CHENNAI: With industrial and urban pollutants slow-poisoning the Ennore Creek, local fishermen, who are struggling to survive due to reduced fish catch, have now turned to plucking out bristle worms (polychaetes), a vital bio-marker for pollution as well as an important food for marine organisms in the estuary.
“The creek has been severely affected by pollution, which in turn has taken away our livelihood. We have to scour through the water for these poochis (insects). It has huge value abroad,” says a fisherman.
Otherwise known as bristle worms, polychaetes belong to a group of annelids (segmented worms) that form the natural diet and important source of nutrient for fish larvae in the marine environment. They are present in every seafloor regardless of depth and temperature. There is a huge demand for polychaetes in the aquaculture industry in India and abroad, luring the fishermen here to collect them from the creek.
It is not easy work. They set out before the sun turns harsh, wading through the creek and scanning the water to collect the worms. It takes hours to collect a kilogramme, which could fetch them `1,000–`3,000, if exported.
For these men struggling to make ends meet due to lack of fish catch in the creek, it is an inevitable way to earn their livelihood. However, most are not aware that losing this vital link in the food chain is only worsening the situation.
Dasan, a fisherman, says that since the worms are snuffed out from the estuary, there is hardly any fish left. “The collection of polychaetes has resulted in the dwindling of fish as well as other marine life which feeds on these worms,” says an official from the Integrated Coastal and Marine Area Management Project Directorate (ICMAM), which is conducting a survey of the creek.
Once the paradise for mangroves, turtles and rare marine species, the creek was a means of livelihood for the fisherfolk of three hamlets.
However, the water has turned toxic due to effluents released from industries as well as sewage flow. Making matters worse, the creek is choked with construction debris that was dumped after building the Ennore railway bridge.
Waking up to the threat caused by the exploitation of polychaetes in the creek, the National Institute of Ocean Technology is mulling regulation. “The plan is to regulate the collection of polychaetes only by trained people by issuing licences as practiced in Australia,” says NIOT director M A Atmanand.
Due to its omnipresence in every marine and brackish water ecosystem, marine biologists in many European countries and the US consider them as an indicator to study the effect of pollutants, and natural and human-induced changes. Through bio-monitoring, experts assess the impact of chemicals on the biosphere by studying the effects on polychaetes.
“Since they are now part of the livelihood of farmers who are battling alarming levels of pollution, the government, instead of taking any drastic measure, should form a nodal agency to develop polychaete culture in Ennore Creek. This may solve the livelihood issue of the fishermen,” says a social activist.
According to Atmanand, dredging another 1.5 km till the railway bridge will ensure the tidal and the minimum flow required to maintain the creek ecosystem. However, he adds, it needs to be studied for its impact on polychaete and other faunal diversity.