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

Table 5

Methylmercury concentrations in representative trophic level IV organisms.

Trophic level IV	Methylmercury (MeHg) concentration	Comments	Literature citation
Tertiary consumers: carnivores that consume other carnivores	Range: 0.008–1.6 ppm	Mercury toxicity leads to the following reproductive consequences in avian life: eggshells of developing bird embryos are thinner and more fragile, and offspring exhibit decreased appetite and poor development	[55]
Salmon (canned)	0.008 ppm		[49]
Salmon (frozen/fresh)	0.022 ppm		[49]
Halibut	0.241 ppm	Fish are likely to experience reproductive complications due to bioaccumulation of methylmercury in the viscera, which lines the abdomen	[49]
Forster’s tern (eggs) sampled from SFBA	0.9–1.6 ppm		[27]