Abstract
On March 11, 2011, a large earthquake occurred, causing a tsunami which struck the Pacific coast of northeast Japan. We investigated the ecological and genetic effects of the large tsunami on the threespine stickleback (genus Gasterosteus) populations in Otsuchi Town, which was one of the most severely damaged areas after the tsunami. Our environmental surveys showed that spring water may have contributed to the habitat recovery. Morphological analysis of the stickleback before and after the tsunami showed morphological shifts in the gill raker number, which is a foraging trait. Genetic analyses revealed that the allelic richness of one population was maintained after the tsunami, whereas that of another decreased in 2012 and then started to recover in 2013. Additionally, we found that the large tsunami and ground subsidence created new spring water-fed pools with sticklebacks, suggesting that the tsunami brought sticklebacks into these pools. Genetic analysis of this population showed that this population might be derived from hybridization between freshwater Gasterosteus aculeatus and anadromous G. nipponicus. Overall, our data indicate that tsunamis can influence morphologies and genetic structures of freshwater fishes. Furthermore, spring water may play important roles in the maintenance and creation of fish habitats, faced with environmental disturbance.
Highlights
Natural disasters, such as typhoons, volcanic eruptions, earthquakes, and tsunamis, can cause catastrophic damage, to human livelihood and to natural animal and plant populations
It is crucial to investigate the changes in genetic structures for a better assessment of the extinction risk of natural populations affected by a tsunami
After the 2011 tsunami, the water quality of the main rivers and their tributaries in Otsuchi Town were deteriorated because of several factors, including sea water and marine slime brought in from the sea and chemicals released from debris and deposits
Summary
Natural disasters, such as typhoons, volcanic eruptions, earthquakes, and tsunamis, can cause catastrophic damage, to human livelihood and to natural animal and plant populations Such catastrophic events may lead to drastic changes in the habitat qualities of various organisms, resulting in a decrease or possibly an increase in the numbers of particular species, and affect dispersal of organisms[1,2,3]. Tsunami waves transported marine materials, such as seawater and sea bottom slime, into freshwater habitats[13,14,15], and thereby, freshwater-adapted and stenohaline organisms, including several freshwater fishes, may become extinct in these salinized environments[20] These effects can lead to biodiversity loss in tsunami-inundated areas. Since a river levee of the Otsuchi River was broken by the tsunami, overflowing water flooded the urban area (Supplementary Fig. S1b)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
