DEEP SEA FISH RESOURCES DIVERSITY AND POTENTIAL IN THE WATERS OF WESTERN SUMATERA OF THE EASTERN INDIAN OCEAN

Theavailabilityofdataandinformationonthediversityandpotentia|oifishresourcesprov|oe 'rport"ni "ip""ti for exploitation and managemenl' Most.of the deep sea regions. provide the ,most ili5;d;il;, ili ,ntii|,J""ntry information o; its biodiversity and potenriat is verv little. aata anatvzed were parts of the resutts of expa*,"rv'iriwr"s u" "g inu At-aiuti" J,aya lv carded oul in June to July 2005. The most lmponance specres ii term oinumb-ers were the lantern fish, Diaphrs sp.1, the rat tails macrourid, caelorinchus dlveryans, the neoscopetids. ^,/eoscopelus macrolepidotus, the spinytins, 'i;i;;;ie;" pauciradiatus, th6 alepocepnatio, Bajacatifornia enm.orensis' and the trachichthyds ;;il;"]a Jrr"i"prl" n""rv.i, o? i"ri resourcei indicated that the towesr density of about 0.08 tonnes km-was obse-eo ,n tne oepih ione of zsl tq 1 ,ooo m in the waters of the north western part of #;;;; ""; th;;ighe;t density oi .t z.z tonn"" km'2 was occurred in the depth zone 500 to 750 m, in G *uter" oitn" we"stern part oh Banda Aceh. In relation with the environmental aspects such as the iirg; pi;""rt" u"d scarcity of food .rpprv, it i" likety that.the deep se-a fishes might have a very high "uit"i'nment tor su.uive. The most interesting aspeais tnat me chemicat substances of their flesh, such ;;-fti;;;. lipids and olhers wi need fudhEr pharmacotogicat analysis and research, lt is advised that ",,ilolt"tion of duep "u" nsn resouice! nowadays shorid. be dir'ecled to get the benefit from the reiources diversity and bioactive substances rather lhan catching fish for consumption'


INTRODUCTION
The demersal resources are a group of fishes that most of their life cycle living at or around the bottom waters.Characteristics of demersal.fish behaviour compared with those pelagics fish are forming a relatively smaller school, lower movement, and relatively shorter migration ranges.
Catch compositions of the most economically important demersal fish in the continental shelf area and relatively shallow waters are usually consisted of red snappers, silver bellies, white pomfrets, groupers, croackers, and catfish (Saeger et a/.,   1976).The fishing gears used for the demersal flsh exploitation are trawl, bottom long line, bottom gill net, traps and hook and line.The shallow waters demersal fish has been widely known and easily found in most landing places and fish market, however.most of the deeosea demersal fish are rarely encountered while some fishes provide as identified new species that have not even been found in the literatures.As demersal fish had a relatively short distance migration range, their fishing grounds in the Indian Ocean untill recently are still limited to the narrow continental shelf areas.Based on the available marine charts, the fishing areas are considered not more than 100 m isodepth.In relation with the relatively limited capability in both fishing gears and fishing fleets of most Indonesian fishers, it is believed that the '' R€Eearch Institule for Marine Fisheries, Muara Baru.Jakarta ' Research C€nter for Caoture Fisheri€s deepsea demersal fish resources at the depth range more that 100 m are consldeled untapped.The fish resources include deep sea shark and rays, groupers, snappers (Etelis sp.) and some conger eels (Wbowo, 2005).Some deep sea fish that have been found during the exploratory bottom lono lininq in the Sunda Strait were Gepyroberix so.]andFeristedlon sp. (Hufiadi et a/.,2003).The first fish species can be considered as food fish, while the later has been known as a very poisonous fish.
ln relation with the fish resources potential, information on this aspect regarding the deep-sea fish resources in Indonesian waters is still very scare compared to the similar aspect on the shallow demersal fishes that have been widely reported (Losse & Dwiponggo, 1977; Dwiponggo &  Badrudin, 1978; 1979; 19801  Badrudin & Sumiono,   2002: Badrudin et al ., 2002: 2004i 2004a: 2005) .
Most of the deep sea region provides the most widely habitat with little information on its blodiversity.Ninety percent of the ocean volume consisted of deep water which are dark, cold.Mean white information on the aspectb of life is still very rare (Nybakken, 1986), The main environmental factors affecting deep-sea region are light, hydrostatics pressure, salinity, temperature, oxigen, and food supply.These factors will undoubtedly tnd.Fish Res.J. Vol.12 No.2 Deseribibr-Zooa: tts-tzt affect the behaviour, life, survival, sustainment and diversity of most organisms including fish.
This paper provides information that can be used as a benchmark for further research and assessment activities in both similar marine waters or other marine areas with simtlar waters characteristics and biophysical conditions.Results of the anaylisis presented in this paper provide a complementary information found in the results of the exploratory trawling carried out by the RA/ Baruna Jaya lV (Anonymous, 2006): MATERIALS AND METHODS Data analyzed were parts of, the resutts of exploratory trawling using the RA/ Baruna Jaya lV, carried out in the framework of The Japan- Indonesia Deep Sea Fisheries Resources Joint ExDloration Marine Research 2004, with one of the main objectives is to study the catch per unit area as an index of abundance of the deepsea demersal fish resources in the lndian Ocean Southern Java and Western Sumatera (Anonymous, 2006).
A total of 50 trawl fishing stations was done completly during June to July 2005.The catches of each species or species group were weighted' counted, and recorded in the fishing log sheet.The combined data for analysis were inputted in the form of Excel format.Trawl sampling sites include the waters of SE Enggano (S-1 area), Western off Bangkulu (S-2 area), NW of Simeuleu (S-4 area)' and Western off Banda Aceh (S-5 area).Oue to some technical problems (Anonymous, 2006), trawling activity in the S-3 area has been cancelled (Figure 1).Exploratory fishing covered the depth range of 250 to 1,200 m, while data analysis was limiied only to the exploratory results carried out in the western Sumatera of the Indian Ocean.These data were grouped into three depth fishing zones, the <500 m, 5Oo to 750 m, and 751 to 1,000 m.
Estimation of stock density and standing stock size was carried out by using the swept area method following Saeger ef a,. (1976)with the assumption that the constant mouth openning oi the trawl was 500/o of the head rope length and escapement factor was 75%.Species identifications were done following Nakabo (2002).Deep sea trawl sampling sites (S-1 = SE Enggano; S-2 = W-off Bengkulu; S-3 = W of Nias, where trawling iite-has been cancelled; and S-4= NW Simeuleu; S-5 = W off Banda Aceh).

Total Catch
A wide range of marine organisms was found in the catch.These included fishes group of both bony fish and elasmobranch.Other groups were crustaceans, cephalopods, echinoids, asteroids, ophiuroids, holoturoids, and anthozoa.A total of more than 550 species was found in the catch. of which until now some species were still unknown and not yet found in the literatures.The following analysis will only be limited to the fish resources.The Wateis ol thg SE Part of Enggano It is likely that within the depth range of 250 to 1,000 m in this waters, the number of species seems to increase toward the deeper waters.This is reflected in the Richness index, where the index in the depth zone 750 to 1,000 m is 40.00/6 higher than the index in the depth zone 500 to 750 m.Similary the index in the later depth zone was 40.5% higher than the index in depth zone <500 m.This phenomenon is also happened to the Shannon index, where the values seems to decrease toward the deeper waters.ln other words, the greater the depth zone the smaller the diversity.The highest index, H=2,171, occurred in the depth zone of <500 m, while in the respective deeper zones these value were 37.5 and 1 1.4% decreased (Table 1).The value of Simpson index reflects the domination of certain species.This index is also known as the index of domination.lt seems that within the waters of Enggano, the species domination occurred in the deeDer waters.The three fish groups abundantly found in the depth zone of 750 to 1,000 m, were the macrourids, the melanonids and the oDhidiids.From a total of 759 Rsh caught, their percentage was around 500/6.The most abundant macrourld species was  (-37 .5o/o)0.31 7 (+36.1016)8.36 0.344 0.043 '15,061 (+396.10/6)2,394 (+497 .ooh)0.089 (-81.80/o)7,338 (+ 66.90/6)  1,812 (+198.0%)0.281 (-66.50/6)2.82 (+40oh) 1 ,2O3 (-1 I .4oh)0.049 (-84.50/6)10.00 (+19.60/6), 0.498 (+44,8o/o)   0.067 (+55.8%)15,403 (+2.3o/o) 1 ,956 (-18.3%)0,044 (-50.6%)I,232 (+?5.8oh)   1 ,019 (-43.80/6)t 0.839 0.255 (-9.3%) Caelorinchus sp.1, Gadamus colletti, Ventrifossa sp.1, Nezumia sp.2, Nezumia sP.1, and Pse udonezumia iaponica ('l able 2).
The Waters of tho Western Part off Bgngkulu Due to the limited area of the trawlable ground' number of trawl haul allocated in this waters was only two hauls in the 500 to 750 m depth zone and another two hauls in the 750 to 1,000 m depth zone.As in the Enggano area, the diversity indices including Richness, Shannon as well as Simpson index seem to increase toward the deeper waters Richness index in the 750 to 1,000 m depth zone was about 19.6 (20%) higher than in the 500 to 750 m depth zone.Similarly, the Shannon index in the depth zone 750 to 1,000 m was 4506 higher' while th6 Simpson index was 560/6 higher than in the depth zone 500 to 750 m (Table 1).The most abundance species in each of the two depth zone in the western part off Bengkulu as represented by the highest percentage was placed by the macrouiid Caelorinchus divergens.This benthopelagic species seems to have either a wider rang-of depth distribution or the bottom habitat in ihis area are similar.The percentage of this species in the two depth zones was '1 1olo and 19% respectively (Table 2).
The Waters of the NW Part off Simeuleu Species diversity in the <500 m depth zone was rather poor compared with diversity in ihe deeper zone.As reflected by the Richness index which is only 3.0, the Richness index in the deeper waters of 15,061 was more than five times higher, an increase or about 3960/6.Similar phenomenon with the value of Shannon index, where in the <500 m deoth zone ttre value of H=0.4, in the 500 to 750 m depth zone was six times higher as thefe was an increase to about 4960/6 (almost 500%), while in the 750 to 1,000 m depth zone was five times higher (Table 1) compared with the <500 m depth zone.
The occurring Simpson diversity index is likely consistence with the Richness index, where the hioher the value of the index the lower the diversity Tlie lower value of the Simpson index occurred in the 750 to 1.000 m depth zone, mean higher diversity occurred as indicated by the higher Richness index.The lowest value of Simpson index occurred in the 750 to 100 depth zone mean that The dominant families and species of the deep sea fish in the western sumatera  divergens diversity rn this waters was relatively low but the domination index was high, which mean that the fish community was dominated by a small number of species.The most abundance species in the <500 m depth zone was only three species, while in the 500 to 750 m depth zone was 12 soecies and in the deeper zone was 14 species.This information indicates that the deep sea fish community in the <500 m depth zone was dominated by only three species.As already mention earlier that the very abundance species in the <500 m depth zone was only one.This species was Ostracoberyx dorgenys of the family Ostracoberycidae with the percentage number reaching to about 68% (Table 2).
Comparing wilh the Enggano.area, this species orovides the second most abundance in the same deDth zone.while in the other deeoer zone of both Enggano and off Bengkulu area it was hardly ever found.lt is likely that the depth distribution of this species might be relatively limited up to the depth of less than 750 m.
In the 500 to 750 m and 750 to 1,000 m depth zone the percentage of the most abundance species was not as high as the percentage in the <500 m depth zone.Thls appearence indicated that the habitat of fish community in the deeper zone was slightly dlfferent compared with the shallower depth zone, The fivb most abundance soecies found in the 500 to 750 m depth zone were the spinyfins, Dhetmoides pauciradiatus (Diretmidae), the macrourid, Caelorinchus divergens, the alfonsinos, Beryx splendens, the ophidiid, Glyptophidiun sp., and the slimeheads, Hoplostefhus crassisplnus of the family Trachichthyidae.The respective percentage compositions of these species were almost 22%, each of the following three species of about 100i6 and the last species of almost 90/6.The four most abundance species in the 750 to 1,000 m depth zone were the ophidiid,l Lamprogrammus niger, the macrourid, Caelorinchus divergens, lhe mefanonid or pelagic cod, Melanonus zugmayeri and the other ophidiid, Glyptophidium sp., with a lower percentage of about 1'1, 10, almost 7, and 6% respectively (Table 2).
The Waters of the Western Part off Banda Aceh As already mentioned earlier that the Richness index always increased toward the deeper waters in each of the preceding areas, the similar appearences were also happened to the deep sea fish community in northest part of the waters of western Sumatera.Difference with the oattern of Shannon index in the Enggano area where the highest index occurred in the <500 m depth zone, and was decreasing toward the deeper zone, the highest index of H=1.8 in the Western part off Barida Aceh occurred in the 500 to 750 depth zone (Table 1), While the pattern of the Richness index in this area which increased toward the deeoer wat€rs.This is in line with the occurring reversed pattern of Simpson index that seems to be a normal phenomenon in ecology.
The most abundance species in each of, the three depth zone was one species, three species, and two species respectively.The most abundance species in the <500 m depth zone in this waters was occupied by the mycthopid, Dlaphus sp.1, where approximalely 92oA Of the total number of individual fish in this depth zone was contributed by this species alone.The two abundance species were placed by the phosichtyds, Polymytme elongatus, followed by the green eyes, Chlorophth al m us sp. 1 (Chloropthalmidae).
As in the Simeuleu area, where the spinyfins, Dietmoides paaciradiatus provlded the most abundance species in the 500 to 750 m depth zone. in the western Dart off Banda Aceh area this species respresented the most abundance species in the deeoer zone of 750 to 1000 m.Based on this appearence, it is likely that the spinyfins would 118 provide the major inhabitant of the deeper waters of the Eastern lndian Ocean.

Ranking of lmportance
This rank of importance was tabulated based on the abundance data in term of frequency of occurence of the species in each depth zone in the four areas and the percentage to the total number on fish caught.The six species that were frequent to occun in the catch were labuleted.The high rank of importance was Lased on the number of fish caught in each depth zone of the four areas.The myctophids, D,apl,us sp.1, represented the first rank of important in the <500 m depth zone in the area of both SE Enggano and Western off Banda Aceh.This species was almost absence in the area close to the imaginary equator line, except in the area around Simeuleu at the 500 to 750 m depth zone with almost close to the lowest rank of imoortant.The rat tails macrourid, Caelorinchus divergens, seems to be represented the main important fish within the deoth zone of more than 500 m.lt seems that this species provides a relatively cosmopolitant fish as the fish oflen presenled in the catch in each of the four areas.The neoscopelids, Nooscope/us macmlepidotus was likely forming a southern waters inhabitant, as no record of the catchas in the north€rn ar€a of S-5. while in the S-4 area the imoortance was the lowest rank of the 750 to 1,000 m deoth zone and in the 500 to 750 was close to the lowest rank.The spinyfins, Diretmoides pauciradiatus represented the deeper waters fish similar with the macrourid, Caelorinchus divergens.It is likely that this species prefers to inhabit in the waters of the northern part of the equator.The alepocephalid, Bajacalifornia ermorensis might prefer to inhabit in the deepest depth zone of 750 to 1,000 m. and in the shallower zone of the northern and southern waters Qlose to the equalor, while the slimeheads, Hoplostetus crasslsplnus might represent the northern inhabitant of the western Sumaiera waiers.

Catch Rates
Catch rate which is equivalent with the catch per unit of effort provides one of the indices pf abundance of fish resources.Fluctuation of catch rates can be assummed as the response of the fish communities against some influencing factors both internal and external.In the exploited fisheries, especially in the shallow coastal waters, fishing pressure provides the most influencing factor' However, what is the most influencing factor affecting the fluctuation of fish abundance in the deeo-sia is not known The availability of data and informations on the catch rates in a certain waters in both spatial and temporal provide one of the  In the waters of south eastern part of Enggano both the minimum of 5.5 kg per hr and the max]irum of 330.1 kg per hr were obtained from the deDth zone of 500 to 7S0 m.The average catch rate of ihe following three depth zone of <S0b m, 5OO to 7OO m. and 751 to 1,000 m were 91.0, 121.7, and 103.2 kg per hr, respectively (Table 4).Catch rate data ln the waters of western part off Bengkulu area were based on only two trawl hauls from the deoth zone 500 lo 750 m and two trawl hauls in the deoth zone 751 to 1,000 m.The rsspective minimum caich rates were 7,5 and 17.5 kg per hr, while the maximum w-ere 18.1 and 20.5 kg per hr, with the average of '12.8 and 19.0 kg per hr.
Fifty percent of the total number trawl hauls in the Western Sumatera of the eastern Indian Ocean during this cruise were carried out in the waters of North Western Simeuleu.The minimum catch rate of only 3.3 kg per hr occurred in the depth zone 7S1 to 1,000 m, while the maximum catch rate of 90.1 kg per hr was observed in the depth zone 500 to 750 m.During this cruise, the minimum catch rate in this area provided the lowest catch rate of the whole depth zone in the four areas of western Sumatera.The average catch rates from the thfee depth zone were 43.4,45.7, and 25.8 kg per hr repectively (Tabte 4).
In the western part off Banda Aceh, the lowest catch rates were found in the the depth zone <5OO m, while the highest catch rates occurred in the S0O to 750 m depth zone.The respective average catch rates in the western off Banda Aceh were g.4, 110.0, and 84.8 kg per hr (Tabet 4).Based on these catch rates data, through some further calculations procedures and asumptions, a number oJ stock parameters such as stock density (Shindo,  1973), standing stock size (Saeger et a/., 1976) as well as potential yietd (Gulland,'1983) of the deeD sea fish resources in the western part of Sumatera may be estimated.

Stock Density and Standing Stock Size
In the waters of the South Eastern part of Enggano the estimated density of fish varied from the mintmum of 0.6 to o.g tonnes km'2 to the maximum of 3.3 to 9.9 tonneq km'2, with the average of 2.3 to 3.8 tonnes km-.. Based on these figures, the estimated standing stock sizb (biomass) in this waters was aboui 3,176 tonnes.derived from the following depth zone of <500 m, 500 to 750 m, and 751 to 1,000 m of about 700: 1,179; and 1297 tonnes, respectivety (Tabte S).
Due to the limited number of trawl hauls in the western part otf Bengkulu waters which was onlv covered two depth zone of S00 to 750 m and 751 t6 1,000 m, the estimated mean density of fish was between 0.4 to 0.6 tonnes, with the total biomass of about 62.5 tonnes, which was originated from the two depth zone of about 7.S and 55 tonnes respectively, Based on 25 trawl fishing stations canied out in the north western part off Simeuleu, it was found that a relatively wider range of fish  104.0 densities in each depth zone have been obsewed l.he minimum density in thi^s waters was between o 08 to 0.24 tonnes km-' ^with the maximum cctween 2.4 to 2.7 tonnes km-' The estimated total biomass in this area was about 4,827 tonnes This.was contributed from the previous three zones ol 455, 2,525, and '1847 tonnes respectively Simila.r with the area off Simeuleu, in the western pan ofi Banda Aceh, the northest fishing area during this cruise.a relatively wider range of fish density has also been detect'ed.The minimum density.within the three depth zones was 0 2 tonnes k]n'',whtle the maxtmum density was 17'714 tonnes kml ne averaoe density beginning from the shallower to the deeDe-r depth iones were 0 26' 5 7' and 2 5 tonnes km-2 respectively.The total biomass in this area was ab6ut 4,491 tonnes This figure w-as cummutateO from the three depth zone of 90; 2.905: and 1,497 tonnes respectively Other rnformation regarding the density and the standing stock size of the deep sea fish in the western pan 120 of Sumatera of the Indian Ocean is presented in Table 5.
The Russian investigation in the western troplcal Pacific Ocean and the seas on the Indo-Australlan   ArchiDelaqo oroduced a wealth of mesopelaglc nin"J ffie biomass of these fishes in the entire water column to 1,000 metres had been measureo' in the Kuroshio zone the density of fish were 5 0 to 6.0 mq m'3: equatorial waters, 3.1 to 8 1 lng m-": centrai water 'mass 0.6 to 2.0 mg m' Their investigation barely extended to the bathypelagic fish fzuna.In the waters column from 1'000 to 4,000 m, the comparable biomass is likely to fall to a tenth of the mesopelagic value.Eventhough these results could not directly be compared with the present finding due to the dltferences in the method of measurements, the following estimation of demersal fish from the western of the Norih Atlantic waters has been reported by Heidrich & Rowe in 1977 (Marshall, 1979).Based on 116 trawl Table 5.
Estimated mean slock density (tonnes km'') and standing stock size (tonnes)  hauls, the fish which were identilied and wejghed, estimates of absolute abundance were obtained from a series of exposures in a pair of cameras.
The density of fish, expressed in weight per square metre of bottom over areas bet\iyeen 497 to 2,790 m, varied from 0.63 to 5.78 g m'' (Marsha , 1979).This means that the estimated densig of the deep sea fish in that area was between 6.3 to S7.b tonnes km-'.Comparing with the density of deep sea fish in other part of the world ocean, particularly in the North Atlantic waters, it can be stated that tha density of tish in the western part of Sumatera of the eastern Indian Ocean during the survey period was relatively low.
From experimental fishing using bottom long line in the waters of Semangka Bay, Lampung, three species of deepsea fish that never been seen before in any other part of the Sunda shelf were Gepyroberix sp., one spgcies from the family of Triglidae and one species from familv of Macrouridae (Hufiadi el a/., 2OO3).The cotour of the first two species was reddish and bright red.lt was informed that Gepyrcberix sp. has been normally consumed in Japan.The species ol peristadion sp. of lhe family of Triglidae provides a very poisonous fish (Figure 2 and 3).In general, it is tikety that untit recently lhe exploratory trawling of the deepsea demersal fish are still considered as one of the scientifics purposes rather than searching fish resources for direct human consumption.Some implications from the environmental asDects such as a very huge pressure and scarcity of food supply, it is likely that the deep sea fishes would have a verv hi{th sustainment for survive.The most interestini biological aspect is that the chemical substances ol their flesh, such as protein, lipid and other . biochemical substances which will need further pharmacological laboratory analysis and research.lt was reported by the crews of the research vessel during this cruise that they were hardly ever to sleep for the whole night after they consumed the ,boiled, afepochepalid lish (Bajacalifomia ermorensis), This aspect 6eems to be important for the future frontier research in the framework of the exploitation of fish resources biodiversity.

Catch Composition
Catch composition in the SE off Enggano The availability of catch composition data provide one of the basic information needed for the.
development of resources exploitation.In each depth stratum there were at least three species from three different tamilies dominated the caich.ln the depth stratum of <5OO m, these species were L{esiob?trs sp. (Ptesiobatidid ae), Diaphus sp.1 (Myctophidae), and Ostracoberyx dorgeitys (Ostracoberycidae).These three species amountird to about 600/6 of the total catch in the stratum, while the rests consisted of more than 10 species (Table 6).Gepyroberix sp.deep sea fish species caught by bottom long line in the wateis of Semangka Bay, Lampung.Peristedion sp. (Triglidae), a very poisonous deep sea fish caught by bottom long line in the waters of Semangka Bay, Lampung.
fhe Diaphus sp.1 is one of the species of Myctophidae.The myctophid which is also known as the lantern fishes provjdes the most diverse mesopelagic fish in both number of species and individuals (Marshall, 1979).lt was likely that an acoustically detected large schooling traces found in the Bay of Tomini at the depth of more than 200 m during the east monsoon in 2003 provide one the examples (Anonymous, 2005).
(Plesiobatididae) that amounted to about 650/0 of 122 the total catch !n this stratum.lt can be stated that the species of P/esrbbatls sp., provides the most wider depth range distribution as the fish species always occurred in each depth stratum, Other species that were likely to be found substantially in the depth strata were the family of Macrouridae and Alepocephalidae.
Catch composition in the western part off Bengkulu ln the western part off Bengkulu area the trawl samples covered only tvvo depth strata, the 500 to 750 m and the 750 to 1,000 m as the trawlable ground was only found within the depth range of 500 to 1,000 m.
The most dominated fish families found in the catch were Ophidiidae, Marouridae, and   Chimaeridae.In the depth stratum of 500 to 750 m, the Ophidiidae sp.1 and Lamprogrammus niger, ?,Ob oth of them made up to 27%, followed by- Ti"toin"ir-i iilrrrs"ri of the familv ot M;;;;;;d";.The lasl species of Macrouridae has lil"'iJi"]""i"0 ine catch within the stratum of 750 t. i OOO rn in"t reached to about 340/o while the .-""oni-ootin"t"dspecies was the rat tails Cin"ir" ip. (Chimai:ridae) amounted to about ii"z" ii"or" ?l 'ihe rest of ihe catch consisted of more than 15 species in each stratum' Catch composition In the Nw Simeuleu More than 93% of the total catch in stratum <500 m contibuted by only three species These werc Ostracoberyx dorgenys (Ostracoberycidae) Bervx sptendens (Berycidae).and Xenotepidichtnys aat6terstri (Grammicolepididae) with the percentage oi "auout ie, 33, and 8olo respectively The most Ootinlnt species found within the depth stratum of 500 to 750 m were Hoplostethus crass'sp'nus firachichthvidae), Beryx splendens (Berycidae)   biretnoiaei pauciradiatus (Diretmidae),.and Caelorinchus divergens (Macrouridae) wlth tne 124 resoective percentage of about 29, 19, 17' and  1o%.With the relaiively lower percentage catch composition.the species ot Hexatrygon longirostra (Hexatrygonidae), Lamprogrammus ntger ioonioiio2e), and Caelorinchus divergens itrrticrouriO je) were substantially found in the catch iraote a).The species ol Beryx splendens was iikelv to liave wide depth distribution as this spec'es *aJtouna in both debth range of <500 m and 500 to 750 m, The similar case were also applied to the soecies of Hoplostethus crassisp'nus (irachichthyidae), Caelorinchus divergens iMacrouridie), Diretmoides pauciradiatus idiretmidae).'Centrophorus sp (centrophoridae) ina aaiacltitornia erimoensis (Alepocephalidae)   ihat occurred in the deeper water of both the strata 6ocj io zso m and 750 io 1,000 m The species of uuii,Vg* longirostra' the--second domihant "oeci"i"*itnin the sratum of 750 to 1,000 m in the waiers around Enggano lsland provided the.most dominated the catch within the same stratum ln tne waters around Simeuleu lsland' The catch composjtion in the western part off Banda Aceh seems to be the lesser diverse in catch composition compared with the previous areas of Western part of Sumatera.Similar with the composition in the previous areas where the catches in the deoth stratum <500 m were dominated by the species of P/eslobafis sp.
(Plesiobatididae) and Diaphus sp.1 (Myctophidae), in the North western part of Simeuleu lsland the species of Dlaphus sp.1 and P/es,bbatrs sp.provide the most dominant species found in the catches, with the respective percentage of each species of about22o/o.
The third dominant species in this stratum was Zenopsis conchifer (Zeidae) of about 19%, followed by Polymixia japonicus (Polymixiidae) which percentage to about 8%.The other species in this stratum consisted of about more than 6 species, where each species contributed to only <60/6   (Table 9).
In the depth stratum 500 to 750 m, more than two-third of the catches were contributed by the species of Diretmoides pauclradiatus and   Ostracoberyx dorgenys that reached to about 70% of the total catch in the stratum.The rests of the catches consisted of more than 7 species, each of the species contributed to only <50/0.The first soecies of Diretmidae that was dominated in this stratum, has been the second dominant species in the depth stratum of 750 to 1,000 m, that contributed to about 25% of the total catch in this stratum.The first dominated species was contributed by deep sea shark, Alopias superciliosus of the family Alopiidae.The third dominant species amounted to about 140lo of the total catch in this stratum was Hoplosfefhus rubelloDterus.

CONCLUSION
From the analysis of only fish resources it was found that the highest mean catch rate of about 121.7 kgs per hr was occurred in the depth range of 500 to 750 m, in the south western part of Enggano area, while the lowest mean catch rate of 3,3 kgs per hr was occurred in the depth zone 751 to 1,000 m in the waters of North Western Simeuleq.The lowest density of about 0.08 tonnes km-' was observed in the depth zone of 751 to 1,000 m in the north western part of Simeuleu, w[ile the highest density of 17,714 (17.7) tonnes km-' was occurred in the depth zone 500 to 750 m in the western part off Banda Aceh.By multiplying the estimated sea surface areas and the mean density in each depth zone and in the survey area, the total deep-sea fish' standing stock size can be calculated.
As reflected by the Richness index of lvlargaleff, within the depth range of 250'to 1000 m in the waters of Western Sumatera, the number of species seems to increase toward the deeper waters.The six species of important in term oi numbers of individual fish available were the lantern fish myctophids, Diaphus sp,1, the rat tails macrourid, Caelorinchus divergens, the neoscopelids, Neoscope/us macrolepidotus, lne spinyflns, Diretmoides pauciradiatus, the alepocephalid, Bajacalifornia erlmorensls, and the trachichthyds Haplosletus crasslsprinus.
In relation with the environmental aspects such as the very huge pressure and scarcity of food supply, it is likely that the deep sea fishes would have a very high sustainment for survive.ln this asDect.the chemical substances of their flesh, such as proteins, lipids, and other biochemical substances will need further pharmacological laboratory analysis and research.These aspects seem to be important for the future frontier research.lt is advised that exploitation of deep sea fish resources nowadays shoud be directed to get the benefit from the fish resources biodiversity and bio active substance rather than searching fish for direct human consumption.

Table 1 ,
DiversityBiological diversity or biodiversity is the diversity of living things.The greater the variety of animal, the greater the biodiversity.The number of species and the number of individuals of each species are used to estimate biodiversity index.Biodiversity can vary with location, habitat, season, and other factors as well as with the means of esilmation.

Table 3 .
Ranking of importance of the six abundance species in the waters of Western Sumatera,

Table 4 .
Catch rd{es of deep sea flsh resources in each depth zone in the waters of Western in the waters of Western Sumatera

Table 6 .
Percentage catch composition of deepsea fish in the south eastern part of Enggano

Table 7 .
Percentage catch composilion of deep sea fish in the westhern part otf Bengkulu

Table 8 .
Percentage catch composition of deep sea fish in the north western part of Simeuleu

Table 9 .
Percentage catch composition of deep sea fish in the westhern part off Banda Aceh