scholarly journals BIODIVERSITY AND LENGTH FREQUENCIES OF SHARKS CAUGHT IN THE INDIAN OCEAN

1970 ◽  
Vol 32 (2) ◽  
pp. 139-146
Author(s):  
Dharmadi ◽  
K. Sumadhiharga ◽  
Fahmi
Keyword(s):  
Indian Ocean ◽  
Field Observation ◽  
Size Structure ◽  
West Java ◽  
Central Java ◽  
Landing Sites ◽  
The Indian Ocean ◽  
High Diversity

Study on biodiversity and size structure of sharks in the Indian Ocean was conducted at several landing sites and fish markets, i.e. Pelabuhanratu (West Java), Cilacap (Central Java), Kedonganan (Bali) and Tanjung Luar (East Lombok ). Field observation was done from April 2001 to March 2006. The results showed that there were 86 species of sharks belonging to 16 families in the Indian Ocean. The sharks were dominated by family of Carcharhinidae and Squalidae with 24 and 23 species, respectively. A high diversity of sharks was found at Kedonganan-Bali (49 species), at Tanjung Luar (47 species), at Cilacap (32 species) and at Pelabuhanratu (27 species). Size of sharks landed at those landing sites varied in length, the length of Carcharhinus amblyrhynchos was between 90 cm and 170 cm TL, C. sorrah (55-155 cm), C. obscurus (205-295 cm) and P glauca was caught at length between 205-300 cm.

scholarly journals Recruitment and abundance estimation of glass eel genus Anguilla in three large estuaries on the coast of Sukabumi West Java

2021 ◽  
Vol 322 ◽  
pp. 01037
Author(s):  
Triyanto ◽  
Gadis Sri Haryani ◽  
Mohammad Mukhlis Kamal ◽  
Iwan Ridwansyah ◽  
Fauzan Ali ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Rainy Season ◽  
Dominant Species ◽  
Water Discharge ◽  
Abundance Estimation ◽  
West Java ◽  
Glass Eel ◽  
The Indian Ocean ◽  
Glass Eels

The rivers on the Sukabumi Coast flow into the Indian Ocean. Three major rivers, namely the Cimandiri River, Cikaso River, and Cibuni River, are sources of glass eel fishing. This study aims to determine the recruitment and estimate of glass eel abundance for future glass eel management. The study was conducted from November 2020-April 2021. Estimation of glass eel abundance was carried out using a fyke net. The glass eel calculation is determined based on the number of glass eels caught, the water discharge entering the fyke net, the water discharge in the estuary, and other variables. The results showed that glass eel recruitment began at the beginning of the rainy season in November 2020 and lasted at the end of the study in April 2021. Anguilla bicolor bicolor is a dominant species of glass eel found in the three river estuaries. The estimated abundance of glass eel was approximately 2,583,438-13,556,650 ind./year or 326,24-1,812 kg/year. The abundance of glass eels at the estuary of Cimandiri River was higher than that of the estuary of Cibuni River and the estuary of Cikaso River.

scholarly journals Comparison of handline tuna catches in Indian Ocean and Banda Sea waters

2021 ◽  
Vol 322 ◽  
pp. 03004
Author(s):  
Ignatius Tri Hargiyatno ◽  
Regi Fiji Anggawangsa ◽  
Moh. Natsir ◽  
I. Gede Bayu Sedana ◽  
Agustinus Anung Widodo ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Average Length ◽  
Fishing Ground ◽  
Katsuwonus Pelamis ◽  
Thunnus Obesus ◽  
Significant Difference ◽  
Landing Sites ◽  
The Indian Ocean ◽  
Catch Composition ◽  
First Maturity

There are two essential landing sites for handline tuna in Indonesia: Palabuhanratu (in the Indian Ocean) and Kendari (in the Banda Sea). This paper analyzes handline catches from the Indian Ocean and Banda Sea waters as the main fishing ground. The catch composition of the handline tuna landed in Kendari is more varied than Palabuhanratu. Several species commonly caught are yellowfin tuna (Thunnus albacares), skipjack tuna (Katsuwonus pelamis), bigeye tuna (Thunnus obesus) as a target species, and some billfish species as bycatch. Mean CPUE for handline tuna landed in Palabuhanratu is lower than Kendari. A significant difference is based on the monthly mean CPUE variation between Palabuhanratu and Kendari landing sites (p < 0.001). Handline catches in Palabuhanratu had a more comprehensive range of length sizes than Kendari, using a two-sample K-S test showed significant differences (p < 0.001). The fish size landed in Kendari is relatively smaller than Palabuhanratu. The average length of fish caught by handline is smaller than the length at first maturity (Lm) value in both landing sites. The use of large size hook for hand lines is recommended for catching tunas in this area.

The influence of the Indian Ocean Dipole on interannual variations in phytoplankton size structure as revealed by Earth Observation

2012 ◽  
Vol 77-80 ◽  
pp. 117-127 ◽  
Author(s):  
Robert J.W. Brewin ◽  
Takafumi Hirata ◽  
Nick J. Hardman-Mountford ◽  
Samantha J. Lavender ◽  
Shubha Sathyendranath ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Indian Ocean Dipole ◽  
Size Structure ◽  
Earth Observation ◽  
Interannual Variations ◽  
The Indian Ocean ◽  
Phytoplankton Size ◽  
Phytoplankton Size Structure

scholarly journals PERIKANAN TUNA SIRIP KUNING (Thunnus albacares Bonnaterre, 1788) PADA ARMADA TONDA DI SAMUDERA HINDIA SELATAN JAWA

2019 ◽  
Vol 11 (3) ◽  
pp. 161
Author(s):  
Maya Agustina ◽  
Bram Setyadji ◽  
Prawira Atmaja Rintar Pandapotan Tampubolon
Keyword(s):  
Indian Ocean ◽  
Size Structure ◽  
Landing Site ◽  
Yellowfin Tuna ◽  
Fishing Gear ◽  
Thunnus Albacares ◽  
Skipjack Tuna ◽  
The Indian Ocean ◽  
Average Size ◽  
Relationship Of

Tuna sirip kuning (Thunnus albacares) merupakan hasil tangkapan terbanyak dibandingkan dengan jenis tuna lainnya di Indonesia. Ketersediaan stok tuna sirip kuning di Samudra Hindia, pada saat ini, diperkirakan dalam keadaan lebih tangkap. Oleh karena itu, pengelolaan secara tepat dan bertanggungjawab penting dilakukan untuk melindungi spesies tuna, salah satu caranya dengan mengkaji alat tangkap yang digunakan. Tulisan ini bertujuan untuk mengungkapkan produktivitas dan hasil tangkapan armada tonda, serta struktur ukuran dan hubungan panjang bobot ikan tuna sirip kuning yang di daratkan di selatan Jawa. Komposisi tangkapan tertinggi dari armada tonda diseluruh pendaratan ikan tuna di selatan Jawa terdiri atas tuna sirip kuning dan cakalang. Analisis CPUE menunjukkan hasil yang fluktuatif di setiap lokasi pendaratan tuna sirip kuning di Selatan Jawa. Tuna sirip kuning yang tertangkap di selatan Jawa dengan armada tonda sebagian besar adalah ikan yang belum layak tangkap karena berukuran kurang dari 100 cmFL. Struktur ukuran panjang tuna sirip kuning yang tertangkap semakin ke Timur semakin panjang ukurannya. Pola pertumbuhan tuna sirip kuning yang tertangkap di Binuangeun memiliki pola isometrik, PPN Palabuhanratu bersifat allometrik Positif, PPP Sadeng, P2SKP Pacitan, PPN Prigi dan P2SKP Sendang Biru bersifat allometrik negatif. Yellowfin tuna (Thunnus albacares) is the largest catch compared to other tuna species in Indonesia. The availability of yellowfin tuna stock in the Indian Ocean, at present, is estimated to be in overfished condition. Therefore, proper and responsible management is important to protect the species. One of the ways is by studying the used fishing gear. This paper aims at determining vessel’s productivity, as well as composition, size structure and length-weight relationship of yellowfin tuna catches from troll line fleet in the Indian Ocean part of south Java. The highest catch of tuna in all of the troll line landing places was yellowfin tuna, following by skipjack tuna. CPUE analysis showed fluctuating results at each landing site. Yellowfin tuna sizes caught by troll line fleet were mostly less than 100 cmFL and categorized as should not be properly caught. Geographically, getting to the east the average size of the catches tend to be larger. The growth pattern of yellowfin tuna catches landed in Binuangeun was isometric; Palabuhanratu was positive allometric; while those landed in Sadeng, Pacitan, Prigi and Sendang Biru were negative allometric.

scholarly journals KOMPOSISI DAN FLUKTUASI HASIL TANGKAPAN IKAN CUCUT DOMINAN YANG TERTANGKAP RAWAI TUNA PERMUKAAN

2017 ◽  
Vol 14 (4) ◽  
pp. 371
Author(s):  
Dharmadi Dharmadi ◽  
Suprapto Suprapto ◽  
Agustinus Anung Widodo
Keyword(s):  
Indian Ocean ◽  
Total Catch ◽  
Fishing Activity ◽  
Prionace Glauca ◽  
Long Line ◽  
Landing Sites ◽  
Silky Shark ◽  
The Indian Ocean ◽  
Carcharhinus Falciformis ◽  
Catch Composition

Perikanan rawai tuna memiliki kontribusi cukup besar terhadap hasil tangkapan ikan cucut (Requiem shark sp.) di perairan Samudera Hindia. Hasil tangkapan rawai tuna sebagian besar didaratkan di 2 pendaratan ikan utama yaitu Pelabuhan Perikanan Pelabuhan Ratu dan Pelabuhan Perikanan Samudera Cilacap. Kegiatan penelitian untuk mengetahui komposisi dan fluktuasi hasil tangkapan ikan cucut (Requiem shark sp.) dominan pada rawai tuna permukaan berbasis di 2 lokasi pendaratan ikan tersebut dilakukan pada tahun 2004. Hasil penelitian menunjukkan bahwa komposisi hasil tangkapan cucut (Requiem shark sp.) pada rawai tuna permukaan didominansi oleh jenis ikan cucut karet atau selendang (Prionace glauca) antara 40 sampai dengan 90%, sedangkan komposisi jenis ikan cucut lain seperti ikan cucut lanjaman (Carcharhinus falciformis dan Carcharhinus sorrah), cucut paitan (Alopias superciliosus), cucut tikusan (Alopias pelagicus), dan cucut mako (Isurus sp.) antara 3 sampai dengan 30%. Hasil tangkapan ikan cucut (Requiem shark sp.) terhadap hasil tangkapan total rawai tuna permukaan antara 5 sampai dengan 25% pada tahun 2004 dari rata-rata 85 unit kapal rawai tuna yang beroperasi di perairan Samudera Hindia. Hasil tangkapan ikan cucut (Requiem shark sp.) tertinggi terjadi pada bulan Juli sampai dengan Agustus. Hasil tangkapan ini berkaitan dengan kondisi cuaca (Requiem shark sp.) pada saat nelayan melakukan penangkapan ikan di laut. Tuna long lines fisheries have more contributed on the catch of shark (Requiem shark sp.) in the Indian Ocean. Most of catch from tuna long lines landed at two main landing sites of tuna long line which operated in the Indian Ocean were Pelabuhan Ratu and Cilacap. This study was conducted at that two landing sites during 2004. The result showed that shark (Requiemshark sp.) catch composition on tuna long line was dominated by blue shark, Prionace glauca (40 to 90%), while other sharks i.e. silky shark (Carcharhinus falciformis), spot tail shark (Carcharhinus sorrah), big eye thresher (Alopias superciliosus), pelagic thresher (Alopias pelagicus), and mako shark (Isurus sp.) between 3 to 30% from the total catch of shark (Requiem shark sp.). Percentage catch of sharks (Requiem shark sp.) againts total catch of tuna surface long line during 2004 was ranging 5 to 25% from everage of 85 unit of tuna long line boat that operated in the Indian Ocean. Catch fluctuation related with the weather conditon when the fishers are fishing activity at sea. The high catch of shark (Requiem shark sp.) was occur on July until August.

scholarly journals DUGAAN MUSIM PEMIJAHAN IKAN CAKALANG (Katsuwonus pelamis) DI PERAIRAN SAMUDRA HINDIA SELATAN JAWA DAN NUSA TENGGARA

2020 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Yoke Hany Restiangsih ◽  
Anthony Sisco Panggabean ◽  
Erfind Nurdin
Keyword(s):  
Indian Ocean ◽  
Spawning Season ◽  
Katsuwonus Pelamis ◽  
Landing Sites ◽  
The Status ◽  
The Indian Ocean ◽  
Biological Sampling ◽  
Average Size ◽  
First Maturity ◽  
Somatic Index

Sumberdaya ikan cakalang (Katsuwonus pelamis) merupakan ikan ekonomis penting dan utama di Indonesia. Tingginya tingkat pemanfaatan ikan cakalang di Samudra Hindia menjadi hal yang sangat rawan dan perlu kehati-hatian dalam pengelolaannya. Tersedianya data dan informasi tentang musim pemijahan merupakan bagian dari pengetahuan yang diperlukan untuk mengetahui status sumberdaya bagi upaya pengelolaannya. Penelitian ikan cakalang dilakukan berdasarkan pengambilan contoh biologi dibeberapa tempat pendaratan ikan (Palabuhan Ratu, Prigi dan Labuhan Lombok). Penelitian dilaksanakan pada bulan Januari sampai dengan Nopember 2016. Pendugaan musim pemijahan menggunakan pendekatan indeks kematangan gonad (IKG) bulanan. Distribusi ukuran ikan yang tertangkap dengan menggunakan pancing tonda berkisar antara 24 – 66 cm. Ukuran rata-rata pertama kali tertangkap (Lc) pada panjang 41,6 cm, ukuran pertama kali matang gonad (Lm) 42,5 cm. Berdasarkan fluktuasi IKG musim pemijahan ikan diduga berlangsung pada bulan April dan Nopember.Skipjack tuna (Katsuwonus pelamis) are most important and economically fish in Indonesia. The highest exploitation skipjack in the Indian Ocean is very vulnerable are requires caution in its management. The availability of data and information about the spawning season is a part of the knowledge needed to determine the status of resources for management efforts. This research was carried out based on biological sampling at several fish landing sites (Palabuhanratu, Prigi, and Labuhan Lombok). This research was conducted from January until to November 2016. Estimating of the spawning season was used a monthly Gonado Somatic Index (GSI) approach. The range of size distribution from of fish caught using troll line were 24 until 66 cm. The average size of first caught (L50%) at a length was 41.6 cm, the size of the length of first maturity (Lm) was 42,5 cm. Based on the GSI fluctuation, spawning season was done in April and November.

scholarly journals Estimating Fishing Effort and Spatio-Temporal Distribution of Longline Vessels in the Indian Ocean

2021 ◽  
Vol 8 ◽  
Author(s):  
Febrianto W. Utama ◽  
Xavier Hoenner ◽  
Britta Denise Hardesty ◽  
David Peel ◽  
Jessica H. Ford ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Temporal Distribution ◽  
Fishing Effort ◽  
Fishing Activity ◽  
Widespread Occurrence ◽  
Fisheries Resources ◽  
Spatial Shift ◽  
Landing Sites ◽  
The Indian Ocean ◽  
Spatio Temporal

Protein from fish is essential for feeding the world’s population and is increasingly recognized as critical for food security. To ensure that fisheries resources can be sustainably maintained, fisheries management must be appropriately implemented. When logbook and landing records data are not complete or are incorrect, it is challenging to have an accurate understanding of catch volume. Focusing on Indonesian longline vessels operating in the Indian Ocean from 2012–2019 (n = 1124 vessels), our aims were to (1) assess compliance through identification of landing sites and potentially illicit behavior inferred by interruptions in VMS transmission, and (2) understand how the fishery operates along with quantifying the spatio-temporal distribution of fishing intensity by applying a Hidden Markov Model, which automatically classified each VMS position as fishing, steaming and anchoring. We found vessel compliance gaps in 90% of vessels in the dataset. Compliance was questionable due both to the widespread occurrence of long intermissions in relaying VMS positions (mean = 17.8 h, n = 973 vessels) and the use of unauthorized landing sites. We also observed substantial changes in fishing effort locations among years. The introduction of regulatory measures during the study period banning transshipment and foreign vessels may be responsible for the spatial shift in fishing activity we observed, from encompassing nearly the whole Indian Ocean to more recent intense efforts off western Sumatra and northern Australia.

scholarly journals Notes on the Bryophytes of Madagascar 6. Epiphyllous liverworts from Zahamena National Park

2021 ◽  
Vol 9 (1) ◽  
pp. 36-43
Author(s):  
Tamás Pócs ◽  
Min Chuah-Petiot
Keyword(s):  
Indian Ocean ◽  
Vascular Plants ◽  
National Park ◽  
Type Locality ◽  
Missouri Botanical ◽  
Northeastern Part ◽  
The Indian Ocean ◽  
High Diversity ◽  
Ocean Islands

Dr. Min Chuah-Petiot, together with staff of Missouri Botanical GardenAntananarivo station, visited in 2002 the Zahamena National Park in the northeastern part of central Madagascar. They collected epiphyllous liverworts, which are deposited in TAN and a set of small duplicates were sent to Tamás Pócs for identification, which are now kept in EGR in the form of microslides. The Zahamena National Park is notorious for its high diversity of animals and vascular plants, including several endemics. But hitherto, few liverworts were collected there. This enumeration contains 28 species. None of them is new to the island, but three were known before only from their type locality (Allorgella rabenorii Tixier, Cololejeunea plagiochiliana Tixier, Cololejeunea subinflata Tixier) and eight are endemics of Madagascar or the Indian Ocean islands.

scholarly journals Spawning Potential Ratio (SPR) Approach as a Management Measure of Skipjack Sustainability Record from Cilacap Fishing Port, Central Java, Indonesia

2021 ◽  
Vol 13 (2) ◽  
pp. 199
Author(s):  
Yonvitner Yonvitner ◽  
Mennofatria Boer ◽  
Rahmat Kurnia
Keyword(s):  
Growth Rate ◽  
Size Structure ◽  
Size Distributions ◽  
Frequency Data ◽  
Central Java ◽  
Management Measure ◽  
Spawning Potential Ratio ◽  
The Indian Ocean ◽  
The Impact ◽  
Poor Management

Highlight Research:Spawning potential ratio (SPR) based on the length and frequency data is a substitution approach for data-poor management in fisheriesGonad maturity is an indicator to ensure recruitment and stock sustainability. Therefore important to evaluate the impact of fishing capture on the size and length of fishSpawning potential ratio of skipjack relatively low and potential medium impact on risk sustainability AbstractWhen data is limited, management measurement from fisheries makes it possible to use natural history data to analyze the potential spawning ratio (SPR). This research aimed to determine skipjack fish management measure from the Indian Ocean landed at Cilacap Fishing Port through the SPR approach. The study was conducted in December 2014 to March 2015 using length and reproduction data. The analysis consisted of the size structure, growth rate, and asymptotic length that were analyzed using FISAT II program and length at fifty percent maturity (Lm50). The SPR analysis used SPR software from the application in http://barefootecologist.com.au/lbspr. The size distributions of skipjack obtained were a length of 220-790 mm and an average dominant length of 311-371 mm. The asymptotic length obtained was 831.57 mm, with growth rate and natural mortality of 1.1 and 1.44 per year respectively. The population proportion of 50% reaching gonad maturity (Lm50) was found at a length of 494.75 mm and (Lm95 = 522.39 mm) with an M/k ratio of 1.309. The length selectivity level was caught 50% (SL50 = 317.36 mm) and 95% (SL95 = 373.1 mm). The spawning potential ratio (SPR) ranged from 2-4 with an average of 4% during observation. The SPR potential, which is lower from the standardized threshold of 40%, indicates many young fish populations are caught, and the potential for overfishing is high, high risk, and low sustainability.

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