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

Table 3

Methylmercury concentrations in representative trophic level II organisms.

Trophic level II	Methylmercury (MeHg) concentration	Comments	Literature citation
Primary Consumers: these are primarily herbivores, filter feeders, small prey fish, etc.	Range: 0.009 to 4.83 ppm	Methylmercury is sequestered in adipose and visceral tissue, and concentrations continue to accumulate in higher trophic levels	[41, 47]
Zooplankton	0.009 ppm		[47]
Clams	0.009 ppm		[48]
Sardines	0.013 ppm		[33]
Cod	0.111 ppm		[49]
Small-prey fish	Range: 1.22–4.83 ppm		[4]