Broad-scale patterns of abundance of non-indigenous soft-bottom invertebrates in Denmark

Table 1 Number of grab-samples and species-specific dominance rankings (no. 1 = most abundant) of NIS compared to the entire assemblage within 26 spatio-temporal groupings (no rankings could be provided for groupings where the species was not recorded at all)

Period	Region	Depth	No. of samples	Bal	Cre	Ens	Mar	Mya	Nea	Pet	Pot
1970–1984	West	<5 m	411		118			8	16	35
1970–1984	West	5–20 m	1,341		99			12	35	66
1970–1984	Northeast	<5	43					22
1970–1984	Northeast	5–20 m	165					64
1970–1984	Northeast	>20 m	884					477
1970–1984	Southeast	<5	640					20	87		4
1970–1984	Southeast	5–20 m	240					9	117		29
1970–1984	Southeast	>20 m	44					12
1985–1994	West	<5	5,335	59	71	187	16	12	94	124	18
1985–1994	West	5–20 m	4,734		116	147		20	59	137
1985–1994	West	>20 m	130					6
1985–1994	Northeast	<5	156					17	38		10
1985–1994	Northeast	5–20 m	1,441					56	0		293
1985–1994	Northeast	>20 m	1,459					261	0
1985–1994	Southeast	<5	3,048	45				2	39	134	6
1985–1994	Southeast	5–20 m	6,391	303				13	41	273	54
1985–1994	Southeast	>20 m	1,079				301	21	250
1995–2004	West	<5	5,249	54	114	122	11	6	47	93	25
1995–2004	West	5–20 m	2,187	209	41	75		43	32	65
1995–2004	West	>20 m	135			160	98	48
1995–2004	Northeast	<5	106					15	30		64
1995–2004	Northeast	5–20 m	3,056		313			31	150		295
1995–2004	Northeast	>20 m	1,619					68	265
1995–2004	Southeast	<5	1,985			125	58	3	14	0.74	25
										134
1995–2004	Southeast	5–20 m	5,628	186		241	344	16	40		169
1995–2004	Southeast	>20 m	1,845			244		31	78		15

Bal balanus improvisus, Cre crepidula fornicata, Ens ensis americanus, Mar marenzellaria viridis, Mya mya arenaria, Nea neanthes succinea, Pet petricola pholadiformis, Pot potamopyrgus antipodarum

ISSN: 1438-3888