The researchers concluded that the extraordinarily high populations of Pseudo-nitzschia in 2015 were related to the strength and timing of upwelling events. But the extremely high concentrations of domoic acid were probably caused by unusual ocean chemistry—specifically a low ratio of silicate to nitrate in bay waters.
Where is Pseudo-nitzschia found?
Pseudo-nitzschia species have been observed in all oceans of the world, including the Arctic and Antarctic. In North America, they have been documented along the Pacific coast from Canada to California, along the Atlantic Northeast coast of Canada, North Carolina, and the Gulf of Mexico.
What is Pseudo-nitzschia bloom?
The phenomenon is an example of a “harmful algal bloom,” or HAB. When Pseudo-nitzschia bloom, they sometimes produce a neurotoxin called domoic acid. Shellfish eat the algae and accumulate the toxin in their tissues, and when humans and marine mammals eat the shellfish, they can get sick, and in some cases, die.
Is Pseudo-nitzschia an algae?
Pseudo-nitzschia australis is a pennate diatom found in temperate and sub-tropic marine waters, such as off the coast of California and Argentina. This diatom is a Harmful Micro Algae that produces toxic effects on a variety of organisms through its production of domoic acid, a neurotoxin.
Does Pseudo-nitzschia cause disease?
Blooms of some species of the diatom Pseudo-nitzschia produce a neurotoxin that accumulates in shellfish, which can cause illness and even death in humans who eat them. Shellfish managers monitor these toxins and close affected fisheries to protect public health, but these sudden closures can disrupt coastal economies.
Where is pseudo found?
Distribution in the U.S. Impacts of DA-producing Pseudo-nitzschia blooms have been reported in coastal waters along the West Coast, Gulf of Mexico, and in the Gulf of Maine.
What toxin does Pseudo-nitzschia australis produce?
The neurotoxin domoic acid is produced by the globally-distributed diatom genus Pseudo-nitzschia. This toxin is responsible for amnesic shellfish poisoning, which can result in illness or death in humans and regularly causes mass mortalities of marine mammals and birds.
Where is nitzschia found?
Occurrence. Nitzschia is found mostly in colder waters, and is associated with both Arctic and Antarctic polar sea ice, where it is often found to be the dominant diatom.
What eats Karenia brevis?
brevis. Fish species through the food chain are impacted, up to and including large predatory species such as sharks, as well as species typical in human consumption.
What toxins does alexandrium produce?
The dinoflagellate alga Alexandrium fundyense produces a suite of potent neurotoxins (saxitoxin and its derivatives) resulting in Paralytic Shellfish Poisoning (PSP). PSP is known to impair physiological functions in bivalve molluscs and copepods.
What is amnesic shellfish poisoning?
Amnesic shellfish poisoning is caused from the ingestion of toxin-contaminated bivalve shellfish and crustaceans. Toxins accumulate in filter feeding bivalves, like mussels, when algal blooms of diatoms, such as Pseudo-nitzschia occur – usually during the warmer months of June to October.
Where is alexandrium found?
Alexandrium catenella | |
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Scientific classification | |
Phylum: | Dinoflagellata |
Class: | Dinophyceae |
Order: | Gonyaulacales |
Is Microcystis a cyanobacteria?
Microcystis is one of the most common and dominant bloom-forming cyanobacteria in freshwater worldwide.
What is domoic acid poisoning?
Domoic acid (DA) is a kainic acid-type neurotoxin that causes amnesic shellfish poisoning (ASP). It is produced by algae and accumulates in shellfish, sardines, and anchovies. When sea lions, otters, cetaceans, humans, and other predators eat contaminated animals, poisoning may result.
How do you treat Karenia brevis?
brevis toxin may confirm red tide intoxication, in addition to the presence of increased dinoflagellate counts in water samples. Treatment focuses on prevention of drowning. Generally, affected manatees are propped up on foam to keep their heads above water for 24 to 48 hours and closely observed.
What does Karenia brevis do to humans?
brevis, produce neurotoxins that can cause respiratory problems in humans and attack the central nervous systems of fish and other wildlife. Many scientists refer to blooms of K. brevis as harmful algal blooms (HABs) due to the impacts they can have on the environment, humans, and our coastal economies.
How does Karenia brevis affect humans?
The red tide organism in Florida, Karenia brevis, produces brevetoxins that can affect the central nervous system of fish and other vertebrates, causing these animals to die. … For people with severe or chronic respiratory conditions, such as emphysema or asthma, red tide can cause serious illness.
Why is Alexandrium spp harmful?
By producing potent neurotoxins, known as saxitoxins (STXs), A. fundyense is responsible for outbreaks of paralytic shellfish poisoning (PSP), which is potentially fatal to humans (Llewellyn, 2006).
Where does saxitoxin come from?
Introduction. Saxitoxins are produced in freshwater and marine environments. In marine environments, they are often referred to as PSPs. Most human saxitoxin toxicoses have been associated with the ingestion of marine shellfish, which accumulate saxitoxins produced by marine dinoflagellates (Cusick and Sayler, 2013).
How does alexandrium Catenella contributions?
Alexandrium catenella is a species of dinoflagellates. It is among the group of Alexandrium species that produce toxins that cause paralytic shellfish poisoning, and is a cause of red tide. … The dinoflagellate produces saxitoxin, which is a highly potent neurotoxin.
What causes neurotoxic shellfish poisoning?
CAUSATIVE AGENT: Neurotoxic Shellfish Poisoning (NSP) is caused by the consumption of molluscan shellfish (e.g. clams, oysters, coquinas, mussels and other filter feeders) contaminated with brevetoxins, which are produced by a marine dinoflagellate called Karenia brevis.
How does neurotoxin work?
Neurotoxins inhibit neuron control over ion concentrations across the cell membrane, or communication between neurons across a synapse. Local pathology of neurotoxin exposure often includes neuron excitotoxicity or apoptosis but can also include glial cell damage.
Is domoic acid harmful to humans?
Domoic acid, a naturally occurring toxin produced by certain types of algae, can be harmful or even fatal to humans if contaminated shellfish is consumed.
What group of plankton does alexandrium belong to?
Alexandrium is a genus of dinoflagellates. It contains some of the dinoflagellate species most harmful to humans, because it produces toxic harmful algal blooms (HAB) that cause paralytic shellfish poisoning (PSP) in humans.
Where is alexandrium Fundyense from?
Alexandrium fundyense grows primarily in low-salinity, marine environments during the spring and summer months. The highest concentrations of Alexandrium cells are generally seen near the surface waters of the Gulf of Maine.
What is the common ecosystem of Alexandrium Catenella?
Classification | |
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Distribution | |
Habitat | Coastal and Estuarine Of or relating to estuaries. estuarine |
Geographic | Cold temperate waters |
Seasonal | Late May and early June |
Where are Cyanotoxins from?
Cyanotoxins are toxins produced by cyanobacteria (also known as blue-green algae). Cyanobacteria are found almost everywhere, but particularly in lakes and in the ocean where, under high concentration of phosphorus conditions, they reproduce exponentially to form blooms.
Is Microcystis a phytoplankton?
Microcystis | |
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Genus: | Microcystis Kützing, 1833 |
Species | |
Many (see below) |
What causes Microcystis?
What causes Microcystis blooms? microcystin is drinking water, followed by recreational exposures and food supplements. Typical water treatment processes do not fully remove microcystin that might be present in drinking water supplies stored in reservoirs.