Table 2.

Biomagnification factors (BMFs) of mercury in the Tagus estuary food web. Sp, spring; Su, summer; Au, autumn; Wi, winter; C. maenas, Carcinus maenas; H. diversicolor, Hediste diversicolor; L. littorea, Littorina littorea; P. ulvae, Peringea ulvae; Gammarus sp.; Ulva sp

(Predators/grazers) (Preys)	C. maenas H. diversicolor Sp/Su/Au/Wi	P. ulvae Ulva sp. Sp/Su/Au/Wi	Gammarus sp. Ulva sp. Sp/Su/Au/Wi	L. littorea Ulva sp. Sp/Su/Au/Wi
Trancão	-/1.27/-/2.72	0.92/-/14.85/-
Samouco	-/-/4.25/-	0.36/-/-/-	1.37/-/-/-	-/-/3.12/-
Seixal	6.50/-/-/3.3	-/1.63/2.76/-