DEPIK Jurnal Ilmu-Ilmu Perairan, Pesisir dan Perikanan
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571 research outputs found
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Manipulation of the aquatic environment to optimize the natural spawning of sunu grouper (Plectropomus leopardus) in controlled tanks
Full text linkAquaculture within culture techniques is needed to support the optimization of a number of juveniles which sunu grouper natural spawning techniques. To optimize the natural spawning of Sunu Grouper (Plectropomus leopardus) its is needed to know in details about the environment condition. Random design method by using several treatments consisted of one factor, temperature, and consisted of four treatments which are 26, 28, 30, and 32 which were repeated five times. Five steps were conducting start with the preparation, acclimatization of the eggs, stocking, and hatching of the eggs, and larval maintenance. Good quality feed is required to support gonad development and egg quality during brood stock-rearing. Environmental management of culture within culture techniques is needed to support the optimization of the number of juveniles. Temperature changes made by raising and lowering the temperature are a form of stimulation that trigger spawning to occur naturally.Keywords:aquacultureaquatic environmentsunu groupe
Eleven years consecutively coral reef rehabilitation in Tobok Batang, Bontang
Full text linkCoral reefs in Tobok Batang, a nearby estuary of Bontang Regency, have a vital role in the threatened ecosystem due to non-environmental-friendly fishing practices and a global threat in the form of coral bleaching. In response to these conditions, PT Pupuk Kalimantan Timur initiated the Kilau Samudera Program to support damaged coral reef recovery through community-based rehabilitation by developing and maintaining artificial reef modules. The study objective was, therefore, to determine the rehabilitation efficacy in Tobok Batang, through (1) coral growth informed by colony diameter, and (2) targeted reef fishes informed by abundance and biomass. Data was collected by purposive sampling in eleven clusters of three modules: pyramid, dome, and cube. The result shows that coral had been found attached in all these eleven clusters, while the targeted fishes had been found in most clusters. Clusters deployed in 2015 and 2017 have an average colony diameter of 30 cm (SE), the two highest among the other clusters. The highest abundance of corallivores was found in the cluster deployed in 2017 and 2020 (9 ind/100 m2). The highest herbivore abundance also was found in the cluster deployed in 2017 and 2020 (23 ind/100 m2), while its highest biomass was found in cluster 2020 only (40 kg/100 m2). The highest carnivore abundance was found in cluster 2017 only, with four fish per 100 m2 as well as the biomass in the same cluster (9kg/100 m2). All these cluster groups have provided new habitats in shallow waters, indicating that the cluster has a good position and probably good material composition that can trigger coral juveniles to attach, settle, and grow, which also became a unique habitat for some targeted reef fish. This study showed that the location and these three modules were proven effective for rehabilitating methods in damaged coral reefs.Keywords:Coral Reef,Rehabilitation,Tobok Batang,Bontang,Reef Fis
Enhancing Catfish (Clarias sp.) Farming Production and Economic Viability through Molasses Application in Biofloc System
Full text linkIn addition to having high economic value, catfish (Clarias sp.) can also be cultivated quickly and they can adapt well. The demand of catfish is in line with the increase in production which is expected to remain efficient and environmentally sound. Biofloc technology has also been implemented in catfish for increasing productivity. Biofloc utilizes the activity of heterotrophic microorganisms and autotrophs for the conversion of organic waste into floc and is used as fish feed. This study aims to examine the effect of the use of molasses with different doses (C/N ratio) on the growth and survival rate of catfish. This study was conducted with as many as 3 treatments with 3 repetitions each except for the control. The treatment with the ratio of molasses in each of them: A: C/N of 10:1; B: C/N of 15:1; C: C/N of 20:1, and D without molasses given as control. The study using 240 catfish measuring 10-12 cm was carried out for 30 days with sampling every 10 days. It aims to determine the average growth, daily growth, and survival rate of test biota during the study. Based on the results of this study, it can be concluded that the use of different doses of molasses in catfish farming, and biofloc technology will affect the growth and survival rate of farmed catfish. Catfish farmed with biofloc technology at a C/N ratio of 15:1 show the best results on their growth and survival rate. In addition, catfish farming with a biofloc C/N ratio of 15:1 has a better economic analysis when compared to conventional catfish farming. In summary, the use of biofloc based on research results can be a recommendation to be applied in the community, especially among catfish farmers
Phylogenetic positions of the rotifer Brachionus plicatilis species complex from Indonesian waters
Full text linkThe Brachionus plicatilis species complex comprises a group of rotifers commonly found in marine and brackish water environments worldwide. This group has garnered substantial attention due to its ecological significance and its utility in aquaculture research. Notably, the B. plicatilis sp. complex is renowned for its remarkable genetic diversity, which has been extensively investigated through molecular and taxonomic studies. Various genetic markers, including ribosomal DNA and mitochondrial DNA, have been employed to identify several distinct genetic lineages within the B. plicatilis sp. complex. Understanding the taxonomy and phylogenetic relationships within the B. plicatilis sp. complex holds significant implications for its application in aquaculture and ecotoxicology research. In this study, we conducted an analysis of the mitochondrial DNA cytochrome c oxidase subunit I (COI) gene using a dataset of 305 sequences, including four Indonesian rotifers belonging to the B. plicatilis sp. complex. These rotifers were obtained from Sulawesi Island (MNBO and MNSL), Bali Island (AY785226), and Sumatra Island (LMPG). Our primary objective was to determine their phylogenetic positions relative to molecular data available in the GenBank database. We calculated genetic distances among these rotifers using the Tamura Nei model. The results of Maximum Likelihood tree analyses revealed distinct clustering patterns among the Indonesian rotifers. Those originating from Sulawesi Island (MNBO and MNSL) and Bali Island (AY785226) formed the SS1 group (B. ratundiformis), whereas those from Sumatra Island (LMPG) comprised the SM2 group (B. koreanus). This study underscores the importance of molecular phylogenetic analysis in advancing our comprehension of the diversity and evolutionary relationships within the B. plicatilis sp. Complex.Keywords:PhylogenyRotiferaBrachionus plicatilisSpecies complexIndonesi
Condition and zonation of mangrove ecosystems in the small islands around the area crossed by the equatorial line of North Maluku Province
Full text linkThe South Halmahera Islands feature a comprehensive marine coastal ecology. The ecosystems found were seagrass, mangrove and coral reef ecosystems. The components that sustain the existence of this ecosystem are employed equitably because of its geographical location on the equator. Mangrove ecosystems that provide benefits directly and indirectly to the community. The purpose of this study was to determine the condition of the mangrove ecosystem based on the hemispherical photography method and the type of zonation. Tawabi Island, Kayoa, South Halmahera Regency served as the site of the equator research. The research station is determined as many as 3 stations. Mangrove percent cover canopy using the hemispherical photography and transect quadrant for density. Field data gathering procedures with transects drawn perpendicular from the sea to the land. Zonation characteristics and thickness using zone tracking. Density mangrove using ecology analysis and zonation using canvas 9.0. The results of the research founded were Rhizophora apiculata, Rhizophora mucronata and Sonneratia alba. Mangrove percent cover canopy were good category (75-81%), where station I (75%), station II (81%) and station III (77%). Station I having 600 trees per ha, station II having 500 trees per ha, and station III having 400 trees per ha (low density category). Mangroves were found in 3 zones Sonneratia alba, Rhizophora apiculata and Rhizophora mucronata. The mangrove thickness from sea to land at station I (65 meters), station II (69 meters) and station III (42 meters).Keywords:biodiversitycoastalequator lineHalmaheratropica
Utilization of natural stimulants on crab survival and molting acceleration: progresses and challenges
Full text linkThis study investigates the potential of natural stimulants, specifically ecdysteroids, in accelerating the molting process in mangrove crabs. The research was conducted by analyzing various plants containing ecdysterone and their effects on the crabs. The results indicate that forest fern leaves and mulberry leaves are effective sources of ecdysterone in stimulating molting and growth in crabs. The use of such natural stimulants has the potential to enhance productivity and reduce reliance on synthetic hormones in crab cultivation. However, further research is needed to determine the optimal dosage and to understand the mechanisms of ecdysterone action in crabs in more detail. The main challenge in implementation is adjusting the dosage and frequency of natural stimulant administration to achieve optimal results without disrupting the balance of the cultivation ecosystem. This approach offers an environmentally friendly alternative for the sustainable development of crab farming
Amino acid profile and chemical characteristics by-product process wet rendering of fish lele (Clarias Sp.) and tuna (Euthynnus Spp.)
Full text linkThis study was conducted to determine the amino acids profile and chemicals content (moisture content, protein, and fat) catfish and tuna products. Wet rendering process, each sample is steamed at 1500C for 30 minutes, after the sample is pressed with the aim of removing fluid from the fish's body. The liquid is centrifuged to separate the layers of oil and air. After obtaining fish oil, the byproducts are liquid / broth and solids (fish dregs). The byproducts (fish pulp and broth) were analyzed for amino acid profiles using High Performance Liquid Chromatography (HPLC) (AOAC, 2005) Chemical characteristics (air content, protein, fat) were analyzed using the AOAC (2005). The results showed that glutamic acid was higher in tuna pulp which was 11.83% and catfish 8.85%, while tuna broth contained amino acid histidine which was quite high at 10.49%, and 11.53% glycine in fish broth catfish. Furthermore, the levels of pulp and fish stock are 12.63% and 78.28% respectively, catfish 11.58%; and 83.45%. The fat content of catfish is higher that is 1.84% and 3.26% compared to tuna which is 1.57% and 2.74% tuna protein is 81.16% higher than catfish which is 75.46%, but the protein content of tuna broth is 56.84% lower than that of catfish broth which is 69.16%.Keywords: amino acid profiletuna fishcatfishwet renderingby-produc
Comparative appendicular osteology of Tor spp. (Cyprinidae) in Indonesia
Full text linkTor tambroides, T. tambra, T. douronensis, and T. soro are native fish species to Indonesia with their natural habitat generally being upstream of rivers in hilly areas with clear water and strong currents. Information of the structure and function of appendicular osteology is necessary to understand how fish accelerate and maintain body balance in the water. This study used 5 samples per fish species obtained from Tor fishermen around the habitat of these fish. The results of the comparison showed morphological differences between the appendicular structure of Tor species, consisting structure of the pinnae pectoralis, pinnae pelvicalis, pinnae dorsalis, pinnae analis, and pinnae caudalis. The highest variation was found in the pinnae caudalis. The pointed shape of the pinnae caudalis with long fin rays indicates that the Tor species is capable to swim at a high speeds.Keywords:ossa appendiculareTor douronensisTor tambraTor tambroidesTor sor
The presence of harmful algae in the coastal waters of Bintan Island, Riau Islands
Full text linkEnvironmental mitigation measures are being undertaken as a proactive approach to prevent the adverse consequences associated with Harmful Algal Blooms (HABs). Presently, there is a lack of comprehensive information regarding the occurrence of HABs in the waters surrounding Bintan Island, and routine monitoring to assess the potential for eutrophication is absent. This research should begin by gathering information about potential sources that contribute to the emergence of HABs, the specific types of algae with the capacity to trigger HABs The primary objective of this study is to identify the harmful algae species present in the coastal waters of Bintan Island. The research was conducted in August 2023, with the sampling process taking place at four specific locations within the coastal waters of Bintan Island. These sampling stations were selected deliberately to capture the varying activities predominant in each respective area. The microalgae found consisted of four groups, namely Bacillariophyta, Cyanophyta, Dinophyta, and Chlorophyta. Bacillariophyta is a group of microalgae with the highest abundance proportion at all observation stations. Harmfull Algae found in the coastal waters of Bintan Island generally come from the Dinophyta group of the types Ceratium sp., Peridinium sp., Prorocentrum sp., and Dinophysis sp. Harmful microalgae from the Dinophyta group were found at all research stations, with the highest proportion of abundance at Station 2 (6%) and the lowest at Station 3 (1%). The difference in these findings is thought to be due to the dynamics of the hydrosanographic parameters of the waters, especially nutrient concentrations.Keywords:BintanCeratiumDinophytaHarmfulMicroalga