Retting of coconut husk ‐ a unique case of water pollution on the South West coast of India

Abstract

The extensive backwaters of Kerala are the sites for a flourishing cottage industry -the coir industry. This enterprise almost exclusively located along the 590 km coastal belt of Kerala, provides direct employment to over half a million people in the state and produces nearly 90% of the total coir goods in the world. The shallow bays and lagoons of the 30 backwater systems of the state are traditional areas for the retting of coconut husk for the production of the coir fibre. The paper examines the environmental status of the retting grounds in Kerala, in relation to the biotic communities. The study revealed that retting activity has caused large scale organic pollution along with the mass destruction of the flora and fauna, converting sizeable sections of the backwaters into virtual cesspools of foul smelling stagnant waters. High values of hydrogen sulphide, ammonia, BOD 5 associated with anoxic conditions and low community diversity of plankton, benthic fauna, fish, shell fish, wood boring and fouling organisms were the outstanding feature of the retting zones.

Impact of Jute Retting on Physicochemical Profile of Chhariganga Oxbow Lake in Nadia District, West Bengal, India

“…Like present findings BOD values were observed quite similar (Das et al 2009;Srinivasan, 1967;Biswasroy et al, 2011) and BOD was seen increased during jute retting during monsoon (Dasgupta et al, 2006;Ghosh and Biswas, 2015c). High BOD values are generally associated with anoxic conditions and low community diversity of fish and shell fish in coconut husk retting zones (Nandan, 1997). By contrast, it was also reported (Dasgupta et al, 2006) that jute retting has dual effects also as it creates anaerobic condition for fish mortality for a short period and releases nutrients with the passage of time to help the growth of the aquatic life.…”

“…The impact of urbanization the urbanization of surrounding areas leads to the discharge of domestic sewage and industrial effluents into lake (Chandrasekhar et al, 2003). Varied studies have been conducted on oxbow lake ecosystems across the world in general (Banerjea, 1967;Zutshi et al, 1972Zutshi et al, , 1980Vass and Zutshi, 1979;Trisal, 1985;Patil and Panda, 1986;Joo and David, 1995;Nandan, 1997;Sugunan et al, 2000;Obire et al, 2003;Aswathi and Tiwari, 2004;Chindah et al 2005;Hart and Zabbey, 2005;Sikoki and Zabbey, 2006;Koliyar and Rokhare, 2008;Joadder, 2009;Feresin et al, 2010;Das et al, 2009Das et al, , 2011Das et al, , 2011a and in Nadia district in particular (Dasgupta et al, 2006;Biswasroy et al, 2011;Bala and Mukherjee, 2011;Ziauddin et al, 2013). Despite studied effect of jute retting on the water of an oxbow lake (Dasgupta et al, 2006) and assessed impact of jute retting on native fish diversity and aquatic health of roadside transitory water bodies (Ghosh and Biswas, 2015c) considering limited parameters, the present study was specifically conducted to revisit the impact of jute retting on physico-chemical condition of a randomly chosen semi-closed oxbow lake ecosystem (Ghosh and Biswas, 2017b;2017d) in the northern side of the Nadia district, West Bengal through the analyses of as much as 16 physico-chemical parameters during April 2013-March, 2014 to assess the pollution due to jute retting and trophic status on broader aspects for its sustainable management.…”

Impact of Jute Retting on Native Fish Diversity and Aquatic Health of Roadside Transitory Water Bodies: An Assessment in Eastern India

“…Table 1 and Figure 5 show variation of soil and water quality parameters in their mean values. All val- 5 associated with anoxic conditions and low community diversity of fish, shell fish were the outstanding feature of the coconut husk retting zones in Kerala back water [11]. Jute retting makes the cemented tank water body near neutral by lowering the pH of water and there is a reduction in bicarbonate alkalinity Total 100.00 100.00 100 100.00 100.00 100.00 100 100.00…”

Efficiency of Pollution Tolerance Index (PTI) of macroinvertebrates in detecting aquatic pollution in an oxbow lake in India

“…In India, a limited number of studies have used aquatic macroinvertebrates in water quality bioassessment (Nandan, 1997;Balachandran & Ramachandra, 2010;Latha & Thanga, 2010;Alakananda et al 2011;Balachandran et al 2012;Gupta & Narzary, 2013;Kumar & Khan, 2013;Rashid & Pandit, 2014;Doley & Kalita, 2014), and only one has addressed the ecological aspects of macroinvertebrates in an oxbow lake (Chakrabarty & Das, 2006). Nonetheless, the use of aquatic macroinvertebrates to rate the water quality of oxbow lakes in India remains poorly documented and macroinvertebrates, seasonal distribution in relation to physicochemical variables is neither well known in West Bengal oxbow lake ecosystems.…”