• The Journal of Fisheries Business Administration
• /
• v.44 no.3
• /
• pp.77-84
• /
• 2013

While some steps in laver aquaculture production can be controlled artificially to a certain extent, the culturing process is largely affected by natural factors, such as the characteristics of seawater, climatic and oceanographic conditions, etc. This study aims to find a direct relationship between climatic and oceanographic factors (water temperature, air temperature, salinity, rainfall, sunshine duration and wind speed) and laver aquaculture production in Wando region, the biggest aquaculture production area of laver, located in the southwest coast of Korea using a multiple regression analysis. Despite the small sample size of a dependent variable, the goodness of model fit appeared acceptable. In addition, the R-squared value was 0.951, which means that the variables were very explanatory. Model results indicated that duration of sunshine, temperature, and rainfall during the farming period from the end of September to the end of April would be important factors affecting significantly to the laver aquaculture production.

• Journal of Environmental Impact Assessment
• /
• v.14 no.3
• /
• pp.127-134
• /
• 2005

Recently, aquaculture farm sites have been increased with demand of the expensive fish species and sea food like as seaweed, laver and oyster. Therefore coastal water quality have been deteriorated by organic contamination from marine aquaculture farm sites. For protecting of coastal environment, we need to control the location of aquaculture sites. The purpose of this study is to detect the laver aquaculture sites using multispectral remotely sensed data with autodetection algorithm. In order to detect the aquaculture sites, density slice and contour and vegetation index methods were applied with SPOT and IKONOS data of Shinan area. The marine aquaculture farm sites were extracted by density slice and contour methods with one band digital number(DN) carrying 65% accuracy. However, vegetation index algorithm carried out 75% accuracy using near-infra red and red bands. Extraction of the laver aquaculture site using remotely sensed data will provide the efficient digital map for coastal water management strategies and red tide GIS management system.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.56 no.1
• /
• pp.45-54
• /
• 2020

In this study, an automatic system for improving the working environment and increasing production efficiency of a laver aquaculture industry in Korea was developed by combining a hydraulic control system and a load cell in a current landing work of the laver. The improved gathering laver system allowed the automatic gathering process of the laver in the sea with the hydraulic control system connected to a cutting machine of the laver on the operating ship, which has been used for gathering the laver semi-automatically in a form of the traditional farming method. The transporting process of the laver from an operating ship to the land was improved as follows. A frame installed on the operating ship and the bag nets were designed and made to hold about 1,000 kg of the laver inside. The bag nets contain the laver on the improved operating ship were tied in knots and hooked on a crane using a load cell. The weight is measured immediately by lifting the bag nets through the load cell system. Weight information is communicated to the fishermen and successful bidders through the application. The advantages of the improved system can help fishermen to fish by improving their working environment and increasing production efficiency. The field survey to improve the landing operation of the laver aquaculture was conducted in Gangjin, Goheung, Shinan, Wando, Jindo, and Haenam in South Jeonnam Province. A total of 10 sites including Gunsan in Jeonbuk Province, Daebu Island in Ansan City, Jebu Island in Hwaseong City in Gyeonggi Province, and Seocheon in Chungnam Province were searched to collect data. Prototypes of the system were tested at the auction house of laver located in Goheung, where laver collection using hydraulic control and landing using road cell could be improved.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.59 no.2
• /
• pp.181-187
• /
• 2023

Laver aquaculture, which occupies a large proportion in the aquaculture industry in Korea, is still highly dependent on human labor. Therefore, it is necessary to study the development of an automatic system to improve the working environment and increase the efficiency of aquaculture production systems. The purpose of this study is to evaluate the economic feasibility of an improved system in a study for the loading-unloading and automatic weighing systems in laver aquaculture industry. Economic analysis of the developed unloading and automatic weighing system were implemented under various conditions to calculate more accurate benefits and costs. As a result of this study, the economic feasibility was found to be very high in the three models: net present value (NPV), benefit-cost ratio (B/C), internal rate of return (IRR). Moreover, the results of sensitivity analysis showed that the economical efficiency of the automatic loading, unloading, and weighing system in laver aquaculture was very high.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.4
• /
• pp.343-351
• /
• 2017

Sanitary evaluation of seawater and Pyropia sp. laver collected from the five major laver growing areas in Korea was performed four times over the course of a year. The seawater quality in four of these five areas was regarded as the clean area according to Korean criteria, but the seawater at one investigation site in Seoheon area was found to exceed the standard for fecal coliform. In the bacteriological safety analysis of laver (raw source), the percentages of samples not conforming to Chinese criteria at the five sites were 55.6% (Seocheon), 70.0% (Shinan), 81.8% [Jindo (Haenam)], 63.6% (Wando), and 28.6% [Goheung (Jangheung)]. Pathogenic bacteria were not detected in all laver samples. The food safety of laver (raw source) based on heavy metal concentration was confirmed using Korean criteria; the concentrations of heavy metals in laver samples collected from the major laver growing areas were 0.008-0.632 mg/kg wet weight (ww) lead, 0.024-0.137 mg/kg ww cadmium, 0.908-2.892 mg/kg ww total arsenic, and 0.003-0.013 mg/kg ww total mercury. Therefore, pollution source management and periodic monitoring of heavy metals may be required to improve the food safety of laver produced in these laver growing areas.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.2
• /
• pp.156-164
• /
• 2020

To develop a seasoned laver from cooking oyster effluent (C-COE), this study optimized the C-COE concentration, roasting temperature and time using response surface methodology (RSM). The optimal C-COE concentration, roasting temperature and time for producing seasoned laver from C-COE were 31.0%, 182.2℃ and 21.1 sec, respectively. The proximate composition of the seasoned laver prepared with C-COE under the conditions was 5.2% moisture, 37.4% crude protein, 8.2% crude lipid, 11.1% ash, 38.1% carbohydrate. The water activity of the prototype seasoned laver was 0.038. The prototype had stronger taste and flavor intensities than a commercial product. There was no difference (P>0.05) in the Hunter color value between the prototype and the commercial product. The peroxide (POV) and acid values (AV) of the prototype were 6.0 meq/kg and 1.4 mg KOH/g, respectively, which are considered acceptable. The results suggest that the seasoned laver with C-COE developed can be industrialized.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.59 no.3
• /
• pp.215-220
• /
• 2023

This study developed and evaluated a load cell-based automatic weighing system for the automated harvesting of laver (Porphyra tenera) in seaweed aquaculture. The current manual harvesting process was compared with the load cell-based automated system, and quantitative measurements of time, distance, and weight were conducted. The results demonstrated that the load cell-based system reduced the unloading time and increased the throughput compared to the manual method. In addition, statistical analysis confirmed that there was no significant difference from the mean in the weight measurement obtained using the load cell-based system. Based on these findings, the load cell-based automatic weighing system holds potential for efficient production and transactions in laver cultivation, contributing to cost reduction and improving the quality of life for aquaculture workers.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.3
• /
• pp.382-387
• /
• 2020

This study compared the nutritional characteristics of seasoned laver Pyropia yezoensis with conger eel Conger myriaster seasoning sauce (SL-CES) with those of commercial seasoned laver (C-SL). SL-CES had higher protein and lower ash contents than those of C-SL. However, the moisture and lipid contents did not differ between them (P>0.05). The total amino acid content of SL-CES was 21.79 g/100 g, similar to that of C-SL (21.49 g/100 g). The major amino acids in SL-CES were aspartic acid, glutamic acid, and alanine. The SL-CES contained 125.7 mg calcium, 461.6 mg phosphorus, 2183.7 mg potassium, 9.5 mg iron, and 2.6 mg zinc per 100 g SL-CES. These amounts were all higher than those in C-SL, except for Zn. The major fatty acids in SL-CES were 16:0, 18:1n-9, and 18:2n-6.

• The Journal of Fisheries Business Administration
• /
• v.54 no.2
• /
• pp.045-058
• /
• 2023

This study aims to analyze the cost of climate change damages to laver and sea mustard aquaculture, which are considered to be highly vulnerable to climate change in Korea. For this purpose, the correlation between aquaculture production and climate factors such as water temperature, salinity, air temperature, and precipitation was estimated using a panel regression model. The SSP scenario was applied to predict the changes in production and damage costs due to changes in future climate factors. As a result of the analysis, laver production is predicted to decrease by 18.0-27.2% in 2050 and 20.6-61.6% in 2100, and damage costs are predicted to increase from 29.7-50.8 billion KRW in 2050 to 35.7-116.1 billion KRW in 2100. Sea mustard production is projected to decrease by 24.5-37.2% in 2050 and 24.0-34.5% in 2100, with similar damage costs of 41.1-61.8 billion KRW and 41.1-58.6 billion KRW, respectively. These damage costs are expected to occur in the short term as damage caused by fishery disasters such as high temperatures, and in the long term as a decrease in production due to changes in aquaculture sites. Therefore, measures such as strengthening the forecasting system to prevent high-temperature damage, developing high-temperature-resistant varieties, and relocating fishing grounds in response to changes in aquaculture sites will be necessary.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.53 no.3
• /
• pp.368-381
• /
• 2020

This study was conducted to optimize the processing conditions of seasoned laver Pyropia yezoensis with conger eel Conger myriaster seasoning sauce (CES) using response surface methodology (RSM). The RSM program results for bonesoftness showed that the optimum independent variables based on the dependent variables (Y₁, lipid removal rate; Y₂, texture; and Y₃, sensory fish odor score) were 431.0% for X₁ (water amount), 115.6℃ for X₂ (retort-operated temperature), and 50.1 min for X₃ (retort-operated time). The RSM program results for the CES blend showed that the optimum independent variables (X₁, amount of bone-softened conger eel by-products; X₂, mixed sauce amount; and X₃, starch amount) based on the dependent variables (Y₁, amino-N; Y₂, Hunter redness; and Y₃, drying time) were 44.8% for A (pre-treated conger eel by-product), 36.0% for B (mixed sauce), and 19.2% for C (starch). The RSM program results for seasoned laver with CES showed that the optimum independent variables based on the dependent variables (Y₁, water activity; Y₂, Hunter yellowness; and Y₃, overall acceptance) were 5.0% for X₁, (CES amount), 313.8℃ for X₂ (roasting temperature), and 6.0 s for X₃ (roasting time). The seasoned laver with CES prepared under the optimum conditions was superior to commercial seasoned laver in terms of overall acceptance.