Hae-Hoon Park

Analysis and prediction of walleye pollock (Theragra chalcogramma) landings in Korea by time series analysis

Abstract Forecasts of monthly landings of walleye pollock, Theragra chalcogramma , in Korea were carried out by the seasonal autoregressive integrated moving average (ARIMA) model. The equation of Box–Cox transformation on the walleye pollock catch data which handles nonstationary variance was Y ′=( Y 0.31 −1)/0.31. The model identification was determined by minimum Akaike information criteria (AIC) to identify the model as an objective criterion. Monthly forecasts of the walleye pollock landings for 1993–1994 were compared with the actual landings. Total observed annual landings of walleye pollock in 1993 and 1994 were 16 610 metric tons and 10 748 metric tons, respectively, while the model predicted 10 459 metric tons and 8203 metric tons (absolute percentage error 37.0% and 23.7%, respectively). The spectrum analysis of the monthly catches of walleye pollock in Korea showed some dominant fluctuations in the periods of 12 months, 4.4 years, 12.6 months and 6 months in descending order.

Behavioral characteristic of Japanese flying squid, Todarodes pacificus to LED light

Squid jigging fishery is very important in that there are about 1,000 jigging vessels more than 10 tonnage and about 5,000 ones less than 10 tonnage in Korea. But the cost of oil which is used to light fishing lamps, goes significantly up to almost one hundred million won for 50 tonnage vessels and forty million won in case of vessels less than 10 tonnage. This cost has almost taken 40% of total fishing costs. That is, the fishing business condition of squid jigging fishery is recently in the very difficult situation. As oil price increases, the business condition of the fishery gets worse and worse. Therefore it is very urgent to develop an economical fishing lamp, to solve this problem of fishery`s business difficulty. This research aims at developing a fishing lamp for squid jigging fishery using the light emitting diode which has very excellent efficiency and durability. We made a water tank with 20 meters width which is a shape of raceway to research behavioral characteristics of Japanese flying squid to LED light, and made an experiment to investigate optimum wave of LED light to lure squid. The method is to establish LED lamps on both ends of water tank and to observe squid`s behavior. Colors and wave lengths of LED lamps, used in experiment, are red(634nm), yellow(596nm), green(523nm), blue(454nm) and white(454nm+560nm). In experiment for attractive capability of LED lamp to squids, Japanese flying squid are highly attracted to blue lamp and white lamp. However, they are dispersed to red and yellow lamps. In addition, Japanese flying squid have moved and stayed in both dark ends of water tank. When compared intermittent lamp with continuous lamp, Japanese flying squid are highly attracted to intermittent lamp when intermittent interval is 0.25 second.

Fishing investigation and species composition of the catches caught by a bottom trawl in the deep East Sea

. The rate of discarded catchesin situ was about 50%. The diversity indexes of 2005 and 2006 were 1.152 and 0.878, respectively, and theevenness indexes at those years were 0.752 and 0.583, respectively, which implied one dominant speciescaught in 2006.Key words : Deep sea, Bottom trawl, Species composition, Discarded fish, East Sea

Design and performance evaluation of fish-luring system using the air-cooled LED lamp for jigging and angling boat

The fishing lamp is a fishing gear that gathers fish at night. But the cost of oil, which is used to light fishing lamp, has been risen significantly up to 30-40% of total fishing costs. Therefore it is very urgent to develop an energy economical fishing lamp in order to solve the business difficulties of fisheries. Under this background, this research aims at developing a fishing lamp for squid jigging and hairtail angling fishery using the LED, which has excellent energy efficiency and durability. The LED fishing lamp developed can be controlled to fix a fit direction of fish shoal deep because a fishing lamp can be adjustable up and down directions. One unit of fishing lamp has about an 80Watt capacity and the frame of fishing lamp is made of aluminium to emit generated heat of LED to outside. The LED lamp developed was highly durable, only 5.7% of emitting efficiency decreased for 18 months. The illuminance of a unit LED lamp was 2,070lux at 1m and 21lux at 10 m distance, and the intensity of LED lamp system emitted 2,580lux and 400lux at the respective distances. After development of this fishing lamp, 100 units are installed on operating fishing vessels. Experimental results show that energy consumption of squid jigging and hairtail angling was reduced by 40% and 87%, respectively. In conclusion, our methods showed elevated fishing power, compared with traditional fishing method: 37.7% for squid jigging and 24.5% for hairtail angling.

A tension measurement method of a towing cable or a buoy cable

An indirect tension measurement method of a towing cable in midwater or a buoy cable is proposed using underwater acoustic positioning systems, etc., to give the in-water cable tension. The most simple and traditional cable tension measurement method is to apply a mechanical tension meter at the one end of the cable, but the method has limits in the aspects of continuous monitoring and manual operation. However, the technique in this study is to apply the Podes analysis of the equilibrium configuration and tension of a flexible twine, in which the cable tension is given as a function of the geometric positions of both ends of the cable. A set of nonlinear integral equations is formulated and solved numerically by the Newton-Raphson method. Then the inclination angles and the tensions at the lower and the upper ends of the cable could be obtained. The derived method enables us to track a towed object, to measure the tension of a towing cable or a buoy cable and is also applicable to the remotely operated vehicle (ROV) tethered to a mother ship.

Fishing power estimation of biodegradable traps in the East Sea

For an effective management of fisheries resources, it is very important that to make clean inhabitation environment and to preserve fisheries resources. The material which is mainly used as fishing gear in modern times, is polyethylene, polypropylene, polyamide, etc., chemical fiber. And lost fishing gears which are make of these, occur ghost fishing and ocean pollution. To solve these problem, we development biodegradable fishing trap using the polybutylene succinate (PBS). Developed traps are for red snow crab (Chionoecetes japonicus) and shrimp, major traps in the East Sea, and we carried out fishing research using two kind traps in the coastal sea of Ayajin-port (Goseong) to analysis fishing efficiency of PE trap and PBS trap. As a result for fishing experiment (year 2005-2006) of red snow crab trap, two kind traps were almost the same in catches and length composition. During a experiment, parts of meshes, used for over 1 year, were cut by biodegradation. As a result for fishing experiment (year 2007) of shrimp trap, northern shrimp (Pandalus eous), coonstripe shrimp (Pandalus hypsinotus) and morotoge shrimp (Pandalopsis japonica) were catched, and the almost is northern shrimp. Two kind traps were almost the same in catches and length composition. In accordance with these result, it is recommended that the developed traps are have to commercialized because the fishing powers of PE traps and PBS traps were same. But biodegradation speed is have to controled in consideration of ocean microorganism volume and traps life.

Mesh Selectivity of Durm Net Fish Trap for Elkhorn sculpin(Alcichthys alcicornis) in the Eastern Sea of Korea

The mesh selectivity of the drum net fish trap for elkhorn sculpin(Alcichthys alcicornis) in the estern sea of Korea was described. The selection curve for the elkhorn sculpin caught from the experiments between June 2003 and December 2003 was by SELECT(Share Each Length Class`s Catch Total)model and by Kitahaa`s method to a polynomial equation and two parameter logistic selection curve. The selection curve by SELECT model showed to be equal probability of entrance of the elkhorn sculpin in the large(55mm) and small(20mm) mesh traps by minimum AIC (Akaike Information Criteria). The equation of selectivity curve obtained by Kitahara`s method using a logistic function with least square method was

Catch characteristic and present condition of by-catch & discard of trammel nets fishery in the East Sea

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Size selectivity of gill net for female snow crab, Chionoecetes opilio

For an effective management of fisheries resources, we need fisheries informations necessary for theestablishment of reasonable fishing effort and TAC distribution. To study the present state of by-catch anddiscard of gill-net fishery in the East Sea, we carried out fishing research using trammel nets in the coastalsea of Susan-port (Yangyang), Jangho-port (Samcheok) and Hupo-port (Uljin). As a result, a total of catchof Susan was 259,172g and that of Hopo was 577,638g. Thus Catch of Susan was 1.49 times more than thatof Hupo considering the number of used fishing gear. And catch of Janho was 7.4 times more than that ofSusan considering the number of experiment. Two methods of by-catch analysis in this study were used, onemethod is standardizing of listed species catching possible in fishing license, another method is regardingcatch species under 1% of total catch as by-catch. As a result of by-catch analysis of two method, by-catchrate of Susan was 6.55% and 5.87% respectively, that of Hupo was 44.70% and 5.24% and that of Janghowas 0.96% and 2.31%. Discard rate of fish in Susan, Hupo and Jangho were 1.59%, 3.42%, 2.23%respectively.Keywords: Fishing capacity, Trammel nets, By-catch, Discard

Size Selectivity of a Shrimp Beam Trawl for the Southern Rough Shrimp Trachysalambria curvirostris with the Extended SELECT Method

the extended Kitahara s method. The selection curve showed that the gill nets of larger mesh size allowed more female crabs of small carapace size to escape. The optimum values of RL/m for 1.0 of retention probability was 0.563 and RL/m was estimated to be 0.249, 0.290, 0.319, 0.344 and 0.367 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.