Assertion: albacore's mercury level | /r/HasProperty | risen over past 20 years
Facets:
value: according to a 2009 study
type: OTHER
Source sentences:
text: Mercury levels in the northern Pacific Ocean have risen about 30 percent over the past 20 years and are expected to rise by 50 percent more by 2050 as industrial mercury emissions increase, according to a 2009 study led by researchers at the U.S. Geological Survey and Harvard University.