Changes in macroalgal assemblage with sea urchin density on the east coast of South Korea

• Published in: Algae (Korean Phycological Society) Vol. 30; no. 2; pp. 139 - 146
• Main Authors: Jeon, Byung Hee, Yang, Kwon Mo, Kim, Jeong Ha
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Phycology (Han'gug Joryu Haghoe) 01.06.2015; 한국조류학회I
• Subjects: Artificial reefs; Coastal ecosystems; Echinoidea; Vegetation changes; 생물학; Korea, Rep
• ISSN: 1226-2617; 2093-0860
• DOI: 10.4490/algae.2015.30.2.139

Urchin barrens have been a major issue of rocky coastal ecosystems in temperate regions. In South Korea, the east coast and Jeju Island have especially been a focus because the area of barren ground increases in spite of continual efforts to install artificial reefs. This study approached the urchin barrens issue in South Korea, by focusing on a correlational analysis of urchin and macroalgal abundance. Urchin density and algal species coverage were obtained using a quadrat image analysis. Subtidal sites were then classified into three groups according to the average densities of urchins to evaluate the characterization of the macroalgal community: no urchin zone; transition (TR) zone, 4 inds. m-^sup 2^; and urchin zone, ≥8 inds. m-2. The significant correlations indicate that the abundance of some macroalgal species is proportionally regulated by sea urchin density. This study also shows how macroalgal vegetation changes in response to an urchin's density gradient in a natural condition; and there is a TR zone that existed with respect to an intermediate level of algal abundance.