Final answer:
Signs of saxitoxin poisoning, a toxin found in some seafood, primarily include neurological symptoms such as tingling, numbness, and muscle paralysis, as well as gastrointestinal issues like nausea, vomiting, stomach cramps, and diarrhea. These symptoms result from consuming shellfish contaminated during harmful algal blooms, such as red tides.
Step-by-step explanation:
Signs of saxitoxin (seafood toxin) poisoning can vary but commonly include neurological problems due to its potent neurotoxic effects. Saxitoxin is produced by certain types of plankton, such as dinoflagellates, which can create algal blooms, commonly referred to as red tides. These toxins can accumulate in shellfish, and when humans consume contaminated shellfish, they could experience severe neurological and gastrointestinal symptoms. Symptoms may include nausea, vomiting, stomach cramps, and diarrhea, along with more specific neurological symptoms such as tingling, numbness, and in severe cases, muscle paralysis.
Marine species like Gonyaulax and Alexandrium are known to cause paralytic shellfish poisoning, manifesting these symptoms. In order to protect public health, areas affected by red tides and high saxitoxin levels in shellfish are often closed for harvesting until levels are safe again. The effects of these toxins are not limited to gastrointestinal distress; they can also cause long-term health problems or even lead to death in extreme cases.