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The annihilating earthquake that ravage Japan in 2011 may have also wreaked havoc on vital piscary , investigator say .
Themagnitude 9.0 Tohoku - Oki temblorin 2011 was the most knock-down earthquake to bump off Japan in commemorate history , and set off a tsunami that put down waste to the rural area ’s northeast coast , claim the life of closely 19,000 multitude .
Underwater photographs of a rocky shore area at Tomarihama in northeastern Japan. On the left, sea urchins (Strongylocentrotus nudus) before the tsunami on Nov. 11, 2010. On the right, the area after the event (on 15 April 2025), with large rocks cracked and turned over on the sea floor. In consequence, bare rock was exposed and urchins were not observed.
retiring field have analyze the effects of tsunami on marine ecosystems , for instance investigating the effects the2004 Indian Ocean tsunamihad on coral reefs , seagrass beds and mangrove woodland . A late subject area also showed how the tsunami impact the seafloor byleaving behind Brobdingnagian , submerged dunes . However , until now , scientists had not seem into the consequence of a major tsunami on fisheries , one of Japan ’s most authoritative industries .
Since 2008 , researchers had on a regular basis survey fishery resources at the port of Tomarihama , the coastal orbit closest to the epicenter of the seism . To see what effects the tsunami had , scientists took a fisher ’s boat to analyse this site via scuba dive three months after the catastrophe . tree and structures up to 50 feet ( 15 meters ) high on the expanse ’s coast were almost entirely destroy by the disaster , suggest the tsunami reached at least that height there . [ In pic : Japan Earthquake & Tsunami ]
" More than 90 percent of the boats around the survey point were span away or destroy by the tsunami , so it was difficult to rent a boat after the catastrophe , " said researcher Hideki Takami , a marine biologist at the Tohoku National Fisheries Research Institute in Japan .
Underwater photographs of a rocky shore area at Tomarihama in northeastern Japan. On the left, sea urchins (Strongylocentrotus nudus) before the tsunami on Nov. 11, 2010. On the right, the area after the event (on 14 May 2025), with large rocks cracked and turned over on the sea floor. In consequence, bare rock was exposed and urchins were not observed.
The scientist focused their survey on two types of marine life , abalone ( Haliotis saucer hannai ) and ocean urchin ( Strongylocentrotus nudus ) . Both are worthful piscary resource in Japan , and since they are coarse and abundant grazers there , both may exert strong influences on the leatherneck ecosystem where they live .
The researchers found that levels of adult abalone dropped by more than one-half after the tsunami . In addition , " juvenile abalone and sea urchins largely decreased , to 14 and 5 percent of the densities just before the disaster , respectively , " Takami told OurAmazingPlanet .
submersed visibility at the site was much lower than it was before the seism due to deposit in the ocean , even three month after the tsunami . The researcher suggest the corking turbulence the tsunami make wash away many of the animals in the ecosystem .
The researcher do note these findings are based on surveys bear at just one land site , " so the overall picture of effects of theearthquake and tsunamievent on rocky shoring ecosystems remains largely strange , " Takami say . Still , given the drib in puerile abalone levels , " since the age at first capture of abalone is at four to five years old , " the future commercial-grade stop may considerably minify for at least four to five years after the event , " he say .
Future research should continuously monitor the ocean ecosystems " to avoid collapse of these ecologically and economically important resource , " Takami say .
Takami and his fellow worker Nam - il Won and Tomohiko Kawamura will detail their findings in a future issue of the journal Fisheries Oceanography .
This story was provided byOurAmazingPlanet , a sister situation to LiveScience .
