• Strategy21
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• s.41
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• pp.85-107
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• 2017

The purpose of this article is to explore recent developments in piracy attacks at the global level. This article provides an overview of global trend of recent piracy attacks and presents global counter-piracy efforts at the international and governmental as well as industry level. The issue of piracy has been a grave concern of the globe, becoming the biggest threat to the safety and security navigation and seaborne trade. Overall, piracy attacks in recent years have greatly diminished owing to multi-faceted counter-piracy efforts. However, Southeast Asia and West Africa have reemerged as an hotspot of piracy. A worrisome trend in these regions is that many of piracy attacks are committed by militant groups for financing their activities. As a result, the level of violence and the sophistication of attacks have escalated. The problem of contemporary piracy is beyond a particular region or coastal state, but a common concern of the international community. In order to address the global piracy problem, international cooperation should be further strengthened at the global level as well as the regional level. As a way of counter-piracy measures in Southeast Asian waters, the creation of a joint regional coast guard to patrol the highly piracy concentration areas needs to be considered.

• Fisheries and Aquatic Sciences
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• v.19 no.9
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• pp.36.1-36.3
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• 2016

Balssaxius habereri (Balss, 1903) has been newly reported in Korean waters. This species was previously known from the Pacific coast of northern Japan, Korea Strait, Yellow Sea, and Japanese coast of the East Sea. Specimens were collected from western Jeju Island using otter trawls at depths of 65-85 m. Regarding Korean axiid shrimps, a single species, Boasaxius princeps (Boas, 1880), previously known as Axiopsis princeps in Korea, has been recorded. B. habereri is easily distinguished from B. princeps as it does not have tufts of setae on its body and males do not have the first pleopod. Morphological descriptions and color photos of the specimens are provided.

• Journal of Environmental Science International
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• v.8 no.6
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• pp.677-684
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• 1999

To investigate size distribution and metallic elements of surface sediments in Hampyong Bay, the southwestern coast of Korea, sedimentological and geochemical studies on surface sediments are carried out. The surface sediments of Hampyong Bay are classified into gravel, muddy sandy gravel, gravelly muddy sand, gravelly sandy mud, mud facies in accordance with areal characteristics. The coarse sediments are distributed on the subtidal zone along the main tidal channel and southeast intertidal flat of Hampyong Bay. On the other hand, the fine sediments are dominated in northeast and west intertidal flat of Hampyong Bay. Most metallic elements except for Ba in the sediments are closely interrelated with fine sediments and mutually with each element. Ba is maybe related with sandy sediments and inversely related with carbonate contents. Normalized by Al content, the sediment do not show any remarkable metal enrichments influenced by resonable artificial or environmental factors.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.451-454
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• 2008

Potential tsunamis which may occur near Ryukyu Islands were simulated. Propagation characteristics of the potential tsunamis over the southwestern sea and the influence of tsunamis on the southwestern coast of Korean Peninsula were analyzed. The shallow water area in the east sea of China and the deep water Okinawa Trough play an important role in wave transformation and propagation of the potential tsunamis. The propagation characteristics of the potential tsunamis generated near Ryukyu Islands can be described as in followings : In the first stage after generation, the tsunamis propagate with high speed both northeastward and southwestward along the Okinawa Trough. As a result the waves are elongated and the tsunami height is significantly reduced. The elongated crest of tsunamis spans the whole distance of the Okinawa Trough and lines up toward the edge of the continental shelf of East China Sea. Then, the tsunamis are propagating towards the southeast coast of China. Thus, the influence of tsunamis on the Korean coasts becomes weak.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.6
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• pp.673-681
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• 2018

We isolated and characterized Escherichia coli (E. coli) from oyster Crassostrea gigas and inland pollution sources on Yongnam-Gwangdo island and neighboring areas on the southern coast of Korea in 2014-2015. A total of 222 strains of E. coli were isolated from 132 oysters and 88 samples from inland pollution sources. These 222 isolates were tested for their susceptibility to 24 antimicrobial agents, and 221 isolates were found resistant to the tested antibiotics. Of these 99.5% and 70.7% of the isolates showed very high resistance to rifampin and cephalothin respectively, followed by tobramycin (23.4%), streptomycin (20.2%), tetracycline (19.4%), cefepime (18.9%), ceftazidime (18.9%) and nalidixic acid (16.7%). The resistance rate of E. coli isolated from oysters was higher than that from inland pollution sources. In addition, multiple resistance to at least four antibiotics were present in 73.2% and 26.5% of E. coli isolates from oysters and inland pollution source samples, respectively.

• 한국해양학회지
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• v.24 no.2
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• pp.63-68
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• 1989

Deep current was observed at 620 m and 790 m in water 840 m deep off the mid-east coast of Korea from August 26 to November 7, 1986. Data analysis showed that the deep current in the subinertial frequency range was directed to southeast with a vector-average speed of about 3 cm/s. The deep flow had a large temporal variability with the same pattern of variation at the two depths. The maximum speed of the low-frequency current reached to a value larger than 11 cm/s just after the passage of Typhoon Vera over the study area. We also observed occurrence of sharp direction changes from southeast toward north persisting for a few days.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.259-266
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• 2011

To produce cupped oyster sprat consistently, we investigated the efficiency of nine settlement substrates using selective breeding of Pacific oyster Crassostrea gigas, with the goal of popularizing off-bottom culture on the west coast of Korea. We also compared the growth and survival of selectively bred sprat (diploid) with triploid sprat from an off-bottom culture system. Considering, the attachment rate and detachment efficiency, producing cupped oyster in a polypropylene gunny bag proved to be the most effective method. There were no differences in shell growth or total weight between the diploids from selective breeding and triploids from off-bottom culture for 5 months. However, the survival rate was 8 times higher in the diploids than the triploids. Transplanting sprat from selective breeding is one way to restore oyster farms and nurture off-bottom culture along the west coast.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.6
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• pp.450-458
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• 1991

The thermal structures and their spatio-temporal fluctuations in the upper 200m layer off the southeast coast of Korea are studied using the bimonthly temperature data for 17years(1967-1983) at 37 stations. We analyzed the fluctuations of the temperatures in the surface(0-100m) and in the subsurface(100-200m) layers. The fluctuations of temperatures in the surface water are dominated by the annual variation, whereas the subsurface layer temperatures contain considerable non-seasonal fluctuations. The distributions of water temperature anomalies in the subsurface layer are closely related with those in the surface layer. The predominant periods of temperature fluctuations in the subsurface layer, other than the annual variation, are 14 and 70 months. The period of 14 months coincides with that of the pole tide or Chandler wobble. The cluster analysis shows that our study area can be divided into the cold, the frontal and the warm regions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.6
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• pp.740-746
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• 2011

Subtidal benthic macroalgal flora and community structure on barren grounds were examined seasonally along vertical shore gradients on the rocky shore of Hajung, Pohang, on the southeast coast of Korea, from February 2005 to November 2006. Twenty-six seaweed species were identified, including 5 green, 7 brown, and 14 red algae. The number of seaweed species ranged between 7 and 17 among seasons and between 13 and 20 species were found in vertical gradients along the shore. Over the study period, average seaweed biomass (g wet wt/$m^2$) was 299.88 g and it ranged seasonally from 120.99 to 620.00 g. Seaweed biomass declined with increasing seawater depth and ranged between 323.06 and 593.68 g. The dominant seaweed species, in terms of biomass, were Desmarestia ligulata and Sargassum honeri, which grew at depths between 5 and 10 m. The red alga Delisea pulchra was also abundant at a depth of 15 m. No seasonal patterns were found in community indices. Along vertical shore gradients, community indices showed different patterns; the dominance index increased and the richness, evenness, and diversity indices decreased with seawater depth.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.6
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• pp.481-492
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• 2009

The characteristic of cold water by upwelling in the southeast of the Korean Peninsula and the effect of sea breeze in this region are investigated. The coastal upwelling around the southeast coast of the Korea Peninsula is analyzed by using Coastal Oceanographic Data statistical analyses for 5 years were carried out. The period of an cold water event, on the average, was observed southwesterly wind events. The analysis suggests that strong and persistent southwesterly winds in period of an cold water play an important role of bring the moisture to the surface, generating persistent cyclone as jangma. In order to investigate the effect of cold water on sea breeze, we considered two case. First, Exp. 1 is not occurred coastal upwelling on sea breeze. Second, Exp. 2 is occurred cold water on sea breeze. Two experiments were completed separately to the effects of cold water by upwelling. The results show the sea breeze is stronger in Exp. 2, when the cold water occurs, and weaker in Exp. 1, when there is no cold water. In order to verify the effect of the sea breeze on the cold water by upwelling, on the intensification and change of direction of the prevailing wind, the sea breeze effectively intensify cold water condition.