Impacts of the Fukushima Nuclear Accident on Fish and Fishing Grounds

233 Pages·2015·10.61 MB·English

by  Kaoru Nakata

Kaoru Nakata · Hiroya Sugisaki Editors
Impacts of the
Fukushima
Nuclear Accident
on Fish and
Fishing Grounds
Impacts of the Fukushima Nuclear Accident
on Fish and Fishing Grounds

Kaoru Nakata (cid:129) Hiroya Sugisaki
Editors
Impacts of the Fukushima
Nuclear Accident on Fish
and Fishing Grounds
Editors
Kaoru Nakata Hiroya Sugisaki
Research Management Department National Research Institute of Fisheries
Fisheries Research Agency Sciences
Yokohama , Kanagawa , Japan Fisheries Research Agency
Yokohama , Kanagawa , Japan
ISBN 978-4-431-55536-0 ISBN 978-4-431-55537-7 (eBook)
DOI 10.1007/978-4-431-55537-7
Library of Congress Control Number: 2015939907
Springer Tokyo Heidelberg New York Dordrecht London
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Foreword
On March 11, 2011, the most disastrous earthquake and tsunami in modern Japanese
history occurred in northeast Japan. They caused a great calamity for the people
and industries on the Pacifi c coast of the Tohoku region of Japan, one of the most
important regions for Japanese fi sheries. The Fukushima Dai-ichi Nuclear Power
Plant (FNPP) was covered by a 15-m-high tsunami, and the electric power supply to
its four nuclear reactors was severed, resulting in hydrogen explosions and the melt-
down of the core. This accident caused the elevation of the level of anthropogenic
radioactivity in the marine environment in the western North Pacifi c from atmo-
spheric fallout and direct discharges of highly radioactive waters. Security of food
safety of marine products is a great concern for the people in the world and espe-
cially for the people involved in the fi sheries industry.
The Fisheries Research Agency (FRA) has been conducting research and monitoring
the radioactivity of fi sh and shellfi sh since the 1950s, when we were worried about the
effect of nuclear arms tests in the ocean to marine environments and products. Because
the FRA has enough experience and knowledge of research on the radioactivity of large
quantities of specimens, we accepted the requests from the national government to
analyze the radioactivity of marine products fi shed all over Japan and started to make a
plan to monitor radioactivity of various marine products fi shed around Japan in coop-
eration with local governmental institutes just after the accident.
This book describes the results of the research on the effect of radioactivity to
ocean and coastal ecosystems and various marine and freshwater fi sh caused by the
FNPP accident of the huge magnitude of radioactivity on the ecosystems around
Japan. This is the fi rst report on the effect on the hydrosphere ecosystem from the
point of view of marine ecology and fi sheries oceanography. A scientifi cally precise
description of the distribution and variation of radioactive elements in the ecosystem
is presented in detail in this publication. Of course, this is the fi rst step in revealing
v
vi Foreword
the anthropological effect of radioactivity on the ecosystem, and we should con-
tinue the research. I trust that this book will contribute to overcoming the tragedy
and enhance the culture of human beings in the world.
President of the Fisheries Research Agency Masanori Miyahara
Yokohama , Japan
Pref ace
On March 11, 2011, the Great East Japan Earthquake occurred. The earthquake
itself and the resulting tsunami caused the Fukushima Daiichi Nuclear Power Plant
(FNPP) accident. As a result, a large volume of radionuclides was released into the
environment as fallout, which contaminated both freshwater and marine systems.
On April 2, heavily contaminated water was released around the No. 2 reactor into
the ocean. Several further leakages of water contaminated with radionuclides, as
well as a release of low-level contaminated water by the Tokyo Electric Power
Company (TEPCO), occurred around FNPP up until May 2011. This was the fi rst
time that heavily contaminated water originating from a nuclear power plant acci-
dent had been directly released into the ocean over a relatively short period. Since
then, contaminated fi sh with relatively high radiocesium concentrations (higher
than ca. 100 Bq/kg-wet) have often been caught in the coastal areas of Fukushima
and in adjacent prefectures.
The Fisheries Research Agency (FRA) has monitored radioactive substances in
marine organisms around Japan since 1954, when the H-bomb test was carried out
on Bikini Atoll. Soon after the FNPP accident, the FRA began monitoring radionu-
clides in fi sheries resources and their habitats. Decreasing trends of radiocesium
concentration in small pelagic fi sh and demersal fi sh have been obvious since sum-
mer 2011 and winter 2012, respectively, based on intensive monitoring of radioac-
tivity in fi sheries products by local governments and the FRA ( h ttp://www.jfa.maff.
go.jp/j/housyanou/kekka.html ) .
H owever, incidents that have worried the general public, including fi shermen,
have often occurred, including catches of cod with relatively high radiocesium con-
centrations in areas distant from Fukushima Prefecture, a catch of extremely highly
contaminated fat greenlings, and continuing contamination of fi sh in some freshwa-
ter systems. Various questions have therefore been raised by the public, such as:
When will the radiocesium concentrations of fi sh and fi shing grounds recover to the
level before the accident? Will the radiocesium in fi sh continue to be accumulated
in fi sh via the food chain, like heavy metals and some kinds of chemicals? What is
vii
viii Preface
the mechanism for the occurrence of extremely highly contaminated fi sh? Is the
contamination of fi sh with radiocesium an ongoing phenomenon?
I n order to restore trust in fi sheries products from the Tohoku district, both abroad
and among the Japanese people, it is important to answer these questions based on
scientifi c data. Accordingly, the FRA has conducted research to clarify the impacts
of the FNPP accident on fi sh and fi shing grounds, and the dynamics of radionu-
clides through both marine and freshwater systems by in situ investigation, rearing
experiments, and the use of simulation models.
A lthough our research is ongoing, the main body of our investigations was con-
ducted from 2011 to 2013.
Yokohama, Japan Tokio Wada
Kaoru Nakata
Hiroya Sugisaki
Contents
1 Introduction: Overview of Our Research on Impacts
of the Fukushima Dai-ichi Nuclear Power Plant
Accident on Fish and Fishing Grounds ................................................. 1
Kaoru Nakata and Hiroya Sugisaki
Part I Seawater and Plankton
2 134 Cs and 1 37 Cs in the Seawater Around
Japan and in the North Pacific .............................................................. 11
Hideki Kaeriyama
3 Temporal Changes in 1 37 Cs Concentration in Zooplankton
and Seawater off the Joban–Sanriku Coast, and in Sendai
Bay, After the Fukushima Dai-ichi Nuclear Accident .......................... 33
Hideki Kaeriyama
Part II Sediments and Benthos
4 Three-Dimensional Distribution of Radiocesium
in Sea Sediment Derived from the Fukushima Dai-ichi
Nuclear Power Plant ............................................................................... 53
Daisuke Ambe , Hideki Kaeriyama , Yuya Shigenobu , Ken Fujimoto ,
Tsuneo Ono , Hideki Sawada , Hajime Saito , Mikiko Tanaka ,
Shizuho Miki , Takashi Setou , Takami Morita , and Tomowo Watanabe
5 Radiocesium Concentrations in the Organic
Fraction of Sea Sediments ...................................................................... 67
Tsuneo Ono , Daisuke Ambe , Hideki Kaeriyama , Yuya Shigenobu ,
Ken Fujimoto , Kiyoshi Sogame , Nobuya Nishiura , Takashi Fujikawa ,
Takami Morita , and Tomowo Watanabe
ix