• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.4
• /
• pp.529-541
• /
• 2015

We examined the species composition and community structure of demersal fish in the middle and southern coastal waters of the East Sea of Korea by surveying a commercial Danish seine fishery from 2010 to 2013. We considered the waters north of $37^{\circ}N$ as middle and those south of $37^{\circ}N$ as southern waters. A total of 79 demersal fish species belonging to 18 families were collected. Of these, 59 species (77.6%) inhabited only the East Sea as opposed to the West and South Seas of Korea, and most were resident species. The species and biomass were similar between the two portions of the study area. The sandfish Arctoscopus japonicus (78.0%) and the blackfin flounder Glyptocephalus stelleri (65.1%) were the most common species and accounted for the most biomass in the middle and southern waters, respectively. Fish were most abundant at shallow depths (50-100 m) in the middle portion of the East Sea. Using a cluster analysis, we divided the species composition and community structure at the sampling stations into three groups: middle portion (group A), deep area of the southern portion (group B), and shallow areas of the southern portion (group C). A. japonicas and G. stelleri were dominant in groups A and B, while G. stelleri and Clupea pallasii were dominant in group C.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.40 no.3
• /
• pp.113-116
• /
• 2007

We investigated the characteristics of various Tofu coagulants extracted from sea tangle using treated deep ocean water (DOW) as the solvents. The coagulants were typical solutions extracted from sea tangle using raw DOW and strongly electrolyzed acidic (SAC) or alkaline (SAK) water. The total dissolved solids (TDS), NaCl and electric conductivity were increased in the coagulant solution extracted by SAC than the others. In the coagulant solutions extracted by acidic electrolyzed solvent, aspartic acid content (13.5 mg/100 g) was higher than others (11.2 and 12.1 mg/100 g). The Tofu obtained using coagulants extracted with treated DOW had the water contents ranging from 79.55% to 80.04%. The contents of crude protein (12.1 g/100 g) and Na, Ca, K and Mg were relatively higher than general Tofu commercially available. Therefore, coagulant solutions extracted from sea tangle using treated DOW can be used to develop natural high-grade tofu for practical use.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.3
• /
• pp.298-307
• /
• 2011

The species composition and distributions of subtidal marine algae on the east coast of Korea were studied. We examined all species found in permanent quadrats at three depths (3 m, 5 m and 10 m) at Sacheon between October 2008 and December 2009. Coverage and frequency data were collected monthly via underwater photography and analyzed using a modified photo quadrat method. Of the 82 species identified, 10 were chlorophytes, 21 were phaeophytes, 50 were rhodophytes, and one was a seagrass. The largest number of species (59) was found 10 m deep, while the fewest (39) species were present at 5 m. A total 17 species (two green, five brown, and 10 red algae) occurred at all three depths. The vertical distribution of the study site was characterized by the melobesioidean algae, Ulva pertusa, Sargassum confusum, Phyllospadix iwatensis, and Codium arabicum at 3 m deep, melobesioidean algae and U. pertusa at 5 m deep, and Corallina pilulifera, Prionitis cornea, Chondracanthus tenellus and melobesioidean algae at 10 m deep. Given that coralline algae such as melobesioidean algae and C. pilulifera play important roles in coastal ecosystems, thorough studies on the spatial and temporal variations of coralline algae and the dynamics of marine algal communities on the east coast of Korea are now required.

• The Korean Journal of Malacology
• /
• v.20 no.2
• /
• pp.135-140
• /
• 2004

Twenty five marine molluscan species were added to the malacofuana of Dokdo Island, Korea based on the samples collected from inter- and subtidal rocky shore of the island on April and November 2004. As a result, seventy five marine molluscan spacies were recorded from Dokdo Island hitherto.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.45 no.2
• /
• pp.167-172
• /
• 2012

Minerals from marine materials such as deep ocean water and Dead Sea water have been used since ancient times. We made a mask pack sheet including deep ocean water and salt from the Dead Sea and evaluated the function of the mask pack sheet through animal study. Three full-thickness skin defects were made on the backs of Sprague-Dawley rats. The wounds were left untreated in group Con, and mask pack sheets including deep ocean water or deep ocean water and Dead Sea water were used as treatment for 20 min on the skin of animals in groups DP and DDP, respectively. We analyzed the gross, histological and biochemical findings. Groups DDP and DP showed decreases in wound size, as compared to group Con at 7 days after wound infliction. The histological findings revealed that wound healing had progressed further in groups DP and DDP than in group Con, with more rapid collagen deposition and regression of neutrophils. Also, the expression of vascular endothelial growth factor and transforming growth factor ${\beta}1$ were increased in groups DDP and DP compared with those in group Con at 3 days after wound infliction. Mask sheet packs including deep ocean water and Dead Sea salt affected wound healing by reducing the inflammatory phase and stimulated wound contracture by facilitating the deposition of collagen.

• Fisheries and Aquatic Sciences
• /
• v.25 no.12
• /
• pp.589-600
• /
• 2022

Longline fishery targeting tunas and tuna-like species is known to produce a significant amount of catch not only for the target species, but also for ecologically related species like sharks, marine turtles, sea birds and marine mammals. Recognizing this seriousness, tuna related regional fisheries management organizations (t-RFMOs) have established conservation and management measures (CMMs) to reduce bycatch and/or interaction with ecosystem vulnerable species including sea turtles and are obliged to implement bycatch mitigation measures and guidelines on safe release to their member countries. Along with development and strengthening of those measures, various case studies have been conducting to verify the effectiveness of bycatch mitigation for ecologically related species. This study examines the background and progress on developing CMMs of t-RFMOs and regulation programs of the United States related to sea turtles, which have recently become one of the main issues, and reviews case studies on sea turtle bycatch mitigation measures to find out the effectiveness of reducing bycatch rate and impacts to the fisheries. In order to respond the consultation process on certification determination with the United States, it was confirmed the current status of implementation on related measures conducted by Korean tuna longline fishery based on scientific observer data and survey for captains. Even though all Korean tuna longline fleets belong to the deep-set longline fishery (100-300m), which is not subject to the obligation of those mitigation measures, they are voluntarily implementing both measures, use of circle hook and whole finfish bait, regardless of which RFMO's Convention area they operate. And the national regulatory and management programs for sea turtle bycatch prevention adopted by Republic of Korea seems to be comparable in effectiveness to that of the United Stated. However, Korea needs to take preemptive measures in establishing sustainable fisheries, including the protection of the marine ecosystem and environment, as stronger requests are anticipated to be made by the international community on this matter.

• Fisheries and Aquatic Sciences
• /
• v.15 no.2
• /
• pp.99-105
• /
• 2012

The biochemical composition of muscle from three deep-sea animals, Tanaka's eelpout Lycodes tanakae magistrate armhook squid Berryteuthis magister, and ocean sunfish Mola mola caught in the East sea in South Korea was determined. The moisture (81.4-93.8 g/100 g), crude protein (5.0-15.6 g/100 g), crude lipid (0.1-1.5 g/100 g), and ash (1.0-1.1 g/100 g) contents of the two fishes were analyzed. The proximate composition of magistrate armhook squid was: moisture 84.0 g/100 g, crude protein 12.4 g/100 g, crude lipid 0.7 g/100 g, and ash 1.5 g/100 g. There was little difference in the proximate compositions of the three animals. The total amino acid contents of Tanaka's eelpout, magistrate armhook squid, and ocean sunfish were 14.64, 10.75, 3.10-9.95 g/100 g, respectively. High levels of glutamic acid, aspartic acid, lysine, leucine, and arginine were found, while low levels of histidine, glycine, and cysteine were detected in the animals. A survey of the free amino acid contents of the animals revealed large amounts of alanine and glycine. Significant differences were found in the fatty acid composition among the three species. Specially, different saturated fatty acids (17.14-40.49%) such as C16:0, and C18:0, monounsaturated fatty acids (19.19-46.88%) such as C16:1, and C18:1, and polyunsaturated fatty acids (35.41-57.08%) such as EPA, and DHA was identified. Our results suggest that each of these deep sea animals possesses nutritional value and should be considered as a foodstuff.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.3 no.3
• /
• pp.165-169
• /
• 1998

In August 1996, seawater salinity and nutrient distribution were investigated at surface waters in the South Sea of Korea. The low-salinity (< 20.00 psu) waters were observed in the western and southwestern offshore areas of Cheju Island. Relatively low saline (< 30.0 psu) waters occupied most of the survey areas only except in the eastern part. The observed minimum salinity was lower by 11.78 psu than that of the average between 1963 and 1995. The low saline waters appeared in the upper layer of generally 10-20 m deep, and were obriously distinguished from high-salinity (> 32.00 psu) waters, 30 m deep. The low saline waters may originate from the freshwater discharge of vast amount of from Yangtze River during the heavy rainfall season in China. Phosphate concentrations in the surface waters were relatively low and were less variable than those of nitrate and silicate. The maximum concentrations of nitrate and silicate occured in the western and southwestern offshore areas of Cheju Island, where the salinities were the lowest. The concentrations of nitrate and silicate were inversely correlated with salinity, whereas that of phosphate showed a considerable scatter and non-conservative behaviours. This indicates extensive desorption reactions of suspended materials releasing phosphate.

• Journal of Ocean Engineering and Technology
• /
• v.26 no.1
• /
• pp.78-83
• /
• 2012

The abundant nutrients contained in deep seawater are delivered by natural upwellings from the deep sea to the surface sea. However, the natural upwelling phenomenon is limited to specific areas of the sea; in other areas, the thermocline separates the surface sea from the lower layer. Thus, the surface layer is often deficient in nutritive salts, causing the deterioration of its primary productivity and ultimately leading to an imbalance in the marine ecosystem. Without a consistent supply of nitrogenous nutritive salts, they are absorbed by phytoplankton, resulting in a considerable problem in primary productivity. To solve this issue, a floating type of artificial upwelling system is suggested to artificially pump up, distribute, and diffuse deep seawater containing rich nutritive salts. The key technologies for developing such a floating artificial upwelling system are a floating offshore structure with a large diameter riser, self-supplying energy system, density current generating system, method for estimating the emission and absorption of CO2, and way to evaluate the primary production variation. Strengthening the primary production of the sea by supplying deep seawater to the sea surface will result in a sea environment with abundant fishery resources.

• Proceedings of the KIEE Conference
• /
• 2007.04a
• /
• pp.319-321
• /
• 2007

This paper introduces a general overview of the 6000m class deep-sea ROV. Hemire and Henuvy. and then describes its motion control system. It is developed by Korea Ocean Research & Development Institute(KORDI) for 6 years since 2001. sponsored by the Ministry of Maritime Affairs and, Fisheries (MOMAF). Hemire is remotely operated by a fiber optic telemetry. where 6 thrusters are controlled by operator in manual mode and by auto depth control and auto heading control in auto mode. In this paper. operational mechanism of manual and automatic mode with some convenient functions for operator is desc.ribed. Finally, results of sea trial conducted at the Philippine sea where a depth is 5.770m are shown.