5.4.3.1 Cochin backwaters

5.4.3.1 Cochin backwaters

The total area of the Cochin backwaters is about 500 km². Of the 44 rivers in Kerala, 41 flow westward from the Western Ghats to the Arabian sea through backwaters. The rivers like Achenkovil, Manimala, Meenachil, Muvattupuzha, Pamba, Chalakudi and Periyar discharge their water into the Arabian sea through the Cochin backwaters. The tidal influence extends upto 11 km south of Cochin during the monsoon period. The northern portion of the Cochin backwater is called the Varapuzha lake and the southern portion of the Cochin backwater is known as the Vembanad lake.

Fish and Fisheries

In general, the fish and fisheries of the Cochin backwaters are similar to the Vembnad backwaters. T. ilisha , Mackerel (Rastrelliger kanagurta), Oil sardine (Sardinella longiceps) and penaeid prawns especially F. indicus form good fishery. In addition to these species, juveniles of Anchovella, Ambassis, Sciaena, Thrissocles and Leiognathus spp. also occur. In the seasonal fields, paddy is grown during the monsoon months (June – Sep) when the backwaters become freshwater dominated. Soon after the monsoon, paddy is harvested and when the water becomes brackish, postlarvae and juveniles of prawns, which are commercially important, migrate into these fields in large numbers. They are allowed to grow on natural food and are harvested from time to time through the suitably located sluice gates. The season ends in April/May. The perennial fields, where prawns are harvested throughout the year, are deeper than the seasonal fields. Maximum production (362 kg/ha) is obtained in February and minimum (40 kg/ha) in December. In the perennial fields of the same area, production goes on intermittently from January to April (60 to 125 kg/ha). Among the commercially important prawns, three species, namely F. indicus, Metapeanaeus dobsoni and M. monoceros are the most important. The seeds of these three species are collected in large numbers from the backwaters for aquaculture. The seeds of F. indicus are most abundant during the premonsoon months, (April – May). Their numbers decrease during the monsoon months but increase again from September and October (postmonsoon) and continue to do so in subsequent months.

Last modified: Wednesday, 27 June 2012, 10:17 AM