선박평형수를 통해 유입되는 왜래식물플랑크톤의 생존 가능성

Abstract

Ballast water has been widely recognized as a serious environmental problem due to the risk of introducing non-indigenous species. Ballast water samples were collected from three commercial vessels in their ports; ASASHIO MARU in Ulsan, SUN ACE in Pusan and SNK LUCKY in Pohang, Korea. Sub-samples of water were analyzed for environmental factors including phytoplankton community composition and were also examined to assess species survival under a range of laboratory conditions. A total of 29 phytoplankton species were observed in the ballast water from the 3 voyages. Among them, potential harmful species such as Pseudo-nitzschia pungens and Pseudo-nitzschia delicatissima were observed in SNK LUCKY and SUN ACE. The most abundant species consisted of centric diatom species such as Skeletonema coatatum, Eucampia zodiacus and Chaetoceros spp., which are commonly recorded in Korean coastal water and adjacent areas. In the survivability and adaptability experiments, phytoplankton species collected from the three vessels did not grow in the typical ballast water samples (as control; without nutrients) even if they are provided with favorable light intensity, whereas these species gradually increased in nutrient rich medium even at low temperature (around 10˚C). In particular, phytoplankton species in SNK LUCKY increased more quickly than species of ASASHIO MARU and SUN ACE under high temperature conditions. This implies that they would be able to survive if the ballast water of SNK LUCKY was discharged in nutrient rich water in high temperature areas.