Changes in Abiotic Drivers of Green Sea Urchin Demographics following the Loss of a Keystone Predator

Table 3

PERMANOVA results for the main tests of sea urchin density, biomass, size distributions, and recruitment index.

(a) Density

Source	SOS	df	MS	Pseudo-
Island		14	39892	32.637	0.001	0.344
Period	12426	3	4142	3.389	0.018	0.009
Island×period		28	10660	8.721	0.001	0.213
Residual		757	1222.3			0.434

(b) Biomass

SOS	df	MS	Pseudo-
	14		7.943	0.001	0.118
	3		10.697	0.001	0.057
	28		4.350	0.001	0.145
	757				0.680

(c) Size distribution

Source	SOS	df	MS	Pseudo-
Island		14		61.519	0.001	0.375
Period		3		55.700	0.001	0.113
Island×period		30		13.837	0.001	0.224
Residual		808				0.288

(d) Recruitment index

SOS	df	MS	Pseudo-
28.157	11	2.56	51.716	0.001	0.367
6.175	3	2.058	41.586	0.001	0.120
8.662	25	0.347	7.001	0.001	0.127
37.321	754	0.049			0.386