Understanding the geographic distribution of tropical anguillids is important for the conservation of these species. Delimitation of species distribution area is a fundamental task with important implications for the understanding of biodiversity and conservation. However, their geographic ranges are poorly understood, mostly because of the technical difficulties of identifying anguillids by morphological characteristics, especially at the glass eel stage. The current work aims to provide the information on recruitment of tropical anguilid eels in the Kedurang River by using analysis of species identification of an informative DNA segment of Cytochrome Oxidase Sub unit1. Results showed that PCR, sequencing and analysis of an informative DNA can be a useful complement to morphological study for more complete biodiversity assessments. The anguillid eels found in Kedurang River were identified and further validated as A. bicolor bicolor, A. interioris, A. bengalensis bengalensis, and A. marmorata through glass and adult eels. This study suggests the occurrence of A. interioris in Estuary of Sumatera River would provide the first confirmation for this species in the territory. The information can be useful for understanding the geographic distribution this species for the establishment and allocation of risk categories to species, both in national protection lists and in those of treaties and international conventions.
Indonesia is one of the countries with high biodiversity of freshwater fishes. One freshwater fish with a wide distribution in Asia with high economic potency for ornamental fish is dwarf snakehead. However, research on genetic characterization of dwarf snakehead from Indonesia is very limited. Therefore, this research aimed to compare genetic characterization of the dwarf snakehead from rice field irrigation at Donomulyo Village (Malang, East Java) and from Keji River (Magelang, Central Java). This study used a PCR method with universal primers: 16Sar and 16Sbr. The data obtained in this study were then analyzed using DNASTAR, BLAST, Mesquite, MEGA, DnaSP, and NETWORK. The results revealed the genetic distance between dwarf snakehead from rice field irrigation at Donomulyo Village and from Keji River was 1.36%. The divergence of GC content, haplotype number, variables sites, haplotype diversity, and nucleotide diversity in both populations exist. The results of this study are expected to arrange 16S mitochondrial DNA Library of dwarf snakehead from Indonesia which is useful for a reference in the conservation and utilization and management of dwarf snakehead in their habitat.
Increasing the amount of by-catch has become one of the causes of the decline in fish stocks that can threaten the sustainability of world fisheries. It may occur in small local brackish-water fisheries, especially in one of the tidal canals of North Aceh, i.e., Krueng Jambo Aye. Therefore, the investigation composition of the main catch and by-catch in a tidal channel of Krueng Jambo Aye is an essential indicator to describe the ecosystem impact by these fisheries. This study aims to determine the comparison of the composition of the main catches and by-catches, to determine the types of by-catches, and to identify the catch rate. The method used in this study is a field data collection and survey methods. The data analysis used was a capture rate analysis. The results showed that the main catches are more dominated by 72% while the by-catch by 28%. There are five species of by-catch with high economic value and nine species with low commercial value. The catch rate of the two catches are 0.42 kg per hour for the main catch and 0.16 kg per hour for the by-catch. It is expected that the results of this study can be used as necessary information to develop the fisheries improvement program in this area.
This research examines tuna pole-and-line landings data by focusing on trend and effort levels in Larantuka, Flores Timur District, Nusa Tenggara Timur Province, Indonesia. The analyzed fisheries data indicate trends that might be useful for monitoring and management purposes. The research data used were from the landings, number of trips, and fishing gear data on tuna pole-and-line from 2005 to 2014 provided by local fisheries authority. Data was also sourced from previous publications and field surveys. This research analyzes data on tuna pole-and-line fishery trends, relationships between landings, number of trips, and fishing gears used. Overall, the data on tuna landings from 2005-2014 increased whilst on the contrary there was a decrease in the numbers of trips and fishing gears used. The relationship between landings to trips (slope = -0.0087; p-value = 0.7639) and gears (slope = 8.1285; p-value = 0.2715) can be interpreted as being a unit increase in number of trips, which tended to be linked with a decrease of 0.0087 tons in landings. In contrast, a unit increase in gears tended to be associated with an increase of 8.1285 tons in landings.The research did not show statistically significant relationships among landings, numbers of both trips, and fishing gears.
In order to obtain detailed characteristic of skipjack (SKJ) supply chain on pole and line (PL) fishery operates in Indonesia Fisheries Management Area (I-FMA) 714 and its adjacent areas, Center for Fisheries Research (CFR)-MMAF with WCPFC carried out a research in Sikka Regency. Data and infomation obtained through port sampling program, observer program and stakeholders workshop. Result shows that primary actors and processes of supply chain of skipjack on PL fishery based in Sikka consisted of PL fishers (skipper and crews), collector and traders, processors and market. Total active PL boats were 67 which supported by ± 40 lift-net (bagan) to provide 300-400 tonnesnes live bait, 11 small-medium scale and 5 large scale collectors and traders, 5 small and 4 large processors and local, domestik, export market. About 3556.9 tonnes SKJ caught by PL based in Sikka in 2017, about 56% were processed as katsuwobushi (smoke fish) for being exported to Japan, 35 % were frozen processed for being exported and marketed to Europe-US and domestic market in Makassar, Bali, and Surabaya. About 9% of the total catch of PL fishery based in Sikka were locally marketed as cold-fresh SKJ.
