STOCK STATUS OF BLUE SWIMMING CRAB (Portunus pelagicus) IN TANAH LAUT, SOUTH KALIMANTAN, AND ITS ADJACENT WATERS

A study on the stock status of blue swimming crab (Portunus pelagicus Linnaeus, 1758) was conducted in Tanah Laut, South Kalimantan waters, based on data collected in March to November 2017. The results showed that the growth pattern of blue swimming crab in Tanah Laut waters was negatively allometric and the sex ratio of males to females was 1.0 : 1.7. The chi-square test indicated that the total males and total females of the blue swimming crab was significantly different. It means that there was an imbalance in numbers between males and females. The estimated length at first capture (Lc) was 127.26 mm (carapace width; CW), smaller than the length at first maturity (Lm) at 133.24 mmCW. The growth parameter of blue swimming crab was 1.1year with a maximum carapace width (L) of 204.3 mmCW. The estimated instantaneous total mortality (Z) and natural mortality (M) were 3.04/year and 1.24/year, respectively. While fishing mortality (F) and exploitation rate (E) were 1.80/year and 0.59/year, respectively, the estimated spawning potential ratio (SPR) was 11.1 %. Therefore, the stock status was categorized as overfishing. In order to ensure the sustainability of the blue swimming crab, a precautionary approach,, such as reducing fishing effort by 18 % of the current situation, is strongly recommended to apply.

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POPULATION PARAMETERS OF ENDEAVOUR SHRIMP (Metapenaeus ensis de Haan) IN BINUANGEUN AND ADJACENT WATERS, WEST JAVA

Indonesian Fisheries Research Journal ◽

10.15578/ifrj.25.1.2019.19-26 ◽

2019 ◽

Vol 25 (1) ◽

pp. 19

Author(s):

Ali Suman ◽

Prihatiningsih Prihatiningsih ◽

Pratiwi Lestari ◽

Andina Ramadhani Putri Pane

Keyword(s):

Carapace Length ◽

Total Mortality ◽

Growth Parameter ◽

Fishing Effort ◽

Population Parameters ◽

Chi Square ◽

Exploitation Rate ◽

Chi Square Test ◽

Males And Females ◽

First Maturity

Study on the population dynamic of endeavour shrimp (Metapenaus ensis) was conducted in Binuangeun waters based on data collected during period of survey, January to November 2016. The purpose of the study was to identify population parameters of the endeavour shrimp. Result showed that the endeavor shrimp growth pattern in Binuangeun waters was negative allometric and sex ratio of males and females was 1.0 : 2.7. The chi square test indicated that comparison of male and female of the endeavour shrimp was significantly different. It mean that there was imbalance in number between males and females. The length at first capture (Lc) of endeavour shrimp was 28.9 mm (carapace length),smaller than the length at first maturity (Lm) at 37.7 mm (carapace length). The growth parameter of endeavour shrimp was 1.33/year with maximum carapace length (Loo) of 51.45 mm. Instantenous total mortality (Z) and natural mortality (M) were 7.74/year and 1.88/year, respectively. While fishing mortality (F) and exploitation rate (E) respectively were 5.86/year and 0.76/year. The exploitation rate of endeavour shrimp in Binuangeun and adjacent waters was high. It was, therefore, recommended that fishing effort of the endeavour shrimp in that waters should be reduced about 52 % in the next year.

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THE POPULATION DYNAMIC OF BANANA PRAWN (Penaeus merguiensis de Man) IN TANAH LAUT WATERS, SOUTH KALIMANTAN

Indonesian Fisheries Research Journal ◽

10.15578/ifrj.23.1.2017.17-22 ◽

2017 ◽

Vol 23 (1) ◽

pp. 17

Author(s):

Ali Suman ◽

Ap’idatul Hasanah ◽

Tri Ernawati ◽

Andina Ramadhani Putri Pane

Keyword(s):

Population Dynamic ◽

Total Mortality ◽

Growth Parameter ◽

Fishing Effort ◽

Chi Square ◽

Exploitation Rate ◽

Chi Square Test ◽

Males And Females ◽

First Maturity ◽

De Man

Scientific advices on population dynamic of banana prawn (P. merguiensis de Man) are required as an input to support an apropriate fisheries management. This study aims to identify the population parameters of the banana prawn in Tanah Laut waters. The study was conducted in Tanah Laut based on monthly enumeration data (January to November 2016). Results has been shown that the length size of carapace at first maturity of banana prawn was 43.39 mm. Sex ratio of males and females was 1 : 0.8. The chi square test indicated that comparison of male and female of the banana prawn was significantly different. It means that there was not balance in number between males and females. The spawning season of banana prawn in Tanah Laut waters happened throughout year and reached the peak on November (south-east monsoon). The growth parameter of banana prawn was 1.05/year with maximum carapace length (Loo) of 55.0 mm. Instantaneous total mortality (Z) and natural mortality (M) were 6.05/year and 1.58/year, respectively. While fishing mortality (F) and exploitation rate (E) respectively were 4.47/year and 0.74/year respectively. The exploitation rate of banana prawn in Tanah Laut waters was high. Therefore, fishing effort of the banana prawn in that waters should be reduced to about 48 % for next coming year.

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Sex Ratio And Size At First Maturity Of Blue Swimming Crab (Portunus pelagicus) Salemo Island Pangkep Regency

ILMU KELAUTAN Indonesian Journal of Marine Sciences ◽

10.14710/ik.ijms.21.1.17-22 ◽

2016 ◽

Vol 21 (1) ◽

pp. 17 ◽

Cited By ~ 2

Author(s):

Muh. Saleh Nurdin ◽

Syamsu Alam Ali ◽

Dewi Yanuarita Satari

Keyword(s):

Sex Ratio ◽

Coral Reefs ◽

Swimming Crab ◽

High Demand ◽

Chi Square ◽

Portunus Pelagicus ◽

Ratio Size ◽

Chi Square Test ◽

First Maturity ◽

Size At First Maturity

Blue swimming crab (Portunuspelagicus) is aeconomical valuable fisheries importantcommodity due to the high demand and availability jobs created for the fishermen. Due to their high demand blue swimming crab heavily exploited from Salemo Island. This study aimed at comparing the sex ratio and the size at first maturity of blue swimming crab caught in mangrove ecosystems, coral reefs, and seagrass. Sex ratio was analyzed using chi square test and the size at first maturity was analyzed using the Spearman-Karber formula. The results showed the sex ratio ofmales and femalessmall crab caught in every ecosystem is balanced. The size at first maturity of blue swimming crab caught in mangrove, seagrass and coral reefs, each to the male 81,08 mm, 102,36 mm and 102,87 mm in width and size of female 94,54 mm, 83,35 mm, 98,31 mm width. In a reference to government regulations, the blue male swimming crab caught in the coral reef and seagrass ecosystems have yet to size at first maturity is allowed to be captured. Keywords: blue swimming crab, sex ratio,size at first maturity, Salemo Island

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Biologi Rajungan Portunus pelagicus Linnaeus, 1758 (Crustacea: Portunidae) Ditinjau Dari Aspek Distribusi Ukuran Dan Parameter Pertumbuhan Di Perairan Rembang, Jawa Tengah

Journal of Marine Research ◽

10.14710/jmr.v8i4.24539 ◽

2019 ◽

Vol 8 (4) ◽

pp. 402-408

Author(s):

Nathanael Ganang Anindityo Wibowo ◽

Chrisna Adhi Suryono ◽

Ibnu Pratikto

Keyword(s):

Size Structure ◽

Carapace Width ◽

Growth Parameter ◽

Survey Method ◽

Average Weight ◽

Swimming Crab ◽

Female Crab ◽

Potential Yield ◽

Portunus Pelagicus ◽

Male Crab

Rembang merupakan salah satu kabupaten di Jawa Tengah yang dikenal sebagai daerah penghasil sumberdaya rajungan yang cukup tinggi permintaannya dan terus meningkat setiap tahunnya. Hal tersebut dapat menyebabkan terjadinya penurunan potensi hasil rajungan akibat intensifnya penangkapan di Perairan Rembang. Kajian tentang kondisi stok sumberdaya rajungan terkait sebaran dan dinamika populasi ini sangat diperlukan dalam pengelolaan potensi rajungan. Tujuan dari penelitian ini adalah untuk menganalisis struktur ukuran dan parameter pertumbuhan rajungan di Perairan Rembang. Penelitian ini dilaksanakan pada bulan Maret – Juni 2019 di Perairan Rembang, dengan menggunakan metode survei yang bersifat deskriptif. Total sampel rajungan selama penelitian adalah 1200 ekor yang terdiri dari 574 ekor jantan dan 624 ekor betina. Hasil penelitian menunjukkan kelas ukuran lebar karapas rajungan didominasi oleh rajungan muda, dengan rata – rata 105.01 ± 11.99 mm untuk jantan dan 107.73 ± 10.68 untuk betina. Berat rata – rata rajungan jantan yaitu sebesar 95.2 ± 27.1 gram dan rajungan betina sebesar 97.9 ± 23.1 gram, sehingga menunjukkan rajungan jantan lebih kecil dibandingkan dengan rajungan betina. Pola pertumbuhan rajungan di Perairan Rembang bersifat allometrik negatif. Laju pertumbuhan rajungan di Perairan Rembang yang didapatkan adalah berupa nilai panjang asimptotik (L∞) sebesar 71.4 mm dengan koefisien pertumbuhan (K) sebesar 1.5/tahun.Rembang is a coastal region in Central Java which known as to producer of blue swimming crab resources that are in high demand and continues to increase every year. It will because decreasing the potential yield of blue swimming crab due to intensive fishing in Rembang Waters. Study on the stock condition of the blue swimming crab resource related to the distribution and dynamics of the population is required for the management of the blue swimming crab potential. The current research aims to assess the size structure and growth parameter of blue swimming crab in the Rembang Waters. The research was conducted from March to June 2019 in Rembang Waters, using a descriptive survey method. The total number of crab samples during the study was 1200 animals consisting of 574 male and 624 female. The results showed that the size of the crab carapace width class was dominated by young crabs, with an average of 105.01 ± 11.99 mm for males and 107.73 ± 10.68 for females. The average weight of male crab is 95.2 ± 27.1 gram and female crab is 97.9 ± 23.1 gram, indicates that male crab is smaller than female crab. The crab’s growth in Rembang Waters is allometric negative. The growth rate of crab in the Rembang Waters obtained is in the form of asymptotic length (L∞) was 71.4 mm with a growth coefficient (K) 1.5/year.

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Stock Status of Blue Swimming Crab (Portunus pelagicus Linnaeus, 1758) in Tiworo Strait Waters, Southeast Sulawesi, Indonesia

ILMU KELAUTAN Indonesian Journal of Marine Sciences ◽

10.14710/ik.ijms.25.2.85-90 ◽

2020 ◽

Vol 25 (2) ◽

pp. 85-90

Author(s):

Yustika Permatahati Intan Permatahati ◽

Nila Nikmatia Bugis ◽

La Sara ◽

Tezza Fauzan Hasuba Hasuba

Keyword(s):

Carapace Width ◽

Growth Patterns ◽

Fishing Ground ◽

Swimming Crab ◽

Portunus Pelagicus ◽

Male And Female ◽

Gonad Maturity ◽

Stock Status ◽

Spawning Potential Ratio ◽

Very High

The blue swimming crab (BSC) fishery in Tiworo Strait has been heavily exploited since two decades ago when its worldwide demand and price was very high. Study on population aspects of this organism in this waters is limited. The aim of present study was to investigate growth patterns, population stock status, and size at first gonad maturity of Portunus pelagicus. One of the main fishing ground of BSC around Tiworo Strait waters is at Bangko and Gala Islands. Samples of BSC were taken monthly using gillnet and collapsible trap. Each sample taken was identified its sex, measured its carapace width, and weighed. Data collected from fishing ground of BSC were analyzed to find out growth patterns, population stock status using spawning potential ratio (SPR) method, and the first gonad maturity (CW50). The results of study showed that growth patterns of BSC male and female following isometric growth patterns (b=0) (P<0.05). It was found out that SPR of BSC from both fishing ground was 22.46% and 23.71%, respectively which indicates that population stock status of BSC in Tiworo strait waters is “moderate level” (SPR > 20%). The size at first gonad maturity (CW50) was attained at carapace width of 9.16 cm for male and 10.16 cm for female. Those imply that BSCs allowed to be caught should be >10 cm.

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VARIABILITY OF CARAPACE WIDTH SIZE AND ABUNDANCE OF BLUE SWIMMING CRABS (Portunus pelagicus Linnaeus) IN PATI WATERS

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.28930/jitkt.v7i2.10996 ◽

2016 ◽

Vol 7 (2) ◽

Author(s):

Dyah Ika Nugraheni ◽

Achmad Fahrudin ◽

. Yonvitner

Keyword(s):

Coastal Waters ◽

Accretion Rate ◽

Carapace Width ◽

Management Strategies ◽

Fishing Effort ◽

Swimming Crab ◽

Nearshore Zone ◽

Portunus Pelagicus ◽

Males And Females ◽

Swimming Crabs

Fishing effort enhancement would put pressure on blue swimming crab resources and its ecosystem. The objective of this study was to determine the spatial distribution based on the size of the carapace width (CW), abundance, temperature, salinity, depth, and fishing intensity in Pati waters which was divided into two zones (zones 1=nearshore, zone 2=offshore). The result showed that the average of carapace width in zone 1 to zone 2 was significantly different (p <0.05), as well as between males and females. Average number of individual (abundance) was significantly different according to fishing areas and sex (p <0.05). The average of water temperature in zone 1 was higher than in zone 2, salinity in zone 1 was smaller than in zone 2, and the water depth in zone 1 was shallower than in zone 2. The higher the crab catch intensity leaded to the smaller the abundance and size of carapace width. Alternative management strategies were proposed such as to divert fishing grounds from coastal waters to offshore during low productivity season, to uphold rules on minimum legal size for catching (Lm = 107 mm), to release of berried females catch, and to reduce accretion rate of gear and fishing fleet mainly in the coastal zone waters.Keywords: blue swimming crab, carapace widht (CW), abundance, intensity of fishing

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PARAMETER POPULASI DAN TINGKAT PENGUSAHAAN RAJUNGAN (Portunus pelagicus) DI PERAIRAN ASAHAN, SELAT MALAKA

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.9.2.2017.93-102 ◽

2017 ◽

Vol 9 (2) ◽

pp. 93

Author(s):

Andina Ramadhani Putri Pane ◽

Heri Widiyastuti ◽

Ali Suman

Keyword(s):

Mortality Rate ◽

Carapace Width ◽

Total Mortality ◽

Optimum Level ◽

Market Demand ◽

Swimming Crab ◽

Portunus Pelagicus ◽

Monthly Data ◽

Management Measures ◽

Exploitation Rate

Tingginya permintaan pasar terhadap rajungan mengakibatkan aktivitas penangkapannya berlangsung secara intensif. Selat Malaka merupakan salah satu daerah penangkapan rajungan yang penting di Indonesia. Tujuan penelitian ini adalah untuk mengestimasi parameter populasi dan tingkat eksploitasi rajungan (Portunus pelagicus) di perairan Asahan dan sekitarnya. Pengumpulan data bulanan dilakukan pada bulan Juni 2015 sampai dengan Nopember 2016. Hasil penelitian menunjukkan bahwa musim penangkapan berlangsung sepanjang tahun dengan puncak pada bulan Juli dan Oktober, puncak pemijahan terjadi pada bulan Januari dan Agustus. Ukuran lebar karapas pertama kali tertangkap dengan gillnet (Lc) dan ukuran pertama kali matang gonad (Lm) masing-masing sebesar 109,6 mm dan 104,1 mm. Laju pertumbuhan (K) sebesar 1,38/tahun dan lebar karapas asimtotik (L) sebesar 183,10 mm. Laju kematian total (Z) rajungan sebagai 4,31 per tahun, laju kematian karena penangkapan (F) dan laju kematian alami (M) masing-masing 2,96 per tahun dan 1,35 per tahun; laju eksploitasi (E) diestimasi sebesar 0,69. Tingkat pemanfaatan rajungan di perairan Asahan diduga telah melewati optimal, sehingga perlu dilakukan pengelolaan melalui pengurangan jumlah unit gillnet rajungan sebanyak 38% dari kondisi saat ini. Blue swimming crab faced intensive fishing pressure due to the high market demand. The Malacca Strait is one of important fishing area for blue swimming crab. The research aims to estimate the population parameters and exploitation rate of blue swimming crab (Portunus pelagicus) in the Asahan and adjacent waters. A monthly data were collected from June 2015 to November 2016 that caught by Gillnet. The results showed that the fishing season takes place throughout the year with peaks in July and October, meanwhile peak of spawning season in January and August. The carapace width at first capture (Lc) and first mature (Lm) were 109.6 mm and 104.1 mm, respectively. The growth rate (K) was 1.38 / year and the asymptotic length (L) was 183.10 mm. Total mortality rate (Z) was 4.31 per year, fishing mortality rate (F) and natural mortality rate (M) were 2.96 per year and 1.35 per year respectively; Exploitation rate (E) was estimated at 0.69. It means that the exploitation rate of swimming crab in the Asahan waters found exceed the optimum level, therefore the management measures needs to reduce effort (unit) of gillnet by a 38% of actual level.

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STRUKTUR UKURAN DAN BIOLOGI POPULASI RAJUNGAN (Portunus pelagicus Linnaeus, 1758) DI PERAIRAN KEPULAUAN ARU

Jurnal Penelitian Perikanan Indonesia ◽

10.15578/jppi.1.1.2018.51-60 ◽

2018 ◽

Vol 1 (1) ◽

pp. 51

Author(s):

Duranta Diandria Kembaren ◽

Adi Surahman

Keyword(s):

Population Biology ◽

Size Structure ◽

Carapace Width ◽

Total Mortality ◽

Swimming Crab ◽

Fishing Mortality ◽

Portunus Pelagicus ◽

Precautionary Approach ◽

Exploitation Rate ◽

Average Size

Penelitian struktur ukuran dan biologi populasi rajungan di perairan Kepulauan Aru telah dilakukan pada Januari-April, Juni dan Agustus-November 2016. Penelitian ini bertujuan untuk mengidentifikasi struktur ukuran dan biologi populasi yang meliputi pertumbuhan, laju kematian, dan tingkat eksploitasi rajungan. Pemahaman struktur ukuran dan biologi populasi dapat dijadikan dasar masukan untuk pengelolaan perikanan. Rata-rata ukuran lebar karapas rajungan yang tertangkap sebesar 136 mm untuk jantan dan 141 mm untuk betina. Rajungan yang tertangkap pada Januari dan Juni memiliki rata-rata ukuran yang lebih besar. Rata-rata rajungan yang tertangkap sudah melawati ukuran matang gonad (Lc = 133,4 mm > Lm = 119,9 mm). Puncak musim pemijahan terjadi pada Februari-Maret dan Agustus-September. Lebar karapas asimtosis (CW) sebesar 185 mm dengan laju pertumbuhan (K) 1,15 tahun-1 serta laju kematian total (Z) 4,94 tahun-1, laju kematian alamiah (M) 1,20 tahun-1 serta laju kematian akibat penangkapan (F) 3,74 tahun-1. Laju eksploitasi sudah berada pada kondisi lebih tangkap (E=0,76). Hasil kajian menyarankan bahwa pengelolaan perikanan rajungan perlu dilakukan secara hati-hati agar sumberdaya ini dapat lestari. Salah satu upaya yang dapat di tempuh adalah dengan menerapkan sistem penutupan musim penangkapan rajungan pada saat terjadinya puncak musim pemijahan yaitu pada Februari-Maret dan Agustus-September. Dengan demikian diharapkan proses regenerasi dan rekrutmen rajungan selalu dapat mendukung ketersedian stok sumberdaya rajungan di perairan Kepulauan Aru ini. Study on the size structure and population biology of blue swimming crab in the waters of Kepualuan Aru was conducted in January to April, June and August to November 2016. The aim of this study was to identify the size structure and population biology i.e. growth, mortality, and exploitation rate of blue swimming crab. Understanding on the size structure and population biology can be used as basic information for managing blue swimming crab fisheries. Average size of carapace width of blue swimming crab was 136 mm for male and 141 mm for female. Catch on January and June was bigger size than others months. Length at first capture was higher than length at maturity (Lc = 133,4 mm > Lm = 119,9 mm). Spawning peak season occurs in February-March and August-September. Asymptotic carapace width (CW) of blue swimming crab was 185 mm with the growth rate (K) was 1,20 year-1, total mortality (Z) was 4,94 year-1, natural mortality (M) was 1,20 year-1, and fishing mortality (F) was 3,74 year-1. Exploitation rate was exceed the sustainability limit (E = 0,76). Thus, it is needed to manage the blue swimming crab fishery with precautionary approach. Based on this study, we suggest to apply the fishing closure system at the peak of spawning season. Thus, the regeneration process and recruitment will support the availability of blue swimming crabs resource in Kepualuan Aru waters.

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Growing Pattern of Blue Swimming Crab, Portunus pelagicus at Two Different Locations in Manado Bay

JURNAL ILMIAH PLATAX ◽

10.35800/jip.6.1.2018.19545 ◽

2018 ◽

Vol 6 (1) ◽

pp. 149

Author(s):

Frank Rijkaard Makahinda ◽

Rose O.S.E Mantiri ◽

Boyke H. Toloh

Keyword(s):

Growth Pattern ◽

Carapace Width ◽

Market Demand ◽

Swimming Crab ◽

Chi Square ◽

Portunus Pelagicus ◽

Relationship Analysis ◽

Weight Relationship ◽

Relationship Of ◽

Swimming Crabs

Portunus pelagicus (blue swimming crab) is one of the important economical marine commodities produced from Indonesian coastal waters that has increasing market demand among fishery commodities. The purpose of this research is to reveal the relationship of carapace width and weight, the growth pattern and the carapace width-weight ratio of P. pelagicus crabs at two different research sites in Manado Bay. The benefits of this study, can be a reference for further studies on blue swimming crabs, P. pelagicus, and information obtained in this study could become important information needed for the maximum sustainable utilization of blue swimming crab, P. pelagicus.This research was conducted at two locations, namely Kelurahan Bahu, Sub-district of Malalayang with coordinates of 1 ° 27'49.86 "North and 124 ° 49'35.79" East and second location in Tumumpa Dua, Sub-district of Tuminting with coordinates 1 ° 31'14.51"North - 124 ° 50'28.67"East. Samples of blue swimming crabs were collected by deploying traps which are placed at 5-7 meters with the distance between traps 10 meter. Traps were placed at 17.00 pm and lifted on the next day at 06.00 am. Measurement of the width of the carapace conducted by using the ruler with 0.1 cm accuracy and weight measurement using the scales with 0.1 gram accuracy.The correlation value obtained for the wide and weight relationship of blue swimming crabs in the Sub-district of Malalayang is 0.953 for males and 0.898 for females. In Kelurahan Tumumpa Dua, Sub-dis ittrict of Tuminting 0.829 for males and 0.920 for females respectively. Based on these values the increase in the width of the carapace will affect the weight gain of the crab. The growth pattern of P. pelagicus crab in Kelurahan Bahu, Sub-district of Malalayang and Tumumpa Dua Sub-district Tuminting showed negative allometric growth pattern with b <3 value which means faster carapace growth compared to the weight of crab. From the result of chi square test on wide body and weight relationship analysis, is found same for both locations with value x2 table = 7.815 <x2 count = 112.3134. This is presumably due to one of the external factors is the availability of food.Keywords: Rajungan, growth pattern, Manado Bay AbstrakPortunus pelagicus merupakan salah satu komoditi hasil laut ekonomis penting yang dihasilkan dari perairan pantai Indonesia dengan permintaan pasar terhadap komoditas rajungan yang terus meningkat. Adapun tujuan penelitian ini yaitu mengetahui hubungan lebar berat rajungan P. pelagicus, pola pertumbuhan rajungan P. pelagicus dan perbandingan lebar berat rajungan P. pelagicus di dua lokasi penelitian yang berbeda di Teluk Manado. Manfaat penelitian ini, dapat menjadi bahan acuan untuk studi lebih lanjut mengenai rajungan P. pelagicus serta infomasi yang didapat dalam penelitian ini bisa menjadi bahan kajian untuk pemanfaatan rajungan P. pelagicus secara maksimal serta berkelanjutan.Penelitian ini dilaksanakan pada dua lokasi yakni di Kelurahan Bahu Kecamatan Malalayang dengan koordinat 1°27'49.86"LU - 124°49'35.79"BT dan lokasi kedua di Kelurahan Tumumpa Dua Kecamatan Tuminting dengan koordinat 1°31'14.51"LU - 124°50'28.67"BT. Pengambilan sampel dilakukan dengan alat tangkap bubu yang diletakan pada kedalam 5-7 meter dengan jarak antara bubu 10 meter. Bubu diletakan pada pukul 17.00 wita dan diangkat pada esok harinya pukul 06.00 wita. Pengukuran lebar karapas menggunakan mistar dengan ketelitian 0,1 cm dan pengukuran berat tubuh menggunakan timbangan 0,1 gr.Nilai korelasi yang didapat untuk hubungan lebar berat rajungan P. pelagicus di Kelurahan Bahu Kecamatan Malalayang 0,953 untuk jantan dan 0,898 untuk betina. Di Kelurahan Tumumpa Dua Kecamatan Tuminting 0,829 untuk jantan dan 0,920 untuk betina. Berdasarkan nilai tersebut pertambahan lebar karapas akan berpengaruh pada kenaikan berat tubuh dari rajungan. Pola pertumbuhan rajungan P. pelagicus di Kelurahan Bahu Kecamatan Malalayang dan di Kelurahan Tumumpa Dua Kecamatan Tuminting menunjukan pola pertumbuhan yang bersifat allometrik negatif dengan nilai b < 3 yang berarti pertumbuhan karapas lebih cepat dibandingkan pertambahan berat rajungan. Dari hasil analisis chi square lebar berat tubuh, sama untuk kedua lokasi penelitian dengan nilai x2 tabel = 7,815 < x2 hitung = 112,3134. Hal ini diduga karena salah satu faktor eksternal yakni ketersediaan makanan.Kata kunci : Rajungan, Pola pertumbuhan, Teluk Manado.

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PENENTUAN STATUS STOK SUMBERDAYA RAJUNGAN (Portunus pelagicus Linnaeus, 1758) DENGAN METODE SPAWNING POTENTIAL RATIO DI PERAIRAN SEKITAR BELITUNG

Jurnal Penelitian Perikanan Indonesia ◽

10.15578/jppi.21.2.2015.63-70 ◽

2015 ◽

Vol 21 (2) ◽

pp. 63

Author(s):

Tri Ernawati ◽

Duranta D Kembaren ◽

Karsono Wagiyo

Keyword(s):

Carapace Width ◽

Population Decline ◽

Swimming Crab ◽

Portunus Pelagicus ◽

Average Value ◽

Stock Status ◽

The Status ◽

Spawning Potential Ratio ◽

Individual Size ◽

Stock Recovery

Sumber daya rajungan (Portunus pelagicus Linnaeus, 1758) di perairan sekitar Belitung dieksploitasi terus menerus dilakukan sebagai sumber mata pencaharian. Pemanfaatan intensif sumber daya rajungan dapat menurunkan ketersediaan stok rajungan di perairan. Indikasi tangkap berlebih (overfishing) terhadap pemanfaatan sumber daya rajungan sudah mulai terlihat dari penurunan hasil tangkapan dan ukuran individu. Tulisan ini bertujuan mengetahui kondisi dan status stok sumber daya rajungan berdasarkan pada hasil penelitian yang dilakukan dari Februari sampai dengan November 2014 di perairan sekitar Pulau Belitung. Metode yang digunakan untuk penentuan status stok rajungan dengan menggunakan pendekatan metode Spawning Potential Ratio (SPR). Hasil penelitian menunjukkan bahwa status stok sumber daya rajungan di perairan sekitar Belitung mengalami penurunan yang ditunjukkan dengan hasil SPR 5% atau telah mengalami heavily exploited. Indikasi penurunan populasi juga ditunjukkan dengan nilai ratarata ukuran lebar karapas (CW) rajungan yang tertangkap (CW50) sebesar 93 mm, dibawah ukuran lebar karapas rata-rata pertama kali matang gonad (CWm) sebesar 118,9 mm. Upaya pemulihan stok dapat dilakukan dengan cara meningkatkan SPR pada level 10% dan 20% sebagai batas dan target pengelolaan untuk keberlanjutan sumber daya rajungan atau pada rata-rata ukuran lebar karapas (CW) rajungan yang tertangkap adalah 12 cm. The blue swimming crab (BSC) resources in waters around Belitung waters continously exploited as a livelihood resource. Intensive utilization of BSC resources can reduce the availability of stock in the waters. Indication of overfishing to the BSC resource have been seen by declining in catches and individual size of BSC. The research aims to determine the condition and stock status of BSC resource based on the results of research conducted from February to November 2014 in the waters around the island of Belitung. The method used for determining the status of BSC stocks by using a method Spawning Potential Ratio (SPR). The result showed that stock status of BSC in the waters around Belitung decreased as indicated by the results of SPR 5% or has suffered heavily exploited. The indication of population decline is also indicated by the average value of the size of the carapace width (CW) at capture (L50) as 93 mm, it is below the average carapace width at first maturity (Lm) as 118.98 mm. Stock recovery can be done by SPR at level 10% and 20% as biological sutainaibility as limist and target for management. It could reached if the minimal average value of the size of the carapace width of capture is 12 cm.

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