Case Study: Migration of Fish and Marine Toxins

Marine Toxins
Botana (2018) reported a high incidence of toxic events related to climate in the marine environment. The main toxins include those produced by Gambierdiscuc (ciguatoxins), bacteria (tetrodotoxin) and Osteopsis (ostreocins, palytoxins and ovatoxins).In particular, Tetrodotoxins (TTXs) is a highly potent neurotoxin responsible for the highest fatality rate of all marine intoxicants. TTX is a sodium channel blocker preventing nerves from triggering muscle movements such as breathing in humans.Traditionally, Tetrodotoxin is associated with species of fish from the Tetraodontidae family, such as puffer fish. The poison is not produced by the fish itself, but is a product of environmental bacteria that accumulate in fish, including Vibrio, and Pseudomonas. There is evidence that tetrodotoxin contaminated seafood is spreading northwards, potentially due to changing climate conditions. It has recently been identified in European bivalve molluscs, including those in the south east coast of England.In the United Kingdom, sea temperatures around the coastline have already shown an increase. This is expected to continue along with increased rainfall as a result of global warming. Thus, it is expected that conditions will become increasing favorable for the tetrodotoxin-producing bacteria.Worryingly, this increases the risk of Tetrodotoxin accumulation in bivalves which can enter the food chain and consumers and those fishing outside of Asian countries aren’t always aware of the dangers of TTX. Moreover, EU regulations for marine toxins in bivalve molluscs do not currently include TTXs so there is no statutory need to monitor this potential threat in national official control monitoring programs, furthering the risk of contaminated shellfish entering the market and exposing shellfish consumers to Tetrodotoxin Shellfish Poisoning (TSP).What we would like you to do
Please share your thoughts about one or both of the following questions.- Have you heard of any changes or sightings of new and novel aquatic species in your local waters? If so, what are they?
- Do you think the migration of seafood and toxins in aquatic ecosystems is a significant issue?
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