The soybean aphid, Aphis glycines Matsumura, was introduced from East Asia (EA) into North America (NA) and is now widely established in NA. To compare soybean aphid populations between the native and invasive regions, we examined 689 individuals obtained from 28 different collections in NA and EA. A total of 8 microsatellite loci were used for population genetics statistics. Gene diversity and mean number of alleles in NA populations averaged 0.40 and 2.70, respectively, whereas in EA they averaged 0.55 and 4.32, respectively. Structure analysis of all populations revealed two distinct structures in the invaded and in the native regions. Among EA populations, certain Korean populations were genetically closest to NA populations, especially those from Ohio and Delaware. An approximate Bayesian computation test also supports an introduction into NA from Korea.

To understand size fractioned chlorophyll a and material cycles of coastal ecosystem in Uljin marine ranching area (JMRA) of East Sea, 4 times of survey were conducted from April to November 2008. Picoplankton, nanoplankton and netplankton in the surface of UMRA fluctuated with an annual mean of 0.26 μg L-1 between the lowest value of 0.03 μg L-1 and the highest value of 0.87 μg L-1, annual mean 1.32 μg L-1 between 0.11 μg L-1 and 5.60 μg L-1, annual mean 0.45 μg L-1 between no detected (nd) and 4.68 μg L-1, respectively. And the relative ratio of picoplankton, nanoplankton and netplanktons on the phytoplankton biomass was on annual average 12.9%, 65.0% and 22.1%, respectively. The 10 m layer was similar to the surface. The relative ratio of pico- and nano-plankton was higher throughout the year. That is, the material cycle of UMRA consists of a microbial food web rather than traditional food chain at a lower trophic levels. Primary production is deemed to have a higher possibility of being adjusted by top-down dynamics, such as micro-zooplankton grazing pressure rather than nutrients supply.

지음향 모델링은 퇴적층과 기반암의 해저 지층을 통해 전파되는 음파 특성을 예측하기 위해 사용된다. 이 연구는 동해 한국대륙주변부의 정동진 해역에서 50 m 퇴적층 심도의 4개 지음향 모델을 구성하였다. 지층 모델은 고해상 에어건 탄성파 자료, SBP 자료, 퇴적물 코어에 근거한다. P파 속도는 신호투과법에 의해 측정되었고, 압전기 트랜스듀서의 공진 중심 주파수는 1 MHz를 유지하였다. 42개 P파 속도와 41개 음감쇠 측정이 세 개 코어 퇴적물에서 수행되었다. 실제 모델링을 위해, 모델의 P파 속도는 Hamilton 방법을 이용하여 해저면 아래 현장 심도 속도로 보정하였다. 연안 지층의 이 지음향 모델은 동해 정동진 해역에서 지음향 특성의 수직/수평 변화를 반영하는 지음향/수중음향 실험을 위해 활용될 것이다.