• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.24 no.1
• /
• pp.170-186
• /
• 2019

The marine ecosystem survey investigates and analyzes multi-parameters at various times from various sites. Therefore, it is very difficult to analyze the complex ecological data of multi-items effectively, and it is more difficult to identify the current status and diagnose the problems of ecosystem through data analysis. Therefore, this paper aims to provide an example of interpretation of complex ecological data through analysis of distribution characteristics and outliers of ecological survey data. The main contents of the study are to elucidate the background levels of coastal ecosystem parameters considering the distribution characteristics of data, and to establish ecosystem monitoring indicators and an adaptive management system for the coastal waters in Korean Peninsula. The data used in this paper are based on the coastal ecosystem survey of the National Marine Ecosystem Monitoring Program conducted by the Ministry of Oceans and Fisheries (MOF) and the Korea Marine Environment Management Corporation (KOEM), and the major citations are from year 2015 to 2017. This article is a preliminary study to establish the above processes and the final result will be derived in 2020 when the coastal ecosystem survey is completed three times along the Korean coast.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.5
• /
• pp.456-461
• /
• 2023

The Korea Maritime Environment Corporation is conducting a comprehensive survey of the national marine ecosystem under the commission of the Ministry of Oceans and Fisheries (MOF) to ensure continuous use of the ocean, preserve and manage the marine ecosystem. The survey has set major peaks to investigate changes in the marine ecosystem around the Korean Peninsula. However as the peak has been set around the coast, it is necessary to expand the scope of investigation to encompass offshore areas. Meanwhile, the Aids to Navigation Division of the MOF supports a comprehensive national marine ecosystem survey providing photographs of fouling organisms during the Aids to Navigation lifting inspection, however, the photographs are provided only in consultation with the Korea Maritime Environment Corporation. Therefore, a study was conducted to generate information on fouling organisms using deep learning-based image processing algorithms by the lifting Aids to Navigation and dorsal buoys so that Aids to Navigation could be used as the major component of a comprehensive national marine ecosystem. If the Aids to Navigation are used as the peak of the survey, they could serve as fundamental data to enhance their own value as well as analyze abnormal marine conditions and ecosystem changes in Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.60 no.1
• /
• pp.37-46
• /
• 2024

This study was conducted to provide the basic information on environment effects on appearance of ichthyoplankton in the Yeongsan River Estuary in Spring and Summer from 2018 to 2020. Data were obtain from the database of 'Coastal Ecosystem' in "National Survey of Marine Ecosystem." Among the abundance ichthyoplankton species, the Gobiidae spp. dominated, accounting for 85% of the total abundances with the secondary dominant species being the Parablennius yatabei, representing 3% of the abundances. Cluster analysis results revealed a composition differentiated between spring and summer. The Yeongsan River Estuary is known to be significantly influenced by the opening and closing of estuarine gates. In this study, the fluctuation in the number of occurrence groups and abundance among the years and season is attributed to the phenomenon of high water temperature period and the freshwater discharge.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.2
• /
• pp.130-142
• /
• 2014

The Korean government is considering implementation of the marine ecosystem restoration technology program (MERTP) to analyze the current status of the marine ecosystems and causes for the ecosystem deterioration as well as to eventually establish a master strategic plan for restoring ecosystem functions and preventing ecosystem functional loss. In order to determine likelihood of successful implementation, it is essential to perform an analysis of the economic feasibility of the program. The present study assessed economic feasibility of the MERTP. To this end, the dichotomous choice contingent valuation (CV) method is used. In particular, dichotomous choice (DC) format is employed as a method of eliciting willingness-to-pay (WTP) response to incentive-compatible mechanisms. The study also employed the spike model to deal with zero WTP responses from the DC CV survey. This survey of 1,000 randomly selected households in accordance with the guidelines provided by the National Oceanic and Atmospheric Administration (USA) was carried out nationwide in 2013. And, the respondents were asked in person-to-person interviews about their WTP for implementing the MERTP. The results showed that the annual mean WTP was estimated to be 5,414 won per household. Consequently, the annual benefit from the MERTP would be about 98.6 billion won for the next five years. Economic feasibility assessment utilizing the MERTP investment cost and expansion cost of the value provided that net present value, benefit/cost ratio, and internal rate of return are 337.8 billion won, 5.20, and 65.9 %, respectively, which are bigger than 0, 1.0, and 5.5 %, and that the MERTP passes the cost-benefit analysis.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.50 no.4
• /
• pp.476-486
• /
• 2014

This study is aimed to understand the vertical distribution of fish in the daytime and nighttime using an acoustic survey in Yondam reservoir of Jeollabuk-do, and an acoustical backscattering strength of dominant species, bass (Micropterus salmoides) and a bluegill (Lepomis macrochirus), which are classified as the ecosystem disturbing species. The results showed that the fish school was distributed in the shallow areas of less than 10 m depth during the period of Aug. and Oct. where it had a strong thermocline, otherwise, it was distributed over 10-times density under stable water temperatures as $13^{\circ}C$ in Nov. There was no vertical patchiness difference between daytime and nighttime unlike the typical marine ecosystem. The dominant species were crucian carp, bluegill, bass. The hydroacoustic method can provide the spatial distribution and effective removal ways of the ecosystem disturbing species in inland fisheries.

• Ocean and Polar Research
• /
• v.23 no.4
• /
• pp.425-431
• /
• 2001

From an ecological point of view, the western part of the Atlantic sector is one of the most productive areas in the Southern Ocean. Antarctic krill (Euphausia superba) and krill-dependent predators such as fish, seals, and birds are abundant there, and most krill fisheries have operated in this area since 1970s. The hottest issues for the proper management of krill resources nowadays are to determine total biomass in this area, and to identify environmental forces controlling stock fluctuation. This paper reviews and collates information on ongoing oceanographic activities in the Antarctic Peninsula region concerning these issues. To delineate the status and function of Antarctic krill population in Antarctic marine ecosystems, multinational researches along the Antarctic Peninsula area have been developing recently. Four member states of CCAMLR (Japan, Russia, UK, and USA) had conducted acoustic surveys in January-February 2000 (socalled CCAMLR-2000 survey), and krill standing stock at 120 kHz was estimated to be 44.29 million metric tonnes in the western Atlantic sector of the Southern Ocean. On the other hand, the Southern Ocean GLOBEC (SO-GLOBEC) Programme has prepared a serial winter survey to examine the factors that govern krill survivorship and distribution in relation to shelf circulation processes. Ship-based surveys using ice-breakers are being conducted by three nations (Germany, UK, and USA) around the Marguerite Bay during the austral fall and winter 2001 and 2002. In addition to these two large-scale surveys, some CCAMLR members have carried out joint oceanographic surveys near the South Shetland Islands to detect ecosystem changes since 1994. Especially from December 1999 to February 2000, in conjunction with CCAMLR-2000 survey, four nations (Japan, Korea, Peru, and USA) conducted acoustic surveys to produce time-series information on krill distribution and biomass near the South Shetland areas. Though the aims of each program and the approach to solve the scientific questions were different each other, the results from each program fill the gaps between programs. Further cooperation and exchange in these activities could be beneficial to each program.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.24 no.1
• /
• pp.64-78
• /
• 2019

The background concentrations of heavy metals in Korean coastal sediments were estimated using heavy metal data for 495 sediments obtained from 'National Marine Ecosystem Survey (Coastal ecosystem) in 2016-2017' and the extent of contamination was assessed. Al, Cs, and Li are chosen as appropriate indicators for sediment grain size. In the relationships between heavy metal and indicators concentrations, the lowest slope data were selected through the outlier removal and residual analysis, and the background concentrations were presented as a linear regression line between metal and indicator. Comparing the previous studies for the background concentrations of heavy metals in Korean coastal sediments, concentration levels were generally consistent but those for As and Cd were presented for the first time, and the background concentration using Li as the indicator was presented for the first time.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.46 no.3
• /
• pp.265-275
• /
• 2010

The main purpose of this study is to estimate willingness to pay (WTP) by the general publics, assuming that they pay tax or charge for protecting marine living resources and environment through developing and supplying biodegradable fishing nets. This study employed a contingent valuation method (CVM) which is an econometric method. The survey was conducted by using both double-bounded dichotomous choice and open-ended survey. Tobit model was used for the analysis. The variables included concerns about marine environment and fishing net discarded, sex, age profile, number of family members, educational level and personal disposable income. Annual average WTP per family for the biodegradable fishing net development and supply was estimated at 5,294 won and national WTP amounted to some 84.2 billion won. This includes both of use and non-use value of biodegradable fishing nets.

• Journal of Environmental Science International
• /
• v.21 no.10
• /
• pp.1275-1286
• /
• 2012

Coastal marine ecosystem plays important role of spawning and nursery grounds for fisheries resources. Yongil Bay is one of major coastal marine ecosystems, which is located in the southwestern East Sea of Korea. Species composition and abundance of marine organism in the Yongil Bay were investigated by season from March to November 2009. Gill net and pot fisheries were used for survey of pelagic and demersal species composition, and collected 106 species, 67 families, and 7 taxa of fisheries resources from the coastal ecosystem. Species were included 2 species in Ascidiacea, 2 species in Bivalvia, 6 in Cephalopoda, 22 in Crustacea, 5 in Echinodermata, 12 in Gastropoda, and 57 in Pisces. Diversity indices (Shannon index, H') showed seasonal variation with low value of 2.11 in winter, and high value of 2.63 in autumn. Main dominant species were Asterias amurensis, Pleuronectes yokohamae, Siphonalia spadicea fuscolineata, Trachurus japonicas, Sillago japonica, Conger myriaster, Volutharpa ampullaceal, Engraulis japonicus, Asterina pectinifera, and Portunus (Portunus) sanguinolentus that were occupied over 71.5% of total individuals, and 52.9% of wet weight. Seasonal variations of fisheries resources composition were discussed on correlationships with those of environmental factors in the coastal ecosystem of the Yongil Bay in Korea. Those results from this study will provide scientific data and information to develop the ecosystem-based coastal fisheries assessment and management system in Korea.

• 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.