• Parasites, Hosts and Diseases
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• v.61 no.3
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• pp.332-337
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• 2023

Infestations of parasites, particularly those caused by copepods and monogeneans, are a major hindrance to aquaculture and have a big negative economic impact. Sebastes schlegelii, a farmed Korean rockfish, is particularly prone to copepods and monogeneans. This study comprehended how parasitic copepods and rockfish from a farm in Tongyeong-si, Gyeongsangnam-do, Korea, are related to the monogenean trematode Microcotyle sebastis. Our research revealed that monogeneans predominated, with a rate of 98.4% and an average infection intensity of 7 per infected fish. With an average infection intensity of 4 per sick fish, the infection rate for parasitic copepods was equally considerable, coming in at 91.7%. The high co-infection rate of both parasite families, at 90.8%, is noteworthy. Furthermore, Lepeophtheirus elegans and Peniculus truncatus, 2 parasitic copepod species, were discovered to have M. sebastis eggs attached to their bodies. This demonstrates a connection between parasitic copepod infestations in farmed Korean rockfish and the monogenean trematode M. sebastis. These discoveries highlight the necessity for creating more potent parasite control methods for the aquaculture sector and shed light on the intricate relationships between various parasite species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.6
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• pp.350-355
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• 2007

The optimal substrates and reaction flavoring conditions were examined to develop pearl oyster extract (POE) flavor using the Maillard reaction under a model system. The sugar for the Maillard reaction was glucose, and the amino acid was cysteine, with glycine as the reaction substrate. A three-dimensional response surface method was used to monitor the dynamic changes of the substrates during the Maillard reaction. To enhance the flavor of POE, a two-step enzymatic hydrolysate (Brix $20^{\circ}$) was reacted with the precursors (1:1, v/v). A 2:1:1 mixture of 0.4 M glucose:0.4 M glycine:0.4 M cysteine (v/v) was selected as a suitable reaction system for the reappearance of baked potato odor and boiled meat odor, and masking the shellfish odor. The two-step enzymatic hydrolysate and selected precursors were reacted in a high-pressure reactor to optimize the reaction parameters. The optimum conditions were 150 minutes at $120\;^{\circ}C$ and pH 7.0. The pH was the most critical factor for the response of the baked potato odor and masking the shellfish odor, while the reaction time affected the reappearance of the boiled meat odor.

• ALGAE
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• v.34 no.1
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• pp.45-56
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• 2019

Ecklonia cava (EC) has been widely utilized as an ingredient in commercial products such as functional foods and cosmeceuticals. Recently it has been found that Sargassum horneri (SH) has been invading on Jeju Island coast area by its huge blooming. Moreover, both seaweeds are considering as important ingredients in traditional medicine specifically in East-Asian countries (China, Japan, and Korea). In the present study, we attempted to compare anti-inflammatory properties of 70% ethanolic extracts of EC (ECE), SH (SHE), and their different combinations on lipopolysaccharide (LPS)-activated RAW 264.7 cells. Results indicated that 8 : 2 combinations of ECE : SHE significantly inhibited LPS-activated inflammatory responses (cytokines, protein, and gene expression) in RAW 264.7 macrophage cells compared to the respective extracts and other combinations. The synergistic effect of ECE and SHE was found to be prominent than the effects of ECE or SHE alone. These observations provide useful information for the industrial formulation of functional materials (functional foods and cosmeceuticals) using these two particular seaweeds in Jeju Island of South Korea.

• Fisheries and Aquatic Sciences
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• v.24 no.11
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• pp.341-350
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• 2021

The energy production of offshore wind farms plays an important role in expanding renewable energy. However, the development of offshore wind farms faces many challenges due to its incompatibility with marine environments and its social acceptability among the local community. In this study, we reviewed the marine environmental impact assessment status of offshore wind farm development projects for 2012-2019 in South Korea. A total of nine projects were selected for this study, all of which experienced considerable conflict with local fisheries resources. To appropriately respond to the underlying challenges faced by offshore wind farm development and in order to better support decision-making for future impact assessment, our findings identified: i) a need for adequate preliminary investigation and technical examination of fisheries resources; ii) a need to assess and estimate the impact of underwater noise, vibration, and electromagnetic waves on fisheries resources during wind farm construction and operation; and iii) a need for a bottom-up approach that allows for communication with local stakeholders and policy-makers to guarantee the local acceptability of the development.

• Journal of fish pathology
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• v.23 no.3
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• pp.429-440
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• 2010

We constructed a rock bream (Oplegnathus fasciatus) gill cDNA library and a total of 1450 expressed sequence tag (EST) clones were generated. Gene annotation procedures and homology searches of the sequenced ESTs were locally done by BLASTX for amino acid similarity comparisons. Of the 1450 EST clones, 1022 EST clones showed significant homology to previously described genes while 428 ESTs were unidentified, and 259 clones were hypothetical, or unnamed proteins. Encoding 313 different sequences were identified as putative bio-defense genes or genes associated with immune response.

• Journal of Marine Bioscience and Biotechnology
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• v.5 no.4
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• pp.1-7
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• 2011

Bone health is maintained by balance between bone resorption and bone formation, and bone homeostasis requires balanced interactions between osteoblasts and osteoclasts. Most of drugs and functional foods for bone health have been developed as bone resorption inhibitors, which maintain bone mass by inhibiting the function of osteoclasts. The recent studies have shown beneficial effects of marine natural products on bone health. Therefore, this review is aimed to study effects of marine-derived natural substances on osteoarthritis inhibition via attenuation of MMPs and osteoblastic differentiation via activation of alkaline phosphatase (ALP), osteoclacin (OC), bone morphogenic protein-2 (BMP-2) as an important factor for bone formation, and mineralization. The present review can provide new insights in the osteoblastic differentiation of marine natural products and possibility for their application in bone health supplement.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.419-424
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• 2009

Water and 70% ethanol extracts obtained from a sea cucumber (Stichopus japonicus) body wall by heat reflux or pressurized solvent extraction showed 2,2-diphenyl-1-picrylhydrazyl ($DPPH^{\cdot}$) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation ($ABTS^{{\cdot}+}$) scavenging activities comparable to those of fruits and vegetables. The highest activities were observed for the water extract from heat reflux extraction. Crude saponins exhibited higher radical scavenging activities than the soluble matters in the extracts. However, they were responsible for only about 3 to 15% of the scavenging activities of the extracts. Total phenolic contents showed a significant correlation with $DPPH^{\cdot}$ scavenging activities, suggesting a significant contribution of phenolic constituents to the antioxidant properties of the extracts. However, total flavonoid contents showed little correlation with the radical scavenging activities. The results suggest that the water or 70% ethanol extract obtained from sea cucumber body wall by simple heat reflux extraction could provide considerable antioxidant benefits.

• Ocean and Polar Research
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• v.44 no.4
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• pp.355-364
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• 2022

When the 60-ton-class patrol boat '72' of the Korea Coast Guard (KCG) was on duty and she accidentally collided with another patrol boat ('207', 200-ton-class) and sank. A month-long search found a small amount of lost items, but neither the crew nor the ship was found. For the first time in 39 years since the accident, the Korea Institute of Ocean Science and Technology (KIOST) searched the boat 72 using the latest integrated geophysical techniques. A number of sonar images presumed to be of a sunken ship was acquired using a combined system of side scan sonar and marine magnetometer, operated at an altitude of approximately 30 m from the seabed. At the same time, a strong magnetic anomaly (100 nT) was detected in one place, indicating the presence of an iron ship. A video survey using a remotely operated underwater vehicle (ROV) confirmed the presence of a shielding part of a personal firearm at the stern of the sunken vessel. Based on these comprehensive data, the sunken vessel discovered in this exploration was assumed to be '72'. This result is meaningful in terms of future ocean exploration and underwater archaeology, as the integrated system of various geophysical methods is an efficient means of identifying objects present in the water.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2218-2218
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• 2013

• Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.197-206
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• 2021

Marine brown seaweeds are a source of functional ingredients with various biological properties. They have been used in the food and functional food industries. Brown seaweeds are divided into three parts of blades, stipe, and root. Normally seaweed blades were used as raw materials for biological research. However, there are limited uses on stipes of Ecklonia maxima (E. maxima) depending on the physicochemical, nutritional, and biological properties. Besides, the comparative studies of two structures of E. maxima, blades and stipe didn't discover previously. This study aimed to compare the potent antioxidant and anti-inflammatory activities of the two structures of E. maxima, blades and stipe in vitro studies to increase the utilization of the two structures of E. maxima. The enzyme-assisted hydrolysate from E. maxima showed significant antioxidant and anti-inflammatory activities. Among them, celluclast-assisted hydrolysate from E. maxima blades (EMBC) and viscozyme-assisted hydrolysate from E. maxima stipe (EMSV) expressed significant protection on hydrogen peroxide-induced oxidative stress. Moreover, EMBC and EMSV treatment remarkably reduced nitric oxide production by downregulation of pro-inflammatory cytokine expressions in lipopolysaccharide-stimulated Raw 264.7 cells. Especially EMBC showed strong inhibition on pro-inflammatory cytokine production compared to EMSV. Taken together research findings suggest that EMBC and EMSV possessed potent antioxidant and anti-inflammatory properties and may be utilized as functional ingredients in the food and functional food sectors.