Blanco Gonzalez Enrique, Aritaki Masato, Knutsen Halvor, Taniguchi Nobuhiko
The Research Institute of Marine Bioresources, Fukuyama University, Onomichi, 722-2101, Japan; University of Agder, N-4604, Kristiansand, Norway; Institute of Marine Research (IMR), Flødevigen, N-4817, His, Norway.
Coastal Fisheries and Aquaculture Division, Seikai National Fisheries Research Institute, Fisheries Research Agency, Nagasaki, 851-2213, Japan.
PLoS One. 2015 May 20;10(5):e0125743. doi: 10.1371/journal.pone.0125743. eCollection 2015.
Large-scale hatchery releases are carried out for many marine fish species worldwide; nevertheless, the long-term effects of this practice on the genetic structure of natural populations remains unclear. The lack of knowledge is especially evident when independent stock enhancement programs are conducted simultaneously on the same species at different geographical locations, as occurs with red sea bream (Pagrus major, Temminck et Schlegel) in Japan. In this study, we examined the putative effects of intensive offspring releases on the genetic structure of red sea bream populations along the Japanese archipelago by genotyping 848 fish at fifteen microsatellite loci. Our results suggests weak but consistent patterns of genetic divergence (F(ST) = 0.002, p < 0.001). Red sea bream in Japan appeared spatially structured with several patches of distinct allelic composition, which corresponded to areas receiving an important influx of fish of hatchery origin, either released intentionally or from unintentional escapees from aquaculture operations. In addition to impacts upon local populations inhabiting semi-enclosed embayments, large-scale releases (either intentionally or from unintentional escapes) appeared also to have perturbed genetic structure in open areas. Hence, results of the present study suggest that independent large-scale marine stock enhancement programs conducted simultaneously on one species at different geographical locations may compromise native genetic structure and lead to patchy patterns in population genetic structure.
全球范围内，许多海洋鱼类都进行了大规模的孵化场放流；然而，这种做法对自然种群遗传结构的长期影响仍不明确。当在不同地理位置对同一物种同时开展独立的增殖放流计划时，这种知识的匮乏就尤为明显，日本的真鲷（Pagrus major，Temminck et Schlegel）就是如此。在本研究中，我们通过对848条鱼的15个微卫星位点进行基因分型，研究了密集放流后代对日本列岛真鲷种群遗传结构的假定影响。我们的结果显示出微弱但一致的遗传分化模式（F(ST) = 0.002，p < 0.001）。日本的真鲷在空间上呈现出结构化，有几个具有不同等位基因组成的斑块，这与接收大量孵化场来源鱼类流入的区域相对应，这些鱼类要么是有意放流的，要么是水产养殖作业中无意逃逸的。除了对栖息在半封闭海湾的当地种群产生影响外，大规模放流（无论是有意还是无意逃逸）似乎也扰乱了开阔区域的遗传结构。因此，本研究结果表明，在不同地理位置对同一物种同时开展独立的大规模海洋增殖放流计划可能会损害本地遗传结构，并导致种群遗传结构出现斑块状模式。
