International Journal of Marine Science, 2017, Vol.7, No.7, 59-66
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sand, in combination with the organic enrichment, from which these epistratum feeders scrape off bacteria and
unicellular eukaryotes. Further, because of the coarser sediment at the shelf, the upper sediment layers dry out
faster and are therefore disadvantageous to a deposit-feeding feeding strategy. The mid region of OMZ area was
represented by a maximum contribution (35%) of omnivores and non-selective deposit feeders. The reason behind
the dominance of omnivores and deposit feeders could be the high enrichment of organic material. The outside of
OMZ was dominated by deposit feeders.
Table 3 Percent distribution of nematode feeding type in the study area
Depth (m)
1A
1B
2A
2B
500
18
49
5
28
650
12
38
22
28
700
27
32
25
16
799
29
19
13
39
800
27
34
18
20
900
16
40
15
29
1100
15
15
22
48
1956
32
14
24
30
The correlation of total meiofauna, and nematode with key environmental variables was attempted (Figure 3;
Figure 4). There was negative insignificant correlation between total meiofauna and dissolved oxygen of the
bottom water (Figure 3; Regression Y= -0.093X + 21.01; r= -0.137). In contrast sediment organic carbon showed
a strong positive correlation with total meiofauna (Y=0.017X +1.94; r=0.521).
Figure 4 Correlation between meiofauna and organic carbon
3 Discussion
Benthos play important role in re-mineralization of organic matter and biogeochemical cycle (Jaleel, 2012). The
presence of OMZ between 200 and 1200 m of western Arabian Sea has been reported by many authors (Naqvi et
al., 2006; Ingole et al., 2010). The upwelling in the north east Arabian Sea typically enriches the sediment with
organic matter (Qasim, 1982). The high production and seasonal deposition of organic matter in the Arabian Sea
results in seasonality in high benthic microbial production that consumes the oxygen that results in the
development of hypoxia at the end of south-west monsoon (Gage, 2000). The observed high values of sediment
organic carbon on the slope, and low values in the basin region, were in agreement with earlier record from
Arabian Sea and western Indian margin (Rao and Veeraya, 2000; Cowie, 2005).
Preliminary studies on metazoan meiofauna of Arabian Sea OMZ areas have been carried out. High to very high
densities of meiofauna particularly nematode have been reported from OMZ areas (Cook et al., 2000; Neira et al.,
2013) In the present study, density of 3-8 times lower was recorded. Meiofauna dissolved oxygen produced
