Sieving alive or after fixation: effects of sieving procedure on macrobenthic diversity, density and community structure

Table 2 Quantification of the sieving strategy effect on the species densities

	Loc.	Fixed sieving		Alive sieving		Relative loss	Stat. sign.
	Loc.	Mean	SE	Mean	SE	Relative loss	Stat. sign.
Amphipoda
Pontocrates arenarius	N1	16	5	2	2	88	0.043
Bathyporeia guilliamsoniana	N1	97	16	45	14	54	0.035
Bathyporeia pilosa	ES	29	13	25	6	14	0.500
Pontocrates altamarinus	N2	24	4	22	5	8	0.866
Bivalvia
Fabulina fabula	AM	380	66	368	42	3	0.917
Donax vittatus	AM	60	16	66	22	-10	0.596
Abra alba	AM	10	8	12	4	-20	0.381
Echinodermata
Leptosynapta minuta	OG	29	27	0		100	0.136
Ophiura ophiura	AM	14	4	8	4	43	0.268
Polychaeta
Hesionura elongata	OG	96	42	0		100	0.018
Spio filicornis	N2	113	29	0		100	0.018
Saccocirridae sp.	OG	14	13	0		100	0.317
Polygordius appendiculata	OG	329	152	6	4	98	0.008
Spiophanes bombyx	N2	49	8	5	3	90	0.018
Eumida sanguinea	AM	19	13	2	2	89	0.065
Sphaerosyllis hystrix	OG	68	51	10	6	85	0.228
Pisione remota	OG	74	46	12	12	84	0.118
Eteone longa	N2	27	5	13	5	52	0.028
Nephtys juvenile	N1	123	17	60	9	51	0.027
Magelona johnstoni	AM	556	145	281	28	49	0.094
Glycera lapidum	OG	78	14	41	17	47	0.094
Nephtys assimilis	AM	18	7	12	7	33	0.511
Sigalion mathildae	AM	49	18	35	7	29	0.831
Nephtys cirrosa	N2	104	18	77	8	26	0.173
Scolelepis squamata	ES	2932	271	2236	247	24	0.043
Lanice conchilega	AM	60	31	49	22	18	1.000
Nephtys hombergii	AM	47	5	55	9	−17	0.512
Cephalochordata
Branchiostoma lanceolatum	OG	4	10	4	8	60	0.521

Loc., location at which the species attained highest density; mean, mean-density (ind. m⁻²); Relative loss, density decrease relative to fixed sieving density (%); Stat. sign., statistical significance (P value) of the effect; SE standard error (ind. m⁻²)

ISSN: 1438-3888