Species Distribution Model-based Habitat Change Projections of the Kelp Species, Ecklonia cava under SSP Scenarios

The main kelp forest-forming alga Ecklonia cava (E. cava), plays an important role in coastal ecosystems of South Korea. Despite this coastal ecological importance, there is a lack of research on the prediction of macroalgal distribution. In this study, we examined the distribution of E. cava recorded since 1955 and predicted distribution changes starting from 2000, under different climate change scenarios (SSP1-1.9 and SSP5-8.5) using the species distribution model (MAXENT). It reported that E. cava has expanded its range to 38°N latitude since 2000. We found seawater temperature, primary productivity and seawater velocity were controlling factors that determine the habitat of E. cava. Under the low emissions scenario (SSP1-1.9), the habitat suitability and distribution of suitable habitats did not show significant changes. While, under the high emissions scenario (SSP5-8.5), a decline in the southern distribution and an expansion of the northern distribution was predicted. In particular, most of the current habitats of E. cava were found to have decreased habitat suitability, thus the existing population of the species in South Korea may experience a sharp decline. The results of this study can be used as a basis for developing sustainable conservation measures to maintain coastal ecosystems of rocky shore in South Korea.