Cost of Production at Business Unit in Aquaculture Industry： Study at Aquafarm Nusantara Company

Types of industry are manifold, patterns used in the determination of the cost of production can also vary. Elements of the cost of production are raw materials, direct labor, and factory overhead. Value of raw materials used in aquaculture industry in particular needs to calculate the cost of feed consumed by fish, thus greatly affect the price of fish feed cost of production. The calculation of the value of raw materials in fish production cost element to consider is the calculation of the value of raw material components, namely, （1） biomass of harvestable fish as the basic multiplication cost of production per kilogram or per fish harvested fish; （2） the ratio of fish feed intake by the amount of fish produced or often called the Feed Conversion Ratio （FCR）; and （3） the average purchase price of feed on fish harvest period is used as the basis for calculating the cost of production as well. This research is applied research that uses data archive aquaculture companies. The results in the observed period, the value FCR is 0.80, which means to fish have been consumed as much as 0.80 kg of fish feed. Biomass of fish that are harvested at 47,399.95 kg or 1,869,647 individuals. The average purchase price of fish feed on the observation period amounted to IDR 4,855.79. So the price of raw materials contained in harvested fish in the observation period calculates the value of multiplying all the components of raw materials （i.e., IDR 184,131,362.57）. Method of calculating the cost of production companies is process method and charging method used is the full costing method.

Research on China's Aquaculture Efficiency Evaluation and Influencing Factors with Undesirable Outputs

Taking the aquaculture area, the number of farming boats and that of aquaculturist as input variables, the aquaculture production as desirable output variable and polluted economic loss as undesirable output variable, this paper conducts SBM model to evaluate the aquaculture efficiency based on the data of 16 aquaculture-developed provinces in China from 2004 to 2011. The results show the efficiency in China has not changed much in recent years with the efficiency values mainly between 0.39 and 0.53, and the efficiency of marine-aquaculture-dominated provinces is generally higher than that of freshwater-aquaculture-dominated ones. To analyze the difference under the efficiency, the panel Tobit model is used with education level factor, training factor, technology extension factor, technical level factor, scale factor and species factor as the efficiency influencing factors. The results show that technology extension factor and technical level factor have significant positive influence.

Impact of dissolved organic matter on the photolysis of the ionizable antibiotic norfloxacin

Norfloxacin（NOR）, an ionizable antibiotic frequently used in the aquaculture industry, has aroused public concern due to its persistence, bacterial resistance, and environmental ubiquity.Therefore, we investigated the photolysis of different species of NOR and the impact of a ubiquitous component of natural water — dissolved organic matter（DOM）, which has a special photochemical activity and normally acts as a sensitizer or inhibiter in the photolysis of diverse organics; furthermore, scavenging experiments combined with electron paramagnetic resonance（EPR） were performed to evaluate the transformation of NOR in water. The results demonstated that NOR underwent direct photolysis and self-sensitized photolysis via hydroxyl radical（U OH） and singlet oxygen（1O2） based on the scavenging experiments. In addition, DOM was found to influence the photolysis of different NOR species, and its impact was related to the concentration of DOM and type of NOR species. Photolysis of cationic NOR was photosensitized by DOM at low concentration, while zwitterionic and anionic NOR were photoinhibited by DOM, where quenching of U OH predominated according to EPR experiments, accompanied by possible participation of excited triplet-state NOR and1O2. Photo-intermediate identification of different NOR species in solutions with/without DOM indicated that NOR underwent different photodegradation pathways including dechlorination, cleavage of the piperazine side chain and photooxidation, and DOM had little impact on the distribution but influenced the concentration evolution of photolysis intermediates. The results implied that for accurate ecological risk assessment of emerging ionizable pollutants, the impact of DOM on the environmental photochemical behavior of all dissociated species should not be ignored.