The Mid-1970s Demersal Resources in the Indonesian Side of the Malacca Strait a

Similar documents
SCIENTIFIC COMMITTEE THIRTEENTH REGULAR SESSION. Rarotonga, Cook Islands 9-17 August, 2017

Stock Assessment of Oceanic Tuna in South China Sea off Sarawak and Sabah, Malaysia.

JIMAR ANNUAL REPORT FOR FY 2001 (Project ) Project Title: Analyzing the Technical and Economic Structure of Hawaii s Pelagic Fishery

The fish community of Rat Cove, Otsego Lake, sumn,er 1997

Evaluation of a Center Pivot Variable Rate Irrigation System

First digit of chosen number Frequency (f i ) Total 100

ALASKA DEPARTMENT OF FISH AND GAME DIVISION OF COMMERCIAL FISHERIES NEWS RELEASE

DISTRIBUTION AND ABUNDANCE OF TEN SELECTED FISH SPECIES (DEMERSAL FISH) OFF THE.EAST COAST OF PENINSULAR MALAYSIA

Research Institute for Marine Fisheries, Jakarta Indonesia ABSTRACT

Archimer

Supporting Online Material for

Engineering Analysis of Implementing Pedestrian Scramble Crossing at Traffic Junctions in Singapore

Muscle drain versus brain gain in association football: technology transfer through

This document is downloaded from DR-NTU, Nanyang Technological University Library, Singapore.

Canadian Journal of Fisheries and Aquatic Sciences. Seasonal and Spatial Patterns of Growth of Rainbow Trout in the Colorado River in Grand Canyon, AZ

Reduced drift, high accuracy stable carbon isotope ratio measurements using a reference gas with the Picarro 13 CO 2 G2101-i gas analyzer

UMPQUA RIVER FALL CHINOOK SALMON ESCAPEMENT INDICATOR STOCK PROJECT

A Study on Parametric Wave Estimation Based on Measured Ship Motions

The impact of foreign players on international football performance

THIS PAPER NOT TO BE CITED WITHOUT PRIOR REFERENCE TO THE AUTHOR. stock assessments of Haddock, Blue Whiting and Greater Silver Smelt on Rockall Bank

VOLUME TRENDS NOVEMBER 1988 TRAVEL ON ALL ROADS AND STREETS IS FOR NOVEMBER 1988 AS COMPARED UP BY 3.4 PERCENT TO NOVEMBER 1987.

'!' CORDOVA BRANDON GREEN

Risk analysis of natural gas pipeline

Major League Duopolists: When Baseball Clubs Play in Two-Team Cities. Phillip Miller. Department of Economics. Minnesota State University, Mankato

Steelhead Broodstock Acclimation and Monitoring (BAM) Program in the Okanogan Basin, Annual Report 2012

GAS-LIQUID INTERFACIAL AREA IN OXYGEN ABSORPTION INTO OIL-IN-WATER EMULSIONS

Terminating Head

STUDY ON THE BIG PURSE SEINERS FISHERY

A Prediction of Reliability of Suction Valve in Reciprocating Compressor

M.H.Ahn, K.J.Lee Korea Advance Institute of Science and Technology 335 Gwahak-ro, Yuseong-gu, Daejeon , Republic of Korea

English Premier League (EPL) Soccer Matches Prediction using An Adaptive Neuro-Fuzzy Inference System (ANFIS) for

Decomposition guide Technical report on decomposition

Gripping force, O.D. gripping. MPZ 20 / 4 bar MPZ 20 / 6 bar. MPZ 20-AS / 4 bar MPZ 20-AS / 6 bar. Gripping force, I.D. gripping

Product Information. Universal gripper PZN-plus

Crash Frequency and Severity Modeling Using Clustered Data from Washington State

Applications on openpdc platform at Washington State University

Comparisons of Means for Estimating Sea States from an Advancing Large Container Ship

PERFORMANCE AND COMPENSATION ON THE EUROPEAN PGA TOUR: A STATISTICAL ANALYSIS

Response based sea state estimation for onboard DSS Safe and Efficient Marine Operations

Pedestrian Facilities Planning on Tianjin New Area program

Catch per unit effort of coastal prawn trammel net fishery in Izmir Bay, Aegean Sea

School of Civil Engineering, Shandong University, Jinan , China

A comparison study on the deck house shape of high speed planing crafts for air resistance reduction

High Speed 128-bit BCD Adder Architecture Using CLA

Investigation on Rudder Hydrodynamics for 470 Class Yacht

I of Pamwak site, I Manus Island, PNG. Fauna1 composition. Manus Island 6. I Figure 1 Map showing Manus Island, Papua New Guinea.

Study on coastal bridge under the action of extreme wave

Aalborg Universitet. Published in: 9th ewtec Publication date: Document Version Publisher's PDF, also known as Version of record

Dynamic Analysis of the Discharge Valve of the Rotary Compressor

Availability assessment of a raw gas re-injection plant for the production of oil and gas. Carlo Michelassi, Giacomo Monaci

Product Information. Gripper for small components MPG-plus

COMPENSATING FOR WAVE NONRESPONSE IN THE 1979 ISDP RESEARCH PANEL

Evaluating the Effectiveness of Price and Yield Risk Management Products in Reducing. Revenue Risk for Southeastern Crop Producers * Todd D.

SMALL BOAT TUNA LONGLINE FISHERY NORTH-WEST COAST OF SRI LANKA R. Maldeniya

Investigation on Hull Hydrodynamics with Different Draughts for 470 Class Yacht

BETHANY TAX INCREMENT FINANCING DISTRICT NO. 1 NOTICE OF TWO PUBLIC HEARINGS

Driver s Decision Model at an Onset of Amber Period at Signalised Intersections

Journal of Environmental Management

Bit shape geometric considerations when sampling by dry drilling for obtaining chloride profiles in concrete

Modeling the Performance of a Baseball Player's Offensive Production

Coastal Engineering Technical Note

Pneumatic level indicator Unitel

Mechanical Engineering Journal

Internal Wave Maker for Navier-Stokes Equations in a Three-Dimensional Numerical Model

Sectoral Business Cycle Synchronization in the European Union *

ASSEMBLY INSTRUCTIONS. TECHART roof spoiler

Evolutionary Sets of Safe Ship Trajectories: Evaluation of Individuals

Planning of production and utility systems under unit performance degradation and alternative resource-constrained cleaning policies

2017 GIRLS DISTRICT-SPECIFIC PLAYER DEVELOPMENT GUIDE

SCIENTIFIC COMMITTEE SIXTH REGULAR SESSION August Nuku alofa, Tonga

Numerical Simulation on a Gas Distributor Used In Slurry Column Reactor Yating CAI

AMBLYGASTER SIRM (WALBAUM) OFF THE NEGOMBO COAST

Development of Accident Modification Factors for Rural Frontage Road Segments in Texas

Degassing of deep groundwater in fractured rock

For models: 660 EF/EFO

Underground Natural Gas Storage

2017 GIRLS CENTRAL DISTRICT PLAYER DEVELOPMENT GUIDE

DRAFT FOR PUBLIC CONSULTATION INTERCONNECTION AGREEMENT v.2.0 FOR IP KULATA/SIDIROKASTRO DEFINITIONS, BUSINESS RULES, EXCEPTIONAL EVENT

Neritic Tuna Catch, Species composition and monthly average landings in Sri Lankan Tuna Gillnet Fishery operate within EEZ

Trawl Fishery Management Myanmar

Equilibrium or Simple Rule at Wimbledon? An Empirical Study

An Enforcement-Coalition Model: Fishermen and Authorities forming Coalitions. Lone Grønbæk Kronbak Marko Lindroos

International Journal of Engineering and Technology, Vol. 8, No. 5, October Model Systems. Yang Jianjun and Li Wenjin

Incidence and Risk Factors for Concussion in High School Athletes, North Carolina,

EVALUATION MISSION ON OMT PROGRAMMES IN THE URBAN AND SEMI-URBAN WATER SUPPLY SECTOR SUPPORTED BY THE NETHERLANDS GOVERNMENT. March - April 1986

CS 2750 Machine Learning. Lecture 4. Density estimation. CS 2750 Machine Learning. Announcements

Heart rates during competitive orienteering

2018 GIRLS DISTRICT-SPECIFIC PLAYER DEVELOPMENT GUIDE

Aalborg Universitet. Published in: 9th ewtec Publication date: Document Version Accepted author manuscript, peer reviewed version

Summary and Cruise Statistics 8

and D.paulyl.2.3) "'Abstract:

OWNERSHIP STRUCTURE IN U.S. CORPORATIONS. Mohammad Rahnamaei. A Thesis. in the. John Molson School of Business

R.P. Prabath K. JAYASINGHE National Aquatic Resources Research and Development Agency (NARA) Colombo 15 SRI LANKA

RBS 6 NATIONS 2013 DECISION OF THE DISCIPLINARY COMMITTEE. Held at Sofitel Hotel, Heathrow, England. 19 March 2013

Evaluating Rent Dissipation in the Spanish Football Industry *

Monitoring Physical Activity from Active Transport. Dr Russell G. Thompson Institute of Transport Studies Monash University

Product Information. Radial gripper PRG 52

Keywords: Ordered regression model; Risk perception; Collision risk; Port navigation safety; Automatic Radar Plotting Aid; Harbor pilot.

Safety Impact of Gateway Monuments

AGA / API Auditing Requirements of Fiscal Gas Metering Systems and FCRI Experiences

Transcription:

The Md-197s Demersal Resources n the ndonesan Sde of the Malacca Strat a P. MARTOSUBROTO Marne Resources Servce Fshery Resources Dvson FAO of the Unted Natons Vale delle Terme d Caracalla 1 Rome, taly T. SUJASTAN Deceased, formerly wth the Marne Fsheres Research nsttute Jakarta, ndonesa D. PAULyb nternatonal Center for Lvng Aquatc Resources Management MCPO Box 2631,718 Makat Cty Phlppnes MARTOSUBROTO, P., 1. SUJASTAN and D. PAULY. 1996. The md-197s demersal resources n the ndonesan sde of the Malacca Strat [Sumberdaya kan demersal d Selat Malaka bagan ndonesa pada pertengahan tahun 197anj. p. 4-46. n D. Pauly and P. Martosubroto (eds.) Baselne studes of bodversty: the fsh resources of Western ndonesa. CLARM Stud. Rev. 23. 312 p. Abstract The results of demersal surveys n the ndonesan half of the Malacca Strat area by the research trawlers Mutara 1, 2 and 4 conducted n 1973 and 1975 gave an estmate of the standng stock of 73. t. Comparng wth other areas. and consderng the state of explotaton of the resources n the md-197s. the unexploted stock was estmated to have been around 15, or 2.66 t km 2. Catch rates and catch composton by depth are gven. The commercal trawl fshery n the ndonesan Malacca Strat prevalng n the 197s was analyzed on the bass of the statfstcs n provncal reports and of feld ntervews. Sustanable elds for two dstnct fsheres, Aceh and North Sumatra-Rau, were estmated to be 8, t year 1 and 77, t year ', respectvely. The stocks were, at the tme, begnnng to be overfshed. Abstrak Hasl surve sumberdaya demersal d Selat Malaka dengan kapal trawl Mutara 1, 2, dan 4 yang dlaksanakan pada tahun 1974 hngga 1975 memberkan estmas kelmpahan kan sebesar 73. t. Dbandngkan dengan daerah lan, dan mengngat tngkat eksplotas pada perlengahan tahun 197-an. stok kan pada tngkat awal dperkrakan 15. t atau 2,66 t. per km2, Hasl tangkapan rata-rata dan komposs hasl tangkapan dsajkan dalam tulsan n. Keadaan perkanan trawl d Selat Maaka d sektar tahun 197-an danalss berdasarkan data statstk propns dan kabupaten serla wawancara d lapangan. Potens lestar perkanan d sektar dua daerah, Aceh dan Sumatra Utara-Rau, dperkrakan masng-masng sebesar 8. t. dan 77. t. per tahun. Saat tu sudah terlhat adanya gejaa lebh tangkap. ntroducton The Malacca Strat (Fg. 1), beng one of the world's man shppng routes, s rather well documented n the geologcal and martme lterature (see Emery 1971; Valenca 1979 and Box 1). alclarm Contrbuton No. 147. banother contact address: Fsheres Centre, the Unversty of Brtsh Columba, 224 Man Mall, Vancouver, B.C. Canada V6T 124; e-mal: pauly@fsheres.com The fsheres of the Malacca Strat are also well documented (SCSP 1976a, 1976b, 1978), although the small pelagcs (especally mackerels and scads) have receved far more attenton than the demersal fshes (c.f. Sujastan 1975, 1976; Anon. 1976a, 1976c, 1976d, 1987 for pelagcs; Mansor Mat sa 1987; Svasubramanam 1987; Tampubolon and Sedana Merta 1987; Tampubolon 1988; Sorano et al. 1988 vs Menasveta 197; Anon. 1976b, 1976e; and Mahyam Bnt Mohd. sa 1988. 4

! 6 5... 4 Z -Q) 3...." "'..,. U..., :J ~.-. 2...J tl R'f""" area Provncal ----boundares o L---J::-- ---"---_-=-~~""_.L L L _"_'.L_.._._=~ l 96 98 1 12 14 Longtude ( E ) Name of Gross h.p. Length Gear Length of boat tonnage (m) head rope (m) Mutara 1 124 365 23.6 double rga 23.4 (each) Mutara 2 53.4 165 18.9 double rga 19. (each) Mutara 4 11 316 24. Thaland trawl 36. ashrmp trawl. Fg. 1. The ndonesan part of the Malacca Strat (shaded), coverng an area of about 55, km 2. [Gambar 1. Selat Malaka bagan ndonesa (darsr), melput luas sektar 55. km2.] Table 1. Specfcatons of the research vessels and gear used for trawl surveys on the "ndonesan sde of the Malacca Strat, 1973 and 1975. [Tabel 1. Spesfkas kapal dan alat yang dgunakan dalam surve d Selat Malaka, 1973 1975.] Menasveta (197) revewed the bottom trawl surveys conducted n the Malacca Strat, notablythe results of trawlng by the RV Tongko (Brtwstle 1928), the RN Manhne (Ommanney 1961), and the Seayang (Pathansal et al. 1966). Later surveys were conducted wth K.M. Jenahak (Latff 1973). Most of these surveys were conducted n what are now Malaysan terrtoral waters: less nformaton s avalable on the ndonesan sde ofthe Malacca Strat. A frst report on catcheffort and catch composton data obtaned by two ndonesan fsheres research vessels, RNMutara 1and RNMutara 2, on the ndonesan stocks of the Malacca Strat, was publshed n ndonesan by Martosubroto (1973). The staton grd of RV Mutara 1 and 2 was not truly random,.e., fshng was drected. Nevertheless, ther catch rates are ncorporated n the present paper, tself an updated verson of Sujastan et al. (1976). 16 Anon. (1976e) reported on the composton of 12 trawl hauls taken on the ndonesan sde of the Malacca Strat n January 1975 by RN Lemuru (see Venema, ths vol., for detals on RN Lemuru). Further data for the present contrbuton orgnate from the survey conducted by RV Mutara 4 n the Malacca Strat, n early 1975 (see Pauly et a., ths vol. for the context of ths Mesh sze of codend (mm) survey and the samplng methods used, and Torres et al. (ths vol.) for a 3 descrpton of a database wth detals on 3 4 these and RN LemurUs statons). The fourth source of materal used here s the landng and effort statstcs of the Provncal Fsheres Offces of the Provnces of Aceh, North Sumatra and Rau.Addtonally, ntervews wth skppers of commercal trawlers operatng n the area were conducted towards the end of 1975 by the second author. Fg. 1 shows the area covered here. Materals and Methods Box. 1. Sedments and benthos of the Malacca Strat. [Boks 1. Sedmen dan benthos d Selat Malaka.} Emery (1971), based on Keller and Rchards (1967) and other sources, descrbes the sedments of the Malacca Strat as consstng manly of "sand (detrtal or calcareous grans.5 to 2 mm n dameter and havng a hard smooth to rppled surface), sand-and-mud (fne sand and slt havng a frm to soft smooth surface), mud (slt and clay havng a soft surface), gravel (pebbles and cobbles of broken rock, locally contanng many calcareous shells), rock (outcrops of bedrock and boulders near outcrops), and coral (large areas or reefs of massve calcareous algae and coral)". The benthos of the Malacca Strat appears to be sparse, at least offshore, far from the mouth of rvers. Neman (1973) reports of three benthos statons (see Fg. 2 for ther locatons) from west to east whch yelded denstes of 4.4 g-2 (shallow water) 1. g-2 n (deep water) and 2.4 g-2 (shallow water). He also mentons that far from the mouths of rvers, otter trawls often catch sponges and soft corals. and sea urchns. Trawl Survey Data The specfcatons of RN Mutara 1, 2, and 4 and the gears used for ther surveys are summarzed n Table 1. The survey by Mutara 1and 2 n the Malacca Strat lasted from July to September 1973. A total of 148 hauls were made, 61 by Mutara 1 and 87 by Mutara 2. The survey of Mutara 4 lasted from 27 January to 14 March 1975 and yelded 4 vald hauls (Fg. 2, Table 2). The surface area of each depth horzon s also gven n Table 2. These data were used to estmate standng stock sze usng the swept area method as descrbed n Pauly et al. (ths vol.) and usng the same assumptons as to the catchablty of the gear. Partcularly, the same escapement factor was assumed to apply to Mutara 1, 2 and 4. 41

5 Q) "C ~ 4 "'C~.-r...,.. '., :::",,. ",.,,;,,,~~,.. :.'LL-.- ----- ---'- '.~ '.. North East Sum atra......... Fg. 2. Locaton n the Malacca Strat of trawl hauls performed by FRV Mutara 1 and 2 n 1973, by FRV Mutara 4 n JanuaryFebruary 1975. by FRV Lemuru n January 1975. [Also ncluded are three benthos grab hauls made by RN Akademk Knpovch n 1966J. [Gambar 2. Lokas stasun trawl d SelalMalaka oleh kapal peneltan Mutara 1 dan 2 pada tahun 1973, kapal Mutara 4 pada JanuarFebruar 1975, kapal Lemuru pada Januar 1975. (Termasuk juga tga stasun pengamblan contoh benthos oleh kapal peneltan Akademk Knpovch pada tahun 1966).] -o...j 3 D square corresponds to approx. 4 hauls each by MUfara and MUfara 2 haul by Mutara 4 (n =4) haul by Lemuru (n = 12).. benthos haul (n = 3) --- Border of survey area ', ' -.. '. 96 97 98 99 Lon tude (OE) 1 Box 2. Standardzaton of trawlng effort. [Boks 2. Pembakuan upaya penangkapan trawl.] Standardzng the effort of trawlers can be done by relatng ther catch per effort to ther tonnage (as ndex of "power", snce large boats requre large engnes). The table below documents how the large, medum, and small trawlers were standardzed such as to obtan a measure of fshng effort (days fshed per year) comparable between provnces. Vessel characterstc Large Medum Small trawlers trawlers trawlers Boat class (GT) > 2 1-2 1 Mean gross tonnage 3 2 1 Average catch (kg day 1) 276 218 16" Power factor 1.27 1.74 Nomnal effort b (by provnce) Aceh 264 North Sumatra 288 264 24 Rau 28 Effectve effort C (by provnce) Aceh 335 (264) North Sumatra 336 264 178 Rau 356 (28) "As obtaned by lnear extrapolaton, down to 1 GT, of rato of catch:tonnage. btrawler days at sea. CDays at sea of a standard trawler. The FRV Lemuru data were not used for standng stock estmates owng to the small number of hauls (Fg. 2). Commercal Catch Data The fsheres catch data orgnate from the Provncal Fsheres Offces of the Provnces of Aceh, North Sumatra, and Rau and go back as far as reports were avalable (to 1969). The second author also conducted feld ntervews n the three abovementoned provnces from November to December 1975. n Aceh Provnce, four large landng places were vsted wth about three ntervews of trawler skppers at each landng ste. n North Sumatra Provnce, landng stes were vsted wth the same rate of ntervews. n Rau Provnce, only three landng places were vsted wth four ntervews each. Catch per unt of effort data and effort data (actual fshng days) for large and medum trawlers n the three provnces were derved from these ntervews. The provncal reports dd not assgn the lanued fsh and shellfsh to the gear that caught them. t was thus necessary to dentfy, from the catch data, those groups of fsh and shellfsh whch could be assumed to orgnate from trawl catches. Ths was done on the bass of Table 3 by assumng that fsh contrbutng more than 2% to the survey catches of Mutara 1, 2 or 4 were manly demersal. Those fshes were then selected from the reports' lsts and ther catches combned to represent the trawler's catches. When presentng the data, care was taken to avod double accountng, as occurred between the Provnce of North Sumatra, where many trawlers from Rau landed ther catch, and the latter provnce.as no fgure was avalable on the amount of ths double accountng, a fgure of 5% was assumed; accordngly, the catches reported from Rau Provnce were cut by half. Annual catch was plotted aganst the correspondng levels of effort for the Malacca Strat as a whole and foraceh Provnce and North Sumatra-Rau Provnces. 42

Table 3. Demersal fsh catch composton (% of weght) n the Malacca Strat by research vessel and depth range. [Tabe3. Komposs hasl tangkapan sumber daya demersal (berat daam %) d Seat Maaka berdasarkan kapa dan kedaaman.] Depth range (m) -9 1-19 2-29! 3-39 4-49 5-59 6-69 7+ Group or specesmutara 1 2 1 2 1 2 4 1 4 4 4 4 4 Sharks and rays.2.4.7 1.7 3.1.3 3.3 1.1.5 15.7 1.4 1..9 Engrauldae.2.1 1.4 2.6 1.4 1.4 -.8 1.7 1.2.1 8. - Clupedae 1.7 4.9 1.1 4.1.8 2.5 41.9.1 3.9 4.1 3.9 12.8.7 Chroeentrus dorab.6 1. 4.1 1.6 2.9 1.6 1.8.1.4.1.1.8 Anadontostoma chacunda - -.3.1.1 -.1 - - - - - Synodontdae.4 1.5 2.3 5.3 1.8 3.9 9.8 2..5 2.6 2.4 2.8 Ardae -.7.9.4 2.6.5 2.9.7 4.3 1.8 7..2 Sphyraena spp..3.3.6.5 1.2.6 -.7 6.9 1.5.2 - Serrandae -.1.5.7 1.5.1-1.9.4.1 2.1 -.6 Terapontdae.9 6.4 2.2 3.8 1.4 1.9.9 9..9.3 1.1 2.6.3 Pracanthdae - -.1.1 1.4.1.9.5 1.3 2..3.3 Rachyeentron canadus - -.1.5 - - - - -.4.1 - - Carangdae a 1.9 8.3 4.3 6.6 3.5 4.6 4.4 3.2 16.5 11.5 6.2 7.3 15.5 Formo nger -.2.3.3.4.1 -.1.5.2.1.1.9 Lutjandae (nc!. Caeso spp.) 1..5.9.8-2.4 1.3 5.4 14.4 8.4.9 Nempterdae b - - 2.1 2.8 1.8 3.5-2.8 7.5 5.6 6.4 6.8 3.5 Leognathdae.5 7.5 26.8 5.1 2.7 12.6 17.7 8.8 2.9 8.4 7.8.3.3 Gerredae.9 1.6 1.3.6.8.6-1.1-2.4 9.5.6 17.6 Pomadasydae C 1.9 6.9 5.8 1.7 5.9 1.6-4.6 3.9 7.5 4.3 19.4 4.9 Scaendae 15.7 11.2 4.4 1. 3.8 8.8.9 4.5-4.2.9 7.7 - Mulldae -.9 3.3 2.4 4.5 5.1 8.9 6.4 1.7 1. 1.3 22.9 Sganus spp. 3.4-3.9-1.9 - - 1. 2.1 1.1.1 -.1 Trchurdae 1.4.9 4. 5.4 2.5 3. 8.8 6.1 2.2 3.3 8.8 6.5 1.4 Rastrellger spp. 1.4.2.6.1 - -.2 1.3 Seomberomorus spp..3.8.9.4 1..7-1.3 - - - - Pampus argenteus - 3.1.5.9.2.8 9.9.1 2..2 -.2 Platycephaldae.5 2.3.5.4 1.5 - - 2.7.1.1.1 - - Psettodes erume -.3 2.1.9.8.8-1.3.3.1.9.6.3 Other flatfshes 13.2 8.9 1.7 4.1 2.5 1.9.4 1.9 -.1.1.2 - Other fshes 45.4 21.9 19.7 26.3 17.3 28.9 4.4 18.4 24.5 7.4 6.5 4.1 3.7 Lolgodae - 1.3-1.8 1.3 2.5.4.3 1.1 3.6 5.3 2.1 3.7 Sepoldae - 1.3.9 2.2 1.3.9 -.1.8.5.8.3.2 Penaedae 1. 1..2 5..4 7.8 4..2.1.1 -.6 Thenus orentals - -.3.1.7 - - 1.1.1.1.2.1 - Other crustaceans - 1.7 1. 1..3.6 2.6 -.1.1 -.1 - aexcludng Decapterus spp. blncludhg Se%pss spp. clncludng Pectorhynchus spp. Commercal Effort Data The offcal reports on the number of boats dd not state whether these were trawlers or seners. t was assumed that the large, medum and small motorzed boats were trawlers, and that none of the salng boats were engaged n trawlng. The small motorzed boats n Rau Provnce were manly gllnetters, and were thus not ncluded; nether were some unregstered motorzed boats n North Sumatra operatng as purse seners. On the bass of the feld data, t appears that the large trawlers had an average gross tonnage of 3 t, the medum trawlers of 2 t, and the small trawlers of 1 t (Box 2). The medum-szed trawlers were selected as standard, and the other type> converted to ths by means of ther catch per unt effort (Box~2). Nomral,fshng days for each type of trawler n each provnce were J~en multpled by the approprate power factor, whch led to a measure of effectve effort ("corrected fshng days"). Combned wth the abovementoned catch data, these estmates of effort allowed the parametrzaton, va plots of catcheffort vs effort, of surplus producton models, subject to the caveats n Martosubroto (ths vol). Results and Dscusson The area covered the surveys of Mutara 1 and 2, and the trawl haul statons of Mutara 4 and Lemuru are shown n Fg. 2. The composton of the catch of Mutara 1 and 2 s gven n Table 3 together wth that of Mutara 4. To facltate comparson, all fgures were converted nto percentages of total catch. For the same reason, those groups of fshes recorded on only one or two of the boats have been added to "other fshes". 43

Table 4. Mean fsh stock denstes by depth n the ndonesan sector of the Malacca Strat. [Tabe4. Rata-rata denstas stok kan pada berbaga daerah d paparan Sunda.} Depth Mean catcheffort (kg.hour 1 ) Bomass (t.km 2) (m) of Mutara based on Mutara: 2 4 a 2 4 a Mean -9 36.7 65.3.5 1.4.9 1-19 77.8 45.4 1.1 1. 1. 2-29 77.7 41. 45.3 1.1.9.7.9 3-39 68.4 63.9 1. 1. 1. 4-49 158.2 2.5 2.5 5-59 1.1 1.6 1.6 6-69 84.1 1.3 1.3 7+ 94.4 1.5 1.5 amean values for the surveys documented n Pauly et al. (ths vol.). A feature dscussed by Menasveta (197), the ncrease wth depth of the percentage of more valuable fsh groups was confrmed for the Lutjandae, Serrandae, Carangdae, Pomadasydae, and others. Less valuable groups such as the Leognathdae, Sgandae, Scaendae, Platycephaldae, and "other fshes" decreased wth ncreasng depth. Table 4 summarzes the estmates of standng stock, by depth range. Overall, a standng stock of about 8, twas estmated for the ndonesan waters of the Malacca Strat, as delmted n Fg. 1., but excludng the depth range -9 m,.e., for a reference area of 47,6 km 2. Ths 26 Malacca Strat 24 [-l... 22...... 2...... 1969,., 18.g 16 ~ ~ _ 14 l- '- ~ 12~ ~.c: 1 -.ld.1 8 1973 1974 =r......... ~969 Fg. 3. Trawler catcheffort vs effort on the ndonesan sde of the Malacca Strat, 1969-1975; note declne, for both subareas consdered here (Aceh and North Sumatra-Rau), and consequently, for the area as a whole (see also Table 5). [Gampar 3. Hubungan antara hasl tangkapan per upaya penangkapan dan upaya penangkapan d Seat Maaka bagan ndonesa, 1969-1975; perhatkan grafk penurunan untuk kedua daerah (Aceh dan Sumatra Utara-Rau) dan seanjutnya untuk seuruh daerah (lhat juga Tabe 5).} Aceh '.197...1972 :~ '97::~ r 1975...,......... L!c-~-----O;';2-----,{;t"",--------;;6,------,OO,,-------' 24[,... North Sumatra [ and Rau......... 2r :969 "' l- $7311974 ~ 1,62C~ 197~.'975... ~ 1972_ '.'. :~ 1,..~"'>~ ""'" r L corresponds to a mean stock densty of 1.67 t km- 2. Here, however, the value forthe depth range 1-19 m, where the Mutara 4 had not been fshng, was assumed to correspond to the relatvely hgh average value of the same depth range from other, mostly unexploted areas covered by Mutara 4 (see Pauly et al, ths vol). n the specfccase of the Malacca Strat, ths assumpton was probably too optmstc, as heavy trawlng was already takng place n the shallow waters. Thus, to correct ths fgure, the stock denstes obtaned from the catch rates ofmutara 1 and 2 were also calculated (Table 4). These estmates were then used for the depth ranges mssng n the Mutara 4 survey, whle overlappng data of the three boats were averaged. The results are also presented n Table 4, from whch an average weghted mean stock densty of 1.33 t km- 2 was derved (ncludng the depth range -9 m). The corrected stock estmate, thus, amounts to 73, t, over a surface area of 55, km 2. The value at 1.33 t km- 2 and the correspondng standng stock are very low when compared wth the data from other areas of the Sunda Shelf (see Pauly et al, ths vol), where the average stock densty was 2.66 t km- 2, exactly double the Malacca Strat fgure. The low densty n the Malacca Strat s 3 9 1,2 ""'.. -,~,-----_----,~=---- ~_= --~-------:-:::'~_--;-:;=_--;"""'J o L 2 4 6 8 1,4 1,2 :,4 Fshng effort (standardzed trawler do,s' year" O') most probably the result of the exstng trawl fshery, whch s backed by the fact that t s manly the shallow waters (down to 39 m) of the Malacca Strat (where almost all, f not all of the trawlng takes place) thatthe stock denstes dffer from those of other areas. t seems, therefore legtmate to assume, as a frst approach, that the unexploted standng stock, before the onset of the trawl fshery, was also double the stock observed n the md-197s, or about 15, t. Based on the plots of catcheffort vs effort (Fg. 3), maxmum sustanable yeld (MSY) was estmated at about 8, t year- 1 for Aceh Provnce, and 77, t year 1 for North Sumatra and Rau combned. Overall, an MSY yeld of 85, t year 1 was estmated for the ndonesan waters of the Malacca Strat (Fg. 4). The above fgure of 85, t year- 1 s compatble wth an unexploted stock estmate (B o ) of 15, t (see above),.e., mplyng that MSY "" M Y2 B a (Gulland 1971), wth M set at 1...1oo 44

1 rv1lacca Strat 9 8...,., 7 +- 6 ---. : U 5 +- U L- 4 Q) 3 3 L- - 2 1 1 o 9!, eo. 4 8 1,2 1 -!"' o Clo North Sumatra "and Rau ". Aceh, 1.. ~ Fshng effort (standardzed t.rawler days year- 1 3 ) Fg. 4. Trawler catch vs effort on the ndonesan sde of the Malacca Strat, 1969-1975. Note that effort was near optmal n the md-197s for the area as a Whole, and for North Sumatra-Rau, but not for Aceh provnce, where effort was then already excessve. [Gambar4. Hubungan antara hasl tangkapan dan upaya penangkapan d Selat Malaka bagan ndonesa, 1969-1975. Perhatkan upaya yang mendekat optmal pada pertengahan tahun 197an untuk seluruh daerah, dan juga untuk Sumatra Utara-Rau, tetap tdak untuk propns Aceh, karena upaya penangkapan sudah melebh optmal.] year- 1, a value commonly used for the r,lultspeces demersal stocks of Southeast Asa (see Pauly, ths vol.). Further, the standng stock estmate of 73, t "" Y2 B o ' as should occur when fshng effort s at the level generatng MSY (Gulland 1971; Rcker 1975; Pauly 1984). Thus, t can be concluded that, overall, the level of trawlng effort appled n the md-197s to the demersal stocks of the ndonesan sde of the Malacca Strat was about rght - except n very shallow waters, where the small shrmps attracted an excessve amount of effort. Sujastan et al. (1976), based on these fndngs, presented a set of practcal recommendatons for managng the fsheres. [These recommendatons, not recalled here, became rrelevant when trawlng was banned n Western ndonesa (Sardjono 198, and see Martosubroto, ths vol.); a move whch also placed constrants on feld samplng wth trawls by MFR scentsts, due to strong objectons by small-scale fshers]. Rather, we pont at the compatblty of the results presented here, whch as n the case of the Java Sea (Martosubroto, ths vol.) ntegrate fsheres and survey data nto a coherent whole. Acknowledgements The knd assstance of the fsheres offcers of the Provncal Fsheres Offces n Aceh, North Sumatra, and Rau, s here thankfully acknowledged. Thanks are also cue to the late Mr. M. Unar, Drector of the MFR and to Mr. Budhardjo, who asssted durng the feld work, and wth the complng of the catch and effort data. References Anon. 1976a. Hstory and development of the purse sene fshery of Pennsular Malaysa, p. 64-66. n Report of the Workshop on the Fsheres Resources of the Malacca Strat, 29 March to 2 Aprl 1976. Jakarta, ndonesa. Part. SCSGEN762, 85 p. South Chna Sea Fsheres Development and Anon. 1976b. Hstory and development of fsh trawlng on the west coast of Pennsular Malaysa. p. 61-63. n Report of the Workshop on the Fsheres Resources of the Malacca Strat. 29 March to 2 Aprl 1976, Jakarta, ndonesa. Part. SCSGEN762, 85 p. South Chna Sea Fsheres Development and Coordnatng Programme. Manla. Anon. 1976c. The Tha fsheres along the ndan Ocean coast ofthaland, p. 67-75. n Report of the Workshop on the Fsheres Resources of the Malacca Strat, 29 March to 2 Aprl 1976, Jakarta, ndonesa. Part. Anon. 1976d. Report of the Workshop on the Fsheres Resources of the Malacca Strat, 29 March to 2 Aprl 1976, Jakarta, ndonesa. Part. Anon. 1976e. RN Lemuru Cruse 751 (Jakarta - Belawan, 8-27 Jan. 1975). Data and observatons. Presented at the Workshop on the Fsheres Resources of Malacca Strat, 29 March - 2 Aprl 1976, Jakarta, ndonesa. WFMS766WP. South Chna Sea Fsheres Development and 45

Anpn. 1987. nvestgatons on the mackerel and scad resources of the Malacca, Strats. BOBPREP39, 149 p. Bay of Bengal Programme, Colombo, Sr Lanka. Brtwstle, W. 1928. Report of the workng of the S. T. Tongkol for the year 1927. Government Prntng Offce, Sngapore. Emery, KD. 1971. Bottom sedment map of Malacca Strat. UN ECAFE CCOP Tech. Bull. (3):149-152. Gulland, J.A. Edtor. 1971. The fsh resources of the ocean. FAOFshng News Books, Ltd., Surrey, England. Keller, G.H. and A.F. Rchards. 1967. Sedments of the Malacca Strat, Southeast Asa. J. Sedmentary Petrology 37:12-127. Latff, S.S. 1973. Resource survey and problems of fshery resource management. Annual Meetng of Fsheres Offcers, March 1973. 17 p. (mmeo). Mahyam Bnt Mohd. sa. 1988. Populaton dynamcs of Nempterus japoncus (Psces: Nempterdae) off Kedah state, Malaysa, p. 126-14. n S.C. Venema, J. Moeller-Chrstensen and D. Pauly (eds.) Contrbutons to tropcal fsheres bology. FAO Fsh. Rep. 389,519 p. Mansor Mat sa. 1987. On the status of the Rastrellger and Decapterus fsheres of the west coast of Pennsular Malaysa n 1984-1985, p. 81-1. n nvestgatons on the mackerel and scad resources of the Malacca Strats. BOBPREP39. Bay of Bengal Programme, Colombo, Sr Lanka. Martosubroto, P. 1973. Studes on demersal fsh stocks n the Malacca Strat and Jamb Bay. Mar. Fsh. Res. Rep. 1, 33 p. (n ndonesan). Menasveta, D. 197. Potental demersal fsh resources of the Sunda Shelf, p. 525-559. n J. Marr (ed.) The Kurosho: a symposum on the Japan current. East West Center Press, Honolulu. Neman, A.A. 1973. Shelf benthos n the northern part of the ndan Ocean, p. 52-61. n A.S. Bogdanov (ed.) Sovet fsheres nvestgatons n the ndan Ocean (Second cruse of the RN Akademk Knpovch). srael Program of Scentfc Translaton, Jerusalem. Ommanney, F.D. 1961. Malayan offshore trawlng grounds. The expermental and exploratory fshng cruses of the FR. V. Manhne n Malayan and Borneo waters. 1955-56 wth a note on temperature and salntes n the Sngapore Stat. Colon. Offce Fsh. Publ. 18:1-95. Pathansal. D., K.S. Ong, S.S. Latff and J.L. Carvalho. 1966. Prelmnary results of trawlng nvestgatons off Penang. Proc. ndo-pac. Fsh. Counc. 12, Tech. Pap. 7, 22 p. Pauly, D. 1984. Fsh populaton dynamcs n tropcal waters: a manual for use wth tropcal waters. CLArM Stud. Rev. 8, 325 p. Rcker, W. E. 1975. Computaton and nterpretaton of bologcal statstcs of fsh populatons. Bull. Fsh. Res. Board Can. 191, 382 p. Saeger, J., P. Martosubroto, and D. Pauly. 1976. Frst report of the demersal fsheres project (Results of a trawl survey n the Sunda Shelf <area). Mar. Fsh. Res. Rep.Contrb. Demersal Fsh. Proj. No.1, 75 p. Sardjono,. 198. Trawlers banned n ndonesa. CLARM Newsl. 3(4):3. SCSP. 1976a. Report of the Workshop on the Fsheres Resources of the Malacca Strat, 29 March - 2 Aprl 1976. Jakarta, ndonesa. Part. SCSP. 1976b. Report of the Workshop on the Fsheres Resources of the Malacca Strat, 29 March - 2 Aprl 1976, Jakarta, ndonesa. Part. SCSGEN766, 113 p. South Chna Sea Fsheres Development and SCSP. 1978. Report of the workshop on management of resources of the Sunda shelf, Malacca Strat and related areas. SCSGEN7815, 13 p. South Chna Sea Fsheres Development and Coordnatng Programme, Manla. Svasubramanam, K. 1987. Scads and chub mackerels (Decapterus spp. and Rastrellgerspp.) n the Bay of Bengal, p. 117-145.ln nvestgatons on the mackerel and scad resources of the Malacca Strats. BOBP REP39. Bay of Bengal Programme, Colombo, Sr Lanka. Sorano, M.L., G. Tampubolon and J. Wdodo. 1988. Dscrmnant analyss of morphometres of ndan mackerel (Rastrellger kanagurta) n the Malacca Strat and scad (Decapterus russelll) n the Java Sea, ndonesa, p. 411-415. n S.C. Venema, J. Moeller-Chrstensen and D. Pauly (eds.) Contrbutons to tropcal fsheres bology. FAO Fsh. Rep. 389, 519 p. Sujastan, T. 1975. Pelagc fsheres n the Malacca Strat of ndonesa. Mar. Fsh. Res. Rep. 1:12-117. Sujastan, T. 1976. Pelagc fsheres of ndonesa n the Malacca Strat. p. 48 6. n Report of the Workshop on the Fsheres Resources of the Malacca Strat, 29 March to 2 Aprl 1976. Jakarta, ndonesa. Part. Sujastan, T., P. Martosubroto and D. Pauly. 1976. A revew of the demersal fshery of ndonesa n the rv1alacca Strat. based on recent surveys and catch and effort data, p. 23-47. n Report of the Workshop on the Fsheres Resources of the Malacca Strat. 29 March - 2 Aprl 1976. Jakarta. Part. SCSGEN762, 85 p. South Chna Sea Fsheres Development and Coordnatng Programme. Manla. Tampubolon, G.H. and. Gede Sedana Merta. 1987. Mackerel fsheres n the Malacca Strats, p. 11-116. n nvestgatons on the mackerel and scad resources of the Malacca Strats. BOBPREP39. Bay of Benpl Programme, Colombo, Sr Lanka. Tampubolon, G.H. 1988. Growth and mortalty estmaton of ndan mackerel (Rastrellger kanagurta) n the Malacca Strat, ndonesa, p. 372-384. n S.C. Venema, J.M. Chrstensen and D. Pauly (eds.) Contrbutons to tropcal fsheres bology. FAO Fsh. Rep. 389, 519 p. Valenca, M.J. 1979. South Chna Sea: present and potental coastal area resource use conflcts. Ocean Manage. 5:1-38. 46