Population genetic structure of eelgrass (Zostera marina) on the Korean coast: Current status and conservation implications for future management.
Seagrasses provide numerous ecosystem services for coastal and estuarine environments, such as nursery functions, erosion protection, pollution filtration, and carbon sequestration. Zostera marina (common name "eelgrass") is one of the seagrass bed-forming species distributed widely in the northern hemisphere, including the Korean Peninsula. Recently, however, there has been a drastic decline in the population size of Z. marina worldwide, including Korea. We examined the current population genetic status of this species on the southern coast of Korea by estimating the levels of genetic diversity and genetic structure of 10 geographic populations using eight nuclear microsatellite markers. The level of genetic diversity was found to be significantly lower for populations on Jeju Island [mean allelic richness (AR) = 1.92, clonal diversity (R) = 0.51], which is located approximately 155 km off the southernmost region of the Korean Peninsula, than for those in the South Sea (mean AR = 2.69, R = 0.82), which is on the southern coast of the mainland. South Korean eelgrass populations were substantially genetically divergent from one another (FST = 0.061-0.573), suggesting that limited contemporary gene flow has been taking place among populations. We also found weak but detectable temporal variation in genetic structure within a site over 10 years. In additional depth comparisons, statistically significant genetic differentiation was observed between shallow (or middle) and deep zones in two of three sites tested. Depleted genetic diversity, small effective population sizes (Ne) and limited connectivity for populations on Jeju Island indicate that these populations may be vulnerable to local extinction under changing environmental conditions, especially given that Jeju Island is one of the fastest warming regions around the world. Overall, our work will inform conservation and restoration efforts, including transplantation for eelgrass populations at the southern tip of the Korean Peninsula, for this ecologically important species.
Molecular Ecology and Evolution Laboratory, Department of Biological Science, College of Science and Engineering, Sangji University, Wonju, Republic of Korea.
Jae Hwan
JH
Kim
Korean Entomological Institute, Korea University, Seoul, Republic of Korea.
Ji Hyoun
JH
Kang
Molecular Ecology and Evolution Laboratory, Department of Biological Science, College of Science and Engineering, Sangji University, Wonju, Republic of Korea.
Ji Eun
JE
Jang
Estuarine and Costal Ecology Laboratory, Department of Marine Life Sciences, Jeju National University, Jeju, Republic of Korea.
Sun Kyeong
SK
Choi
Estuarine and Costal Ecology Laboratory, Department of Marine Life Sciences, Jeju National University, Jeju, Republic of Korea.
Min Ji
MJ
Kim
Estuarine and Costal Ecology Laboratory, Department of Marine Life Sciences, Jeju National University, Jeju, Republic of Korea.
Sang Rul
SR
Park
Molecular Ecology and Evolution Laboratory, Department of Biological Science, College of Science and Engineering, Sangji University, Wonju, Republic of Korea.
Hyuk Je
HJ
Lee
D003247:Conservation of Natural Resources / Q000379:methods*; D017753:Ecosystem; D051456:Gene Flow / Q000235:genetics*; D040961:Genetic Drift; D014644:Genetic Variation / Q000235:genetics*; D005828:Genetics, Population; D057232:Global Warming; D018895:Microsatellite Repeats / Q000235:genetics; D056910:Republic of Korea; D035962:Zosteraceae / Q000235:genetics*