SPECIES COMPOSITION , DISTRIBUTION , AND POTENTIAL YIELD OF DEEP SEA SHRIMP RESOURCES IN THE WESTERN SUMATERA OF THE INDIAN OCEAN EEZ OF INDONESIAN WATERS

study on the catch composition, distribution and potential yield of deep sea shrimp in the westem off sumarera waters was conducled on June to July 2005 using RV Baruna Jaya lV with trawl net. This study was basicarry caffied out by emproying swept area method


MATERIALS AND METHODS
The study was conducted in the Indian Ocean western of Sumatera as shown in Figure 1 and implemented in the frame work ot thjDeep Sea Fisheries Resources Joint Exploration proiect 106 " Figure 1.
Mao of Indian ocean west off sumatera showing location of survey area' between Overseas Fishery Cooperation Foundation J"oin "nO Agency of Marine and Fisheries   Rds"ar"tr; Indoiesia The period of this study was from June to JulY 2005   The suNey area in the waters west of Sumatera lsland was divided into five sub areas along longitudinal line, for the sake of convenience for atto-cating trawl stations (Figure 1).Nevertheless' one of those areas (S-3 area, in ihe western part of Nias lsland) was cancelled because of the absence of trawl suitable depth zone.Each sub area was stratified into three depth zones by the depth contours of 500 and 750 m according to the resull of th" "u*"y in 2OO4 (Anonimous, 2005) The number of trawl stations based on area surveyeo and depth stratified as illustrated in   The research was conducted using Baruna Jaya lV (1.219 GT) bv operating trawl net with head rope ot si.o t in t6ngtn (Anonimous, 2005) Species identification for ieepsea shrimp was based on 160 King (1986)i Holthuis (1991); Carpenter & Niem   (1s98).
A research conducted in Kai, Aru, and Tanimbar lslands waters also found the same species very abundant that reported around 75% from total Fhrimp.catch (qumiono .& ,Soselisa, 1993).The similar result was also reported during research in deeD sea of Pacific and Indian Oceans where Caridea was dominantly catch (Holthuis, 1980;   Kins, 1i186), Durhg'rthis study some dominant species was 'atso inituded.The carapace length of deep sea shrimD in west of Sumatera waters ranged from 11.0 tb 84.5 mm (Table 3), This fact indicated that shrimo stock in this area consisted of sev€ral cohori, There was no relationship between the water depth of fishing ground with size of deep 3ea shrimo.

Distribution of DeeP Sea ShrimP
Table 4 oresents distribution and occurrence of deeD sea shrimp in west Sumatera waters from 50 trawl siations.The high percentage of occurrence of the catch were Aristgus v,r/is (86%) followed by Acanthephyra armata (76oA) and Heferocarpus sp' (76oi6), Disiribution of the those species in west of Sumitera waters was very wide This phenomenon was quite similar with thoie repoted by Sumiono E Soselisa (1993) in Kai, Aru, and Tanimbar lslands waters.in c6ntrast the least percentage of occurrence was occupied by group of deep sea scamoi such as Neph/'opsis stewarti and Puerulus anguiatus.This faci thai might be caused by small nuirber of trawl stations was carried out around coral waters as original fishing ground of thEse spEcies (Carpenter & Niem, 1998).
of Caridea tends to habit in coral waters (King,   1986).ln general, the deep sea shrirnps distribute in water depth of 200 to 1,000 m except for scampi (Nephropsls stewafti, Puerulus angulafus) which dwelling in depth below 300 m (Table 4).All of penaeid shrimp (family Penaeidae and Aristeidae) could be found in all range of water depth from 200 to 1000 m.
Table 4 also shows that family Sergestidae did not distribute in all depth range, They were not found in deoth of 200 to 500 m.While scampi shrimp family Nephropidae and Palinuridae were only found in this area on the depth of 200 to 500 m.This might be due to their habitat in coral waters whereas in west of Sumatera waters, the depth of this fishing ground was 200 to 500 m.In the western Australian watefs it was found the commercial deep sea shrimp that mostly distributed in the deoth of 4OO to 500 m This resource had alreadv been exploited commercially by trawl net (Wadl6v & Moriis, t991).Sumiono & Soselisa i1993) bointed out that the distribution of Penaeid shrimD (Aristeidae and Pandalidae) was at the deoth of 200 to 1000 m while scampi shrimp was oniv cauqht in the depth of 300 to 500 m Disiributio-n of scampi was quite similar pattern with result of research done in north and west of R-u-Jtratian waters (Wallner & Philips, 1988; Davis &  Ward, 1984).
For all species, the highest density of dgeq::?
shrimp resources was recbrded in the depth of 750 to l,OOO m while thg smallest density occurred rn ihe Aepth of 3OO to 500 m as illustrated in Figure 2' it iouli be conctuded that the best flshing ground of deeD sea shrimp rasources in west of Sumatera watilrs was located in the depth of 750 to 1,000 m Stock Density and Potential Yield Distribution of deep sea shrimp has a relation witt' wailii aeptf' of iisning groun'd.Each species Inform€tion of stock density, biomass, and ;;;r;a;J J"obps in c;r6inlh; J"pth r.^s.d, porency is nBsded to arrange development and ii,":ii'.ii.",iiv ir" ii riie in Jinov *aters white fa-mity planning for utilization in fisheries.Table s shows Table 3.
Range of caraPace length for deep water shrimp in west of Sumatera waters Aristeus virilis Ple siope nae us edw ard si an u s Acanthaphyn srmata Heterocatpus sP.
Haterocarpus ensifel H ete roca rp u s I aev ig atu s  According to spatial stock distribution, it could be stated that south area of west Sumatera waters such as--around off Enggano lsland (S-1 area) and yest..ofi Bengkulu (S-2 area),had higher itock oenstty than norlh area such as around off Simeulu lsland (S-4 area) and west otf Aceh waters (S_5 area).In general, stock density in this area was.higher than that of in the southern of lrian Java waters with stock density around of 7.9 kg km-, (Suman et a/., 1993).lnd.Fish Res.J. vol.12 No.2 Desember'2006: 159-167   20G500 500-700 750-1000   Dspth (m)   Figure 2.

Table 1 .
Area code survey areas and allocated trawl stations for fish stock assessment in west off sumatera

Table 4 .
Distribution and occurrence(o/o)of deep sea shrimp caught in the Sumatera waters of Table 5 indicates that stock density of deep sea shrimp in west Sumatera -waters was fluctuated from 1.6 to 90.38.5 kg km'' with averaged of 19.9 kg km-'.The lowest densjty was obtained in station 17 located in around off Simeulu lsland waters, Aceh Province and the highest one was recorded at station 2 in around of Enggano lsland waters.

Table 5 .
DistributionofdeepseashrimpsintheWesternIndianoceanEEzoffSumateraaccordingto the depth of waters.Stock density of deep sea shrimp (kg km''?) in the Indian Oceen wes! off sumatera by area