• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.4
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• pp.263-273
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• 2015

We estimated the global inflow and stock of plastic marine debris. In South Korea, we estimated that the annual inflow of plastic marine debris (72,956 tons) was about 1.4% of annual plastics consumption (5.2 million tons) in 2012. By applying this 1.4% ratio to global plastics production from 1950 to 2013, we estimated that 4.2 million tons of plastic debris entered the ocean in 2013 and that there is a stock of 86 million tons of plastic marine debris as of the end of 2013, assuming zero outflow. In addition, with a logistic model, if 4% of petroleum is turned into plastics, the final stock of plastic marine debris shall be 199 million tons at the end. As the inflow and the stock are different units of measurement, better indicators to assess the effectiveness of inflow-reducing policies are needed. And, as the pollution from plastic marine debris is almost irreversible, countermeasures to prevent it should be valued more, and stronger preventive measures should be taken under the precautionary principle. As this is a preliminary study based on limited information, further research is needed to clarify the tendency of inflow and stock of plastic marine debris.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.967-976
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• 2021

Over the last ten years, the number of entanglement marine accidents has increased more than other accident types. This study analyzed the annual statistical report of marine accidents from the Korea Maritime Safety Tribunal and Korea Coast Guard. Despite some discrepancies between data of the two organizations, it was found that marine accidents involving fishing vessels were more prevalent than those involving non-fishing vessels. In addition, the main floating materials that caused wounded entanglement accidents were fishing nets, fishing gear, and ropes, and the proportion of them was high. Foreign and domestic policies on marine plastics recognize most marine plastics as marine environmental hazards and focus on marine litter recovery and the prevention of marine pollution. The representative Acts related to the marine environment and marine litter, the Marine Environment Management Act and the Marine Waste and Sediments Management Act, recognize marine litter as a type of marine waste, and deal with the types and definition of this waste. However, clearly defining marine waste is difficult. Therefore, this study tried to examine the relevant legal system of marine litter on ship operation and suggested improvement measures. Moreover, the definition of marine litter for the safe navigation and operation of ships was clearly proposed.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.1
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• pp.45-49
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• 2015

Disturbance to marine wildlife is a serious negative impact of marine debris. In this study, the percentages of Black-faced Spoonbill nests that included plastic marine debris were calculated from surveys conducted on an islet named Suhaam off the western coast of South Korea. The percentages of nests including plastic decreased from 71% in 2010 to 37% in 2011 to 33% in 2012. The total number of nests increased from 28 in 2010 to 38 in 2011 to 43 in 2012. These differences in nests and nesting materials were possibly due to natural nesting materials such as tree branches and rice straws that were provided at the breeding site as a protective action in 2011 and 2012. Additional conservation efforts should be made to prevent further negative impacts from marine debris.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.2
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• pp.89-100
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• 2012

The aim of this study knows to occurrence characteristics and monthly transition of foreign marine debris by changing in the marine environment for the national marine debris monitoring areas in the west coastal area. The Jeju Island (5,112) had the highest number for foreign marine debris flowed in the coast. Many areas in the next were surveyed by Hajo Island (1,967), Imja Island (507). Plastic bottles were the most common type to 2,925 piece of the whole collection. Then, the monthly occurrence amount was concentrated in July, September. At this time, analysis results of the marine environment are as follows: The sea surface wind of southerly or southeasterly were predominated. In addition, the sea surface circulations were dominated by inflow of seawater southward along the China Coast and northward from the East China Sea.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.137-137
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• 2023

해양쓰레기는 해안의 심미적 가치 저하뿐만 아니라 생태계 파괴, 유령 어업에 따른 수산업 피해 등의 사회적·환경적 문제를 발생시키며, 그중 70% 이상은 육상 기인으로 플라스틱 및 기타 쓰레기가 주를 이루는 해외와 달리 국내의 경우 다량의 초목류를 포함하고 있다. 다양한 부유쓰레기에 대한 기존의 해양쓰레기량 추정의 한계와 하천·하구 쓰레기 수거의 효율화를 위해 해양으로 유입되는 부유쓰레기 방지를 위한 실효성 있는 대책 수립이 필요한 실정이다. 본 연구는 해양 유입 전 하천의 차단시설에 차집된 부유쓰레기의 수거 효율화 및 지속가능한 해양쓰레기 데이터 구축을 위해 AI기반의 기술을 통해 부유쓰레기 성상 분석 기법(Object Detection)과 차집량 분석 기법(Semantic Segmentation)을 활용하였다. 실제와 유사한 데이터 수집을 위해 다양한 하천 환경(정수조, 소하천, 급경사수로)에 대해 탁도(녹조, 유사), 광량, 쓰레기형상, 초목류 함량, 날씨(소하천), 유속(급경사수로) 등의 실험조건에 대하여 해양쓰레기 분류 기준 및 통계를 바탕으로 부유쓰레기 종류 선정하여 학습을 위한 데이터를 수집하였다. 학습 목적에 따라 구분하여 라벨링(Bounding box, Polygon)을 수행하고, 각 분석 기법별 전이학습을 통해 Phase 1(정수조), Phase 2(소하천), Phase 3(급경사수로) 순서로 모델을 고도화하였다. 성상 분석을 위해 YOLO v4를 활용하여 Train, Test DataSet(9:1)을 구성하고 학습 및 평가는 Iteration마다의 mAP, loss 값을 통해 비교하였으며, 학습 Phase에 따라 모델 고도화로 Test Set의 mAP 값이 성상별로 높아짐을 확인하였으며, 차집량 분석을 위해 Unet을 활용하여 Train, Test, Validation DataSet(8.5:1:0.5)을 구성하고 epoch별 IoU(intersection over Union), F1-score, loss 값을 비교하여 정성적, 정량적 평가 모두 Phase 3에서 가장 높은 성능을 확인하였다. 향후 하천 환경에서의 다양한 영양인자별 분석을 통해 주요 영향인자 도출 및 Hyper Parameter 최적화를 통한 모델 고도화로 인해 활용성이 높아질 것으로 판단된다.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1109-1124
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• 2022

This study proposes a marine debris monitoring methods using satellite and drone multispectral images. A multi-layer perceptron (MLP) model was applied to detect marine debris using Sentinel-2 satellite image. And for the detection of marine debris using drone multispectral images, performance evaluation and comparison of U-Net, DeepLabv3+ (ResNet50) and DeepLabv3+ (Inceptionv3) among deep learning models were performed (mIoU 0.68). As a result of marine debris detection using satellite image, the F1-Score was 0.97. Marine debris detection using drone multispectral images was performed on vegetative debris and plastics. As a result of detection, when DeepLabv3+ (Inceptionv3) was used, the most model accuracy, mean intersection over union (mIoU), was 0.68. Vegetative debris showed an F1-Score of 0.93 and IoU of 0.86, while plastics showed low performance with an F1-Score of 0.5 and IoU of 0.33. However, the F1-Score of the spectral index applied to generate plastic mask images was 0.81, which was higher than the plastics detection performance of DeepLabv3+ (Inceptionv3), and it was confirmed that plastics monitoring using the spectral index was possible. The marine debris monitoring technique proposed in this study can be used to establish a plan for marine debris collection and treatment as well as to provide quantitative data on marine debris generation.

• The monthly packaging world
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• s.360
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• pp.67-73
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• 2023

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.2
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• pp.167-174
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• 2012

Transport of marine debris between countries is a potential source of diplomatic conflicts. U-i Island in Shinan County, Jeonnam Province has been reported by media as being damaged by marine debris from foreign countries. However, scientific researches on those marine debris have not been published. So, the features of foreign marine debris on Seongchon Beach in U-i Island were surveyed on Feb. 2012. The ratio of marine debris from foreign countries was 34.7% by number of items, 56.3% by weight, and 48.5% by volume in $200m^2$ transacts. Most of them, 98.9% in number, were inferred to be originated from China. The most abundant items were plastic beverage bottles and black floats. The total number of black floats was 539 within the 1,100m beach. Fifteen of them had information on manufactured locations, of which 87.6% were Liaoning Province in northern China. As domestic policy cannot prevent the inflow of the marine debris from foreign countries, countermeasures should be sought out from the international cooperation with the neighboring countries. For the black floats, recycling method should be developed as lots of the same types of black floats are drifted ashore in winter. And, as the U-i Island is a National Park with its valuable natural heritages, methods should be designed to minimize impacts on dune topography and ecology.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.4
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• pp.91-98
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• 2000

The present study is the first attempt involving quantification of the different types of debris found on the seabed of Chinhae Bay in the South Sea of Korea. Eleven cruises were undertaken to collect marine debris samples by bottom trawling from February in 1998 to January in 1999. The tows were conducted over a period of 60-90 min, and eight types of debris were counted: plastic, fishing gear, metallic objects, wood, rubber or leather, glass, textile and the others. Results are obtained based on the number and weight of the objects classified as per eight categories and station for a trawling period. The results of this study are that the number and weight of debris found per unit of swept area (1 hectare) were surveyed as 27.8(1,612 in total) and 3,130 g(193,820 g in total), and plastic and fishing gear have the most composition of marine debris by number, on the other hand, metallic objects and fishing gear have the most composition of marine debris by weight.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.3
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• pp.148-154
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• 2007

This study investigated the spatial distribution of the marine debris in Jinudo in the Nakdong river estuary. Types of marine debris in Jinudo are analyzed through sampling around some portion of its sandbar shoreline. The present study and its main results are summarized as follow: 1) Monitoring system, for evaluating the volume of marine debris, was established in the coastal region of $50\;m\;{\times}\;50\;m\;(=0.002\;km^2)$ over the southern part of Jinudo. All the marine debris of conceivable form are collected and their amount was also estimated. 2) During the $1^{st}$ collection in May 2007, the total weight of the marine debris was 1,110 kg in this site, which means the density of marine debris around the shoreline is $444\;ton/km^2$. After one month later, the collected marine debris was 23.75 kg and so we have the average density of $9.5\;ton/km^2$. From these results, it is suggested that the marine debris of 316.67kg was being accumulated per day over unit area($1\;km^2$). 3) The most frequent marine debris collected during monitoring campaigns was wooden material amounting to 85.86% of the whole collection; the rest were fishing gears such as nets and buoys(5.13%), household waste(2.34%), glass(0.94%) and metals(0.27%).