Dangerous reef fish- The frightening truth

Parrotfish eats alage

Living in Mauritius, and operating a diving centre we get occasional health complaints from locals and visitors. Unexplained diarharia, headaches, sore limbs, sometimes even an unexplained death - on one of the most healthy environments in the world? It seems unusual, and certainly until a recent study revealed why, it was inexplicable.

Our air is clean, there are no smoke spewing factories, our earth is clean and our vegetables are grown in hydroponic tunnels or organically. Our water sources are from rainfall into huge reservoirs, gravity fed, and most resorts have water pumps and filters. So we wondered what could be causing these symptoms and illnesses.

Most of our population is vegetarian, but many locals and almost all visitors eat fish.

When diving, we come across brutal sights on the reef. Many artisenal fishermen place fish traps near the reefs. They put seaweed and algae into the traps, and we find them filled with dead and dying reef fish. Sometimes they put a large carcass as in this video.

https://youtube.com/shorts/-XZ6RMh7mV4

Sometimes the reefs around the island are covered in algae, some of it red, some black, some of it smothering the corals. When the algae growth is overwhelmingly concentrated and there are few fish, we see a burst of tiny hatchlings. Like dust in the water, these are the vegetarian fish species whose diet is algae. The hatching is triggered by an overwhelming food source.

And these are among the fish most prized for their delicious flesh. However, as you see below, they can be dangerous. All of them either eat algae, or feast on algae eating species. And in Mauritius, the biggest danger to our corals is the growth of algae. Paradoxically, algae growth is caused by over fishing.

There are many others, but these are on the menus of most resorts and hotels in Mauritius.

Why not eat them, you may ask?

These species store toxins in their flesh. Primarily CIGUATERRA a potent neuro toxin. Headaches, diahorea difficulty walking, sore limbs- all symptoms of ciguaterra poisoning.

As the barracuda eats the parrotfish, the rabbitfish or the triggerfish, the concentration of toxin increases, and eventually the flesh of the barracuda is saturated with a lethal dose of ciguaterrra, and can cause even death.

Unmentioned but also a problem, is the unpalatable fact that the Indian Ocean collects the runoff from the East Coat of Africa, where environmental controls have broken down, from the Middle East, and from India, where environmental controls are in their infancy.

Red lead, Chrome SIX, Mercury- all the heavy metals pour down the rivers of these nations into the Indian Ocean. The bottom feeders - shrimps, crayfish, eels, eel catfish, store them in their flesh, and they are eaten by the great shoals that hunt along the coastlines. The shoaling fish in turn are eaten by the tuna, barracuda, and the fish you find on your plate.

No wonder the British National Health website recommends that eating fish only once a week is safer.

Barracuda eats anything

Source https://www.cdc.gov/nceh/ciguatera/#:~:text=People%20who%20have%20ciguatera%20may,but%20can%20last%20for%20years.