Fishery simulation model for sharks applied to the Gummy Shark, Mustelus antarcticus Gunther, from Southern Australian waters

1992 ◽  
Vol 43 (1) ◽  
pp. 195 ◽  
Author(s):  
TI Walker
Keyword(s):  
Sex Ratio ◽  
Simulation Model ◽  
Mesh Size ◽  
Fishing Effort ◽  
Probability Density Distribution ◽  
Natural Mortality ◽  
Sex Ratio At Birth ◽  
Gill Nets ◽  
Gill Net ◽  
Number Of Births

A dynamic pool simulation model is derived and applied to the gummy shark stock of the southern shark fishery. Inputs to the model are fishing effort reported by fishers for hooks and for gill-nets with mesh sizes of 6 inches (152 mm), 7 inches (178 mm) and 8 inches (203 mm) along with estimates for growth, natural mortality, catchability, hook and gill-net mesh selectivity, size at maturity and fecundity of females, sex ratio at birth, and length-weight relationships. Growth is described by the von Bertalanffy equation; hook selectivity is constant with length for sharks recruited to the fishery; gill-net selectivity is based on the probability density distribution of the gamma function where selectivity varies with the mesh size of the gill-nets and the length of the sharks; number of births is related to the proportion of females mature at each length, and the relationship between number of births and maternal weight is linear; parturition is annual and time is standardized so that parturition occurs at the beginning of each year; sex ratio at birth is based on observations of a 1: 1 sex ratio of embryos; and allometric weight-length is based on the power curve. Natural mortality of recruits, catchability, reproduction and growth parameters are held constant, but density-dependent natural mortality of prerecruits is varied in proportion to stock abundance. The model is used to simulate effects of historical longline fishing effort and gill-net fishing effort for each mesh size on stock biomass, numbers of sharks in the stock, and numbers of births. The performance of the model is evaluated by comparing simulated annual catches and the simulated mean weight of sharks captured with annual catches reported by the fishers and the mean weight of sharks sampled in commercial landings. Uncertainties surrounding estimates of some of the parameters are discussed. Notwithstanding its shortcomings, the model indicates that the stock of gummy shark has been severely reduced and is in danger of further depletion unless immediate action is taken to reduce the commercial catch.

Shark fisheries in Argentina

1998 ◽  
Vol 49 (7) ◽  
pp. 601 ◽  
Author(s):  
Gustavo E. Chiaramonte
Keyword(s):  
Fishing Effort ◽  
Population Trends ◽  
The South ◽  
Gill Nets ◽  
Argentine Sea ◽  
Commercial Importance ◽  
South West ◽  
Gill Net ◽  
Galeorhinus Galeus ◽  
Mustelus Schmitti

In the Argentine Sea there are about 35 species of sharks. Three species are subjected to directed fishing: the smoothhound Mustelus schmitti, the school shark Galeorhinus galeus and the copper shark Carcharhinus brachyurus. Other species of elasmobranchs with commercial importance are the angel shark Squatina spp. and several species of skates and rays. The rise in chondrichthyan declared landings registered from 1988 to 1996 is due to the increase in landings of smoothhound and rays. The most important directed shark fishery in the South-West Atlantic is the Necochea gill-net fishery for school shark, which is carried out by the coastal fleet; details are given of the ships and the gill-nets used in this area. The length frequencies of the catches by gill-nets are presented for the school shark; fishing effort (length (km) of net in the water per ship per day) and CPUE (number of sharks per fishing effort) were found not to be good indicators of population trends in the school shark fishery. Resumen. En el Mar Argentino se han registrado 35 especies de tiburones. Tres de estas especies están sometidas a una pesca dirigida; el gatuzo, Mustelus schmitti, el cazón, tiburón vitamínico o trompa de cristal, Galeorhinus galeus y la bacota, Carcharhinus brachyurus. Otras especies de elasmobranquios de importancia comercial son el pez ángel Squatina spp. y algunas especies de rayas. El incremento en los desembarcos de condríctios declarados a las autoridades pesqueras entre 1988 y 1996 es debido principalmente al incremento del desembarco de gatuzo y rayas. La pesquería dirigida a tiburón más importante en el Atlántico Sudoccidental es la pesquería costera de enmalle de Necochea para el cazón. Se describen el largo de las embarcaciones y las redes utilizadas en el área (la medida de malla, el calado y la operación del arte de pesca). Se presenta la frecuencia del largo total de las capturas de cazón en redes de enmalle. Se halló para la pesquería del cazón que el esfuerzo pesquero (estimado como km de red en el agua por embarcación por día) y la CPUE (estimada como tiburones/esfuerzo de pesca) no son buenos indicadores de la tendencia en la abundancia poblacional.

scholarly journals Catching Technology of Fish Maw Snapper’s: Case Study of the KMN Nur Aqila07 Fishing Boat in Kumbe Village, Malind District, Merauke Regency, Papua

2021 ◽  
Vol 328 ◽  
pp. 08011
Author(s):  
Sajriawati Sajriawati
Keyword(s):  
Data Collection ◽  
Mesh Size ◽  
Fishing Gear ◽  
The Sun ◽  
Running Water ◽  
Gill Nets ◽  
Weight Range ◽  
Fishing Boat ◽  
Gill Net

The purpose of this study was to determine the fishing technology used by fishermen in Merauke to catch snapper and post-harvest handling of fish maw snapper. This research was conducted in January 2021 in Kumbe Village, Malind District. Data collection was carried out by interviewing fishermen on the fishing boat KMN Nur Aqila07. The results showed that the fishing boat KMN Nur Aqila07 has a weight specification of 30 GT. The main fishing gear is a drift gill net with a length of 50 meters with a width of 2 meters with a mesh size of 7.5 inches. The pulley machine is used to help pull the gill nets when they want to pull fishing gear (hauling). Fish maw of snapper is removed manually using a knife, then cleaned with running water and then dried in the sun to dry. Fish maw is sold dry. The highest price for fish maw is in the weight range of 150 grams which can reach Rp. 22,500,000 per kg, while the lowest price is in the weight range of less than 50 grams, which is Rp. 4,500,000 per kg.

scholarly journals KARAKTERISTIK BIOLOGI IKANTONGKOLKOMO(EUTHYNNUSAFFINIS) YANGTERTANGKAPJARINGINSANGHANYUTDILAUTJAWA

2016 ◽  
Vol 8 (1) ◽  
pp. 57
Author(s):  
Rudy Masuswo ◽  
Agustinus Anung Widodo
Keyword(s):  
Sex Ratio ◽  
Size Distribution ◽  
Length Distribution ◽  
Mesh Size ◽  
Male And Female ◽  
Gill Net ◽  
Result Show ◽  
Java Sea ◽  
Euthynnus Affinis ◽  
Fishing Area

<p>Tahun 2015 telah dilakukan<strong> </strong>penelitian tongkol komo (<em>Euthynnus affinis</em>) yang tertangkap jaring insang hanyut berukuran mata jaring 4 inci di Laut Jawa berbasis di PPI Karangsong Indramayu. PPI Karangsong adalah basis perikanan jaring insang di Indramayu dengan daerah penangkapan utama di perairan Laut Jawa. Penelitian ini bertujuan untuk mengetahui karakteristik biologi yang meliputi: distribusi ukuran,  ukuran pertama kali matang gonada (<em>L<sub>m</sub></em>) dan ukuran pertama kali tertangkap (<em>L<sub>c</sub></em>) dan parameter biologi lainnya yaitu hubungan panjang (FL)-bobot (W) ikan dan nisbah kelamin.  Hasil penelitian menunjukkan bahwa distribusi ukuran  ikan antara 27 – 58 cmFL (rata-rata 45,5) dengan median 44 cmFL, L<sub>m</sub> tongkol jantan  45,8 cmFL dan betina 43,2 cmFL, ukuran L<sub>c</sub> 44,5 cmFL, hubungan panjang-bobot menurut persamaan W= 0,0636 L<sup>2,6497</sup> (r<sup>2</sup>=0,8409) dengan nisbah kelamin jantan: betina 52 : 48 %.</p><p><em>A research of kawa-kawa (Euthynnus affinis) caught by 4 inche mesh size drifting gillnets operate in Jawa Sea waters based at Karangsong-Indramayu has been carried out in 2015. Karangsong is a gill net fishery based in Indramayu with a major fishing area in the waters of the Java Sea. The aim of research is to determine the biological carachteristics wich cover: size distribution, length of first matured (L<sub>m</sub>) and length of first captured (L<sub>c</sub>), L-W relationship and sex ratio.  The result show that length distribution ranged 27-58 (ave. 45.5) with median 44 cmFL, the L<sub>m</sub> of male and female of kawa-kawa were 45.8 cmFL and 43,2 cmFL respectively and the L<sub>c</sub> was 44.5 cmFL, L-W relationship was W= 0.0636 L<sup>2.,6497</sup>(r<sup>2</sup>=0.8409), and sex ratio male : female was 52 : 48 %.</em></p>

scholarly journals ANALISIS PENDAPATAN USAHA PENANGKAPAN IKAN LAUT MENGGUNAKAN ALAT TANGKAP GILL NET DI DESA TABANIO KECAMATAN TAKISUNG KABUPATEN TANAH LAUT ((THE INCOME ANALYSIS OF FISHERY EFFORT WITH GILL NET IN TABANIO VILLAGE, TAKISUNG DISTRICT, TANAH LAUT REGENCY)

2016 ◽  
Vol 1 (2) ◽  
pp. 202
Author(s):  
Yarna Hasriani ◽  
Emmy Sri Mahreda ◽  
Irma Febrianty
Keyword(s):  
Cross Section ◽  
Structured Interview ◽  
Fishing Effort ◽  
Payback Period ◽  
Fishing Vessel ◽  
Gill Nets ◽  
Section Data ◽  
Research Activities ◽  
Gill Net ◽  
The Village

<p>Penelitian ini bertujuan untuk mengetahui keuntungan usaha nelayan <em>gill net</em> setelah dikurangi bagian hasil untuk buruh nelayan; dan menganalisis kelayakan usaha penangkapan ikan di laut dengan menggunakan alat tangkap <em>gill net</em>. Kegiatan penelitian ini dilaksanakan di Desa Tabanio, Kecamatan Takisung, Kabupaten Tanah Laut, sebagai desa nelayan di Kabupaten Tanah Laut yang masyarakatnya dominan menggunakan alat tangkap <em>gill net</em>. Data yang dikumpulkan adalah data <em>cross section</em> yang bersumber langsung dari nelayan pemilik kapal/alat tangkap <em>gill net</em>, melalui teknik wawancara terstruktur (menggunakan kuesioner).</p><p>Hasil penelitian menunjukkan bahwa keuntungan yang diperoleh nelayan pemilik kapal dari usaha penangkapan ikan dengan <em>gill net</em> di Desa Tabanio adalah rata-rata sebesar Rp.7.634.223 per trip atau per bulan. Usaha penangkapan ikan dengan <em>gill net</em> di Desa Tabanio menguntungkan dan layak untuk diusahakan, karena nilai <em>NPV</em> yang positip sebesar Rp.61.550.000, dengan nilai <em>Net BCR </em>lebih dari satu<em> </em>(1,38) dan <em>IRR</em> lebih dari<em> </em>suku bunga yang didiskonto (27% &gt; 14%), serta <em>payback period</em> yang lebih cepat dari periode proyeksi selama lima tahun (2,96 tahun).</p><p><em>This study</em><em> aims to determine the business benefits gill net fishing net of proceeds for fishing laborers and analyze their feasibility in the sea fishing using gill net gear. The research activities conducted in the Village Tabanio, Takisung District, of Tanah Laut, a fishing village in the district of Tanah Laut where people predominantly use gill net gear. The data collected is cross section data are sourced directly from the fishing vessel owner/gill net gear, through a structured interview technique (using questionnaires).</em></p><p><em>The results showed that</em><em> the benefits of fishing vessel owners fishing effort by gill nets in the village Tabanio is an average of Rp.7.634.223 per trip or per month. Fishing effort by gill nets in the village Tabanio profitable and worth the effort, because the value of Rp.61.550.000 positive NPV, the net value of BCR is more than one (1.38) and IRR over a discounted rate (27% &gt; 14%), and the payback period is faster than the projected five-year period (2.96 years).</em></p>

Biomass Dynamics of Lake Superior Lake Herring (Coregonus artedii): Application of Schnute's Difference Model

1987 ◽  
Vol 44 (S2) ◽  
pp. s275-s288 ◽  
Author(s):  
Lawrence D. Jacobson ◽  
Wayne R. MacCallum ◽  
George R. Spangler
Keyword(s):  
General Trend ◽  
Lake Superior ◽  
Fishing Effort ◽  
Natural Mortality ◽  
Difference Model ◽  
Gill Nets ◽  
Thunder Bay ◽  
Biomass Dynamics ◽  
Coregonus Artedii ◽  
Lake Herring

Schnute's (1985. Can. J. Fish. Aquat. Sci. 42: 414–429) difference model was used to study the biomass dynamics of lake herring (Coregonus artedii) in Thunder Bay and Black Bay, Lake Superior, during 1948–79. Recruitment to both fisheries appeared to be independent of escapement during previous years. Abundance of lake herring in Black Bay varied without trend during the study period despite a strong peak in effective fishing effort during 1968–70 and a general trend of increasing effort throughout the study period. Abundance of Thunder Bay lake herring declined during 1948–50 and 1959–67 and increased when fishing effort declined. The estimated catchability coefficient for small-mesh gill nets (54–83 mm stretched measure) set in Black Bay for lake herring during November was 0.467/102 km net. The estimated catchability coefficient for small mesh gill nets set in Thunder Bay for lake herring during December was 0.132/102 km net. Estimates of natural mortality rates and recruitment levels for both fisheries were confounded and unreliable. This analysis demonstrates the utility of Schnute's model for management of Great Lakes herring stocks and some difficulties with its application.

scholarly journals Komposisi hasil tangkapan jaring insang dasar di perairan Desa Talise Tambun, Kecamatan Likupang Barat (Composition catches of bottom gillnet in Talise Tambun Waters of Likupang Barat District)

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Fransina Kawarnidi ◽  
Ivor L. Labaro ◽  
Fanny Silloy
Keyword(s):  
Coastal Waters ◽  
Scientific Information ◽  
Mesh Size ◽  
Gill Nets ◽  
Gill Net ◽  
Species Analysis ◽  
The Difference ◽  
Catch Composition ◽  
Descriptive Method ◽  
Better Than

The bottom gill nets are the most common fishing gear in coastal areas, with different mesh sizes.The catch of bottom gill nets is generally dameral fish with different sizes and species. Scientific information about the difference of catch composition in the 3-inch and 4-inch mesh size of bottom gill nets is still poorly available. It is therefore necessary to study a composition of the catch on two bottom gill net mesh sizes of 3 inches and 4 inches, comparing the composition of the quantity and weight of the catch and identify the species of fish caught.  This research was done in coastal waters of Talise Tambun village, Likupang Barat District of Minahasa Utara Regency for two weeks October 2017; following a descriptive method based on case studies. Two unit bottom gill nets were operated seven trips to data colected; and the data were analyzed by composition species analysis and weight composition.The results showed that the composition of the catch quantity of bottom gill net 3-inch 64 fish and 48 species dominated by Rengginan fish 21.88%, while the catching composition of 4-inch mesh size amounted to 91 fishes and 63 species dominated by Swangi as 14.29% .  The weight catch composition of the 3-inch bottom gill net was dominated by sharks of 25.16% with a weight of 33.386 kg, while the 4-inch bottom gill net catch weights were dominated by snapper as 35.71% with a weight of 101,502 kg.The results of the analysis showed that the 3-inch mesh size of bottom gill net catch composition of both the quantity, the species and the catch weight was better than the 4-inch capture composition.Keywords: Bottom gillnet, weight, composition ABSTRAKJaring insang dasar adalah alat tangkap yang banyak ditemukan diwilayah pesisir, dengan ukuran mata jaring yang berbeda-beda.Hasil tangkapan jaring insang dasar umumnya ikan damersal dengan ukuran dan jenis yang berbeda.Informasi Ilmiahtentang perbedaan komposisi hasil tangkapan pada jaring insang dasar mata 3 inci dan 4 inci masih kurang tersedia.Untuk itu perlu suatu penelitian yang bertujuan mengetahui komposisi hasil tangkapan pada dua ukuran mata jaring insang dasar 3 inci dan 4 inci, membandingkan komposisi jumlah dan bobot hasil tangkapan dan mengidentifikasi jenis ikan yang tertangkap.Penelitian ini dilaksanakan di perairanDesa Talise Tambun Kecamatan Likupang Barat Kabupaten Minahasa Utara;  selama 2 minggu, pada bulan Oktober 2017;  dikerjakan dengan mengikuti metode deskriptif yang didasarkan pada studi kasus.Dua unit jaring insang dasar PA Multifilament dengan besar mata masing-masing 3 dan 4 inci dioperasikan selama 7 trip untuk mengumpulkan data; dan data dianalisis dengan analisis komposisi jenis dan komposisi bobot.Hasil penelitian menunjukkan bahwa komposisi jumlah tangkapan  jaring insang dasar mata 3 inci sebanyak  64 ekor dan 48 jenis yang didominasi oleh ikan Rengginan sebesar 21.88%, sedangkan komposisi tangkapan jaring insang dasar 4 inci berjumlah 91 ekor dan 63 jenis yang didominasi oleh  ikan Swangi sebanyak 14.29 %.  Selanjutnya komposisi bobot tangkapan jaring insang dasar mata 3 inci didominasi oleh ikan Hiu sebesar 25.16 % dengan  bobot 33,386 kg, sedangkan komposisi bobot tangkapan jaring insang dasar mata 4 inci didominasi oleh ikan kakap sebanyak 35.71% dengan bobot 101,502 kg. Hasil analisis menunjukkan bahwa komposisi tangkapan jaring insang dasar mata 3 inci baik jumlah, jenis maupun bobot tangkapan lebih baik dibandingkan dengan komposisi tangkapan jaring insang dasar mata 4 inci.Kata-kata Kunci: Jaring insang dasar, bobot, komposisi.

scholarly journals HUBUNGAN PANJANG-BOBOT DAN FAKTOR KONDISI IKAN NILEM (Osteochilus vittatus VALENCIENNES, 1842) DI PERAIRAN WADUK BENANGA, KALIMANTAN TIMUR

2020 ◽  
Vol 19 (2) ◽  
Author(s):  
Jusmaldi Jusmaldi ◽  
Nova Hariani ◽  
Nikmahtulhaniah Ayu Wulandari
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Condition Factor ◽  
Mesh Size ◽  
Growth Patterns ◽  
Male And Female ◽  
Tropical Regions ◽  
Weight Relationship ◽  
East Kalimantan ◽  
Gill Net

Biology of bonylip barb (Osteochilus vittatus Valenciennes, 1842) in Benanga Reservoir, East Kalimantan is not yet known. The purpose of this study was to analyze distribution of the length and body weight of fishes, sex ratio, gonad maturity level, length-body weight relationship, and condition factor. In total 278 fishes samples were collected during the five months, from January to May 2019 with a purposive sampling method at Benanga Reservoir, and gill net with  mesh size 0.5; 1; and 1.5  inches used. The results of this research showed that the total length of the fishes analyzed ranged from 72.21–196.57 mm and body weight ranged from 5.12–89.21 g. The sex ratio of male and female were 1:2.02. The male and female fishes were dominated by mature gonad. The length-body weight relationship models calculated for the total fishes sample was W=1x10-5L2.967 (r=0.988) for males, W=5x10-6L3.199 (r=0.989) for females and W=7x10-6L3.126 (r=0.987) for both sexes. Isometric growth patterns (b=3) were observed in males, meanwhile positive allometric growth patterns (b>3) were observed in females and both sexes. Calculation of the condition factor (K) resulted in 1.181±0.117 for males, 0.949±0.094 for females, and 1.026±0.150 for all specimens. The condition factors of bonylip barb from the Benanga Reservoir inside the range recommended as suitable for freshwater fish species in the tropical regions.   

scholarly journals Fish species composition and size structure exploited by gill net fishery in The New Calabar River, Nigeria

2019 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Olaniyi Alaba Olopade ◽  
Henry Eyina Dienye ◽  
Ogheneforon Oderhohwo
Keyword(s):  
Species Composition ◽  
Fish Species ◽  
Size Structure ◽  
Mesh Size ◽  
Maximum Size ◽  
Abundant Species ◽  
Fish Stock ◽  
Size Selectivity ◽  
Gill Nets ◽  
Gill Net

The purpose of this study was to investigate the species composition and size selectivity of gillnets commonly used by the artisanal fishers in the New Calabar River, Rivers State, Nigeria. The data was collected during February-July 2018 from 3 sampling stations: SI Choba, S2 Ogbogoro, and S3 Iwofe all along the stretch of the river. Twenty-eight fish species were found belonging to 15 families. The prevalent families were Cichlidae, Mugilidae and Clupeidae representing 32.22%, 30.36% and 10.23% of the total catch, respectively. The most dominant species in terms of number were Liza falcipinnis (12.58%) and Mugil cephalous (12.26%) while in terms of biomass, the most abundance species were Xenomystus nigri (24.12%) and Lutjanus agennes (12.50 %). The girth and total lengths of the fishes ranged from 5.20±0.20 to 21.00±0.00 cm and 8.85±0.15 to 28.19±1.13 cm respectively. The length at first capture (L50%) for the most abundant species (Liza falcipinnis) was calculated to be 14.13 cm while that of L25% and L75% were 12.70cm and 15.25cm respectively. It was concluded that the gill nets used in the New Calabar River exploit fish species of small sizes and few medium sized specimens relative to species potential maximum size. It is therefore recommended that for an improved and sustainable exploitation fish stock of the New Calabar River, the use of gillnets of less than 25 mm-mesh sizes and “other gears” should be prohibited.Keywords: gill nets; species composition; mesh size; selectivity; New Calabar River

scholarly journals TIPE PERIKANAN DAN STATUS SUMBERDAYA IKAN TERUBUK (Tenualosa macrura, Bleeker 1852), DI PERAIRAN ESTUARIN BENGKALIS DAN SELAT PANJANG

2018 ◽  
Vol 23 (4) ◽  
pp. 261
Author(s):  
Suwarso Suwarso ◽  
Muhammad Taufik ◽  
Akhmad Zamroni
Keyword(s):  
Sex Ratio ◽  
Species Conservation ◽  
Fishing Effort ◽  
Conservation Area ◽  
Gill Net ◽  
Spawning Stock ◽  
The Status ◽  
Long Time ◽  
Protandrous Hermaphrodite ◽  
Average Size

Ikan terubuk (Tenualosa spp.) adalah ikan estuarin bersifat ‘protandrous hermaphrodite’ dan endemik di estuarin sekitar Bengkalis. Jenis Tenualosa macrura ditemukan di sekitar Bengkalis (Riau), jenis T. ilisha di sekitar Labuhan Batu dan Labuhan Bilik (Sumatra Utara), sedangkan T. toli ditemukan di perairan pantai barat Pemangkat (Kalbar). Sumber daya terubuk di sekitar Bengkalis saat ini sangat menurun akibat eksploitasi dan recruitment overfishing meskipun pembatasan penangkapan telah diterapkan. Tulisan ini membahas status sumber daya ikan terubuk di sekitar Bengkalis dan Selat Panjang berdasarkan data monitoring hasil tangkapan periode 2014-2016 dan observasi lapangan selama 2015-2016. Ikan terubuk merupakan ikan dominan dari enam jenis hasil tangkapan pada gill net, jumlahnya sekitar 15% dari total hasil tangkapan, upaya penangkapan tergolong intensif sehingga penurunan upaya yang dilakukan ternyata kurang signifikan, bahkan pada saat close season dan close area (September sampai November) upaya penangkapan cenderung tinggi. Kondisi ini tentu tidak sesuai dengan tujuan perlindungan terbatas dan konservasi jenis yang diterapkan. Penurunan populasi terubuk tampak nyata dalam bentuk hasil tangkapan (CPUE), sex ratio maupun produksi pendaratan. Ikan kategori “Pias” (ikan jantan) tetap dominan dan semakin banyak, sebaliknya kategori “Terubuk” (ikan betina matang gonad) semakin sedikit, artinya ukuran rata-rata ikan juga semakin kecil. Keberadaan populasi ikan terubuk di sekitar P. Tiga (Kab. Kepulauan Meranti) dengan kondisi matang gonad dan secara genetik memiliki pola DNA yang sama dengan yang berada di Bengkalis. Perluasan daerah konservasi dan perlindungan terbatas terhadap stok-stok tersebut disarankan.The terubuk (Tenualosa spp) or shads, is a estuarine and endemic ‘protandrous hermaphrodite’ fish species. Species Tenualosa macrura is found in estuarine waters around Bengkalis (Riau Province), T. ilisha around Labuhan Batu and Labuhan Bilik (North Sumatera Province) while T. toli in west coast of Pemangkat (West Kalimantan Province). The terubuk reosurce in Bengkalis water is heavily degraded due to high exploitation and recruitment overfishing eventhough fishing limitation is applied. This paper is discussing the status of terubuk/longtail shad (Tenualosa macrura) resources in Bengkalis estuarine and Selat Panjang waters (Kabupaten Kepulauan Meranti) base on data of 2014-2016 catch monitoring data and field observation during 2015-2016. Terubuk is one of 6 dominant catches from gillnet, contributing about 15% of all catch. The fishing effort was so intensive even though management measure is applied to reduce its exploitation. During the close season when fishing on terubuk is banned (in September to November) as well as the ban in close area , the fishing effort has been still high. This condition is not in line with the objective of protecting the terubuk resources. Therefore, this condition must be changed and returned to objective of “limited protection” and “species conservation” by adopting a more strict rule on limiting fishing effort on terubuk through an evaluation. The decreasing of terubuk population can be seen from CPUE, sex ratio and also in landing, short time (2012 – 2016) and long time (18 years). In overall, the “Pias” (adult male) individuals remainned dominant and wereeven getting more in number, while the “Terubuk” (adult female) on the contrary, which means that the average size of actual fish cought was getting smaller. The existence of terubuk population around Pulau Tiga (Kabupaten Kepulauan Meranti) with mature gonad would share the same genetic pattern with population from Bengkalis. This explaines the connectivity between two stocks, at least there might be another spawning stock other than Bengkalis’s. The expand of the conservation area and limited protection on those stocks is highly recommended.

scholarly journals ANALISIS PENANGKAPAN IKAN KAKAP MERAH (Lutjanus spp.) DAN KERAPU (Epinephelus sp.) DI PERAIRAN BARRU, SULAWESI SELATAN

2017 ◽  
Vol 2 (2) ◽  
pp. 101
Author(s):  
Bambang Sumiono ◽  
Tri Ernawati ◽  
Wedjatmiko Wedjatmiko
Keyword(s):  
Growth Characteristic ◽  
Mesh Size ◽  
Catch Rate ◽  
Survey Period ◽  
Gill Nets ◽  
South Sulawesi ◽  
Gill Net ◽  
Long Line ◽  
Catch Composition ◽  
Epinephelus Malabaricus

Perairan di sekitar Barru Sulawesi Selatan merupakan salah satu kawasan terumbu karang yang penting di Selat Makassar. Sebagian besar dari nelayannya melakukan penangkapan ikan dengan menggunakan rawai dasar dan jaring insang dasar. Analisis perikanan ikan kakap merah (Lutjanus spp.) dan kerapu (Epinephelus sp.) dilakukan pada bulan Agustus dan Oktober 2006 dengan penekanan pada deskripsi alat tangkap dan teknik penangkapannya, komposisi hasil tangkapan, dan beberapa aspek biologi ikan kakap merah dan kerapu. Penelitian ini dilakukan dengan cara mengikuti kegiatan nelayan yang menggunakan rawai dasar dan jaring insang dasar di sekitar terumbu karang dan pencatatan data dari pendaratan ikan utama. Untuk kelengkapan data dilakukan wawancara dengan nelayan dan pedagang pengumpul setempat. Hasil penelitian ini menunjukan daerah penyebaran ikan kakap merah dan kerapu terdapat di perairan Barru dan Pangkajene Kepulauan. Pada perairan yang relatif dangkal (<50 m) digunakan pancing ulur dengan satu atau dua mata pancing (nomor 6 atau 7). Jaring insang dasar digunakan di luar daerah karang, satu pis (tinting) mempunyai panjang 40 m dan dalam 5 m dengan ukuran mata jaring 4 inci. Satu unit jaring terdiri atas 60 pis. Di perairan yang lebih dalam (lebih dari 50) digunakan rawai dasar yang terdiri atas 600 mata pancing (nomor 7 atau 8). Lama trip penangkapan tiga hari. Diperoleh laju pancing pada rawai dasar berkisar 6-8% dan laju tangkap jaring insang dasar berkisar antara 40-60 kg/kapal/tiga hari. Komposisi hasil tangkapan didominansi (47,2%) oleh ikan kakap merah (famili Lutjanidae) yang terdiri atas jenis Lutjanus malabaricus, Lutjanus hyselopterus, Lutjanus sebae, Lutjanus vittus, dan Pinjalo pinjalo. Ikan kerapu (famili Serranidae) terdiri atas jenis Epinephelus areolatus, Epinephelus malabaricus, Epinephelus microdon, dan Plectropomus maculatus. Kecuali itu tertangkap juga ikan lencam (famili Lethrinidae). Pengamatan biologi jenis ikan Lutjanus malabaricus dan Epinephelus malabaricus yang merupakan hasil tangkapan dominan masing-masing diperoleh nilai modus panjang cagak 48 dan 56 cm dengan modus bobot masing-masing 1,8 dan 2,15 kg. Karakteristik pertumbuhan kedua jenis tersebut adalah allometrik positif.The sea waters around Barru, South Sulawesi is one of the coral reef parts in Makassar Strait. Most of the fishermen use fishing lines, bottom long lines, and bottom gill nets in their fishing activities. Analysis of red snappers (Lutjanus spp.) and groupers (Epinephelus sp.) fisheries in this area were carried out in August and October, 2006. The emphasis is focused on the discription of fishing gear and fishing technique, catch composition, and some of biological aspect of red snappers and groupers. The research was done by following the fishing operations of bottom long line and bottom gill net conducted by fishers in the waters around coral reefs. Data were recorded in some importantant landing place at Barru, and interview of some fishermen to complete data and information needed. The result showed that the distribution of red snapper and groupers occured in the waters around Barru and Pangkajene Islands. In the shallow waters (<50 m) the fishermen use a lightly weighted hand line, with one or two relativelly small hooks (nomor 6 or 7). Bottom gill nets are frequently used in shallow back reef areas with one piece of 40 m in length, and 5 m in depth, with mesh size of 4 inches. One unit of the gear consisted of 60 piece of the nets. Meanwhile, in deeper waters (50-150 m), the number of hooks (nomor 7 or 8) in bottom long line operated 600 hooks for each unit. All fishing gears usually have three days at sea for a fishing trip. The average of catch rate (hook rate) for a trip of bottom long line was 6-8% (6 or 8 individual fish for 100 hooks). Meanwhile, the catch rate of bottom jaring insang was about 40-60 kgs/boat/3 days trip. The catches were dominated by the family Lutjanidae in which the red snappers species (reached to 47.2% at this survey period) including Lutjanus malabaricus, Lutjanus hyselopterus, Lutjanus sebae, Lutjanus vittus, and Pinjalo pinjalo. Meanwhile the groupers (family Serranidae) were dominated by species of Epinephelus areolatus, Epinephelus malabaricus, Epinephelus microdon, and Plectropomus maculatus. Other groups were emperors (Lethrinidae) and Gymnocranius. The biological measured for Lutjanus malabaricus and Epinephelus malabaricus as a dominant landed showed the modus of length were 48 and 58 cmFL, respectivelly. Meanwhile the modus of weight were 1.8 and 2.35 kg. The growth characteristic of both species were positive allometric. It means that increasing the weight was faster than their length.

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