What causes Alexandrium bloom?

What causes Alexandrium bloom?

Alexandrium blooms occur seasonally and are influenced by a multitude of abiotic conditions from temperature, salinity, nutrient availability and even weather patterns. They also are impacted by biological factors including predation, infection from viruses, bacteria, parasites or cell encystment.

What does alexandrium catenella do?

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.

What does alexandrium Fundyense need to grow?

A. fundyense rely on nitrogen and phosphate nutrients to grow (13).

Where does saxitoxin come from?

Saxitoxin is produced by the dinoflagellates Gonyaulax, Alexandrium, Gymnodinium, and Pyrodinium. Similar to tetrodotoxin, saxitoxin binds to voltage-gated sodium channels within cell membranes, inhibiting membrane depolarization and blocking proliferation of action potentials.

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 causes paralytic shellfish poisoning?

Paralytic shellfish poisoning is caused from the ingestion of toxin-contaminated bivalve shellfish and crustaceans. Algal blooms of dinoflagellates, usually during the warmer months of June to October, result in toxin accumulation in filter feeders such as bivalves.

Why is Alexandrium spp harmful?

Why We Care PSP is known to impair physiological functions in bivalve molluscs and copepods. Saxitoxin can be transferred throughout the food web until it reaches humans. PSP in humans include numbness, paralysis, disorientation, and even death. Hence, toxic Alexandrium spp.

What do alexandrium Catenella eat?

The toxin is produced by dinoflagellates such as Protogonyaulax sp., Gymnodium catenatum, Alexandrium catenella and Alexandrium minutum. Mussels, clams and oysters feed on these dinoflagellates or red algae with which they may be associated and thus become toxic.

Where does alexandrium Fundyense found?

the Gulf of Maine
fundyense occur in the Gulf of Maine, and these are considered to be varieties of the same species (Anderson et al., 1994; Brosnahan et al., 2010; Scholin et al., 1995).

Is saxitoxin a neurotoxin?

Saxitoxin and its derivatives, collectively referred to as paralytic shellfish toxins (PSTs), are unique among neurotoxins in that they are found in both marine and freshwater environments by organisms inhabiting two kingdoms of life.

What is the deadliest shellfish toxin?

When ingested by humans, saxitoxin causes paralytic shellfish poisoning, or PSP, symptoms of which include tingling, numbness, and, if consumed in high enough quantities, paralysis, asphyxiation and death. There is no known cure for saxitoxin poisoning.

How does alexandrium Catenella contribute to the environment?

Alexandrium catenella produces paralytic shellfish toxins that affect marine fisheries and aquaculture as well as ecosystem and human health worldwide. This harmful algal species is extremely sensitive to environmental conditions and potentially to future climate change.