Nature2013-2016West Coast, United States (and Canada/Alaska)high confidence

A toxic algal bloom stretched along the entire West Coast of the United States during the Pacific Blob period.

Notes on verification

Confirmed by multiple independent, authoritative sources (NOAA, UC Santa Cruz, Scripps/UC San Diego, Hakai Magazine). Minor variation in exact geographic boundaries but consensus on unprecedented scale during the Pacific Blob marine heatwave. [tier=gold indep_score=0.963 clusters=4 claim_tier=notable]

Sources