Sediment macrobenthos off eastern Waiheke Island, Hauraki Gulf, New Zealand

Figures & data

Fig. 1  Site distribution and associated substratum type [hatched area depicts Tawera+Purpurocardia formation of Powell (1937)]; insets: North Island, New Zealand; and Waiheke Island, Hauraki Gulf.

Fig. 2  Dry weight composition of sediment grain size class each of the three substrata (mud, mud/gravel and gravel).

Table 1  Classification of relative density and richness using a 7-point scale for all subtidal substratum types, eastern Waiheke Island.

Density/richness (%)	Density/richness score
<5	Very low
510	Low
11–25	Fairly low
26–50	Medium
51–75	Fairly high
76–95	High
96–100	Very high

Table 2  Number of individuals and taxa per sample (0.0336 m²) in each substratum type.

Substrata	# of samples	# of individuals	Average individuals/sample	# of taxa	Taxa range/sample	Taxa endemic to substrata
Mud	139	6805	49.0	142	2–41	36
Mud/gravel	32	2531	79.1	166	11–53	25
Gravel	57	10,559	185.2	255	18–69	106

Fig. 3  Species accumulation curves, all substrata.

Fig. 4  The relationship between species dominance and richness, all substrata, eastern Waiheke Island.

Table 3  Sediment grain size analyses by substratum type.

Substrata	ϕ25	ϕ50	ϕ75	Sorting coefficient
Mud
# of samples	3	3	3	Moderately to moderately well sorted
Mean	4.13	4.97	5.93
SD	0.38	0.15	0.45
Mud/gravel
# of samples	3	3	3	Very poorly sorted
Mean	0.1	1.9	4.63
SD	0.61	0.98	0.4
Gravel
# of samples	2	3	3	Poorly sorted
Mean	−1.15	−0.1	2.07
SD	0.49	0.95	0.67

Fig. 5  Multi-dimensional scaling plot of species assemblages within three substrata.

Table 4  DIVERSE indices by substratum type and depth (mean±SD), square-root transformed data.

	<10 m	10 − 15 m	>15 m	Total
Mud
n	49.17±44.53	39.85±30.72	59.37±78.71	48.96±55.85
d	2.09±0.82	2.05±0.91	2.11±1.06	2.08±0.95
J’	0.62±0.21	0.67±0.15	0.61±0.13	0.64±0.16
H’	1.28±0.51	1.37±0.47	1.3±0.44	1.32±0.47
λ	0.45±0.2	0.39±0.17	0.43±0.15	0.42±0.17
Mud/gravel
n	83.05±56.65	63.67±65.99	81.57±58.38	79.09±57.29
d	4.2±1.81	4.03±1.42	5.67±1.67	4.49±1.78
J’	0.66±0.22	0.78±0.24	0.83±0.08	0.72±0.21
H’	1.88±0.70	2.04±0.65	2.60±0.30	2.07±0.67
λ	0.32±0.23	0.24±0.22	0.13±0.04	0.27±0.21
Gravel
n	186.25±208.01	176.67±50.21	N/A	185.25±197.15
d	6.16±1.35	7.60±2.74	N/A	6.32±1.58
J’	0.73±0.11	0.77±0.05	N/A	0.73±0.11
H’	2.51±0.42	2.80±0.42	N/A	2.54±0.42
λ	0.17±0.11	0.11±0.03	N/A	0.16±0.11
Abbreviations: n, number of individuals; d, Margalef's index of species richness; J’, Pielou's eveness index; H’, Shannon–Wiener diversity index; λ, Simpson dominance index.

Table 5  Breakdown of average similarity in taxon richness by substratum, to Phylum, square-root transformed data.

	Average # taxa	Contribution (%)	Cumulative contribution (%)
Mud (average similarity: 63.63)
Annelida	3.58	38.61	38.61
Arthropoda	2.92	37.53	76.15
Mollusca	1.31	18.71	94.86
Mud/gravel (average similarity: 64.73)
Annelida	10.06	53.45	53.45
Arthropoda	4.53	24.16	77.60
Mollusca	2.28	10.91	88.52
Echinodermata	1.34	8.37	96.88
Gravel (average similarity: 74.97)
Annelida	16.75	56.71	56.71
Mollusca	5.98	17.60	74.31
Arthropoda	6.05	16.95	91.26

Table 6  Breakdown of average similarity in taxon abundance by substratum to level of Class, and Phylum Nemertea (average similarity of samples in parentheses).

SIMPER	Muds (58.26%)	Mud/gravels (50.37%)	Gravels (66.4%)
Cumulative contribution (%)	Bivalvia 41.85%	Polychaeta 41.69%	Polychaeta 42.74%
	Ostracoda 64.79%	Ostracoda 60.07%	Bivalvia 62.09%
	Polychaeta 86.58%	Malacostraca 72.88%	Malacostraca 74.00%
	Malacostraca 96.44%	Bivalvia 83.80%	Gastropoda 81.61%
		Ophiuroidea 90.23%	Ostracoda 85.89%
			Nemertea 89.18%
			Ophiuroidea 92.31%

Table 7  SIMPER results for muds,average similarity: 39.09, square-root transformed data.

Species	Average abundance	Contribution (%)	Cumulative contribution (%)
Theora lubrica	4.05	50.12	50.12
Ostracod sp. 2	2.55	24.77	74.88
Prionospio sp.	0.84	4.73	79.62
Sthenelais sp.	0.51	3.28	82.90
Paraphoxus sp. 1	0.73	3.03	85.93
Cossura consimilis	0.51	2.86	88.79
Echinocardium cordatum	0.41	1.92	90.71

Table 8  SIMPER results for mud/gravels, average similarity: 22.09, square-root transformed data.

Species	Average abundance	Contribution (%)	Cumulative contribution (%)
Ostracod sp. 2	3.30	21.72	21.72
Prionospio sp.	1.54	15.30	37.02
Heteromastus filiformis	2.14	9.38	46.40
Nemertea	0.77	4.83	51.23
Sthenelais sp.	0.52	4.23	55.46
Paraphoxus sp. 1	0.70	4.00	59.46
Amphiura rosea	0.65	3.42	62.88
Echinocardium cordatum	0.40	2.63	65.51
Theora lubrica	0.64	2.56	68.07
Aonides sp.	0.40	2.30	70.37
Trichobranchus sp.	0.39	1.86	72.22
Cirratulid sp. 1	0.36	1.52	73.75
Arabella sp.	0.36	1.47	75.21
Glycera tesselata	0.45	1.42	76.64
Macroclymenella stewartensis	0.42	1.32	77.96
Ostracod sp. 1	0.33	1.24	79.19
Onuphis aucklandensis	0.32	1.11	80.30
Sphaerosyllis sp.	0.34	1.07	81.37
Spionid sp. 1	0.60	1.05	82.42
Leptochiton inquinatus	0.37	0.87	83.30
Cossura consimilis	0.26	0.83	84.12
Exogone sp.	0.33	0.82	84.94
Commensal polychaete	0.52	0.76	85.71
Amphicteis philippinarum	0.37	0.73	86.43
Armandia maculata	0.46	0.72	87.16
Phoronis psammophila	0.32	0.67	87.83
Terebellides stroemi	0.31	0.62	88.45
Nematoda	0.28	0.60	89.05
Notocorbula zelandica	0.27	0.59	89.64
Paraphoxus sp. 2	0.27	0.59	90.22

Table 9  SIMPER results for gravels, average similarity: 38.16, square-root transformed data.

Species	Average abundance	Contribution (%)	Cumulative contribution (%)
Heteromastus filiformis	5.03	17.08	17.08
Notocorbula zelandica	4.45	14.43	31.51
Prionospio sp.	2.24	7.41	38.91
Spionid sp. 1	2.87	6.20	45.11
Macroclymenella stewartensis	1.45	3.97	49.08
Commensal polychaete	1.75	3.25	52.33
Terebellides stroemi	1.28	3.18	55.51
Nemertea	1.09	2.83	58.34
Oridia sp.	1.60	2.74	61.08
Paguristes setosus	1.83	2.47	63.54
Sphaerosyllis sp.	1.01	1.92	65.46
Amphicteis philippinarum	0.93	1.91	67.37
Trochodota dendyi	0.95	1.90	69.27
Ostracod sp. 2	0.97	1.85	71.12
Ophiodromus angustifrons	0.81	1.70	72.82
Aonides sp.	0.82	1.56	74.38
Hydroides norvegicus	1.14	1.54	75.92
Ostracod sp. 1	0.67	1.39	77.31
Anomia trigonopsis	0.76	1.37	78.67
Armandia maculata	0.74	1.35	80.03
Leptochiton inquinatus	0.73	1.33	81.35
Glycera tesselata	0.62	1.21	82.56
Nematoda	0.63	1.15	83.71
Syllid sp. 10	0.68	1.14	84.85
Anthurid sp. 2	0.62	0.98	85.84
Maoricolpus roseus	0.67	0.92	86.76
Paraphoxus sp. 1	0.52	0.87	87.63
Glycinde sp.	0.64	0.86	88.48
Trichobranchus sp.	0.49	0.79	89.28
Amphiura aster	0.55	0.72	90.00
Exogone sp.	0.52	0.62	90.62

Fig. 6  Multi-dimensional scaling plot of species assemblages within muds, grouped by depth (<10, 10–15, >15 m).

Fig. 7  Multi-dimensional scaling plot of species assemblages within mud/gravels, grouped by depth (<10, 10–15, >15 m).

Fig. 8  Multi-dimensional scaling plot of species assemblages within gravels, grouped by depth (<10, 10–15 m).

Fig. 9  Spatial distribution of relative species richness, all substrata (left), muds (right).

Fig. 10  Spatial distribution of relative species density, all substrata (left), muds (right).

Fig. 11  Dendrogram of similarity in faunal composition of all sites (n=228), all substratum types, eastern Waiheke Island, using presence/absence data.

Fig. 12  Dendrogram of similarity in molluscan and echinoderm taxa (n=228), all sites, all substratum types, eastern Waiheke Island, using presence/absence data.

Fig. 13  Dendrogram of similarity in faunal composition of all sites, muddy substrata (n=139), eastern Waiheke Island, using presence/absence data.

Table 10  Nomenclature of taxa reported by Powell (1937) and this study.

Powell (1937)	Current study
Tawera spissa	Tawera spissa
Venericardia purpurata	Purpurocardia purpurata
Cominella quoyana	Cominella quoyana
Cominella adspersa	Cominella adspersa
Nectocarcinus antarcticus	Liocarcinus corrugatus (possibly misidentified by Powell)
Trochus tiaratus	Trochus tiaratus
Zegalerus tenuis	Zegalerus tenuis
Petrolisthes elongatus	Petrolisthes novaezelandiae, or Petrocheles spinosus
Cirostrema zelebori	Not found
Proxiuber australis	Proxiuber australe
Rhyssoplax stangeri	Rhyssoplax stangeri
Zemysia zelandica	Felaniella zelandica
Epitonium jukesianum	Not found
Holothuria (small, pink)	Probably Ocnus brevidentis or Trochodota dendyi
Trachelochismus pinnulatus	Not found
Terenochiton inquinatus	Leptochiton inquinatus
Marginella pygmaea	Not found
Condylocardia concentrica	Not found
Condylocardia crassicosta	Not found
Notosetia micans	Not found
Estea minor	Rissoidae
Notoacmaea subtilis	Not found
Zemitrella choava	Not found
Echinocardium cordatum	Echinocardium cordatum
Dosinia lambata	Dosinia lambata
Amphiura rosea	Amphiura rosea
Neilo australis	Neilo australis
Polychaetes (not ident.)	Many taxa
Cadulus delicatulus	Cadulus delicatulus

Powell , AWB . 1937 . Animal communities of the sea-bottom in Auckland and Manukau Harbours . Transactions and Proceedings of the Royal Society of New Zealand , 66 : 354 – 401 .

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