L - Cochin University of Science and Technology
L - Cochin University of Science and Technology
L - Cochin University of Science and Technology
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Ratnagiri. Density was comparal ively high in the southern transects in both seasons<br />
(Fig. 29&30). All depth zones <strong>of</strong> pre-monsoon season recorded high biomass except<br />
at 30 m depth zone, <strong>and</strong> at few depth zones the seasonal variation was more.<br />
During post-monsoon, generally all the groups have high biomass in shallow<br />
areas (30 m <strong>and</strong> 50 m) <strong>and</strong> low at deeper zones (beyond 50 m). in addition to the<br />
high biomass <strong>of</strong> crustaceans in the shallow depths, it was also more in the middle or<br />
deeper depths <strong>of</strong>f Monnugao (lOO m) Ratnagiri (150 m) <strong>and</strong> Mumbai (75 m). During<br />
pre-monsoon season polychaetes <strong>and</strong> miscellaneous groups showed high biomass up<br />
to 7S m depth <strong>and</strong> low values beyond 75 m while crustaceans showed low biomass in<br />
shallow areas (up to 50 m depth) in all transects <strong>and</strong> high in middle (75 m) or deeper<br />
depths (beyond 75 m). Molluscs were high in deeper stations (from 75 m to 150 m).<br />
In other words, season wise comparison showed that during post-monsoon most <strong>of</strong><br />
the groups have more biomass in shallow areas while during pre-monsoon only<br />
polychaetes <strong>and</strong> other groups have more biomass in shallow areas (30 m <strong>and</strong> 50 m).<br />
Students t statistical analysis (Table 15) showed no significant difference in<br />
biomass <strong>and</strong> density between two seasons except for the polychaete density <strong>and</strong> total<br />
density at 100 m depth zone. Observed difference may be due to the uneven<br />
distribution <strong>of</strong> organisms in various stations. Seasonal comparison for meiobenthos<br />
was not possible due to lack <strong>of</strong> sufficient data, however, average biomass <strong>and</strong> density<br />
<strong>of</strong> meiobenthos showed relatively higher values during pre-monsoon than post-<br />
monsoon.<br />
53. Discussion<br />
In the present study biomass in the whole study area varied from 0.05 to<br />
18.88g/ m 2 (av. 3.81g1 m 2 ) during post-monsoon <strong>and</strong> 0.02 to 15.87g1m 2 (av. 4.53g/<br />
m 2 ) during pre-monsoon season. Density in the whole study area varied from 10 to<br />
4820/ m 2 (av. 1040; m 2 ) during post-monsoon <strong>and</strong> 10 to 10090/m 2 (av. 2104/m2)<br />
during pre-monsoon season. At 30 m to 50 m zones an average biomass <strong>of</strong>7.38 glm 2<br />
102
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