The scientific truth about state fish-Shevto


Nandkumar M. Kamat


Maggie noodles were banned because the lead content was alleged to be above 2.5ppm, the permissible limit. Shevto – the state fish of Goa would be found to have much more lead in its edible part – the muscle, because studies in India had earlier found 3 to 16ppm of lead in the fish. If I were to sum up the current scientific truth about the gray mullet, scientifically known as Mugil cephalus and locally known as shevto, if it is harvested from polluted waters then it is absolutely unfit for human consumption.

My family, familiar with all kinds of fish and shellfish, gave up consumption of shevto about 10 years ago when we found them totally unfit for human consumption, irrespective of site of sale. Many market samples smell strongly of Diesel. The skin and fins too show infections. Government knows that consumers on inspection of marketed shevto would only spot what is visible to eyes and smelt by nose but would never demand rigorous toxicological and pathological analysis or quality standards. The government of Goa which provides a world record subsidy of `29 for every kilogram of fish that is caught in local waters has failed to pass on the benefit of this subsidy given to mechanized and traditional sector to common fish consumers. Besides it has failed to disclose the facts about chemical, biological and microbiological pollution of estuaries and offshore marine areas where fishing is done. All tidal estuaries are polluted (high nitrates, phosphates, heavy metals, oil, grease, agrochemical residues, coliforms etc). Fisheries department is silent on dangerous concentration of radioactive isotopes, toxic heavy metals, pesticide and insecticide residues, pharmacologically active substances and pathogens in fish and shellfish caught and sold in Goa.

On the contrary by hastening to declare Mugil cephalus, a species notorious for its capacity to accumulate toxic metals like cadmium and prone to red spot and parasitic diseases as a ‘state fish’, the government is endangering the lives of the consumers. A reputed MNC like Nestle well known for stringent quality standards and R&D was taken to task for negligible concentration of lead in some noodle samples. Ironically, there is more lead in our potable water, milk, tea, poultry products, vegetables and fish. In a study conducted in 1979, De Souza and Naqvi from NIO had analysed metal concentration in shevto from Vishakhapatanam. They checked zinc, manganese, iron, copper, nickel, cobalt and lead concentration in muscle, gills, brain, bone, eyes and liver. They proved that shevto accumulates these metals from surrounding waters. They found these metals in all tissues. Lead level was 3 to 16ppm in muscle, the edible part.

Shevto belongs to the mullet family (Mugiliformes: Mugilidae). These have a worldwide distribution and are found in tropical and temperate waters. Mugilidae family includes 24 genera and 72 species and the grey mullet Mugil cephalus can be cosmopolitan. Shevto can be produced in aquaculture but scientists are concerned about the pathologic potential of some parasites, in particular Myxosporea which represents one of the important groups of parasites infecting worldwide mullets. If samples of shevto are subjected to toxicological (especially polonium, radium, caesium, heavy metals, pesticides and insecticides, pharmacologically active substances), microbiological and pathological analysis then the fisheries department would repent for its hasty decision.

The gastrointestinal tract of fish is known to constitute one of the major infection routes like the skin and the gills and allows a favorable site for bacteria proliferation. A team of fish pathologists had isolated Myroides sp. during the course of grey mullet gut micro biota studies which they collected from government fish farm, Old Goa. The parasites which would be found in the shevtos of Goa are Myxobolus muelleri, Myxobolus ichkeulensis, Myxobolus episquamalis, Myxobolus exiguus, Myxobolus parvus, and Myxobolus spinacurvatura.

Fish consumers would be shocked to know that the shevto is virtually a factory of dangerous anthropogenic chemicals and parasites. Generally any species of flora or fauna is declared as ‘state species’ is consistent with well laid down state policy. This is a prerogative of Goa State Biodiversity Board under Biodiversity Act, 2002. It has been bypassed in declaring shevto as state fish. Fisheries department should not play with lives, health and safety of unsuspecting consumers by declining to commission detailed studies on quality of fish. Both state fisheries department and the Directorate Of Food and Drug Administration have failed to take expected co-ordinated action to inform the fish consumers on various provisions, rules and amendments to The Food Safety and Standards Authority of India (FSSAI) related to fish and fish products in the Food Safety and Standards (Food Product Standards and Food Additives) Regulation from 2011. They have failed to generate adequate publicity on draft amendment related to pharmacologically active substance prohibited for fish and fishery products.

The local authorities too are passive to engage FDA inspectors and labs to check the quality of marketed fish. So in announcing shevto as state fish, Goa government has committed a blunder which would fail the touchstone of hard science and stringent food safety regulations.