동해안 영일만 내·외해역 조간대의 해조군집 변동

Abstract

Seaweeds in the intertidal zone form various seaweed communities because environmental factors in the intertidal zone differ depending on the topography. These communities serve as a habitat, spawning ground, and lair for marine organisms (e.g., invertebrates, and fish) and play important functions, such as photosynthesis and material circulation. However, recent coastal development has decreased the area and function as a habitat for marine organisms. Moreover, seaweed communities are expected to change because of the rise in water temperature due to climate change, but the available data are insufficient to compare past and present seaweed communities. The purpose of this study is to examine the seasonal and spatial changes in algal community structures in the outer and inner bays of the intertidal zone of Yeongil Bay. In addition to determining whether changes in seawater temperature due to global warming have affected the marine ecosystem through seaweeds, a seasonal survey was conducted on 13 sites in the intertidal zone of Yeongil Bay from August 2021 to July 2022. Samples were collected by a destructive method using a quadrat (50×50 cm), and quantitative data, such as biomass and importance value (IV), were analyzed using the identified algae. Statistical analysis (ANOSIM and SIMPER) was performed using algal biomass and IV. As a result of analyzing the seasonal changes in the algal community structure of Yeongil Bay according to the biomass, the dissimilarity was 70.0-81.7%, and it was confirmed that the contribution of Sargassum spp. was high. When analyzed according to the IV, the dissimilarity was 69.5-82.3%, and it was confirmed that the contribution of Ulva spp. was high. As a result of analyzing the algal community structure in the outer and inner bays according to the IV, the dissimilarity was 69.1%, and it was confirmed that the contribution of Ulva spp. was high. In summary, this paper argued that the algal community structure in the intertidal zone of Yeongil Bay was determined by the biomass based on Sargassum spp. and by the IV based on Ulva spp. The seawater temperature of Yeongil Bay has increased by approximately 0.8°C over the past 50 years, but the current algal community is similar to the past. This study revealed that seaweed communities in the intertidal zone of Yeongil Bay differ by season and between the inner and outer bays. It was found that the intertidal zone of Yeongil Bay is changing due to coastal development and eutrophication, and factors associated with climate change. Therefore, it is necessary to monitor the intertidal zone of Yeongil Bay to respond to changes in the environment and seaweed community, and the health of the marine ecosystem must be managed by managing the quality of water. In addition, this study provided basic data with which to assess the potential of ecological engineering for the restoration of intertidal zones.