1 research outputs found
Distribution, diversity, length-weight relationship and recruitment pattern of deep-sea finfishes and shellfishes in the shelf-break area off southwest Indian EEZ
The results of an exclusive fishing cruise, No. 241, undertaken by FORV Sayar Sampada (Ministry of Earth
Sciences) during January-February 2006, in the shelf-break area (500-1000m depth) in the southwest region
of Indian EEZ (Lat.Q-16" and Long. 72"-75"46) are presented. Bottom trawling was conducted at 33 stations.
A total catch of 1795 kg was realised, out of which the discards formed 31 1 kg. A variety of non-conventional
finfishes (77 species) and shellfishes (shrimps 8 species, crabs 3 species, one species of lobsterette) have
been recorded. Depth-wise 235m zone indicated the maximum catch. The total catch during the entire cruise
was dominated by Psenopsis ryanra. The various population parameters such as La, K, total mortality (Z),
natural mortality (M), fishing mortality (F), exploitation ratio (E), recruitment pattern and length-weight
relationship of some of the important species have been worked out. In most of the deep-sea fishes, the
recruitment appeared to take place almost throughout the year and showed great similarity among the various
species except Luciobrotula bartschi. Presently, all these resources remain unexploited, except the shrimps.
The trawlers based at Cochin, Quilon and Munambam have been exploiting the deep-sea shrimp resources
like the red-ring Arbreus alcocki from the Quilon Bank and other similar areas of< west coast for the last five
years. Interestingly Psenopsis cyanea has been found to occur as bye-catch in these fishing operations.
Therefore, these two species showed higher fishing mortality compared to practically nil value in other
finfishes and shellfishes. The occurrence of the deep-sea glass sponge, Hyalonema sp. off Mangalore is also
reported. Bio-silica, extracted from this sponge, has a vide range of applications in the medical field from
novel biomaterials for bone replacements to the stabilization of tissue. Most of the resources being nonconventional there is need to evolve new processing methods, product diversification and develop export
avenues to make deep-sea fishing venture a success. Inventorisation of the deep-sea biodiversity and preparation
of fishery atlas also merit serious consideration