1 research outputs found
Use of Otolith for Detecting Strontium-90 in Fish from the Harbor of Fukushima Dai-ichi Nuclear Power Plant
To
clarify the level of contamination with radioactive cesium (radiocesium)
discharged from Fukushima Dai-ichi Nuclear Power Plant (FDNPP), three
fish species caught in the main harbor of FDNPP were subjected to
γ-ray analysis. The concentration of radiocesium in muscle differed
among individual fish, even those of similar size of the same species,
and showed little relation to the standard length of fish. The maximum
concentration of radiocesium (202 kBq/kg wet) was detected from fat
greenling samples. A comparison to data from outside the port indicated
that the level of radiocesium contamination inside the port was higher
than that outside. We found that β-rays were emitted from otoliths
of fishes caught in the port of FDNPP. β-ray intensities were
correlated with the concentrations of radiocesium in muscles of the
three fish species. In Japanese rockfish, the β-ray count rates
from otoliths were significantly correlated with the concentration
of radiocesium and <sup>90</sup>Sr in the whole body without internal
organs of Japanese rockfish. However, no β-rays were detected
from brown hakeling samples collected around FDNPP, suggesting that
the detection of β-rays from otoliths may indicate living in
the main harbor of FDNPP