18
Honshu Island and resulted in the loss of nearly
19,000 people and devastated many towns in the
coastal areas of this region. Fisheries are one of
the most important industries in the coastal area
impacted by the tsunami. Assessments are needed
to evaluate the effects of the earthquake and tsunami on coastal populations of fi shery resource
organisms for the future fi shery and stock
enhancement.
On the Pacifi c coast of northeastern Honshu
Island, which was severely disturbed by the
massive tsunami, Ezo abalone Haliotis discus
hannai is one of the most valuable fi sheries
resources and also play an important role in the
food web of the rocky shore ecosystem (Won
et al. 2011 ). The main objective of this study is
to examine the effects of the earthquake and
subsequent tsunami on the abalone populations.
Data on the abalone population before the earthquake and tsunami event are essential to allow
comparison and clarify the scale of impacts.
Before March 2011, we regularly carried out
quantitative analyses on the population of
this fi sheries resources at Iwaisaki, Miyagi
Prefecture. To assess the impacts of the earthquake and tsunami by before and after comparisons, we carried out the survey using the same
method after the earthquake and tsunami, in
order to compare the results with the data collected before the event.
2
Materials and Methods
2.1
Study Site
This study was done in the rocky subtidal habitats at Iwaisaki located near the mouth of
Kesennuma Bay (Fig. 1 ). As the site faces an
open ocean, waves impact this area directly. We
selected four stations of 10 m × 10 m each (named
A, D, E, G) in the study site. Station A was
dominated by crustose coralline alga (CCA)
Lithophyllum yessoense and the other stations
were included in kelp beds (KB) dominated by
the brown macroalga Eisenia bicyclis . A detailed
information of these stations was described in
Table 1 . All fi sheries were closed in the study site
after the earthquake at least until June 2011 when
the last survey was carried out in this study.
2.2
Sample Collection
The abalone Haliotis discus hannai were quantitatively sampled by scuba diving in the mornings of
23 October 2009 (before the earthquake) and 15
June 2011 (after the earthquake) using 2 m × 2 m
quadrats. In each station, fi ve replicate quadrats
were haphazardly located, and all abalone in the
quadrats were collected by hand and placed in mesh
Fig. 1 Location of the study site and stations A , D , E , and G
H. Takami and H. Nakaie
Honshu Island and resulted in the loss of nearly
19,000 people and devastated many towns in the
coastal areas of this region. Fisheries are one of
the most important industries in the coastal area
impacted by the tsunami. Assessments are needed
to evaluate the effects of the earthquake and tsunami on coastal populations of fi shery resource
organisms for the future fi shery and stock
enhancement.
On the Pacifi c coast of northeastern Honshu
Island, which was severely disturbed by the
massive tsunami, Ezo abalone Haliotis discus
hannai is one of the most valuable fi sheries
resources and also play an important role in the
food web of the rocky shore ecosystem (Won
et al. 2011 ). The main objective of this study is
to examine the effects of the earthquake and
subsequent tsunami on the abalone populations.
Data on the abalone population before the earthquake and tsunami event are essential to allow
comparison and clarify the scale of impacts.
Before March 2011, we regularly carried out
quantitative analyses on the population of
this fi sheries resources at Iwaisaki, Miyagi
Prefecture. To assess the impacts of the earthquake and tsunami by before and after comparisons, we carried out the survey using the same
method after the earthquake and tsunami, in
order to compare the results with the data collected before the event.
2
Materials and Methods
2.1
Study Site
This study was done in the rocky subtidal habitats at Iwaisaki located near the mouth of
Kesennuma Bay (Fig. 1 ). As the site faces an
open ocean, waves impact this area directly. We
selected four stations of 10 m × 10 m each (named
A, D, E, G) in the study site. Station A was
dominated by crustose coralline alga (CCA)
Lithophyllum yessoense and the other stations
were included in kelp beds (KB) dominated by
the brown macroalga Eisenia bicyclis . A detailed
information of these stations was described in
Table 1 . All fi sheries were closed in the study site
after the earthquake at least until June 2011 when
the last survey was carried out in this study.
2.2
Sample Collection
The abalone Haliotis discus hannai were quantitatively sampled by scuba diving in the mornings of
23 October 2009 (before the earthquake) and 15
June 2011 (after the earthquake) using 2 m × 2 m
quadrats. In each station, fi ve replicate quadrats
were haphazardly located, and all abalone in the
quadrats were collected by hand and placed in mesh
Fig. 1 Location of the study site and stations A , D , E , and G
H. Takami and H. Nakaie