Unusual Mass Appearance of Salpa fusiformis (Thaliacea: Salpida) in Early Spring at a Nuclear Power Plant at Mid-western Boundary of the East Sea

• Published in: Ocean science journal Vol. 57; no. 2; pp. 269 - 278
• Main Authors: Yoon, Wonduk, Choi, Byoung-Ju, Yoo, Hyunsu, Kim, Byeongho, Bok, Youngwook, Chae, Jinho
• Format: Journal Article
• Language: English
• Published: Seoul Korea Institute of Ocean Science & Technology and The Korean Society of Oceanography 01.06.2022; Springer Nature B.V; 한국해양과학기술원
• Subjects: Aquatic Pollution; Coastal waters; Coastal zone; Coasts; Earth and Environmental Science; Earth Sciences; Fronts; Marine & Freshwater Sciences; Marine invertebrates; Mass; Nuclear power plants; Ocean currents; Oceanography; Offshore; Salpa fusiformis; Sea surface; Sea surface temperature; Surface currents; Surface temperature; Surveying; Surveys; Thermal fronts; Tracking; Waste Water Technology; Water Management; Water masses; Water Pollution Control; Wind; Wind data; Wind direction; 해양학; Demography; Thermal front; Nuclear power plant; East Korea warm current
• ISSN: 1738-5261; 2005-7172
• DOI: 10.1007/s12601-022-00065-z

In the spring of 2021, a large number of Salpa fusiformis suddenly appeared along the east coast of the Korean Peninsula and invaded a nuclear power plant (NPP) in large numbers. To understand the mechanisms and causes of the mass appearance and intrusion of S. fusiformis , field surveys were undertaken and collected observational data such as temperature, salinity, and ocean currents, and wind data were tabulated and analyzed. Field surveys in the offshore area of the NPP revealed that warm, saline, and less-oxygenated water flowed northward at approximately 25 km from the coastline, and that this water mass was that of the East Korean Warm Current (EKWC), with aggregated individuals (blastozooids) dominating the population of S. fusiformis . In the EKWC region, S. fusiformis were more abundant in the coastal area than in the center of the EKWC. Sea surface temperature and surface currents from satellite data showed that a thermal front was formed between the EKWC and the cold coastal waters off the NPP. The main path of the EKWC was close to the coast, and on days when S. fusiformis invaded the NPP in large numbers, the wind direction near the NPP was west-northwest. We suggest that large-scale invasions of the NPP by S. fusiformis can be predicted by incorporating appropriate field survey data into a particle tracking model that considers the direction and speed of the EKWC, the abundance of S. fusiformis in the EKWC, the location of thermal fronts, and wind direction and speed.