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

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2 DSTRBUTON AND ABUNDANCE OF TEN SELECTED FSH SPECES (DEMERSAL FSH) OFF THE.EAST COAST OF PENNSULAR MALAYSA Hadzley Harith Fisheries Research nstitute, Batu Maung. A resource survey off the East Coast of Peninsular Malaysia was carried out between 27 May 1995 and 16 July 1995, covering Kelantan to east Johor and involving 100 sampling stations. Analysis on the distribution of ten selected demersal species obtained from this survey was performed. The most dominant families were PRACANTHDAE, NEMPTERDAE and MULLDAE. The analysis also indicated that most of these species were found at two different locations, from Rantau Abang to Kota Bahru and from Kuantan to Mersing. The total biomass for PRACANTHDAE, MULLDAE and NEMPTERDAE were estimated of 1.06 tonnes, 4.00 tonnes and 1.82 tonnes respectively. Possible reasons for the patterns of distribution are also discussed. Kajian sumber ikan demersal di Pantai Timur, Semenanjung Malaysia telah dijalankan pada 27 Mei 1995 sehingga 16 Julai Kajian ini meliputi perairan Kelantan hingga Johor. Kajian ini melibatkan 100 stesyen. Analisis terhadap taburan 10 spesies ikan demersal terpilih telah dijalankan. Spesies yang dipilih merupakan ahlii famili PRACANUDAE, NEMPTERDAE dan MULLDAE. Kajian menunjukkan bahawa kebanyakan spesies ini dijumpai tertabur di dua lokasi yang berbeza, iaitu, dati Rantau Abang ke Kota Bahru dan dari Kuantan ke Mersing. Anggaran jumlah biomass bagi PRlACANTHDAE ialah 106 tan metrik, 4.0 tan metrik bagi MULLDAE dan 182 tan metrik bagi NEMPT~AE. Fishermen have been complaining about the decline in the abundance of demersal fish resources. A few local papers have also raised this issue to the public. How serious is this matter? How many fish are they out in the sea? Where are they located? All these questions have always been asked. t is hoped that the surveys conducted by the Department of Fisheries Malaysia should be able to provide answers to some of these queries. Chullasom (1986), claimed that Southeast Asia waters are productive areas for commercial fishing basing on infonnation on the total annual catch from the region. The increase in landings is relative to the effort. Effort can be accurately calculated by a mechanization factor rather than by number of fishing boats. These figures were used to calculate the MSY of the fisheries of the west coast of Peninsular Malaysia (Alias, 1994). Nevertheless, the distribution of fish has seldom been discussed. Until now, not much information on the location of potential fishing grounds is available. Fish distribution in the sea is related to certain physical and chemical parameters of the water. Sea surface water temperature can affect the distribution of these species. Since the sea surface water temperature has not changed much all the years, we can

3 assume that the distribution of species has also not changed in the whole area. The distribution of fish can be affected by the availability and distribution of food resources and sea bed conditions. The survey was conducted for 7 weeks. Fig 1: The design of the G~rman sta.ndard otter trawl that used in the survey. The survey was conducted from 27 May to 16 July This was the eleventh survey conducted by the Department of Fisheries off the east coast of Peninsular Malaysia. The main objective of ths survey was to review the status of demersal fish resource in waters m deep. Sampling was done 3 to 4 times a day according to the sea bed conditions. Data were obtained to estimate the total biomass of the species. The survey was conducted by the research vessel K.K. MERSUJ. The specifications of this vessel are: Year built : 1982 Hull Length : Fibreglass : m Width : 5.8m Draught : 2.35m Engine : Marine Yanmar 5185 DT Horse power SAMPLNG GEAR : 500 HP * 900 rpm. The survey area was divided in to 4 sub-area as used by Ahmad Adnan (1981). Since all of the stations were divided into grid mesuring 10 nautical miles by 10 nautical miles, the area surveyed was estimated at 1,000 nautical mile. Table 1. Successful Haul and Area Covered in Sub-Area to V. Ten demersal species were selected basing on the distribution and abundance of these species. The list of selected species is as follows: Table 2. Shows the Selected Species and Family. All these families were among the major families of demersal fish. Estimation Of Total Biomass Using Swept Area Method The total biomass was estimated by using the Swept Area Method (Sparre, 1989). Estimation Of Trawling Area (Swept Area). An estimate of the trawled area was made using the formula: The net that was used in this survey was the German standard otter trawl with 40 mm meshes in the cod end.

4 Where V = Velocity of trawling (3 knots ), a = swept area (effective path swept) D = Distance of trawling surveyed of 1000 nautical mile 2. For trawl nets in Southeast Asia, the value of X) usually used was 0.5 (sarankura, A.P. 1971). Rl~SULTS Basing on the original plan, 127 hauls were to be conducted, but owing to the untrawlable and unsuccessful hauls only 100 hauls were achieved. A breakdown of the successful hauls is given in Table 3. Table 4. An estimate of the total biomass for each species were done and the results are shown below. From the total biomass of each species, the total biomass for each family was calculated. X 2 = fraction = 0.5 (Pauly, 1980) Since all the hauls were standardized to a trawling time of one hour, the swept area was calculated using the above formula. ESTMATON OF TOTAL BOMASS BY SWEPT AREA METHOD Cw/t = Cw Kg/nm 2 aft a This formula estimated the catch per unit of area. f X) is the fraction of biomass in the area trawled then, B = (Cw/a) * A X This estimated the total biomass of the area surveyed. Estimation of the total biomass were based on the total area DSCUSSON AND CONCLUSONS t was found that most of the demersal fish species were located in a few areas. Basing on the distribution of each species as shown in Fig. 2 to Fig. 11, it was found that these species were manly located in two areas. The two areas were from Rantau Abang to Kota Bahru in the north and from Kuantan to Mersing in the south. This distribution pattern was probably attributed to the sea bed conditions and shelter provided by the islands. This

5 pattern could be seen for the family NEMPTERDAE. However Nemipterus nematophorus was found mainly in the north and Nemipterus peronii was found generally in the south. ANALYSS OF CATCH RATES OF THE TEN SELECTED SPECES Table 5. Shows the averages Catch rates of ten selected Demersal fish species. Two species were selected from PRACANTllDAE. Both speces (Pricanthus macracanthus and Priacanthus tayenus) were found distributed almost throughout the whole area surveyed. Pricanthus macracanthus was distributed in the m depth especially in Subareas and n. n these Sub-areas high densities in abundance were rec<;>rded. Sub-area recorded low abundance in comparison to Sub-areas and. The second species selected from PRACANTHDAE was Priacanthus tayenus. This species was found in deeper water of m depth. This species was also usually fouid distributed in the same area of Pricanthus macracanthus. The average catch rate for Priacanthus tayenus is kglhr. Three species of MULLDAE were commonly encountered. These 3 species (Parupeneus heptacanthus, Upeneus tragula and Upeneus sulphureils) were found distributed along the east coast. These 3 species t~ey. could be classified as widely?lstnbuted, basing on their abundance n m depth. The catch rates of these species were Kgfhr for Parupeneus heptacanthus, kg/hr for Upeneus sulphureus and Kg/hr for Upeneus tragula. Ten species ofnempterdae were caught in Malaysian waters. However only 5 species were selected due to the limited distribution of certain species. The 5 selected species were Nemipterus marginatus, Nemipterus nematophorus, Nemipterus nemuru...r;, Nemip'terus peronii and Nemipterus mesoprion. Most of these species were classified as inshore, intermediate and offshore species as indicated by their abundance by depth strata. Most of the species found off east coast were classified as intermediate species. These intermediate species were Nemipterus mesoprion and Nemipterus peronii and they were found widely distributed in all areas. Nemipterus nemurus, Nemipterus nematophorus and Nemipterus marginathus were found distributed in deep sea as shown by their abundance in the m depth. Nevertheless, these species were found distributed in two different locations i.e. north and south locations. ANALYSS OF DSTRBUTON BY DEPTH STRATA AND LOCATON OFF THE EAST COAST Since the sampling stations covered the whole area off the east coast of Peninsular Malaysia it was assumed that landings were representative of the particular Sub-area trawled. Data were obtained to estimate the total biomass of each particular trawled Sub-area. Then an estimate the total biomass of each species was made. The water in the survey area was divided in to 6 depth zones with a range of 10m each. The minimum depth of the survey area was 11 m

6 while the maximum depth was 66 m. As mentioned earlier, all of the demersal fish species could be classified as inshore fish, offshore fish and intermediate. Both species of PRACANTHDAE were mainly distributed in Sub-areas and. The density appeared higher in the northern part when compared to the southern part. Priacanthus tayenus showed the same pattern of distribution as Priacanthus macracanthus, but the density and estimated biomass of this species was half of the estimated biomass of Priacanthus macracanthus. The family MULLDAE showed a few patterns of distribution. Three species from this family were selected. Parupeneus heptacanthus showed a compact distribution in Sub-area for the southern area whereas Upeneus sulphureus showed a compact distribution in the northern part (Subareas and ). Upeneus tragula was evenly distributed in the whole area. The family NEMPTERDAE showed a clear pattern of distribution. Nemipterus marginatus, N. mesoprion and N. nematophorus showed a compact distribution in the northern part (in the middle Sub-areas and ). N nemurus were found in the whole area. The fifth selected species from NEMPTERDAE was N. peronii. Most of this species were found in the southern part. ESTMA TED TOTAL BOMASS OF TEN SELECTED SPECES Basing on the data obtained from this survey, an estimated total biomass for each species was calculated using the Swept Area method as earlier discussed. From the formula mentioned the estimated swept area was sq. n. ml. From the estimated swept area, the estimated total biomass was calculated by using: Cw/t = Cw Kg/nm 2 aft a B = (Cw/a) * A Xl The total biomass of each species is given in Table 5. The author wish to thank Ybhg Dato' Shahrom B. Abdul Majid, Director of Fisheries, for the permission to publish this paper. Thanks also to the Director of Research, En. brahim B. Saleh, Head of Resource Section, Miss Chee P.Ean and En. Ahmad Adnan Nuruddin for the encouragement and support and to all the staff who were involve in these survey. Ahmad Adnan 1990 Demersal Fish Resources in Malaysia Waters (16), Fifth Trawl Survey Of The Coastal Waters Off The East Coast Of Peninsular Malaysia. Ministri of Agriculture, Malaysia, Kuala Lumpw, Malaysia. Alias Man Mechanization of Fishing Boat and in Consequences On The Management Of The Fishery n The West Coast Of Peninsular Malaysia. Page 1-27, n Proceedings Fisheries Research Conference.

7 Department of Fisheries, Malaysia, Kuala Lumpur. Somsak Chullasom Distribution and mportant Biological Features of Coastal Fish sarankura, A. P Assessment of stocks of Resource in Southeast Asia. demersal fish off the west coast of Thailand and Malaysia. FAOUNDP, ndian Ocean Programme, Rome. Pauly D Some Simple methods for the assessment of tropical fish stock. FAO Fish Tech Pap. Sparre P., Erik Ursin and Siebren C. Venema, ntroduction to tropical fish stock assessment Part 1 and 2. FAO - DANDA. FAD, Rome, taly. FAO Tecnical Paper, FAO, Rome, taly. Sub-Areal Sub-Area Sub-Area Sub-Area V Total (10 n. mile 2.)

8 PRACANTHDAE PRACANTHDAE :i~~~1~~3;>iil;/;}. ~ '.:.'.:~:.:..:::..;:<':.~":'::'>'::<"" '",..-:-: ;.. : ~::.>:..::.::..:.:.: Nemipterus marginqjus." 'f....". -: 7. Nemipterus nematophorus 8. Nemipterus nemurus 9. Nemipterus peronii 10. Nemipterus mesoprion NEWPTERDAE NEMPTERDAE" NEMPTERDAE NEMPTERlDAE NEWPTERDAE Successful Hauls Unsuccessful Hauls Sub-total Sub-Areal Sub-Area Sub-Area Sub-Area V Total 100

9 Table 4. An estimate of the total biomass for each species were done and the results are shown below. :mr:.i!/: : i..:.i ::.. :.... (. ii;'.h:e~tilj1a~ed TotalJli9~;~Sf(.. -:..". ::-... <:~::..: :.::.:::.~:.~. :.'::": Priacanthus tayenus 3. Parupeneus heptacanthus 4. Upeneus sulphereus 5. Upeneus tragula 6. Nemipterus marginatus 7. Nemipterus mesoprion 8. Nemipterus nematophorus 9. Nemipterus nemurus 10. Nemipterus peronii , :i.30 l :g; 9.. to }~t3it : ~{};Q8t...>.

10 Charts shows the distribution survey reigion. of each species by depth strata for the whole _0-_ _-_30 3_1-4_0 41_-_50 5_1-6_0 61_-7_0.J L _1_-3_0_. 31_-4_0 41_-5_0._51_-6_0. 6_1-_7o ~ ~ r i os lj a:: c u lj Gl tl) ~ Gl tl) > «0.000 l Nemipterus marginatus Depth Strata

11 ,_..._._ Nemipterus mesoprion o

12 _- 30 3_1-4_0 4_1_-S0 5_1-6_0 6_1_-7_0 J ---~ _ _ Priacanthus macracanthus L _ L _

13 [ '21 ' '"....--, -;.----~-_._.._. :\ _.".. : i..:-y-!~:--i-! Succeujd Haul U~k Grod U1'6JCUUjll Haul Fig. 1 : Survey Area Sho <11

14 Fig. 2 : Distribution of Parupeneus heptacanthus off East Coast of Peninsular Mala sia PENNSULAR. MALAYSA o _ Parupeneus heptacanthus Estimated Biomass: Kg

15 Fig. 3 : Distribution of Upeneus sulphureus off East Coast of Peninsular Mala sia Ll _ Upeneus sulphereus Estimated Biomass: Kg

16 Fig. 4 : Distribution of Upeneus tragula off East Coast of Peninsular Mala sia L _ Upeneus iragula Estimated Biomass: 2, Kg ==============~

17 Fig. 5 : Distribution of Nemipterus marginatus off East Coast of Peninsular Malaysia Legend : ~ _ Nemipterus marginatus Estimated Biomass: Kg

18 Fig. 6 : Distribution of Nemipterus mesoprion. off East Coast of Peninsular Mala sia 102E Legend : 12) _ Nemipterus mesoprion Estimated Biomass : Kg

19 Fig. 7 : Distribution of Nemipterus nematophorus off East Coast of Peninsular Mala sia _ Nemipterus nematophoreus Estimated Biomass: Kg

20 Fig. 8 : Distribution of Nemipterus nemurus off East Coast of Peninsular Mala sia Legend : o -.Nemipterus nemurus. Estimated Biomass: Kg

21 Fig. 9 : Distribution of Nemipterus peronii off East Coast of Peninsular Malaysia - Nemipterus peronii Estimated Biomass: Kg

22 Fig. 10: Distribution of Priacanthus macracanthus o_ff_e_as_t_c_o_as_t_o_f. peninsular Malaysia Legend :.- Priacanthus macracanthus Estimated Biomass: Kg

23 Fig. 11 : Distribution of Priacanthus tayenus off East Coast of Peninsular Mala sia * 6N Silb..tnd 11 ~ SOUTH CHNA SEA S * _Priacanthus tayenus Estimated Biomass: Kg