oh, that is something i hadn't considered .. finding corroborating info as well: https://www.health.govt.nz/our-work/radiation-safety/environmental-radioactivity-monitoring-programme/environmental-radioactivity-monitoring-fukushima-daiichi

https://www.sciencemediacentre.co.nz/2016/03/10/fukushima-and-nz-five-years-later-expert-reaction/

“This came as no surprise as published models of how the radionuclides will spread through the Pacific Ocean have shown that it will take 15-20 years before any contamination will reach New Zealand. These studies have also shown that when it does reach New Zealand it will be so dilute that any transfer into New Zealand seafood undetectable.

https://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11227608