Genetic population structures of fishing resources (abalone, sea cucumber, and sea urchin) off the coast of southern Iwate Prefecture, Japan

Representative Organization: Tohoku University

2015/04/01 - 2016/03/31
Sampling: several times in a year, analysis: any time

Touni Bay and Okirai Bay, Iwate Prefecture

Others(Collection in the field and analysis in the laboratory)

Pacific abalone Haliotis discus hannai, Japanese sea cucumber Apostichopus japonicus, and Japanese sea urchin Strongylocentrotus nudus are economically important marine products in Sanriku Coast, Iwate, Japan. Since fishing of the above species is dependent on their natural resources, it is important to examine the influence of the tsunami that hit the Pacific Coast after the Tohoku Earthquake in 2011, on natural marine resources. We assume that the tsunami caused a reduction in the number of individuals in the parental population, which in turn caused a reduction in the genetic diversity. In this study, to monitor the reduction in genetic diversity, which could cause population decline, we will compare the genetic population structures of the above three species before and after tsunami by using microsatellite (ms) DNA markers. This year, we will collect new generation samples to analyze the increase in ms loci from the previous msDNA analysis of the populations. Furthermore, to examine changes in the genetic diversity, we will also analyze the mitochondrial (mt) DNA for these populations.

We investigated the genetic structure and diversity of Pacific abalone H. discus hannai, Japanese sea cucumber Apostichopus japonicus, and Japanese sea urchin Strongylocentrotus nudus populations in some different locations in Sanriku for four years after the 2011 earthquake using microsatellite DNA and mitochondrial DNA regions. The results of the abalone showed that there are no significant differences in genetic diversity (allelic richness, expected heterozygosity, and haplotype and nucleotide diversity) or significant genetic differentiations (pairwise FST) between locations. This study revealed the gene flow in the abalone populations of Okirai and Touni Bays and their genetic diversity were maintained even after the tsunami. In the genetic structures of sea cucumber and sea urchin, we could not recognize major influence of the tsunami.

FY2015 Genetic population structures of fishing resources (abalone, sea cucumber, and sea urchin) off the coast of southern Iwate Prefecture, Japan