Sources and Toxicity of Mercury in the San Francisco Bay Area, Spanning California and Beyond

Table 2

Methylmercury concentrations in representative trophic level I organisms.

Trophic level I	Methylmercury (MeHg) concentration	Comments	Literature citation
Primary producers: plants and algae that synthesize their own energy and food	Concentrations are species specific	Beginning of accumulation and concentration into biological systems	[22, 25, 27]
Phytoplankton from Lake Almaden, south of SFO Bay	Range: below 1.50 (the detection limit) to 8.2 ng/g dry weight (ng/g equivalent to ppb)		[47]