dinophysis fortii, Dinophysis acuminata, Dinophysis norvegica, Dinophysis acuta • toxin produced: Okadaic Acid

Symptoms • DSP is characterized by gastrointestinal symptoms (nausea, diarrhea, vomiting, abdominal pain). • The patients usually recover within a few days (2 -3 days) • Chronic exposure to DSP is suspected to promote tumor formation in the digestive system.

Neurotoxic Shellfish Poisoning (NSP) • causative organism: Gymnodinium breve • toxins produced: Brevetoxins

Symptoms • It is characterized by gastrointestinal and neurological disturbances usually with recovery within few days. • After people eat contaminated shellfish, they can suffer: Ø numbness ﺗﺨﺪﺭ ﻭﻓﻘﺪﺍﻥ ﺍﻟﺤﺲ , tingling ﺍﻧﻘﺒﺎﺽ , cramps, nausea, vomiting, diarrhea, chills ﻗﺸﻌﺮﻳﺮﺓ and sweats ﺗﻌﺮﻕ. Ø loss of motor control and sever muscular ache.

• In addition, formation of toxic aerosols by wave action can produce respiratory asthmalike symptoms. • No deaths have been reported. • recovery is generally complete in a few days.

Paralytic Shellfish Poisoning (PSP) • causative organisms: Alexandrium excavatum, Alexandrium monilata, Alexandrium tamarense, Gymnodinium catenatum, Pyrodinium bahamense • toxins produced: Saxitoxins

• Symptoms are purely neurological and their onset is rapid. • Symptoms include tingling, numbness and burning of the lips and tongue, ataxia ﺭﻋﺸﺔ ﻭﺗﺮﻧﺢ , giddiness ﺩﻭﺍﺭ , drowsiness ﻧﻌﺎﺱ , fever, rash ﻃﻔﺢ ﺟﻠﺪﻱ , a general lack of muscle coordination in the arms, legs and neck. • The most severe cases result in respiratory arrest within 24 hours of consumption of the toxic shellfish. • Death occur due to respiratory paralysis.

Ciguatera Fishfood Poisoning (CSP) • causative organisms: Gambierdiscus toxicus, Prorocentrum concavum, Prorocentrum hoffmannianum, Prorocentrum lima, Ostreopsis lenticularis, Ostreopsis siamensis, Coolia monotis, Thecadinium and Amphidinium carterae (benthic dinoflagellates). • toxins produced: Ciguatoxin, Maitotoxin.

Symptoms • Ciguatera produces gastrointestinal, neurological and cardiovascular disturbances, and recovery often takes months or even years. • Typical symptoms are diarrhea, abdominal pain, nausea, vomiting and followed by lots of neurological signs. • It can very rarely cause death in humans.

• neurological dysfunction including reversal of temperature sensation, muscular aches and lack of co-ordination, dizziness ﺩﻭﺧﺔ , itching ﺣﻜﻪ , anxiety ﻗﻠﻖ , chills ﻗﺸﻌﺮﻳﺮﻩ , sweating ﻋﺮﻕ and a numbness ﺗﺨﺪﺭ and tingling ﺗﻨﻤﻴﻞ of the mouth and digits ﺍﺻﺎﺑﻊ.

RECOMMENDATIONS

Freshwater • Do not drink untreated water from susceptible water bodies, whether you can see a bloom on the surface or not. As well as the possible taste and odour problems from algal blooms you can get sick from a number of other protozoan, worm, bacterial and viral illnesses which are also spread by drinking untreated water. • Algal blooms do not generally make water unsuitable for irrigation but blooms can clog siphons, filters, valves and sprinklers.

• Do not wade or swim in water containing visible blooms. • If blooms are present, do not allow livestock or pets access to the affected water. • Provide alternative sources of drinking water for livestock and pets. • If possible, remove natural blockages in creeks flowing into or out of lakes or ponds to encourage the free flow of water since blooms grow more quickly in non-moving or stagnant water.

• Divert surface runoff from livestock feedlots away from streams and lakes since blooms flourish in runoff flowing through animal waste. • Do not drink untreated water from susceptible water bodies. • Filter all drinking water at the 1 micron level, before it enters a water treatment plant and undergoes disinfection.

• Do not kill the algae in a reservoir with copper sulphate, or any other algicide. Copper contaminates the sediment making it toxic to benthic organisms. • Prevent point and non-point source nutrient runoff, particularly phosphorus.

Marine

• Prevent point and non-point source nutrient runoff, particularly phosphorus. • Do not gather mussels or other quarantined shellfish for food. • Remove and discard the viscera of all clams and scallops and the siphons of clams. • When domoic acid may be present remove the viscera of anchovies and crabs immediately after capture. • Scallop viscera can remain toxic year-round. Do not eat scallop viscera at any time.

Avoid eating certain species of tropical reef fish. Treat oversize tropical fish with suspicion. Avoid eating viscera of any tropical fish species. Do not eat shellfish in areas where red tides are known to occur. • Cooking and discarding the cooking fluids afterwards diminishes the amount of poison ingested but does not eliminate the problem. • If there is any doubt the shellfish should be tested by public health laboratories. • •