Table 3. Spatial heterogeneity of the indices at the two scales studied (mean values±SD).

	Iberian-Lions	Tyrrhen	Ionian	Adriatic	Aegean	Tests Biogeographical zone scale			Western basin	Eastern basin	Tests at Basin scale			North Mediterranean Sea
	(113)	(668)	(199)	(164)	(187)	Chi-2	p		(781)	(450)	Chi-2	p		(1231)
S mean	14.59±4.18	14.15±4.21	13.16±4.47	14.02±3.81	14.25±5.80	15.16	0.0097		14.22±4.21	14±4.88	6.47	0.01		14.12±4.53
1/d	2.57±0.99	2.18±0.82	2.88±0.96	2.87±0.97	2.25±0.90	63.88	1.316 × 10−15		2.23±0.86	2.62±0.97	63.88	1.316 × 10−15		2.41±0.93
Δ*	68.17±7.44	64.72±6.12	65.75±5.46	66.33±6.07	63.44±8.34	0.07	0.78	ns	65.22±6.43	64.37±6.96	0.08	0.78	ns	64.82±6.70
Δ+	68.57±2.89	68.48±2.62	67.79±3.12	67.90±2.56	69.44±3.26	0.007	0.93	ns	68.49±2.66	68.47±3.06	0.01	0.93	ns	68.49±2.85
Λ+	127.51±46.12	131.93±53.70	137.70±63.40	135.99±57.59	132.30±48.38	0.88	0.34	ns	131.30±52.67	134.15±56.54	0.88	0.34	ns	132.62±54.50
Rarity	0.55±0.70	0.29±0.56	0.36±0.60	0.41±0.77	0.46±0.87	70.83	6.858× 10−14		0.33±0.59	0.50±0.83	11.18	0.0008		0.41±0.72

Kruskal-Wallis tests; ns = non significant effect (p>0.01). Number of hauls is given in brackets. S mean : mean number of species by haul for the corresponding spatial unit. The codes of the other diversity indices are given in Table 1.