” The people of the coastal Districts of Karnataka love their fish. But one incident is all it took to spook these fish lovers.Over 100 people, including workers of a fish exporting company, took ill on October 1st 2016 after eating Red Snapper fish heads. The social media fed on the incident and created a fear psychosis that had the fish loving populace of the coastal districts in a dilemma – to eat or not to eat fish… The fear is still palpable. Rajath Rao investigates ”

The tale of a poisoned fish-1Over a 100 people, including workers of a fish exporting company, took ill on October 1st 2016 after eating Red Snapper fish heads that were supplied from an export firm in Ullal in Mangalore in coastal Karnataka, which in turn had been supplied by a firm in Kochi. The fisheries department has now zeroed in through a GPS lock that the fish catch was transferred to Indian fishermen from Kochi from a bull trawler operating in the in the waters around Diego Garcia.The social media fed on the incident and created a fear psychosis that had the fish loving populace of the coastal districts in a dilemma – to eat or not to eat fish… The fear is still palpable, but it is definitely not possible to stop consuming fish in the preferred form, be it a spicy fish curry or a freshly fried sea food delicacy that goes well with any meal.

Toxic fish

The ciguatera toxin is highly heat stable and lipid soluble compound which is concentrated in fish organs and regions such as head, liver, viscera, gonads (sex organs) in large quantities. Large predator fish generally carry more toxin. Fish like Red Snappers and Grouper get infected with this toxin after consuming the algae bloom of a particular type that has the Ciguatera poison. The Algae bloom can happen anytime and at anyplace in the deep sea. These coral reef fish are generally found in areas around Andaman Islands, Kanyakumari, Lakshadweep, Malpe areas in India.

There are about 400 species of fish all over the world which are susceptible to ciguatera. Larger fish carry higher amounts of toxin. Intriguingly, the toxic fish does not display any external signs of contamination.

Dr. IndraniKarunasagar and her team from Nitte University Center for Science Education and Research based in Mangaluru- Dr. Praveen Rai, Dr.Deekshit and Dr. Kishna Kumar have been conducting research into marine toxins, toxic algal blooms and the socio-economic impacts of climate change on sea temperatures and salinity in collaboration with Prof. Dr. Anna Godhe and her team at University of Goteborg, Sweden for a long time now.They have found that the toxins responsible are made by unicellular microscopic algal species called planktons.These planktons are found in tropical and subtropical coral reef waters. The algae containing the planktons are found in association with underwater vegetation and their numbers increase due to several climatic changes, coral degradation and various environmental impacts.

The heads may be a delicacy, but beware!

After the outbreak, the District Health Officer Dr. H N Ramakrishna gave athumbs down to eating fish heads. He said that there is nothing beneficial in eating the head of a fish, despite it being a delicacy. He says that it is a misconception that by eating a fish head, an individual gets more brainy and intelligent over time; this is absolutely bogus, he avers.

“There are large varieties of reef fish which have considerable amount of flesh in their head and it definitely is a delicacy among the locals. But the consequences of eating the head of the wrong variety of fish can prove to be disastrous. Education among the locals regarding what fish to avoid is to be focused upon. Though the poisonous fish heads have been sent to a lab in Bengaluru for chemical analysis, it is best for people of the coast to not eat the heads of certain fish”, said Dr. Ramakrishna.He goes on to say that the fish which is new to the market should not be consumed without a background check. “Reef fish like Red Snappers are not endemic to our coast. It is always better to ask the fishermen if they have eaten the heads of certain fish before taking the fish home. Precaution is the best measure to keep away from ciguatera”, he added.

YatheeshBaikampady, the head of Panambur Beach Development spoke to Karnataka Today regarding the ciguatera outburst and said that it is all about the way people recognize and clean the fish before consumption.

“Traditional fisherfolk of the land have been netting red snappers all through their lives and over the years they have learnt that at a particular time of the year, red snapper heads can be dangerous. So they have completely avoided consumption of the heads of these fish”
The tale of a poisoned fish-2The local fisherfolk prepare a particular dish called ‘MuluMottha’ which is a delicacy made using the heads of various local fish. “The ‘MuluMottha’preparation has a particular method of cleaning the fish heads. The cleaning procedure plays a major role in determining food safety. Traditional knowledge of the people living on the coast has made it possible not to fall sick on consumption of certain sea food. Clams, prawns and certain variety of fish need to be cleaned adequately and methodically so that it can be consumed without a problem”, Yatheesh added.

Effects of Ciguatera toxins on the human body

It is believed that cats displaythe symptoms of Ciguatera poisoning following consumption of contaminated fish. In the outbreak in Mangaluru, cats indeed did display contamination symptoms after eating the fish.

The determination of ciguatera fish poisoning usually rests with symptomatic diagnosis with symptoms appearing as early as 10 minutes to two hours following consumption of a toxic fish. However, symptoms can appear even as late as six to 24 hours.

The Ciguatera toxin when ingested affects the gastrointestinal, neurological, cardiac organs and causes neurological disturbances with extreme fatigue. Gastrointestinal symptoms manifest as abdominal pain, vomiting, diarrhea, nausea and painful stools. These initial symptoms mimic any other food poisoning and therefore it is important to take cognizance of accompanying neurological symptoms such as giddiness, muscular pain and cramps, itching, intense joint pain, tingling and numbness in the mouth, hands and legs and a condition where there is paradoxical sensation of temperature reversal (cold objects feel hot and hot objects feel cold). In children irritability is a frequent observation. Cardiac symptoms manifest as lowered blood pressure, slow heart rate, arrhythmias and pulmonary edema.

A more sinister complication is the development of respiratory failure secondary to paralysis or cardiac failure. Apart from all this the patient may experience hallucinations, depression and headache with chills and sweating. Those with chronic symptoms can have a recurrence of symptoms with the consumption of fish, alcohol, caffeine and nuts for even up to six months.

Though many treatment strategies are resorted to, there is no single effective antidote or treatment for ciguatera poisoning. The first line of treatment would be to clean the gut by inducing vomiting.

In the end as the District Health Officer Dr. H N Ramakrishna says, awareness and avoidance are the key to eating sea food and staying healthy. Nothing fishy about that is there?

(This article was published in the recent issue of Karnataka Today Magazine)