Population genetic patterns across the native and invasive range of a widely distributed seagrass: Phylogeographic structure, invasive history and conservation implications
Citation:
Zhang, X., Y. Li, J. Kaldy, Z. Suonan, T. Komatsu, S. Xu, M. Xu, F. Wang, P. Liu, X. Liu, S. Yue, Y. Zhang, K. Lee, J. Liu, AND Y. Zhou. Population genetic patterns across the native and invasive range of a widely distributed seagrass: Phylogeographic structure, invasive history and conservation implications. Diversity and Distributions. Blackwell Publishing Limited, Oxford, Uk, 30(3):e13803, (2023). https://doi.org/10.1111/ddi.13803
Impact/Purpose:
Scientists from the Chinese Academy of Sciences Key Laboratory, Japan Fisheries Resource Conservation Association, Pusan National University (Korea) and US Environmental Protection Agency (ORD/PESD) have described the genetic diversity and underlying phylogeographic structure of Zostera japonica in Asia and the USA. The seagrass Zostera japonica is a widely threatened endemic seagrass species in the Northwestern Pacific (Asia), but it is also an introduced species along the Pacific Coast of North America (CA, OR, WA). This is the first large-scale genetic study of Z. japonica (27 native and 7 nonnative populations surveyed from 4 different countries) aimed at elucidating the phylogeographic patterns, genetic diversity, distribution, and evolutionary drivers in the native range as well as inferring the invasion history and possible population origin in its nonnative range. Genetic evidence confirms that nonnative populations in North America most likely originate from the central Pacific coast of Japan with multiple introductions from at least two different source populations and secondary spread in the USA was likely aided by waterfowl. This study provides a basis for restoration and/or management decisions in the native and nonnative regions. Seagrasses provide a variety of important ecosystem services such as nutrient removal, carbon sequestration and habitat for important commercial and recreational fisheries species.
Description:
Understanding the spatial and temporal distribution patterns of genetic diversity and the underlying phylogeographic processes is a fundamental goal of conservation biogeography. The seagrass Zostera japonica is a widely threatened endemic seagrass species in the Northwestern Pacific, but it is also an introduced species along the Pacific Coast of North America. This is the first large-scale genetic study of Z. japonica aimed at elucidating the phylogeographic patterns, genetic diversity, distribution, and evolutionary drivers in the native range as well as inferring the invasion history and possible population origin in its nonnative range. We used sequences of the nuclear rDNA-internal transcribed spacer (ITS) and chloroplast trnK intron maturase (matK), and 24 microsatellite loci to survey 27 native and 7 nonnative populations (>1000 individuals) throughout its whole biogeographic range. All markers support the deep divergence between northern and southern populations in the native region separated by a well-established biogeographical boundary, which may be the result of the combined effects of historical isolation, adaptation to distinct environments (mainly temperature), and a contemporary physical barrier created by the Yangtze River. A secondary contact zone is found along the coasts of South Korea and Japan, which is likely facilitated by the warm northward Kuroshio Current after glacial separation. Nonnative populations most likely originate from the central Pacific coast of Japan with multiple introductions from at least two different source populations and secondary spread likely aided by waterfowl. Surprisingly, the genetic diversity of the nonnative populations are relatively high, indicating the ability for long-term persistence and evolutionary potential under climate change. This study provides a basis for the restoration or management decisions in the native and nonnative regions.
URLs/Downloads:
DOI: Population genetic patterns across the native and invasive range of a widely distributed seagrass: Phylogeographic structure, invasive history and conservation implications