폐기물 배출해역의 저서동물상에 대한 준설토 피복 효과

Abstract

Korea started discharging wastes to the sea in 1988; currently, the discharge of wastes to the sea is prohibited except for some substances. However, the discharging sea area is still polluted due to the effects of wastes heavily discharged in the past. Particularly, it is necessary to prepare remediation and restoration measures for the areas where the pollution is exacerbated, as the areas where discharge was concentrated has become severe and the natural attenuation effect is not noticeable over time. In Korea, a large amount of dredging materials are generated from dredging to maintain sea route and to remediate contaminated sediments, etc. So it has been sought to find methods for beneficial use of these dredged materials as resources rather than wastes. Moreover, when dredged materials satisfy the permission standards for marine discharge, they are allowed to be discharged to the sea. So, the Ministry of Oceans and Fisheries has started capping project as pilot scale in 2013 and 2014 which induces dredged materials to be discharged to places where pollution is concentrated in the section of the West Sea-Byeong. In this study, the sediment environment and benthic fauna were monitored once a year from 2014 to 2020 targeting the capping area and non-capping area in ​​the section of the West Sea-Byeong, and the capping effects of the dredged materials were analyzed and evaluated based on the monitoring results. According to the results of applying the capping methods to the sediments, the number of species and ecological indices were improved for three or four years after the capping but they appeared to slightly decrease later. The reason for this result was that it was additionally capping and disturbed in the benthic fauna. So, long-term monitoring for five to ten years is recommended to determine the remediation and restoration of benthic ecosystems. In the future, it is necessary to manage the waste-discharging area by using the concept of adaptive management, and also to develop and apply a new evaluation method and criteria.