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and 6.08 g/m 2 were recorded during post-monsoon and pre-monsoon seasons respectively, which is comparable with the result of Joydas (2002) who reported a biomass of 8.3 g/m 2 in the 30-50 m depth zone for the continental shelf of entire west coast of India. Average density at the 30 m depth zone was 2654/m 2 and 1220/m 2 during post-monsoon and pre-monsoon seasons respectively. Average density reported by Prabhu et aI., (1993) in the 30 m depth zone off Gangolli, west coast of India was 1725 and 1775 1m2 in the two consecutive years is comparable to the density reported during the present study. In the present study, average density observed at the 30 m and 50 m zone during pre-monsoon was 1922/m 2 , and was comparable with density 0969/m 2 ) reported by Joydas (2002) in the 30-50 m zone of NW coast of India during same period. Since no similar works were available, present study was compared with data from other earliedr works. Neyman (1969) reported a biomass of 20 g/m 2 in the NW coast of India. Parulekar et al., (1982 a) reported an average biomass of 14.06 glm 2 tor both macro and meio benthos together from the 20-40 m depth range. Parulekar et al., (1976) studied the quantitative aspects of benthos off Mumbai from 12 to 77 m depth and reported a low biomass values from nil to 4.63g/m 2 with no uniformity in the macrobenthic production. They reported an average of 1.1 g/m 2 in the study area olTMumbai. Harkantra et al., (1980) reported an average biomass of7.77 g/m 2 in the west coast from 30-70 m zone. Parulekar and Wagh (1975) recorded an average total biomass of 46.9 g/m 2 from 40-140 m depths stations in the NW coast of India. Parulekar et al., (1982a) observed an average biomass for both macro and meiobenthos was 12.39 glm 2 from 20-200 m. Qasim (1982) recorded a mean biomass of6.74g1 m 2 in the NW coast oflndia and biomass reported by Ansari et al., (1996) ranged from 10 to 100g/ m 2 with a mean of 20 g/ m 2 in the NW Indian shelf from 20 to 350m depth. 103
Difference in biomass and density noticed by earlier workers may be due to the use of different types of gears (Neyman, 1969; Parulekar and Wagh, 1975; Parulekar et al., 1976; Harkantra et al., 1980; Parulekar et al., 1982a; Qasim, 1982) or due to sampling in different seasons from diverse ecosystems (Ansari et al., 1996). In addition to the above reasons, biomass reported by Parulekar et al., (1982a) was a total of both macro and meiobenthos. The average biomass value (4.53g1m 2 ) for the study area as a whole during pre-monsoon season in the NW coast is well comparable to that of Joydas (2002) who reported an average value of 5.3g1 m 2 in the northwest coast of India during pre-monsoon. During post-monsoon biomass was generally high in shallow depths (30 m and 50 rn) and during pre-monsoon season it was high from 30 to 75 m and low in the deeper stations beyond 75 m. Density also followed more or less the same trend with high values in shallow stations and low in deeper depths in both seasons. This was in agreement with earlier reports (Kurian, 1953, 1967,1971; Neyman, 1969; Parulekar, 1973; Parulekar and Dwivedi, 1974; Parulekar and Wagh, 1975; Parulekar et al., 1976; Ansari et al., 1977b; Harkantra et al., 1980 & 1982; Parulekar et al., 1982 b; Qasim, 1982; Devassy et al., 1987; Prabhu et al., 1993; Ansari et aI., 1996; Joydas and Damodaran, 2001). Enrichment of coastal waters due to riverine flow and land run off seems to be one of the factors contributing to richness of fauna in the nearshore regions (Parulekar, 1973). Devassy et al., (1987) reported high biomass in the near shore region and attributed it to the influx of nutrient rich river water. Influence of nutrient rich water is reported by other workes also (Kurian, 1971; Harkantra et al., 1980; Harkantra and parulekar, 1981 ). But the work of Gopalkrishnan and Nair (1998) recorded low benthic population in the nearshore areas (Srn) and rich fauna in 20 m contour of Mangalore. Ansari et al., (1996) also reported a decreasing standing crop with increasing depth and distance from the shore. They reported that neritic coastal waters of continental shelf (up to 200m depth) were often highly productive and many of the world's commercial fisheries 104
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Certificate I hereby certify that t
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Contents Page No. Chapter 1. Introd
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the bottom. Ekman (1935) described
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wonns are the most abundant group a
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leadership of Sir James Clark Ross,
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Ansari et al., (1977b) carried out
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Gopalakrishnan and Nair (1998) cond
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Major objectives:- 1. To understand
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CMFRI (Central Marine Fisheries Res
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Joydas, T.V., Damodaran, R., 2001.
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monitoring committee (Atlantic Mari
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Vizakat Lathika, I-Iarkantra, S. N.
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analysed after acidification by tit
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used as stain prior to sorting and
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space. Therefore, it is very essent
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Fig. I - Station locations 32
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affected at high temperature. Most
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layers exhibit different oceanograp
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Transect wise variation in temperat
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3.2.2.3. Dissolved oxygen (DO) Dist
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monsoon temperature initially incre
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opined that limited mixing. high or
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Naqvi, S. W. A., Noronha, R. J., Re
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orr Mormugao orr Vernal 35.36 35.32
Page 62 and 63: The continental shelf and its adjoi
Page 64: sediments (4 stations). Silty sand
Page 68 and 69: fine sediments with comparatively h
Page 70 and 71: Narayana, 1991 ). Limited input of
Page 73 and 74: In general. two ditlerent patterns
Page 75 and 76: et al., (1980) reported values in t
Page 77 and 78: organisms living in the water and t
Page 79 and 80: Hashimi, N. H., Kidwai, R. M., Nair
Page 81 and 82: Postma, H., 1967. In Estuaries, Lau
Page 85: Depths Sand Silt Clay Organic matte
Page 90: • PRE'MONSOON SOUTHERN'TRANSECTS
Page 96 and 97: as the best indicators of the envir
Page 99 and 100: showed that northern transects have
Page 101 and 102: decreased from shallow to deeper de
Page 103: different depth zones showed that a
Page 106 and 107: cm 2 with a dominance of nematodes.
Page 110 and 111: were located in the nearshore water
Page 112 and 113: changes in the hydrographical and t
Page 114 and 115: factor for such a large difference
Page 116 and 117: Belegvad, H., 1932. Investigations
Page 118 and 119: Parulekar, A. H., Harkantra, S. N.,
Page 120: Savich, M. S., 1972. Quantitative d
Page 123 and 124: Traosects Polychaetes Crustaceans M
Page 125: Miscellaneous Transects Nematodes C
Page 128 and 129: Depths Nematodes Cope pods Foramini
Page 136 and 137: Wagh, 1975; Parulekar et ai, 1976;
Page 138 and 139: ones and 17 were included in the 'r
Page 140 and 141: Nephtydae (2%). Among the 20 sedent
Page 143 and 144: At 75 m zone, 31 groups/species wer
Page 145 and 146: Porbandar. At 50 m depth zone, fluc
Page 148 and 149: otTMumbai and Ratnagiri and low eve
Page 150 and 151: species richness at each depth zone
Page 153 and 154: E2.2.2.!. Richness (Margalef's inde
Page 155: I ):.2.2.2.4. Dominance (Pie/ou's i
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Tablc 17. Contd .. - Sternaspidae 0
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Table 20. contd .. G. alba 20 25 20
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150 Taxa 30m 50m 75m lOOm 150 m m D
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9% 1% o poIychaete • crustacea o
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a) c) e) g) Plate 5 a) Prinospio sp
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a) c) e) Plate 7 a) Cardium sp. d)
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7/. /ntroduct ion 7.2. Hydrography
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also showed a similar pattern with
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y most of the organisms. It was als
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with sand of which total density (r
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muddy bottom of the west coast of I
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crustaceans and miscellaneous group
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the organic rich environment with h
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Icvci (p
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mcioHmna serve primarily as rapid m
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surface chlorophyll a was 0.36mg I
Page 231 and 232:
Devassy, V. P., Achuthankutty, C. T
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Longhrust, A. R., Pauly, D., 1987.
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Sikora, W. B., 1977. The ecology of
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Faunal groups Silty Clayey Mixed Sa
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Mannagoa to Porbandar located betwe
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against gastropods during pre- mons
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