Radiocesium in Pacific Bluefin Tuna Thunnus orientalis in 2012 Validates New Tracer Technique

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• 作者：Daniel J. Madigan ; Zofia Baumann ; Owyn E. Snodgrass ; Halim A. Erg眉l ; Heidi Dewar ; Nicholas S. Fisher
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：March 5, 2013
• 年：2013
• 卷：47
• 期：5
• 页码：2287-2294
• 全文大小：321K
• 年卷期：v.47,no.5(March 5, 2013)
• ISSN：1520-5851

文摘

The detection of Fukushima-derived radionuclides in Pacific bluefin tuna (PBFT) that crossed the Pacific Ocean to the California Current Large Marine Ecosystem (CCLME) in 2011 presented the potential to use radiocesium as a tracer in highly migratory species. This tracer requires that all western Pacific Ocean emigrants acquire the ¹³⁴Cs signal, a radioisotope undetectable in Pacific biota prior to the Fukushima accident in 2011. We tested the efficacy of the radiocesium tracer by measuring ¹³⁴Cs and ¹³⁷Cs in PBFT (n = 50) caught in the CCLME in 2012, more than a year after the Fukushima accident. All small PBFT (n = 28; recent migrants from Japan) had ¹³⁴Cs (0.7 卤 0.2 Bq kg^鈥?) and elevated ¹³⁷Cs (2.0 卤 0.5 Bq kg^鈥?) in their white muscle tissue. Most larger, older fish (n = 22) had no ¹³⁴Cs and only background levels of ¹³⁷Cs, showing that one year in the CCLME is sufficient for ¹³⁴Cs and ¹³⁷Cs values in PBFT to reach pre-Fukushima levels. Radiocesium concentrations in 2012 PBFT were less than half those from 2011 and well below safety guidelines for public health. Detection of ¹³⁴Cs in all recent migrant PBFT supports the use of radiocesium as a tracer in migratory animals in 2012.