• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2001.05a
• /
• pp.49-52
• /
• 2001

The more the population grow, the severer the shortage of a basic human needs such as food, clean water, energy resources and so on. We had proved the possibility of utilizing deep ocean water as a environmental friendly resource to solve comprehensively above-mentioned problems for mankind based on observation and analysis of water quality. This study aims to evaluate feasibility of deep ocean water application, and establish multipurpose development and cascade utilization system of deep ocean water in the coastal zone of East sea to promote ocean development and fisheries industries.

• Korean Journal of Remote Sensing
• /
• v.36 no.1
• /
• pp.41-53
• /
• 2020

The production of near- and off-shore fisheries in South Korea is decreasing due to rapid changes in the fishing environment, particularly including higher sea temperature in recent years. To improve the competitiveness of the fisheries, it is necessary to provide fish catch information that changes spatiotemporally according to the sea state. In this study, artificial intelligence models that predict the CPUE (catch per unit effort) of mackerel, anchovies, and squid (Todarodes pacificus), which are three major fish species in the near- and off-shore areas of South Korea, on a 15-km grid and daily basis were developed. The models were trained and validated using the sea surface temperature, rainfall, relative humidity, pressure,sea surface wind velocity, significant wave height, and salinity as input data, and the fish catch statistics of Suhyup (National Federation of Fisheries Cooperatives) as observed data. The 10-fold blind test results showed that the developed artificial intelligence models exhibited accuracy with a corresponding correlation coefficient of 0.86. It is expected that the fish catch models can be actually operated with high accuracy under various sea conditions if high-quality large-volume data are available.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.20 no.4
• /
• pp.355-359
• /
• 1987

Texture and mineralogy of different microlayers of deep-sea manganese nodules are investigted to reveal the environmental changes of nodules during a nodule formation. Basically a nodule can have three types (A, B and C) of microlayer. Some nodules show only one or two types of microlayer. The classification is based primarily on the texture. The surface torture of type A is coarsely porous globular microstructure whereas type B and C are intermediate to finely porous textures. The type A is characterized by its highest Mn content $(30.6\%)$ and relatively well-crystallized todorokite as veil as the rapid growth rate. Smectite and biogenic silica (radiolaria) are also easily observed in the type A layer. It appears that the hydrothermal activity is one of the favorable mechanism of formation for the type A layer. The hydrothermal solution is possibly supplied from nearby fracture zone and spreading center.

• Korean Journal of Ichthyology
• /
• v.19 no.4
• /
• pp.360-364
• /
• 2007

A single female specimen (73.6 mm SL) of ghost pipefish, Solenostomus cyanopterus Bleeker, belonging to the family Solenostomidae (new Korean name: Yu-ryeong-sil-go-gi-gwa), was observed and collected in the water off Yeongdeck, East Sea of Korea. Unlike to syngnathids, solenostomids are characterized by having the brood pouch formed by pelvic fins in female and dorsal fin spines present. This species is characterized by having the deep snout, and short, deep caudal peduncle, but no cirri and striped markings. In the water, the species swims slowly head downward in pairs and looks like a drifting pieces of algae or fallen leaf. We describe this species as new to Korean fish fauna and propose its new Korean name, "Yu-ryeong-sil-go-gi".

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.30 no.4
• /
• pp.283-291
• /
• 1994

This paper describes about the behavior of the Striped mullet (Mugil cephalus) in the setnet by telemetry techniques. The telemetry system consists of a pinger of 50KHz, three omni-directional hydrophones and ultrasonic receivers, a single board computer for the signal processing, two RF transceivers for the data comunication and a personnel computer. The fish tagged the pinger was tracked by the LBL method, and its location was calculated by the hyperbolic method. The fish escaped from sea surface to 7m deep right after release and had been swum near the sea surface after 30 minutes being released. Also, in horizontal movements, the fish stayed long time around the enterance of the square net in setnet, and showed the escaping behavior repeatly. The average speed of the fish was about 0.41m/sec(1.1 times of the body length)

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.42 no.1
• /
• pp.38-43
• /
• 2006

The 3-D modeling of ocean finite element method(OFEM) using $k-{\varepsilon}$ turbulent model and tetrahedron grids has been used to investigate the internal wave generation during the expansion of the deep water from the open sea to the shelf with a simple shape, which can be widely used in the fields of submarine development, ocean environment and meteorology, etc. In this paper, the detailed configuration of internal wave with its length and height and also the distribution of salinity and turbulent kinematic energy, etc. were derived. It is hoped that this OFEM method can be successfully applied to the numerical calculation of internal wave for and the oceanographic problems (tidal flows around underwater hill, plateau, Georges Bank, etc.) and ocean engineering problems(flow past artificial sea reefs) in future.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.52 no.1
• /
• pp.24-35
• /
• 2016

An acoustic and trawl pilot survey using a small vessel was conducted in Jinhae bay of the South Sea of South Korea on April 13~14, May 11~13 and June 8~10, 2015. During the survey, acoustic data was collected and bottom trawls were conducted at the same time. First, various noises were eliminated by using the Park method based on the Wang method (Wang et al., 2015; Park et al., 2015), the species compositions and catch rate from each bottom trawl were observed, and spatial distribution of fishery resources in the water column and their nautical area scattering coefficient (NASC) were investigated through acoustic data. During the entire survey period, 12 orders, 33 families and 41 species were caught. The most caught species in April, May and June were Okamejei kenojei, Zoarces gilli and Pholis nebulosa, respectively. Fish schools were observed near the line of net mouth height in April. Numerous weak scatters were presented on the echograms in May and June. Many fish schools appeared in between the water surface and 20 m deep in May. The NASC value from entire water columns was the lowest in April ($35.9m^2/n{\cdot}mile^2$) and highest in June ($1541.3m^2/n{\cdot}mile^2$).

• Korean Journal of Ichthyology
• /
• v.28 no.4
• /
• pp.283-286
• /
• 2016

A single specimen (276.9 mm standard length) of the scorpaenid Sebastes glaucus was collected by a gill net from Dokdo, East Sea, Korea. The specimen is characterized by yellowish brown body color, deep body, convex frontal region and nape, board occipital region, 14 spines at dorsal fin, and no scales at maxilla. This is the first record of S. glaucus in Korea; we therefore add the species to the Korean fish fauna. According to the NFRDI (1999), we propose the Korean name, "Cheong-hoebol-rak" for this species.

• Fisheries and Aquatic Sciences
• /
• v.26 no.5
• /
• pp.336-343
• /
• 2023

This study aimed to know the response of deep-sea squid Sthenoteuthis oualaniensis to the light colors of the artificial bait. This experiment used the commercial artificial flashlight baits commonly sold in the fishing shop. The bait has several different light color combinations. The light colors were modified into several light colors by inactivating certain colors and used as treatments. The study is expected to be able to find flashlight bait's most effective color for squid fishing. We applied red-green, green, blue, and commercial bait lights in this study. Each treatment has 3 replications. The effect was expressed as the amount of squid caught. Data were analyzed by one-way analysis of variance. Results showed a significant effect on the number of squid catches. There was significantly different squid catches among the treatments. It indicates that this artificial flashlight bait could be developed to maximize squid catches. This finding can be used for the local fishermen's income and the squid fisheries development.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.38 no.3
• /
• pp.205-213
• /
• 2005

A hydroacoustic and a close-open-close zooplankton net survey were conducted to understand the distribution characteristics of the deep scattering layer (DSL) and to estimate the density of zooplankton in the DSL, in the Uljin coastal area. The survey was carried out during March 13-14 and June 4-5, 2003 at each station for zooplankton. The vertical migration mechanisms of zooplankton are very variable to the taxa. In this study, after we grasp the vertical migration of zooplankton through the results of an echo-sounder survey, we verified the mechanisms of their vertical migration in the Uljin coastal area. Also, to estimate effectively the biomass of zooplankton, we researched the acoustic scattering strength according to the species. On the basis of these results, we devised a method for estimating zooplankton biomass through comparing net and echo-soundings. We obtained the results as a follows; 1) According to the examination of collections from the net sampling, in March, 2003, Euphausia pacifica comprised $38\%$ of zooplanktons inhabiting the sound scattering layer, while copepods, chaetognaths, and amphipods accounted for $29\%,\;23\%\;and\;10\%$, respectively. And in June, 2003, the ratio of E. pacifica was $51\%$, copepods $43\%$, and the others comprised $6\%$. In both March and June E. pacifica showed dominance among the species of zooplankton. 2) The analysis of vertical distribution through acoustic data in the scattering layer was more apparent in June (spring/summer) of 2003, than in March (winter/spring) of that year. The vertical migration of zooplankton peaked around sunrise and sunset in both March and June. 3) As for the sound scattering layer, it distributed in the open sea in March, and in the inland sea in June. Therefore it is suggested that some zooplankton species such as E. pacifica performed ontogenic horizontal migration througth the spring and early summer.