Convener, 11th Indian Fisheries and Aquaculture Forum
Abstract
Anthropogenic impacts on sustainability of
coastal ecosystems have always been a
matter of concern for those who depend on
these habitats for their livelihood. A slow and
silent killer of the aquatic habitats is the nondegradable litter or debris which enters these
water bodies due to improper treatment of
solid waste on land. These either settle in the
nearby areas or drift and finally settle in
distant places. Ultimately most of the
untreated and carelessly dumped solid
wastes end up in the coastal waters or the
seas. The Vembanad Lake (VL) in Kerala
spread across three districts is one of the
largest wetlands of the country. A survey was
conducted to understand the spread of litter
in the upstream and downstream areas of
this water body. Five stations (ST) were
fixed; Kumarakom (ST-1), Vaikom (ST-2),
Nettoor (ST-3), Thevara (ST-4) and Cochin
backwaters (ST-5) of which the first two were
upstream, followed by middle stream (ST
3,4) and downstream (ST-5). It was observed
that 30% of the surveyed area at
Kumarakam (ST-1) and 40% of Nettor zones
were without any submerged debris. The
average quantity of submerged debris at ST -
1, ST -2, ST -3 and ST -4 were 0.5, 1.5, 0.6,
and 0.5 kg.m'2 while in Cochin backwaters in
the area adjacent to marine drive, the
submerged litter was estimated as 111
kg.m'2, which is ,100 times greater than in
the upstream areas. While carry bags were
the dominant litter in the upstream stations,
ghost nets (40.6 kg.m'2), nylon ropes (15.6
kg.m'2) cables and metal cans (11.5 kg.m'2)
formed the major litter components in Cochin
backwaters. The study brought out the
urgent need to clean the Cochin backwaters
to restore the ecosystem functioning. The
paper presents the types of litter and its
density in different areas of VL and suggests
the remedial measures to prevent further
degradation
