PARENT SESSION
Poster Session #25: Marine Ecology.
Wednesday, August 8, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall

Demographic variations of a barnacle, Tetraclita japonica, from two islands in Korea.

LEE, HYUK JE¹, SHIN, HYUN WOUNG², KIM, JEONG HA¹, ^{1 2}

ABSTRACT- Demographic parameters of marine invertebrate having a free-living larval stage are often influenced by factors such as geographical difference, microhabitat conditions and number of existing adults. This study was carried out to examine variations in recruitment and other demographic factors of a barnacle, Tetraclita japonica, populations from Cheju and Namhae Islands, Korea with respect to the above factors. Barnacles from 30x30 cm permanent plots were marked using clear plastic plates and monitored with 1-2 month intervals at individual basis. Seasonality of recruitment differed in two locations; July-September peak in Namhae Island (representing a sheltered bay habitat) and no obvious peak in Cheju Island (representing an open coast) where the total number of recruits was about twice. There was no difference in recruitment between wave-exposed and sheltered plots tested in Cheju Island. However, more recruits occurred in the plots with more adults existed. Thus, adult barnacles appeared to induce larval settlement. This indicates that the distance from an adult is a major function in the recruitment of T. japonica. The relationship, however, turned out species-specific, not apparent in other barnacles, such as Chthamalus spp. Mortality of juveniles was significantly higher than that of adults, and the mortality was positively and negatively correlated with wave exposure and crowdedness of individuals, respectively. With spatial variation in some demographic parameters, maintenance of the barnacle populations is strongly influenced by recruitment and survival at juvenile stage.

KEY WORDS: Demography, Barnacle, Intertidal, Population