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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elaatively higher average density in the southern transect (1200/m2) <strong>and</strong> lower in the<br />
northern transect (800/m 2 )(Fig. 29).<br />
5.2.2.2. Pre-monsoon<br />
Average <strong>of</strong> total density in different depth zones is given in Fig. 28. Average<br />
density was highest at 75 m (3578/m 2 ) <strong>and</strong> lowest at >150m (620/m 2 ). Density first<br />
increased from 30 m to 75 m zone then decreased to deeper depths. Transect wise<br />
density distribution in different depth zones during pre-monsoon is given in Table 8.<br />
At 30 m zone total density varied from 570/m 2 (<strong>of</strong>f Ratnagiri) to 1740/m 2 (<strong>of</strong>f<br />
Dwaraka) with an average <strong>of</strong> 1220/m 2 . At an stations polychaetes dominated in the<br />
population counts except <strong>of</strong>f Ratnagiri where density <strong>of</strong> molluscs was more than that<br />
<strong>of</strong> polychaetes. At 50 m zone total density varied from 710/m 2 (<strong>of</strong>f Ratnagiri) to<br />
5250/m 2 (<strong>of</strong>f Mormugao) with an average <strong>of</strong> 2623/m 2 • At all the stations polychaetes<br />
had an obvious dominance over all other groups. In the next depth zone, 75 m, total<br />
density varied from 530/m 2 (<strong>of</strong>fVeraval) to 10090/m 2 (otT Ratnagiri) with an average<br />
<strong>of</strong> 3 578/m 2 • As that <strong>of</strong> previous depth zone, here also polychaete had a wen-defined<br />
dominance at all stations followed by miscellaneous group <strong>and</strong> crustaceans. At 100 m<br />
depth zone total density varied from 1760/m 2 (<strong>of</strong>f Dwaraka) to 2400/m 2 (<strong>of</strong>TVeraval)<br />
with an average <strong>of</strong> 2060/m 2 <strong>and</strong> polychaetes dominated at all stations. At 150 m<br />
zone, total density varied from 140/m 2 (<strong>of</strong>f Veraval) <strong>and</strong> I 885/m 2 (<strong>of</strong>f Mumbai) with<br />
an average <strong>of</strong> 1493 1m 2 • At this zone, <strong>of</strong>f Veraval station, molluscs dominated <strong>and</strong><br />
polychaete density reduced considerably than rest <strong>of</strong> the groups. At > 150 m zone<br />
only two stations were sampled <strong>and</strong> total density ranged between 101m 2 (<strong>of</strong>f<br />
Veraval) <strong>and</strong> 1230 1m 2 (<strong>of</strong>f Mumbai) with an average <strong>of</strong> 620 1m 2 . Off Mumbai,<br />
polychaete dominated followed by miscellaneous group <strong>and</strong> crustaceans while <strong>of</strong>f<br />
Veraval only polychaete was present <strong>and</strong> lowest density in the study area was<br />
observed at this station.<br />
Transect wise density distribution in different depth zones during pre<br />
monsoon is given in Table 8. Transect wise variation <strong>of</strong> density distribution in<br />
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