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

Table 5

Correlation values from BEST analysis of environmental variable with sea urchin size distributions. Among all islands in each time period of sea otter status, the number of variables (# vars.), Pearson correlation value (corr.), and variables included (variables) in the best correlation combinations are shown. Strength of correlation statistic ( value) and significance of test by permutations () separate the results for best correlations with a limited variable set and best correlations by combination variable set.

Correlations with Sea Urchin Size Distributions by Time Period of Sea Otter Status
Sea otter period	Predecline			End of decline			Postdecline 1			Postdecline 2
	# vars.	Corr.	Variables	# vars.	Corr.	Variables	# vars.	Corr.	Variables	# vars.	Corr.	Variables
Number of Variables, Correlations, Variables included	1	0.260	1	1	0.152	1	1	0.354	10	1	0.403	10
	2	0.318	1, 4	2	0.152	1, 9	2	0.375	1, 10	2	0.371	4, 10
	3	0.329	1, 4, 10	3	0.152	1, 4, 11	3	0.352	1, 4, 10	3	0.328	1, 4, 10
	4	0.327	1, 2, 4, 10	4	0.155	1, 3, 4, 8	4	0.312	1, 4, 10, 11	4	0.287	1, 4, 8, 10
	5	0.321	1, 2, 4, 9, 10	5	0.150	1, 3, 4, 8, 11	5	0.267	1, 4, 8, 10, 11	5	0.236	1, 4, 8, 10, 11
	6	0.298	1, 2, 4, 7, 9, 10	6	0.151	1, 3, 4, 8, 10, 11	6	0.220	1, 4, 8-11	6	0.192	1, 2, 4, 8-10
value (best corr.)	0.329			0.155			0.375			0.403
Sig. of sample stat.	0.1%			0.1%			0.1%			0.1%
10 best variable combinations: number of variables, correlations, variables included	3	0.329	1, 4, 10	4	0.155	1, 3, 4, 8	2	0.375	1, 10	1	0.403	10
	4	0.327	1, 2, 4, 10	1	0.152	1	1	0.354	10	2	0.371	4, 10
	3	0.326	1, 4, 9	2	0.152	1, 9	3	0.352	1, 4, 10	3	0.328	1, 4, 10
	4	0.323	1, 2, 4, 9	3	0.152	1, 4, 11	2	0.321	4, 10	2	0.321	1, 10
	4	0.322	1, 4, 9, 10	4	0.152	1, 4, 9, 11	4	0.312	1, 4, 10, 11	3	0.310	4, 8, 10
	5	0.321	1, 2, 4, 9, 10	6	0.151	1, 3, 4, 8, 10, 11	1	0.309	1	3	0.296	4, 10, 11
	2	0.318	1, 4	3	0.151	1, 4, 8	3	0.305	1, 10, 11	2	0.294	8, 10
	3	0.317	1, 2, 4	4	0.151	1, 4, 8, 9	2	0.296	10, 11	2	0.289	10, 11
	4	0.313	1, 3, 4, 10	2	0.151	4, 11	2	0.291	1, 4	4	0.287	1, 4, 8, 10
	5	0.308	1-4, 10	2	0.150	1, 4	3	0.288	1, 8, 10	3	0.281	4, 9, 10

Codes for “variables” are as follows: (1) island size, (2) island thickness, (3) island steepness, (4) exposure (site area), (5) bathymetric slope, (6) depth variability, (7) shallow habitat area, (8) deep habitat area, (9) salinity, (10) temperature, and (11) current velocity.