Wiyono E.S.,University of Indonesia |
Hufiadi,Research Institute for Marine Fisheries
AACL Bioflux | Year: 2014
In order to compete with others, fishermen adopt several fishing technics and tactics, and hence, occasionally, fishermen’s’ responses to environmental changes exceed the requirements. Thus, it is argued that this phenomenon will threaten sustainable fisheries activity. To manage fisheries to be sustainable, we need a study on the factors that influence the success of fishing operations and management. To answer this problem, we have conducted a research on purse seine fishing gear in Rembang, Central Java Indonesia. The results of this study showed that three factors affect purse seine fishing catches, i.e. length of trip (p < 0.01), ice (p < 0.01), and the cost of supplies for fishing operations (p < 0.05). However, the length of trip (days), ice (blocks) and the cost of supplies for fishing operations (Rp.) have a variable input utilization (VIU) number of less than 1. In order to optimize purse seine fishing operations, it is essential to reduce the policy of a fishing trip, ice and the cost of supplies for fishing operations. © 2014, BIOFLUX SRL. All rights reserved.
Nurdin E.,Research Institute for Marine Fisheries |
Nurdin E.,Bogor Agricultural University |
Sondita M.F.A.,Bogor Agricultural University |
Yusfiandayani R.,Bogor Agricultural University |
Baskoro M.S.,Bogor Agricultural University
AACL Bioflux | Year: 2016
Growth and mortality parameters were estimated for the yellowfin tuna (Thunnus albacares - Bonnaterre, 1788). A total of 2,906 individuals were sampled from the types of small scale commercial vessel units operating five fishing gears (troll line, hand line, floating line, vertical line and kite line) around fish aggregating devices (FADs) in the Palabuhanratu waters (eastern Indian Ocean) from April to December 2015. The aims of this study were to estimate the growth and mortality rate. The data were analyzed by using FiSAT II. The von Bertalanffy growth parameters were estimated at L∞= 178 cm fork length (cmFL), k= 0.47 year-1, and t0= -0.213 year. The total mortality rate (Z) estimated was 1,27 year-1, with the natural mortality rate (M) and fishing mortality rate (F) of 0.66 year-1and 0.61 year-1respectively. The exploitation rate (E) was estimated to be 0.48. This condition indicates that exploitation of the yellowfin tuna is still in good condition and it is necessary to manage the fishing pressure on the stock to prevent the probability of overfishing events. © 2016, BIOFLUX SRL. All rights reserved.
Milton D.A.,CSIRO |
Satria F.,Research Center for Fisheries Management and Conservation |
Proctor C.H.,CSIRO |
Prasetyo A.P.,Research Center for Fisheries Management and Conservation |
And 2 more authors.
Continental Shelf Research | Year: 2014
Tropical Panulirus lobster fisheries in many parts of the world are open-access and poorly-regulated. This is in part because tropical Panulirus lobsters have an extended pelagic larval phase (up to 9 months) and their larval settlement may take place in different habitats and depths. When recruits of a fishery are believed not spawned locally, regulatory incentives are weak. We assessed the potential sources of recruits to a small, valuable fishery for six species of Panulirus lobster in southern Java, Indonesia with a larval advection model. The model predicted that between 1993 and 2007, 50-90% of the recruits were sourced locally compared to a mean of 25% from remote locations. The relative intensity of the Indonesian flow-through, the south Java current and seasonal onshore winds appear to be important in the local retention of recruits. Local fisheries records showed a strong seasonality in catch that we compared to potential environmental triggers with boosted regression trees. We found that the increased catch was associated with the rapid onset of increased rainfall (>90. mm) at the start of the monsoon (November-May). Fishers believe the coastal runoff during periods of high rainfall increases turbidity and thus enhanced catchability. Catches declined dramatically during an extended monsoon in 2010-2011, but recovered in early 2012 when rainfall patterns became more seasonal. These combined results show that there may be potential benefit of implementing local fisheries management regulations to increase sustainability. However, their effectiveness may be difficult to detect due to the strong influence of climate and oceanographic variability on both recruitment and subsequent catch. © 2014 Elsevier Ltd.
Nguyen X.P.,Chonnam National University |
Nguyen X.P.,Research Institute for Marine Fisheries |
Jho H.,Chonnam National University |
Jeong Y.-J.,Chonnam National University |
And 5 more authors.
Environmental Engineering Research | Year: 2015
In this study, the characteristics as well as the maturity and stability of chicken manure collected from nine chicken farms in South Koreaduring the summer and winter seasons of 2014 are evaluated. The physicochemical parameter values of the manure, such as BOD, NO3-N and PO4-P etc. were determined using the Korea Standard test Method, HPLC, and APHA standard methods. The results showed that the alkalinity content and COD concentration in winter chicken manure were higher than those of summer chicken manure. The moisture content of summer manure was positively correlated with almost all of the other parameters of the manure, whereas it was negatively correlated with almost all of the other parameters in the winter manure. According to the criterion of C/N ratio, chicken manure indicated good quality compost. However, composted chicken manure showed immature and unstable compost when considering the criteria of the NH4-N/NO3-N ratio and NH4-N concentrations. © 2015 Korean Society of Environmental Engineers.