Retting.of coconut husk is one of the major problems of pollution in the estuaries
(Kayals) of Kerala. This paper discusses the salient features associated with the variation
in gross and net primary productivity values in the Kadinarnkularn Kayal based on
lortnightlydala from twosclected stations frorn Octobcr1987 to September 1988.The gross
primary productivity value in the surface water ranged from 0.06 to 0.29gC/m3/day at
Station Iand from 0.06 to 1.49gC/rn3/dayatstation II. In the bottom wateritrangcdfrorn
oto 0.21 gC/m2/ day at station I whereas that at station II from 0.03 to 1.41gC/m3j day.
The net productivity in the surface water at station I varied from 0 to 024 gC/m Iday
Whereas that atstation II varied from 0.02to 1.44gC/m3Iday.AI the bottomwaterilvaried
from ato 0.19gC/m3/ day at station I and from 0.01 to 1.21gC/m3/day at station II. The
monsoon period showed the highest mean seasonal value at stations I and II. The total
depletion of dissolved oxygen giving rise to anoxic condition coupled with the production
of large quantities of hydrogen sulphide was found to be detrimental to the gross and net
productivity values in the retting zone