Table 5.

Principal Component (PC) analysis of the stressors considered and global methylation in the eight mussel populations examined, showing the Eigenvalue (0.7 cutoff), % variance explained by each PC, and load of each variable in each PC.

	PC 1	PC 2	PC 3	PC 4
Eigenvalue	2.154	0.911	0.722	0.213
% variance	53.84	22.77	18.05	5.34
Population age	−0.627	0.016	0.211	0.749
Salinity	0.451	−0.716	−0.259	0.465
Anthropogenic pressure	0.451	0.696	−0.324	0.454
Methylation	0.447	0.042	0.885	0.124