The first few days of October saw a massive and sudden increase in catch of marine life — fish, crab, shrimp, stingray — close to the shore along the country’s west coast. The phenomenon that was reported almost simultaneously from Varkala in Kerala, Karwar in Karnataka and Alibaug and Mumbai in Maharashtra, offered a huge bonanza for fisherfolk even as it raised questions about the causes and consequences, if any, on daily consumption.
A lively discussion has been going on amongst researchers and scientists, and a number of hypotheses have been put forth to explain the phenomenon. The more alarming suggestions were of increased toxicity because of water pollution. Another explanation suggested algal blooms that can be triggered by increased nutrients on account of pollution. This, in turn, reduces the oxygen content impacting fish and other marine life.
The other cause many researchers have highlighted is the natural condition created due to the withdrawal of the monsoons. A combination of changing temperatures, currents and wave action force the nutrient-rich lower water layers to come up. This upwelling leads to the formation of low oxygen zones, forcing marine life closer to shallow waters.
Understanding ocean ecology
Another theory, particularly in relation to stingrays, is related to their breeding behaviour and near-shore fisheries. It has been suggested that the rays may have been congregating closer to shore either to mate or for mass pupping and were probably caught in shore seine nets. “I have come across bumper ray catches a couple of times, both along the east and west coasts,” says Goa-based marine biologist Aaron Savio Lobo. “They are not common, but they do happen.”
While a clearer understanding and consensus of what really happened is still to be reached, there are a number of other important issues these events have underlined. For one, it shows how little we understand of the ecology of the oceans and our coastline. Add to this, altered land-use along the coastline, increased pollution of the seas, plummeting fish stocks on account of overfishing and changing character of the sea because of climate change.
While scientific research to understand the various interlinked processes is very much needed, it is crucial that fishing communities be made a part of the effort; both because their livelihoods are at stake and also because of their knowledge of the sea and fisheries. An innovative recent example of the use of scientific knowledge and media outreach is the ‘Know Your Fish’ (knowyourfish.org.in) initiative by three young marine researchers — Pooja Rathod, Chetana Purushottam and Mayuresh Gangal.
A voluntary effort that targets urban fish eaters, it provides informed fish choices based on compilation of decades of marine research along the country’s west coast, and seeks to encourage and empower consumers to eat seafood ‘responsibly’. The portal has a calendar that will tell you the best time to eat pomfret, for instance, and when to completely avoid it (March-May, when it breeds). It also rates the vulnerability score of the different species and indicates periods of the year when they are not fished using harmful practices.
And a striking example of the relevance of fisherfolk knowledge is the fact that they even have a name for the recent occurrence. “Here in Mumbai,” notes Pradip Patade of the citizen initiative Marine Life of Mumbai, “the Koli fishermen call this phenomenon ‘ saargi che paani ’”. It refers, in part, to the brown layer of water that brings a huge catch with it. “In many places,” he explains, “local fishermen have traditionally associated such events with certain oceanographic conditions that set in as the monsoon recedes. They expect big catches of mixed species, including large quantities of shrimp, around this time.”
Can we eat those fish?
The health of the ocean is as much a concern as is the well-being of those who consume fish as a part of their daily diet. This was evident in the concerns raised about the large-scale catch and whether the fish were safe to consume.
While the fisheries authorities in Maharashtra were quick to clarify that the die-offs were not because of pollution and that the fish were safe to consume, experts and residents were a little more circumspect. The complexity of the issue was captured rather succinctly in Mumbai-based researcher Abhishek Jamalabad’s Facebook post: “So can you go ahead and eat those fish? Umm... I’d ask you to make informed decisions about that 365 days a year, not just now.”
Clearly, there is a lot more we need to know before tucking into that bowl of fiery red fish curry.
The author researches issues at the intersection of environment, science, society, and technology.