Determination of five alternative antifouling agents in Korean marine sediments

The contamination of marine sediments by five antifouling agents was analysed to examine the changes in the coasts of Korea which were caused by the use of alternative antifouling agents. The average concentrations of chlorothalonil, dichlofluanid, Irgarol 1051 and SEA-NINE(TM) 211 were 10.4, 0.2, 54.5 and 19.2 ng/g, respectively. TCMTB was below detection limits in all sampling sites. In terms of average concentrations, Irgarol 1051 and SEA-NINE(TM) 211 accounted for 87.4% of the total marine sediments contamination; these two substances have been used in Korea at higher rates than other antifouling agents. Irgarol 1051 and SEA-NINE(TM) 211 were also represented by the same factor in the factor analysis, possibly because they are used exclusively as antifouling agents and not as herbicides in Korea. Chlorothalonil and dichlofluanid, found as the second and third factor, respectively, were considered to be affected by not only antifoulants, but also other pollution sources such as pesticides. Thus, the management of Irgarol 1051 and SEA-NINE(TM) 211 and the management of chlorothalonil and dichlofluanid were separately conducted.     

Identifying sharp hydrographical changes in phytoplankton community structure using HPLC pigment signatures in coastal waters along Jeju Island, Korea

In order to characterize the distribution and community structure of phytoplankton, chlorophyll and carotenoid pigments, nutrients, and hydrographic variables were measured in the coastal waters off Jeju Island, Korea, during 11–13 May 2005. The photosynthetic pigments were analyzed using a high-performance liquid chromatograph (HPLC), and were used to calculate the algal class abundances using the CHEMTAX program. There was a distinct difference in phytoplankton abundance and community composition between the northern coastal water (NCW) and the southern coastal water (SCW) of this island. The chlorophyll a concentrations were ～26% higher in NCW than in SCW. Diatoms were predominant (> 50%) in NCW, while the phytoplankton composition was more diverse in SCW. Considering the hydrographic conditions and nutrient distributions in the study region, the sharp structural change in phytoplankton community seems to be mainly due to the slight difference in the origin of NCW and SCW. This study shows that HPLC-pigment measurements are useful for identifying sharp structural changes in phytoplankton communities in dynamic coastal environments.     

Application of a Conceptual Ecological Model to Predict the Effects of Sand Mining around Chilsan Island Group in the West Coast of Korea

Chilsan Island Group, located on the west coast of South Korea, has been recognized as a critical breeding and nursery ground for endangered seabirds because food is abundant and human activity is low. Chilsan Island Group has been under protection as a Natural Monument (Article no. 389) since 1997, but attempts were made in 2004 to exploit the coastal sands around the islands. A conceptual ecological model (CEM) was employed with energy flow diagram (EFD) to predict the effects of sand mining on the islands’ ecosystem. The results showed that sand mining activities caused long-term damage to benthic ecosystems and threatened seabird communities by reducing fish populations throughout the food web. The changes in energy flow in the ecosystem due to sand mining operations predict that reduction in secondary production of benthic animal communities might reduce energy transfer to humans and seabirds by 30%. Different ranges of uncertainty provided by the Monte Carlo simulation lead to the conclusion that sand mining could bring about undesirable consequences. One concern is that such negative consequences would have a much more severe impact on seabirds than humans because seabirds cannot compete effectively against humans for the limited food sources. In this study, the complex interrelationships between ecosystem members were simplified and a CEM was established to clearly identify which elements would be affected. The CEM with EFD was found to be helpful in promoting communication between stakeholders, and it is expected to be widely used as a decisionmaking tool by public officials.