Klorofil-a banyak ditemukan pada fitoplankton dan menjadi indikator kesuburan perairan. Keberadaan fitoplankton ditandai dengan kandungan klorofil-a yang tinggi dan diikuti oleh keberadaan zooplankton yang akhirnya mempengaruhi keberadaan organisme perairan lainnya seperti ikan pelagis kecil maupun ikan pelagis besar sebagai suatu rantai makanan. Interaksi antara konsentrasi klorofil-a terhadap keberadaan dan konsentrasi ikan pelagis di Laut Jawa belum banyak diketahui. Penelitian ini dimaksudkan untuk mengetahui hubungan interaksi antara klorofil-a terhadap konsentrasi ikan pelagis. Penelitian dilakukan dengan mengumpulkan data runtun waktu hasil tangkapan beberapa jenis pelagis besar dan kecil yang didaratkan di PPI Pekalongan tahun 2007-2011 serta data runtun waktu konsentrasi klorofil-a dari perairan utara Jawa yang diperoleh dari informasi sekunder.Metode analisis korelasi linear sederhana (bivariate correlation) digunakan untukmengetahui ada atau tidaknya pengaruh antar variabel klorofil-a dan konsentrasi ikan pelagis. Hasil penelitian menunjukkan bahwa ikan layang (Decapterus russelli) paling nyata mendapat pengaruh dari konsentrasi klorofil-a (P<0,05) dan berkorelasi positif terhadap konsentrasi klorofil-a dengan nilai koefisien korelasi ( r ) sebesar 0,56, sedangkan ikan pelagis lainnya berkorelasi negatif. Ikan tongkol (Euthynnus affinis) posisinya menempati rantai makanan paling tinggi sebagai pemangsa, mempunyai korelasi positif (r = 0,5) terhadap Rastrelliger kanagurta dan r = 0,56 terhadap Amblygaster sirm.Chlorophyll-a is a light-absorbing pigment that can be found in photosynthetic organisms such as algae and phytoplankton. The evidence of phytoplankton that indicated by high contents of chlorophyll-a may followed the evidence of zooplankton and other micro aquatic organism as a food chain component. An overview of interrelationships between chlorophyll-a and pelagic fishes in the waters around Java Sea have not much investigated. The research was attempted to study the interaction between chlorophyll-a abundance and the abundance of small and large pelagic as well as relationship among small and large pelagic as prey-predators component. Research conducted by collecting time series catch data of small and large pelagic species landed at PPI Pekalongan during the period of 2006-2012, as well as the data of chlorophyll-a abundance through previous research studies. The results showed that layang (Decapterus russelli) was the most significant species that positively correlated to abundance of chlorophyll-a (P < 0.05) with value of r = 0.6. while others pelagic species have negative correlation. As a predator species, tongkol (Euthynnus affinis) was positively correlated ( r = 0.5) to the abundance of banyar (Rastrelliger kanagurta) as well as juwi (Amblygaster sirm) with r value 0.56.
<p>Sistem Danau Malili yang terdiri dari Danau Matano, Towuti, Mahalona, Wawantoa, dan Masapi merupakan satu kesatuan sistem danau yang mempunyai keanekaragaman ikan yang cukup tinggi dan endemik. Danau Malili memiliki nilai strategis tersendiri karena keanekaragaman hayati yang tidak ditemukan di daerah lain. Keberadaan sumberdaya ikan tersebut semakin terancam akibat aktifitas manusia diantaranya i) pencemaran, ii) introduksi ikan, dan iii) budidaya ikan dalam happa yang tidak terkontrol. Untuk menjaga kelestarian sumberdaya ikan di komplek Danau Malili diperlukan upaya pengelolaan yang lestari. Tujuan dari penulisan ini adalah untuk merumuskan langkah pengelolaan sumberdaya perikanan di komplek Danau Malili secara berkelanjutan. Hasil studi menunjukkan sebanyak 59 jenis ikan ditemukan di komplek Danau Malili, 38 jenis ikan diantaranya adalah jenis endemik dan 18 jenis ikan dikategorikan sebagai jenis ikan langka berdasarkan IUCN 2001. Disamping itu, di komplek Danau Malili telah diintrodusikan tidak kurang dari 16 spesies ikan. Upaya untuk menjaga kelestarian sumberdaya ikan asli tersebut antara lain: i) pengendalian populasi ikan asing invasif, ii) penetapan suaka perikanan, iii) domestikasi, iv) <em>re-stocking</em>, v) pengendalian usaha budidaya ikan dalam happa.</p><p>The Malili lake system consists of five interconnected lakes: Matano, Towuti, Mahalona, Wawantoa and Masapi. It’s unique habitat plays an important role of various native and endemic fishes. Currently, endemic fish in Malili lake system are increasingly threatened by human activities<br />including i) contamination, ii) invasif fish species or fish introduction, and iii) uncontrolling cage culture. The aim of this paper is to formulate fisheries management effort in Malili Lake system to realize sustainability. Previous studies recorded as many as 59 species were found, consists of 38 endemic, 18 species categorized as endangered and 16 known as introduced species. Management effort should be addressed to preserve sustainable fish resources include: i) controlling invasive alien species, ii) establishing reserve area, iii) domestication, iv) re-stocking, v) controlling of cage culture.</p>
ABTRACTThis study was conducted in western Sumatera and since October 2013 to June 2014. The sampling locations in Banda Aceh and Sibolga-North Sumatera which were the largest base of fisheries in western Sumatera region. Shark landing recorded by enumerators was used as sampling data daily. This research aim to describ sex ratio, size composition, catch composition of sharks, and length at first maturity. In Banda Aceh, the sharks as target fish collected by sorting the bycatch from tuna longlines and tuna handlines. In Sibolga, sharks is bycatch from fish net, bottom gillnet and purse seine. Overall, there were 20 species of shark caught in west Indian Ocean and landed at those fish landing sites, dominated by Spot tail shark (23%) and Silky shark (13%), whereas Hammerhead shark contributed about 10% and Oceanic whitetip shark was only less than 1%. Almost of Spot tail shark, Silky shark, and Scalloped hammerhead that caught in that area were immature, while for the almost part of Tiger shark and Pelagic thresher were matured. The sex ratios for Spot tail shark, Silky shark, Tiger shark, Pelagic thresher, and Scalloped hammerhead caught and landed at Lampulo and Sibolga fish landing sites were not balance. The length at first maturity for Spot tail shark was Lm=87,1 cm and Lm = 213,2 cm total length for Tiger shark.
Cagar biosfir Giam Siak Kecil (GSK) merupakan ekosistem paparan banjiran yang unik dengan sumberdaya ikan yang beragam. Terdapat beberapa permasalahan terkait pemanfaatan sumberdaya perikanan diantaranya penurunan jumlah dan jenis sumberdaya perikanan. Salah satu upaya pengelolaan perikanan yang digunakan adalah pendekatan ekosistem (Ecosystem Approach to Fisheries Management/EAFM). Tulisan ini bertujuan untuk merumuskan pengelolaan sumberdaya perikanan melalui pendekatan ekosistem di rawa banjiran GSK Provinsi Riau. Jenis ikan yang ditemukan sebanyak 37 jenis ikan, 10 jenis diantaranya merupakan ikan ekonomis penting, sementara 5 jenis ikan mengalami kelangkaan diantaranya arwana (Schleropages aureus), belida (Chitala sp), patin (Pangasius sp), jalai (Channa maruliodes). Nilai beberapa domain pada pengelolaan perikanan GSK menunjukkan skor pada kategori buruk (dibawah reference point) yakni pada domain penangkapan, kelembagaan dan ekonomi. Namun, secara umum kondisi pengelolaan rawa banjiran GSK tergolong dalam kategori sedang (nilai 1,53). Focus group discussion merumuskan langkah-langkah pengelolaan yang diperlukan diantaranya: 1) restocking ikan asli. 2) pengembangan kawasan suaka perikanan, 3) peningkatan pengawasan terhadap praktek-praktek penangkapan ikan ilegal dan merusak, 4) penguatan kelembagaan pengelolaan perikanan, dan 5) monitoring hasil tangkapan ikan beserta evaluasi pengelolaannya.Giam Siak Kecil Biosphere Reserve is a part of unique floodplain ecosystem, which is inhabited by various fresh water fish species. The catches of some native species have curtailed over the last decade since the local fishers often use destructive fishing practices and gears. A sustainable management approach needs to be addressed to avoid over-exploitation and to restore the stock. This research aimed to formulate proper management approach that can be applied to the floodplain ecosystem of Giam Siak Kecil Biosphere Reserve. The research found that at least 37 species of fish were recorded, 10 of them were economically important species. There were five species categorized as rare species such as Arwana (Schleropages aureus), Belida (Chitala sp), Patin (Pangasius sp), and Jalai (Channa maruliodes). EAFM indikators showed that the lowest score (below the reference point) were found on fishery domain, organization domain, and economy domain. Nevertheless, it could be concluded that floodplain ecosystem of Giam Siak Kecil Biosphere Reserve was categorized in middle class category, with average scores of 1.53. Based on the findings above, the formulation of management purposed should be addressed to: 1) restocking native fishes, 2) developing fishery sanctuary, 3) increase surveillance of illegal fishing practices, 4) strengthening fishers organizations, 5) monitoring and evaluating the catch on weekly or monthly basis.
Cantrang- a modified Danish seine that targets demersal fish and squid in the Java Sea- has been banned partially in all Indonesian waters since 2015. The policy goal was to limit the ecological impact by reducing the number of the fleet. This study compares the technical efficiency (T.E.) of cantrang fishing before and after the ban and identifies input technology that affects fleet efficiency. A Data Envelopment Analysis (DEA) was used to calculate the Technical Efficiency of the cantrang. In this case, the T.E. measures the ability of cantrang to maximize catch using a given set of production inputs such as Goss Tonnage (G.T.), fishing duration, and the number of skippers using the time series daily landing data from 2007 to 2017. The results show pure and scale efficiency of the fleet increases considerably during the after-ban period compared to the before-ban period. This relatively high technical efficiency at post-ban occurred due to the meaningful reduction of fishing days while optimizing the number of onboard skippers per vessel. Although the portion of skippers per vessel increases substantially at post-ban, this growth minimizes the onboard fishshorting, packaging, and grading works. Therefore, these tasks can be done faster than before.
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