연안 및 하구생태복원 전문가 워크숍(박광재,임양재)

"갯벌"이란 모래,돌,흙 등으로 형성되어 있는 바닷가 및 연중 최만조시 수위선과 지면이 접하는 경계선으로부터 연중 최간조시 수위선과 지면이 접하는 경계선까지의 지역과 「수산업법」2ㅔ8조 제3항에 의한 갯발어업 어장의 수심(水深)범위내의 구역을 말한다.(갯벌 어업의 육성 및 지원에 관한 법률안)."갯벌어업"이란 갯벌어장 주변의 일정한 지역에 거주하는 어업인이 바닷가와 해안에 연접한 일정한 수심(水深)이내의 수면을 구획하여 패류.해조류 등 수산동식물을 관리.조성하여 포획.채취하거나 양식하는 어업을 말한다."갯벌수산물"이란 갯벌어장에서 포획.채취하거나 양식으로 생산된 수산물을 말한다.- 이후 생략【 제1주제 - 국립수산과학원 갯벌연구소 박광재 박사 】 연안(하구 및 갯벌) 모니터링 현황과 과제 【 제2주제 - 국립수산과학원 서해수산연구소 임양재 박사 】 충청남도 연근해 수산자원 및 환경관리 현황과 과

Distribution and Abundance of Japanese Anchovy Engraulis japonicus and Other Fishes in Asan Bay, Korea, estimated Hydroacoustic Survey

The distribution and abundance of coastal fish species in Asan Bay, Korea, were estimated from hydroacoustic survey and net catches. Acoustic data were collected with 38 and 200 kHz from July to October of 2012, and converted to the nautical area scattering coefficient (NASC, m2/mile2 ) for 0.25n⋅mile along ten transects. Japanese anchovy Engraulis japonicus was the dominant specie in the net catches. The virtual echogram technique was used to distinguish E. japonicus from other species based on the differences in the mean volume backscattering strength ( ΔMVBS ) at 38 and 200 kHz. Engraulis japonicus and other fishes are mainly distributed in the center channel and outer part of Asan Bay. E. japonicus tends to move from inner to outer Asan Bay in summer and fall. From NASC data, the target strength and length-weight function of E. japonicus and other fishes were used to estimate the E. japonicus stock at 24.1-93.3 tons, and other fish at 40.6-88.4 tons from July to October 2012. The estimated anchovy biomass compared well with the cumulative catch weight from stow net catches. The hydroacoustic method offers an approach to understanding spatial/temporal structure and estimating the biomass of fish aggregations in coastal areas.22Nkc

수산음향기법을 이용한 아산만 어군의 시·공간적인 분포 특성

수산 음향의 장점을 활용하여 아산만 연안해역의 어류 자원에 대한 하계시기부터 추계시기까지의 시·공간 분포 특성 및 변동성을 파악하였다. 또한 음향자료와 채집자료와의 비교를 통해서 어군 분포의 상관성을 분석하였다. 채집된 멸치의 체장-무게 함수와 멸치의 음향학적인 TS 특성을 활용하여 아산만 연안 해역의 시기 별 현존량을 추정 할 것이며 본 결과는 아산만 연안해역 어류 자원의 연구에 시·공간 분포 특성 파악에 필요한 기초자료를 제공할 것이다. 멸치의 음향학적인 TS 특성을 활용하여 아산만 연안 해역의 시기 별 현존량을 추정 할 것이며 본 결과는 아산만 연안해역 어류 자원의 연구에 시·공간 분포 특성 파악에 필요한 기초자료를 제공할 것이다.2

Study on the linearity of the target strength function between juvenile and adult Japanese anchovy (E. japonicus)

In this study, target strengths of 31 Japanese anchovy (E. japanicus) were measured to verify a linear function between small size (juvenile stage) and large size (young & adult stage). The TS measurement was conducted at 200 kHz split-beam echosounder with a tethered method under the live condition. During acoustic measurements, an underwater video camera was used to continuously monitor fish behavior. After dividing into 3 groups (juvenile, young, and adult) with TL, acoustic TS data were analyzed. In the preliminary analysis, acoustic TS value of the young (50 ~ 60 mm) and adult (70 ~ 90 mm) group corresponded very close with the previous least-squared regression function (Kang et al., 2009). However, the TS value of the juvenile group (30 ~ 40 mm) was relatively very low, thus does not placed on the fitting line in the previous TS function. According to the result from the measurement, there is possibility that the traditionally TS function with TL might be needed to propose modified TS function under the different grow phase. As this is preliminary study using a few small anchovy, more TS measurement for small group is needed in the future. From this study, we could be considered a choice not existing TS function but modified TS function, considering acoustic survey for juvenile anchovy in the spawning area will be planed.beam echosounder with a tethered method under the live condition. During acoustic measurements, an underwater video camera was used to continuously monitor fish behavior. After dividing into 3 groups (juvenile, young, and adult) with TL, acoustic TS data were analyzed. In the preliminary analysis, acoustic TS value of the young (50 ~ 60 mm) and adult (70 ~ 90 mm) group corresponded very close with the previous least-squared regression function (Kang et al., 2009). However, the TS value of the juvenile group (30 ~ 40 mm) was relatively very low, thus does not placed on the fitting line in the previous TS function. According to the result1