SOFT-BOTTOM BENTHIC MACROFAUNAL COMMUNITIES of the EASTERN BAY of ISLANDS, NORTHERN NEW ZEALAND by Bruce W. Hayward*, Roger V. G

TANE 27, 1981

SOFT-BOTTOM BENTHIC MACROFAUNAL COMMUNITIES OF THE EASTERN BAY OF ISLANDS, NORTHERN NEW ZEALAND

by Bruce W. Hayward*, Roger V. Grace** and Fred J. Brook *N.Z. Geological Survey, P.O. Box 30 368, Lower Hutt **274a Birkdale Road, Birkenhead, Auckland, 10 Department of Geology, University of Auckland, Private Bag, Auckland

SUMMARY

The macrobenthos and sediments of forty dredge samples were analysed from a 3 km2 area of sea-bed (0 to 12 m deep), south of Urupukapuka Island in the eastern Bay of Islands. Six macrobenthic "communities" were recognised. Dominant taxa in each of the communities were ranked by calculating a "community score" for each taxon, based on its abundance, fidelity and distribution within each community. The communities were named after one or two characteristic taxa which had the highest community scores. A Tawera spissa community occurs in clean, shelly, medium sand in the current-swept Albert and "Poroporo" Channels. A second community, characterised by Corbula zelandica occupies slightly muddy, shelly sand adjacent to the Tawera but in slightly more sheltered situations. A Pleuromeris zelandica - Pectinaria australis community inhabits muddy fine sand in two basinal areas - one within the shelter of Otehei Bay and the other in the more exposed Rawhiti Inlet. A Zeacolpus pagoda - Zegalerus tenuis community occurs in clean, very well-sorted, medium to fine sand around the shoreward fringes of the Tawera community and passes into a Zostera muelleri - Nucula hartvigiana community in muddy sand that covers most of the sea-bed of Urupukapuka Bay. The clean sand of Urupukapuka Bay beach supports a Mesodesma australe community which is modified by the addition of Chione stutchburyi in the slightly muddy, finer sand of the more protected Otehei Bay beach.

INTRODUCTION

The Bay of Islands is on the east coast of Northland, New Zealand at latitude 35°15'S and longitude 174°15'E. Field work was carried out during the Offshore Islands Research Group trip to the eastern Bay of Islands during January 1980. Forty dredge samples of bottom sediments were taken from an area of approximately 3 km2 in 0 to 12 m of water, south of Urupukapuka Island (Fig. 1,2).

103 ba th metr T y y (contours in metres). Bathymetry is based on the Royal New Zealand Navy Hydrographic Office chart number N.Z. 5122, "Bay of islands. Inset map shows location of study area in the eastern Bay of Islands

104 Fig. 2. Aerial view from the north-east over most of the study area and southern part of Urupukapuka Island. Boundaries of the area studied together with location of dredge stations are shown. Photo: L. Homer, N.Z. Geological Survey, Lower Hutt.

METHODS

Samples were collected using a small dredge similar to that described by Grace and Whitten (1974). The dredge held approximately 4 500 cc of sediment, and under ideal conditions sampled an area of approximately 0.075 square metres to a depth of 6 cm. The dredge was hand-hauled from a 3.8 m aluminium dinghy with an 18 h.p. outboard motor. As the dredge samples only the upper 6 cm of sediment, deep-burrowing organisms such as the bivalves Gari, Zenatia and Bassina, and heart urchin Echinocardium are probably under-represented in the data. Bassina yatei for example, was not dredged at all, although diving observations showed it to be common around station 17. Upon arrival of the dredge at the surface, the volume of each sample was estimated to enable crude quantitative estimates of the biota to be made. About 200 cc of sediment was removed for textural analysis and foraminiferal studies. The rest of the sample was then passed over a wire mesh sieve with 2 mm openings. Organisms retained were sorted fresh, identified where possible and counted, then returned to the sea. Some specimens were preserved for later laboratory identification. Grain size analyses of the sediments were carried out in the laboratory using sieves.

105 Stations were located at the time of sampling, using a sextant to measure horizontal angles between fixed points on the shore.

SEDIMENTS (Fig. 3)

Grain size terminology and sediment nomenclature are adapted from Folk (1968 p. 26-30). Sediment type for each station is given in Appendix 1 and their distribution shown in Figure 3. The beaches around Urupukapuka Bay are predominantly shelly and pebbly, very coarse to medium sand with very little mud, whereas the more sheltered beach at Otehei Bay is a shelly, slightly muddy, medium sand. The more enclosed shallows of both Otehei and Urupukapuka Bays have a covering of muddy medium to very fine sand. Muddy to slightly muddy, fine sand occurs in the deepest part of the study area, south of Cable Bay. Here mud reaches its greatest quantity (32%) at Station 13 in the lee of Paeroa Island (Fig. 5). In the east the shallow, current-swept "Poroporo Channel" has a substrate of shelly medium sand which also extends into the entrance of Otehei Bay. Shelly fine sand stretches across the mouth of Urupukapuka Bay and becomes more coarse southwards towards the more exposed area of the Albert Channel. Here the sediment is shelly and gravelly, medium sand with even coarser, shelly gravel in the channel between Te Ao Island and the mainland. The Tawera shellbeds in the Albert Channel area have accumulated heavy deposits of dead shells. "Rhodoliths" of both living and dead coralline algae are not as common here as they are in the Cavalli Passage (Grace and Hayward 1980) but are of similar size and form. They are limited to the area of coarse sediment in the channel between Te Ao Island and the mainland (Fig. 6a).

MACROBENTHIC COMMUNITIES (Fig. 4)

The analysis of the biota has been approached from the classical point of view by selecting the most obvious, most numerous, or most characteristic species to define benthic communities. The term "community" is used here for a recurring combination of species, in a characteristic biotope, and with a considerable degree of continuity in space. Six communities are recognised here. Community Score The taxa occurring in each community have been ranked according to a value (community score) that has been calculated to reflect their importance in that community. This community score (C.S.) concept

106 muddy sand (>3°/0 mud)

Fig. 3. Distribution of sediment types. has been adapted from that used by Grange (1979) and is based on three criteria (listed separately for each community): (a) The proportion (Prop.) of stations in the community at which the taxon was collected. (b) The relative abundance (Abund.) obtained by ranking the ten most abundant taxa at each station in the community. Ten points are 107 given to the taxon numerically most abundant, 9 for the second most abundant, and so on until the 10th taxon is given 1 point. The points are summed for each taxon for all stations in the community and presented as a proportion of the maximum possible total, (c) The fidelity (Fid.) or degree to which a taxon is restricted to a community, expressed as the proportion of the taxon's total distribution that occurs in that community. The maximum possible value for each of these three criteria is 1.00. The Community Score (C.S.) as used here is defined as: C.S. = (Prop. + 3 Abund.) 25 Fid. The maximum possible value is 100. Fidelity values in each community are dependent on the number of stations in that community so that these and the resulting community scores are not directly comparable between communities.

1. Tawera spissa community Stations: 4, 5,6, 8,10,12, 21, 22, 24, 28, 29, 31, (total = 12). Sediment: Shelly fine sand to sandy gravel, mostly shelly medium sand; 0 to 0.6% mud, mean 0.2% mud. Depth: 1.8 to 7.5 m. Wave energy: Moderate to high. Prop. Abund Fid C.S. Characterising species Tawera spissa 1.00 0.85 0.66 58.6 Associated species Notoacmea helmsi 0.67 0.29 0.73 28.1 Rhyssoplax stangeri 0.92 0.25 0.65 27.1 Owenia fusiformis 0.92 0.60 0.35 23.8 Hermits 0.92 0.54 0.32 20.3 Zegalerus tenuis 0.75 0.47 0.35 18.9 Polychaetes 0.92 0.54 0.29 18.4 Euchone sp. 0.83 0.28 0.42 17.5 Cominella quoyana 1.00 0.28 0.34 15.6 Terenochiton inquinatus 0.58 0.02 0.87 13.9 Trochodota sp. 0.75 0.06 0.47 10.9 Halicarcinus varius 0.58 0.20 0.30 8.8 Gari stangeri 0.58 0.07 0.44 8.7 Cominella adspersa 0.42 0.08 0.50 8.2 Micrelenchus rufozonus 0.25 0.06 0.75 8.1 Nucula hartvigiana 0.50 0.14 0.35 8.0 Trochus tiaratus 0.33 0.07 0.57 7.7 Duplicaria tristis 0.33 0.09 0.50 7.5 This community occurs in the clean shelly sands of the Albert and "Poroporo" Channels (Fig. 4). Both areas contain adult Tawera spissa (between 15 and 25 mm long) throughout, with densities (Fig. 6b) around 700 per square metre in "Poroporo Channel" and averaging 1 500 per square metre in Albert Channel but as high as 25 000 per square metre (average size 17 mm) in the most exposed part of Albert Channel (Station 10). Large quantities of live and dead Tawera shells are typical of this

108 community and provide attachment surfaces for abundant grazing molluscs such as the limpet Notoacmea helmsi, gastropod Micrelenchus rufozonus and chitons Rhyssoplax stangeri and Terenochiton inquinatus. The fairly coarse sediment also provides a suitable habitat for other epifauna such as hermit crabs, the slipper limpet Zegalerus tenuis and the small crab Halicarcinus varius.

Fig. 4. Distribution of benthic macrofaunal communities.

109 Common infaunal members of the community are the polychaetes Owenia fusiformis, Euchone sp. and others.

2. Corbula zelandica community Stations: 1, 2, 7, 14, 18, 23, 25, 35, 39 (total = 9). Sediment: Shelly and pebbly medium sand to very coarse sandy gravel; 0 to 2.8% mud, mean 1.2% mud. Depth: 1 to 7 m. Wave energy: Moderate. Prop. Abund Fid. C.S. Characterising species Corbula zelandica 1.00 0.93 0.75 71.1 Associated species Talabrica bellula 0.55 0.08 1.00 19.8 Small cream anemone 0.67 0.29 0.46 17.6 Venericardia purpurata 0.78 0.18 0.47 15.4 Halicarcinus varius 0.78 0.43 0.30 15.4 Owenia fusiformis 0.89 0.48 0.26 15.1 Polychaetes 0.89 0.52 0.21 12.8 Rhyssoplax stangeri 0.67 0.24 0.35 12.0 Maoricolpus roseus 0.44 0.04 0.80 11.2 Glycymeris laticostata 0.33 0.03 1.00 10.5 Hermits 0.89 0.28 0.23 9.9 Euchone sp. 0.67 0.30 0.25 9.7 Cominella quoyana 0.89 0.18 0.23 8.2 Marginella pygmaea 0.44 0.03 0.57 7.6 Ischnochiton maorianus 0.44 0.01 0.66 7.6 This community occurs in four separate areas adjacent to the Tawera spissa community and characterised by very slightly muddy, shelly sands (Fig. 3, 4). The fauna is characterised by the infaunal bivalves Corbula zelandica, Talabrica bellula and Venericardia purpurata, and where the sediments are coarse sands and gravels, also by the dog cockles Glycymeris laticostata and G. modesta. Corbula is the most abundant with densities (Fig. 6c) averaging 750 per square metre and as high as 1 500 per square metre (station 35). Venericardia, Talabrica and Glycymeris all have low average densities of less than 50 per square metre and local highs of 400, 300 and 100 per square metre respectively. As with the Tawera community, the coarse shelly substrate provides ample attachment surfaces for a small cream anemone and the chitons Rhyssoplax stangeri and Ischnochiton maorianus, and a favourable habitat for other epifauna such as Halicarcinus varius, hermit crabs and Marginella pygmaea. As with the Tawera community, the dominant non-bivalve infauna are Owenia fusiformis, Euchone and other polychaetes. Although not sampled, small patches of the sea grass Zostera occur within the Corbula community across the entrance to Otehei and Cable Bays. Station 2 contains numerous Zeacolpus pagoda and is probably somewhat transitional between the Corbula and Zeacolpus - Zegalerus communities. 110 Fig. 5. a. Percentage of mud (grains finer than 0.0625 mm) in sediments. b. Percentage of pebble size clasts; including dead shells (larger than 4 mm) in sediments.

3. Pleuromeris zelandica - Pectinaria australis community Stations: 11,13,17, 20, 32, 33, 34, 37, 38 (total = 9). Sediment: Muddy very fine sand to slightly muddy medium sand; 3.2 to 32.1% mud, mean 12.6% mud. Depth: 1.8 to 12 m. Wave energy: Low. Prop. Abund. Fid C.S. Characterising species Pleuromeris zelandica 1.00 0.83 0.53 46.2 Pectinaria australis 1.00 0.52 0.69 44.2 Nucula nitidula 0.78 0.47 0.54 29.4 Leptomya retiara 1.00 0.18 0.69 26.6 Associated species Amphiura sp. 0.33 0.18 1.00 22.5 Owenia fusiformis 1.00 0.63 0.29 20.9 Polychaetes 1.00 0.59 0.24 16.6 Nucula hartvigiana 0.56 0.30 0.29 10.5 Echinocardium cordatum 0.33 0.03 1.00 10.5 Zegalerus tenuis 0.67 0.36 0.23 10.0 Maldanidae 0.78 0.13 0.30 8.7 Zeacolpus pagoda 0.56 0.14 0.36 8.7 Felaniella zelandica 0.44 0.03 0.57 7.6 Cominella quoyana 0.89 0.14 0.23 7.5 Hermits 0.67 0.31 0.18 7.1 This community occurs in muddy sands in the deepest part of the area south of Cable Bay and in the enclosed basin of Otehei Bay (Fig. 4). The fauna is predominantly infaunal and is characterised by the 111 bivalves Pleuromeris zelandica, Nucula nitidula and Leptomya retiara and the polychaete Pectinaria australis. Pleuromeris has an average density of 200 per square metre (Fig. 6d) ranging up to a high of 1 400 per square metre (stations 11 and 20). Other abundant members of the fauna are the polychaete Owenia fusiformis, small bivalve Nucula hartvigiana and hermit crabs. The brittle-star Amphiura sp., heart urchin Echinocardium cordatum and bivalve Felaniella zelandica are not abundant but have a high fidelity to this community.

4. Zeacolpus pagoda - Zegalerus tenuis community Stations: 3, 19, 26, 27 (total = 4). Sediment: Slightly shelly medium to fine sand; 0.1 to 0.6% mud, mean 0.4% mud. Depth: 1.5 to 4 m. Wave energy: Low to moderate. Prop. Abund. Fid C.S. Characterising species Zeacolpus pagoda 1.00 0.87 0.29 26.2 Antisolarium egenum 0.50 0.12 1.00 21.5 Zegalerus tenuis 1.00 0.90 0.15 13.9 Associated species Hermits 1.00 0.77 0.12 9.9 Polychaetes 1.00 0.67 0.11 8.3 Neoguraleus sp. 0.50 0.03 0.50 7.1 Myadora boltoni 0.50 0.08 0.40 7.1 Amalda novaezelandiae 1.00 0.03 0.24 6.4 Cominella quoyana 1.00 0.35 0.11 5.6 Duplicaria tristis 0.50 0.12 0.25 5.3 This community has been sampled at only four stations, all of which occur around the mouth of Urupukapuka Bay and "Oirg Bay". It lies between the Tawera community of more open water and the Zostera community of more sheltered situations (Fig. 4). The major characterising species, the turritellid Zeacolpus pagoda, has an average density of about 1 000 per square metre, reaching a peak of 3 500 per square metre at station 27. The slipper limpet Zegalerus tenuis is similarly abundant but is less characteristic because of its widespread occurrence in other communities. The small gastropod Antisolarium egenum is not abundant but is a characterising species because it has not been recorded here outside this community (Fid. = 1.00). The most abundant associated species are hermit crabs, unidentified polychaetes and the carnivorous gastropod Cominella quoyana, none of which are particularly characteristic of this community.

5. Zostera muelleri - Nucula hartvigiana community Stations: 9, 15, 40 (total = 3). Sediment: Fine to very coarse sand; 0.1 to 13.2% mud, mean 7.9% mud. Depth: 0.2 to 2 m. Wave energy: Low to moderate.

112

Associated species Halicarcinus varius 1.00 0.40 0.13 7.1 Alpheus sp. 0.67 0.03 0.33 6.2 Polychaetes 1.00 0.63 0.08 5.8 Hermits 1.00 0.50 0.09 5.6 Cominella quoyana 1.00 0.23 0.09 3.8 This community has been sampled at three stations in Urupukapuka Bay and the small bay to the east, and its distribution mapped by diving and air photographs (Fig. 4). Patchy Zostera also occurs in the Corbula community in Otehei and Cable Bays. The most abundant faunal members of this community are the bivalve Nucula hartvigiana, gastropod Rissoina chathamensis, small crab Halicarcinus varius, unidentified polychaetes and hermit crabs. The bivalve Zearcopagia disculus is uncommon but has a high community score because it has not been recorded outside the Zostera community.

Zeacolpus-Zegalerus

Tawera spissa Pleuromeris-Pectinaria

I Corbula J

gravel sand mud

Mesodesma australe Mesodesma-Chione Zostera-Nucula H tm

-42024 * UNITS Fig. 7. Mean grain-size histograms for the sediments of each benthic macrofaunal community.

6. Mesodesma australe community

Stations: 16, 30, 36 (total = 3). Sediment: Shelly medium sand to pebbly very coarse sand; 0 - 2.0% mud, mean 0.8% mud. Depth: Intertidal Wave energy: Low to moderate.

114 Prop. A bund. Fid. C.S. Characterising species Mesodesma australe 1.00 0.90 1.00 92.5 Associated species Chione stutchburyi 0.33 0.33 1.00 33.3 Eliminius modestus 0.33 0.30 1.00 30.7 Anthopleura aureoradiata 0.33 0.27 1.00 28.5 Cominella glandiformis 0.33 0.17 1.00 21.0 Isocladus armatus 0.33 0.27 0.50 14.2 Nucula hartvigiana 0.67 0.20 0.12 3.8 This community occurs in low tidal beach sands in Urupukapuka Bay and Otehei Bay. The clean sand of Urupukapuka Bay beach contains abundant pipi Mesodesma australe (up to 1 000 per square metre at least) and rare Nucula hartvigiana and the isopod Isocladus armatus. The slightly muddy sand at Otehei Bay contains an association of cockle Chione stutchburyi (1 000 per square metre) and less abundant pipi. Also present are the small mud-tolerant barnacle Elminius modestus, the anemone Anthopleura aureoradiata and gastropod Cominella glandiformis.

COMPARISONS WITH OTHER AREAS

The communities recognised in the eastern Bay of Islands can be related with varying degrees of certainty to those described from other parts of northern New Zealand's inner shelf. The Tawera spissa community is one of the most common and widespread communities existing on our continental shelf and has been described from many places [see Grace and Hayward (1980) for more detailed discussion]. The Corbula and Pleuromeris • Pectinaria communities of the Bay of Islands have not been recognised elsewhere. They are possibly inshore variants of McKnight's (1969) "Echinocardium", "Nemocardium"and "Amphiura" communities. A community with Corbula and Pleuromeris jointly dominant occurs off Great Mercury Island (Grace and Grace 1976) and Kawau Island (Powell 1937) but its division into two distinct communities as in the Bay of Islands is not apparent. The Zeacolpus pagoda - Zegalerus tenuis community has previously been recorded from a similar habitat in the Cavalli Islands (Grace and Hayward 1980). In the Cavallis however, this community is also characterised by abundant juvenile Tawera spissa. Zostera muelleri - Nucula hartvigiana communities are best known from sheltered intertidal to shallow sublittoral harbour flats on the mainland, although similar subtidal occurrences such as these around Urupukapuka Island have been described from Slipper Island and the Cavallis (Grace and Whitten 1974, Grace and Hayward 1980). Mesodesma australe and Chione stutchburyi communities are well known from similar protected sand beaches on the mainland (Morton and Miller 1968). 115 DISCUSSION

Distribution of the macrobenthic communities in the eastern Bay of Islands appears to be strongly correlated with sediment grain size, although degree of exposure to wave action and other factors are also important. The three major infaunal bivalve communities occur in distinctly different sediments (Fig. 7). The Tawera spissa community occupies clean, poorly sorted medium sands with almost no mud but abundant shells of dead Tawera. These sediments, together with the Tawera spissa community, occur in areas with strong wave and current action (in the Albert and Poroporo Channels). The Corbula community occupies slightly muddy, poorly sorted, shelly sand that typically has more mud and often more greywacke pebbles than the Tawera community sediment. The increased mud content probably reflects the slightly more protected locations of the Corbula community. The Pleuromeris - Pectinaria community occupies muddy, moderately sorted fine sand with very little shell or gravel. It occurs in two local basins having distinctly different depth ranges and exposure to wave and current action. On the sea floor however, both basins probably have a very quiet environment that allows fine sediment to accumulate. Sand from the "Poroporo Channel" is gradually advancing into both basins (diving observation of "advancing dune" structure, and evidence from air photos). The Zeacolpus - Zegalerus community occupies clean, very well sorted, medium to fine sand, whereas the adjacent Zostera - Nucula hartvigiana community, occupies muddy, poorly sorted medium sand (Fig. 7). Both these communities are exposed to similar amounts of wave action but the thick Zostera sea grass probably prevents the accumulated mud from being carried away from the Zostera - Nucula hartvigiana community. The Mesodesma australe community occupies the shelly, moderately sorted medium sand of the intertidal beaches. Chione stutchburyi only occurs on the more protected Otehei Bay beach which has finer sand with more mud than Urupukapuka Bay beach (Fig. 7).

ACKNOWLEDGEMENTS

We would like to thank Jessica Beever, Dave Court, Anne Grace, Glenys Hayward, Tom Wilson and other colleagues on the trip for assistance in sorting some of the samples, and Mrs D.A. Saies for the loan of the outboard motor. We also thank Norcott Hornibrook, George Scott and Alan Beu for reading the manuscript and suggesting improvements.

REFERENCES

Folk, R.L. 1968: "Petrology of Sedimentary Rocks." Hemphill's, Texas. 170 p. Grace, R.V. & Grace, A.B. 1976: Benthic communities west of Great Mercury Island, north-eastern New Zealand. Tane 22:85-101. 116 Grace, R.V. & Hayward, B.W. 1980: Macrobenthos of the Cavalli Islands, northern New Zealand. Tane 26: 189-209. Grace, R.V. & Whitten, R.F. 1974: Benthic communities west of Slipper Island, north• eastern New Zealand. Tane 20:4-20. Grange, K.R. 1979: Soft-bottom macrobenthic communities of Manukau Harbour, New Zealand. New Zealand Journal of Marine and Freshwater Research 13 (3): 315-329. McKnight, D.G. 1969: Infaunal benthic communities of the New Zealand continental shelf. New Zealand Journal of Marine and Freshwater Research 3 (3): 409-444. Morton, J.E. & Miller, M.C. 1968: "The New Zealand Sea Shore." 1st Edition, Collins, London. 638 p. Powell, A.W.B. 1937: Animal communities of the sea-bottom in Auckland and Manukau Harbours. Transactions of the Royal Society of New Zealand 66: 354-401.

APPENDIX 1. Station Data.

Stn. Depth' Sediment2 Sample No. of3 Community4 Grid. Ref. (m) Vol (cc) taxa N12(2nd Ed)

1 4 sh,mds 4000 40 C 74405680 2 2 slsh.slm.mdS 4000 31 C 73455720 3 4 slsh.mdS 4000 14 Z 74855760 4 3 sh,fS 2200 14 T 74705765 5 7 s.shG 3600 35 T 74805725

6 5.5 sh,mdS 3600 20 T 74555725 7 4 s.grG 3600 36 C 74555685 8 5 sh,mdS 4000 32 T 74355705 9 1 mdS 3600 17 Zo 74755775 10 7.5 sh,mdS 3000 13 T 75005735

1 1 8 slsh,m,mdS 4000 39 P 74355650 12 5 sh,mdS 4000 39 T 74605615 13 6 m.vfS 4500 15 P 74405695 14 2 sh,slm,mdS 4000 36 C 73955695 15 0.2 m,sh,vcS 3000 25 Zo 74505800

16 int. slg.mdS 4000 3 M 74505805 17 12 slm,fS 4000 20 P 74155635 18 7 s.grpG 2700 24 C 74905645 19 4 sh,fS 4000 29 Z 74505740 20 1.8 slsh,slm,fS 4500 30 P 73655680

21 1.8 sh,mdS 3600 22 T 73505700 22 2 sh,mdS 3600 19 T 73355680 23 3 sh,slm,vcS 4000 35 C 73405640 24 7 sh,mdS 3100 27 T 74905685 25 6 s,slm,grG 3600 23 C 74855615 z 26 1.5 fS 4000 13 74205730 27 2 fS 3100 14 z 74255750 28 (i sh,fS 3100 31 T 74755740 29 5 sh,vcS 3600 24 T 74705650 30 int. g.vcS 4000 5 M 74505805

117 31 5 sh,mdS 3600 26 T 74455635 32 8 slm.mdS 4000 13 P 74205610 33 12 slsh,m,fS 4000 16 P 73605615 34 5 slsh.slm.fS 4000 18 P 73755650 35 1 slsh.slm.mdS 4000 13 C 73405740

36 int. sh,slm,mds 3600 12 M 73655760 37 2.5 m,vfS 4500 20 P 73605750 38 2.5 m.mdS 3600 14 I' 73655735 39 5 g.mdS 4500 20 c 74455685 40 2 m,fS 1800 15 Zo 74505785

'int = intertidal

2G = gravel (>50% gravel size), S = sand (>50% sand), g, sh, s, m = gravelly, shelly, sandy, muddy (10-50% gravel, shell, sand, or mud), slg, slsh, slm = slightly gravelly, shelly or muddy (1-10% gravel, shell or mud), vcS = very coarse sand, cS = coarse sand, mdS = medium sand, fS = fine sand, vfS = very fine sand, p = pebble, gr = granule.

3 Taxa of fauna only have been summed, as listed in Appendix 2. ' C = Corbula zelandica, M = Mesodesma australe, P = Pleuromeris zelandica - Pectinaria australis, T = Tawera spissa, Z = Zeacolpus pagoda - Zegalerus tenuis, Zo = Zostera muelleri - Nucula hartvigiana

APPENDIX 2. Raw species counts. For each species, the station at which that species occurs is given, followed in brackets by the number of individuals occurring in the sample. Where no figures in brackets are given, information is qualitative only.

ALGAE Colpomenia sinuosa 14,23, 24 Coralline "rhodoliths" 7,18,25,29,31,39 ANGIOSPERMS Zostera muelleri 3,4,8,9,15,26,38,40 ACTINIARIA Actinothoe albocincta K7),7(14) Anthopleura aureoradiata 36(52) Edwardsia sp. 6(1),9(1) 7(8),9(2),11(1),12(10),23(5),24(1),25(3),27(1),29(3), Long brown burrowing anemone 31(1),34(1),35(1),39(13) 1(10),5(9),6(5),7(32),9(3),11(13),14(3),19(3),21(1),23(9), Small cream anemone 25(9),29(2),39(8) Small green anemone 7(2) Transparent anemone 15(100) PLATYHELMINTHES Unidentified polycladida 5(1) NEMERTEA Black 5(1),7(1),40(1) Orange 1(1),7(1),11(1),19(2),22(1),24(1) Red 4(1) White 2(1),15(1),20(1),34(1) BRYOZOA membraniporiform 1,7,11,12,24 SIPUNCULOIDEA Unidentified 1(2) POLYCHAETA Aglaophamus macroura 17(1),26(2),32(1)

118 Armandia maculata 2(1),5(3),7(1),9(1),22(1) Boccardia polybranchia 1(24),15(500) Cirratulidae 5(1),7(1),10(1),11(4),14(1) Euchone sp. 1(1),2(4),3(7),5(4),6(2),7(14),8(8),11(43),12(4),14(7), 17(1),19(1),20(1),21(13),22(5),23(23),24(1),27(4),28(11) 29(5),31(12),32(1),34(2),35(70) Flabelligera affinis 5(3) Galeolaria hystrix 5(1),12(1) Glyceridae 2(2),8(1),14(1),15(2),23(2) Hemipodus sp. 14(1),17(1),20(1) Hydroides norvegicus 1(2),5(6),7(4),11(3),12(39),24(2),26(1) Idyanthyrsus quadricornis 12(1),28(1),31(1) Lepidonotus sp. 5(1),7(1),12(3),24(1),25(1),39(1) Lumbriconereis sphaerocephala 13(4) Maldanidae 1(1),2(8),3(1),4(1),6(5),7(1),8(3),9(1),11(1),12(1),13(1), 14(4),17(20),19(3),20(1),23(5),26(1),28(3),32(1),37(1), 38(1),39(1),40(1) Nereidae 5(2),15(7),28(4) Owenia fusiformis 1(68),2(3),4(8),5(120),7(11),8(1),9(2),10(2),11(85), 12(128),13(5),14(24),17(19),20(4),21(8),22(15),23(23), 24(6),25(1),27(74),28(27),29(20),31(26),32(2),33(9), 34(11),35(5),37(8),38(10),39(60),40(1) Pectinaria australis 8(1),11(2),13(7),15(17),17(6),20(10),26(5),28(1),32(1), 33(10),34(2),37(13),38(25) Polynoidae 19(1) Phyllodocidae 3(2),8(1),12(2),14(1),19(2),22(2),29(1),31(1) Spirorbidae 8(3) Sabellidae 15(5),20(1),23(17),39(100) Sigalion sp. 1(1),2(1),8(1) Syllidae 5(3),18(1) Terebellidae 19(1) Unidentified 1(1),2(18),3(19),4(4),5(10),6(25),7(65),8(45),9(8),11(31), 12(11),13(7),14(14),15(57),16(1),17(7),19(8),20(13), 21(10),22(3),23(24),24(7),25(1),26(4),27(8),28(30), 29(8),31(15),32(3),33(7),34(13),35(9),36(2),37(1), 38(14),39(21),40(1) AMPHINEURA Acanthochitona zelandica KD Ischnochiton maorum 1(1),2(1),5(9),18(2),23(1),28(1) Notoplax cuneata 12(2),22(1),28(1),31(1) Rhyssoplax stangeri 1(4),5(24),6(1),7(2),8(2),10(1),12(66),14(3),18(14),21(1), 22(1),23(11),24(63),25(11),28(21),29(1),31(7)

Terenochiton inquinatus 8(2),1(K1),12(5),23'(1),24(1),28(5),29(1)131(1) GASTROPODA Alcithoe arabica 28(1) Amalda novaezelandiae 1(4),3(1),5(1),6(1),7(1),12(1),14(2),17(1),18(2),19(1), 21(1),23(2),26(1),27(1),29(1),33(1),37(1) Antimelatoma buchanani 11(1) Antisolarium egenum 19(6),27(2) Buccinulum robustum Kl),18(2) B. vittatum 7(1) Bulla quoyi 14(2) Cominella adspersa 6(4),7(1),8(1),10(3),11(1),12(2),16(1),20(1),31(3),33(1) C. glandiformis 36(6)

119 C. maculosa C. quoyana

Cylichna thetidis Daphnella cancellata Duplicaria tristis Epitonium jukesianum E. minora Maoricolpus roseus Maoricrypta costata Marginella pygmaea Muricopsis octogonus Micrelenchus rufozonus Neoguraleus sinclairi

N. lyallensis tenebrosus N. sp. Notoacmea helmsi

Peculator hedleyi Phenatoma zelandica Proxiuber australe Pupa kirki Rissoina cf. anguina R. chathamensis Sigapatella novaezelandiae Struthiolaria papulosa S. vermis Taron dubius Tomopleura albula Trochosirius inornatus Trochus tiaratus T. viridus Xymene ambiguus X. plebejus Zeacolpus pagoda

Z. vittatum Zediloma subrostrata Zegalerus tenuis

BIVALVIA Borniola reniformis Chione stutchburyi Corbula zelandica

Dosinia maoriana Felaniella zelandica Gari lineolata G. stangeri

Glycymeris laticostata G. modes ta 120 Leptomya re tiara 11(4),12(1),13(1),15(2),17(1),20(1),21(1),28(1),32(1), 33(1),34(2),37(12),38(2) Limatula maoria 25(1) Macomona liliana 17(1),36(1),38(7) Mesodesma australe 16(2),30(71),36(10) Modiolus areolatus 28(1) Myadora boltoni 3(1),17(1),19(4),20(2),22(1) M. striata 2(1),3(1),19(2),20(1) M. subrostrata 12(1),23(2),29(1) Notocallista multistriata 13(1),17(1) Nucula hartvigiana 4(1),6(D,8(1),11(6),12(16),13(10),15(29),19(1),20(4), 26(1),28(21),30(1),31(29),36(2),37(18),38(17),40(45) N. nitidula 5(1),8(1),1K31),12(1),13(60),20(4),24(1),29(1),31(1), 32(1),33(37),37(19),38(2) Pecten novaezelandiae KD,25(1) Pleuromeris zelandica 2(6),6(1),8(1),11(91),13(21),14(1),17(17),20(111),21(1), 22(1),23(6),31(1),32(13),33(15),34(11),37(7),38(8) Scalpomactra scalpellum 4(1),8(2),9(1),33(1) Soletellina nitida 22(1) S. siliqua 34(1) Talabrica bellula 7(2),14(3),23(21),25(1),39(3) Tawera spissa 1(18),2(1),4(20),5(325),6(101),8(102),10(1230),11(10), 12(53),14(3),18(1),21(41),22(45),24(5),28(84),29(4), 31(22),39(5) Tellina huttoni 37(1) Theora lubrica 37(5) Thracia australica novozelandica 37(1) Venericardia purpurata 1(1),2(2),5(1),7(1),H(5),12(2),13(1),14(14),21(7),23(24), 24(1),29(1),35(1),37(1),39(3) Venerupis largillierti 11(3),22(2),28(1) Zearcopagia disculus 15(1),40(1) Zenatia acinaces 33(1) CIRRIPEDIA Eliminius modestus 36(60) CUMACEA Unidentified KD,15(2) ISOPODA Cilicaea sp. 18(1) Cirolana sp. 34(1),37(1) Isocladus armatus 15(27),30(7) Paranthura sp. 2(2),9(1),37(1),39(1) Unidentified 1(1),6(2),11(1),15(1),19(1),24(1) AMPHIPODA Unidentified 1(5),3(2),5(5),7(8),12(2),14(1),15(7),18(1),22(2),23(4), 29(1),32(2),34(1),35(1) NATANTIA Alpheus sp. 12(2),15(1),23(1),24(1),30(1),40(1) Callianassa sp. 14(2),23(1) Leander sp. KD,4(1) Pontophilus aus trails 4(1),6(1),8(D ANOMURA Petrolisthes novaezelandiae 18(1),25(1) PAGURIDEA Unidentified hermits 1(7),2(1),3(5),4(6),5(14),6(10),7(5),8(14),9(2),10(3), 11(19),12(24),14(3),15(5),17(9),18(40),19(16),20(85), 121 21(1),22(42),24(15),25(9),26(10),27(16),28(45),30(1), 31(4),32(3),34(1),35(5),37(1),39(3),40(10) BRACHYURA Halicarcinus varius 1(31),2(4),5(13),7(26),8(3),9(1),11(18),12(14),13(3), 14(8),15(12),18(7),19(3),20(3),24(12),27(6),28(27), 29(2),31(10),33(2),35(3),39(14),40(8) Liocarcinus corrugatus 12(1),18(1),25(2) Macrophthalmus hirtipes 38(3) Notomithrax minor 1(2),5(1),7(3),11(1),12(1),20<1),23(4),25(1),28(2),29<1), 31(2),39(3),40(1) INSECTA Philanisus sp. 14(1),21(1) ASTEROIDEA Astropecten polyacanthus 8(11,23(1) Patiriella regularis 12(1),18(3),31(2) OPHIUROIDEA Amphipholis squamata K4),14(l) Amphiura spp. 13(160),33(3),37(6) Unidentified 2(1),10(1),11(2),12(1),14(2),15(4),17(1),19(1),20(1), 24(1),25(1) HOLOTHUROIDEA ?Neothyonidium armatum 1(4),12(1),14(1),18(2),23(3),27(4) Trochodota sp. 3(3),4(3),5(3),6(1),7(1),8(4),11(1),12(1),14(1),15{9). 19(2),20(4),23(1),24(1),25(1),26(1),28(1),29(1),31(1) Unidentified 2(1),4(2),11(1),25(1) ECHINOIDEA Echinocardium cordatum 20(1),32(1),34(1) HEMICHORDATA Balanoglossus australiensis 1(1),5(3),7(1),8(1),11(2),14(1),21(2),25(1),27(2) PISCES Trachelochismus sp. 12(1),18(3),19(1),28(2),29(2)

122