Table 2.

Comparison of genetic diversity by testing pooled Baltic Sea populations vs. North Sea populations. The average value of H_o, H_s and allelic richness (corrected for sample size) in the Baltic Sea were significantly lower compared to the North Sea (two-tailed paired samples t-test, H_o, P = 0.019, H_s, P = 0.007, allelic richness, P = 0.0004). The inbreeding coefficient (F_IS) was not significantly different (two-tailed paired samples t-test, P = 0.090)

Population	Sample size	Loci	Ho	Hs	FIS	Allelic richness
BS	40	8	0.25	0.68	0.64	3.96
SF	32	8	0.37	0.65	0.42	4.00
GD	33	8	0.20	0.64	0.68	3.75
GK	33	8	0.36	0.74	0.51	4.28
YS	17	8	0.35	0.62	0.44	3.88
BALTIC SEA, mean			0.31*	0.66**	0.54	3.97***
RO	58	8	0.38	0.74	0.44	4.52
AR	17	8	0.44	0.77	0.41	4.63
BA	33	8	0.44	0.74	0.41	4.48
VI	45	8	0.43	0.75	0.43	4.59
LY	46	8	0.38	0.73	0.48	4.42
NORTH SEA, mean			0.41	0.74	0.44	4.53

^*Value significant at the P = 0.05 level.

^**Value significant at the P = 0.01 level.

^***Value significant at the P = 0.001 level.