The distributions of common minke whales observed in the East Sea in ten surveys in May of 2003, 2005, 2006, 2007, 2009, 2010, 2012, 2015, 2016 and 2020 were investigated using satellite sea surface temperature (SST) derived from the Moderate Resolution Imaging Spectrometer (MODIS). Most of the minke whales were observed in the waters off the Korean Peninsula at 36-38.5° N, which is expected as the highly productive coastal upwelling area. Yet, no minke whale was observed in 2006 when a relatively larger scale coastal upwelling occurred with SST at 11°C. In 2016 and 2020, the warm water higher than 17°C extended widely in the area, and the minke whales were observed in the offshore waters, deeper than 1,000 m. 87.5% of minke whales observed in May appeared in the SST from 13 to 16°C, and they seemed to avoid relatively high temperatures. This suggests that optimum habitat water temperature of minke whales in May is 13-16°C. The SST in the area had risen 1.67°C from 2003 to 2021, and it was remarkably higher than in other parts of the surrounding areas. The future temperature rising may change the route and timing of the migration of minke whales in the study area.

한반도 연안에 서식하는 고래의 조직 내 미량금속 농도 잔류특성을 알아보기 위하여 2009년 동해안에서 혼획된 밍크고래의 간, 창자, 근육, 표피, 지방 내 미량금속(Cu, Cd, Pb, As, Zn, Hg) 농도를 측정하였다. 조직 내 Cu, Cd, Zn, Hg은 간에서 가장 높고 지방에서 가장 낮았다. 이와 대조적으로 As는 지방에서 가장 높은 농도를 보였으며, 근육에서 가장 낮은 농도를 나타내었다. 전반적으로 밍크고래의 조직 내 미량금속은 Zn > Cu > As > Pb > Hg > Cd의 순으로 높은 농도를 나타내었다. 성별에 따른 미량금속은 수컷은 간과 표피에 Cu, As, Zn을, 암컷은 창자와 근육에 Cu와 Pb을 더 효율적으로 축적하고 있는 것으로 나타났다. 성숙도에 있어서는 간의 경우 Cd, 근육은 Hg, 표피와 지방은 As와 Hg, 창자는 Cd, As, Hg이 성숙한 개체에서 미성숙한 개체보다 상당히 높은 농도를 보였다.

To identify subspecies and stocks of minke whale meats purchased from Korean markets during 2005-2007, we first obtained their complete sequences of mitochondrial DNA cytochrome b and control region sequences, and compared these sequences to the corresponding sequences of the common minke whale (Balaenoptera acutorostrata), obtained from GenBank. From analyses with partial cytochrome b sequences (383 bp) and non-coding, partial control region sequences (463 bp), Korean mink whale meats are identified as products from the North Pacific minke whale (B. a. scammoni). In addition, the sequences of the partial control region from these meats showed G at site no. 298 and G or A at site no. 463, and the meats appeared to originate from the J stock within this subspecies. Thus, because the J stock has been protected since 1986, implementation of strict regulation measures to reduce their accidental fisheries by catch seems urgent. In addition, B. a. scammoni is distinct from B. a. acutorostrata, with an average Jukes-Cantor distance of 2.21% in the complete control region sequence analysis (935 bp) and 1.31% in the complete cytochrome b gene sequence analysis; the current results support the current subspecies classification, although further sequencing analyses with nuclear genes are necessary.