Sustainable Gastronomy Day: Of seafood and the plastic ocean
A version of this article was originally published in Mint Lounge; June 18, 2021
Nethili fry served with raw onions (and toddy, if you are in Kerala) is a favourite bar snack through most of coastal south India and Sri Lanka. Nethili in Tamil, netholi in Malayalam, is among a few species of beautiful, small slender white fish called anchovies that are perfectly described by their Konkani name mothiyale—like pearls. For someone who has spent a lot of time working and talking about the overfishing crises and advising on seafood sustainability, I have been a strong advocate of anchovies as a sustainable seafood choice.
As a rule of thumb, it is considered more sustainable to eat the small fish lower down the food web, including the likes of anchovies, sardines and mackerel, as these species generally have shorter lifespans—they reach maturity early on and lay thousands of eggs. As a result, their populations tend to bounce back even if they are subjected to heavy fishing pressure compared to their predatory counterparts, including shark, kingfish, grouper and Asian sea bass. However, I recently came across research from a group at the US’ University of California, Davis that left me a bit flummoxed—they found that anchovies are attracted to the smell of plastic in water; they mistake it for food and eat it.
Sri Lanka recently experienced what could arguably be its worst maritime disaster in recent history when a fire, followed by an explosion, broke out on the cargo ship MV X-Press Pearl. It presumably started because of a leak in one of the containers carrying nitric acid (about 25 tonnes of it), a commonly used raw material in the manufacture of explosives and fertilisers. The fire continued to burn for days, by which time the ship began to sink off the coast of Negombo, releasing a toxic cocktail of urea fertilisers, caustic soda, methanol and other chemicals into the waters. Among the container’s contents were 78 metric tonnes of plastic nurdles. Nurdles are tiny plastic pellets which are melted down to form the basic raw material used in the manufacture of a wide range of products. In this case, the nurdles were made of polyethylene, the most commonly used plastic today in polythene bags, mineral water bottles, plastic cling film and more. Large quantities of these floating nurdles were washed ashore and now coat the once pristine beaches of Sri Lanka’s west coast, like an eerie blanket of snow.
Scientists have used predictive models, which suggest that ocean currents would carry a fair proportion of these microplastics to the southern shores of the island nation before they continue east and beyond. In Sri Lanka itself, many poor fishers, already reeling from the disruptions brought on by the pandemic, have now been told to keep off fishing till the situation is brought under some sort of control. However, many are apprehensive not just about when their fishing activities will resume, but also about the demand for seafood, given that the disaster has stoked fears about consuming seafood.
For all the right reasons, there has been added media focus on the impacts of this disaster on Sri Lanka’s marine environment and livelihoods. But it would not be outrageous to believe that the effects of such events are likely to be felt in distant waters too—and for some time to come.
While it is obvious that these nurdles could be transported far away by oceanic currents, the picture could look a lot grimmer if we add in the role that fish and other marine wildlife play in spreading plastic globally, taking them to places and communities that have had little to do with these disasters. It is not just the anchovies; there are, in fact, a large number of fish and other marine creatures that also consume plastic.
A large study published in Wiley’s Global Change Biology in February 2021 documented plastic being ingested in 386 of the 555 marine fish species examined— 210 of these were of commercial importance. The study also showed that the larger predatory fish, such as the sharks and tuna, consumed far higher quantities of plastic than the smaller ones.
Another challenge is that wildlife does not recognise borders. Many marine species have been documented to make dramatic ocean voyages literally halfway across the globe, sometimes further. Olive Ridley Sea turtles that were fitted with satellite trackers at their mass nesting beaches in Odisha have been known to travel all the way down to their feeding grounds off the coast of Sri Lanka; some of them returned to their nesting beaches, while others continued their journey to the Andaman and Nicobar Islands. Similarly, the high-value Pacific Bluefin tuna is known to undertake voyages that extend all the way from Japan across the Pacific to the west coast of the US. Some of these tunas, tested in the US, had traces of radioactive cesium, indicating that they were contaminated by the leakage brought about by the Fukushima-Daiichi nuclear accident in Japan in March 2011.
Even if the fish don’t make these distant voyages themselves, we do it for them. Our seafood markets are highly globalised and knowing which waters your fish came from, and exactly how it was caught, is not information that’s easy to come by. Therefore, despite the dire state of fisheries globally, India’s urban rich and middle classes enjoy a diversity of seafood like never before. In addition to seafood from all across the country, Indians now have access to international delights such as Norwegian farmed salmon, Tasmanian scallops and Korean seerfish.
It doesn’t end with ocean currents and a globalised seafood market. The chronic, pernicious and overlooked plastic leakage into the oceans that happens every single day from our lifestyle of convenience is something we seem to have normalised. It is predicted that the oceans will have more plastic than fish by 2050. While I am not one for these doomsday deadlines, whichever way we look at it, plastic is now a ubiquitous feature of the ocean. It is not surprising, then, that it has already begun to serve as a habitat for a colourful diversity of marine species—an entire ecosystem called the “plastisphere”.
The science around the human health impacts of consuming plastics is still being decoded. Scientific innovation such as bioplastic has the potential to replace our traditional plastic by at least 90%. The main raw material for bioplastic is cellulose (the building material of plants) and chitin (shells of crustaceans such as crab and shrimp), waste products from agricultural and fisheries operations. Capturing and processing this biowaste would provide additional income as well as contribute to the circular economy. Unfortunately, most of the plastics today continue to be derived from fossil fuels, so the commitment required is twofold—to substitute with bioplastics and meet climate mitigation targets.
The significance of fish like nethili is that they are generally eaten whole, as opposed to the boneless fillets of larger fish you would typically consume at a restaurant. For poor coastal communities, they are not only a crucial protein source but also a vital source of micronutrients (including vitamins A and B 12, iron, calcium, zinc as well as essential fatty acids), which are contained in the organs and bones. Now, however, these valuable nutrients of this otherwise perfectly built superfood come with a dose of plastic sitting in its gut.