TANE 22, 1976

BENTHIC COMMUNITIES WEST OF GREAT MERCURY ISLAND, NORTH-EASTERN NEW ZEALAND

by Roger V. Grace* and Anne B. Grace f *36 Sussex Street, Grey Lynn, Auckland f Department of Geology, University of Auckland, Private Bag, Auckland

SUMMARY Thirty-six dredge samples from the seabed west of Great Mercury Island were analysed for macrofauna, macroflora, and gross sediment characteristics. Three main associations were recognised, all inhabiting sandy or muddy substrates. One was characterised by Zostera muelleri and Nucula hartvigiana in shallow water, with an intertidal facies extending on to harbour flats. Another, characterised by Tawera spissa, occurred in intermediate depths on a sloping bottom. The third association was characterised by Caryocorbula zelandica and Pleuromeris zelandica, and occurred in deeper water. Three minor associations were also recognised, but were poorly sampled. The rocky bottom community characterised mainly by Ecklonia radiata was also briefly described, and mapped with the aid of aerial photographs. The associations recognised have broad parallels elsewhere in New Zealand.

INTRODUCTION Great Mercury Island is the largest island in the Mercury group, off the east coast of the Coromandel Peninsula at latitude 36°37'S, longitude 175°48'E, and approximately 6km from the mainland. The samples and observations on which this paper is based were taken during the Auckland University Field Club scientific trip in May, 1975. The locations of the 36 dredge stations, rocky bottom observation stations, and the bathymetry of the area studied, are indicated in Fig. 1. Depth contours are the authors' sketched metric conversions from the Royal New Zealand Navy Hydrographic Office chart number N.Z. 5318, "Great Mercury Island to Mercury Bay", October, 1971.

METHODS Samples were collected using a slightly more sophisticated model of a small dredge described by Grace and Whitten (1974). The dredge was hand-hauled from a 12-foot aluminium dinghy with 18 horsepower outboard motor. Performance characteristics of the dredge were similar to those described by Grace and Whitten (1974), who estimated that the area sampled by the dredge when 7/8 full was about 0.074sq. metre. The sediment in each sample was briefly described, and passed over a 2mm wire sieve. The fauna retained was identified and counted, then returned alive to the sea. In some cases a few specimens were preserved for subsequent positive identification. Estimates of the volume of residue (mainly comminuted or whole shell) remaining on the sieve after sorting were also made, to give an indication

85 86 of the quantity of sediment coarser than 2mm particle size. Dredge sampling stations were located using a sextant to measure horizontal angles between fixed points on the shore. Rocky bottom areas were investigated using snorkel and scuba diving techniques, and mapped with the aid of aerial photographs.

RESULTS Lists of station data are presented in Appendices 1 and 2. These include the proportion of the dredge filled, sediment characteristics, estimates of volume of residue, number of species in each sample, and faunal counts.

Sediments Sediment distribution is indicated in Fig. 2. The shallow Huruhi Harbour at the northern end of the area studied, and the deeper areas offshore, are dominated by muddy sands. These grade to the east through medium sands to the well-sorted clean fine sands typical of moderately exposed beaches. To the west, sediments become coarse and shelly around the small islands known as The Sisters, where moderate tidal currents occur. The coarsest sediment sampled, at station 26, consists of about 80% of "rhodoliths" of living coralline algae. Each "rhodolith" consists of a small central nucleus of rock or shell about which has grown encrusting coralline algae in the form of numerous narrow fingers projecting radially from the central nucleus. The diameter of the "rhodoliths" measures approximately 10mm to 15mm, and each of the 15 to 20 fingers per "rhodolith" is about 1mm to 2mm in diameter. Smaller numbers of similar "rhodoliths" occur at stations 23 and 28. The Great Mercury Island specimens are much smaller and finer in structure than those known to occur commonly at Army Bay, north of Auckland. Accumulations of dead shell are indicated by the quantity of residue after each sample has been passed over the 2mm sieve. Apart from the shell gravels around the Sisters, considerable quantities of dead Tawera spissa shell occur in the vicinity of stations 11, 17, and 18. The distribution of dead shell here corresponds fairly closely to the bed of living Tawera spissa discussed later.

Fauna The analysis of the fauna has been approached from the classical point of view of selecting the most obvious, most numerous, or characteristic species to define benthic communities. For this purpose, the term "community" is used to apply to a recurring combination of species of organisms, in a characteristic biotope, and with a considerable degree of spatial continuity. An examination of the data has allowed us to define three major soft-bottom communities, as well as three additional soft-bottom communities which are ill-defined because of poor sample coverage. The distribution of the communities is shown in Fig. 3.

87 88 Fig, 3. Distribution of benthic communities.

89 1. Zostera muelleri - Nucula hartvigiana community Stations: 1,2,3,4,35 Marginal station: 19 Biotope Sediment: Fine sand to sandy mud. Depth: Intertidal to 5 metres. Energy: Low to moderate. Characterising species No. of stations % occurrence Zostera muelleri 4 67 Nucula hartvigiana 5 83 Associated species Polychaetes 6 100 Halicarcinus varius 5 83 Neoguraleus sinclairi 4 67 Chione stutchburyi 3 50 Cominella adspersa 3 50 Leptomya retiaria 3 50 Alpheus sp. 3 50 Atrina zelandica 2 33 Cominella glandiformis 2 33 Theora lubrica 2 33 Hermit crabs 2 33

This community occurs in Huruhi Harbour, and marginally in a small bay to the east of the harbour entrance. It is, in the main, subtidal, but an intertidal facies can be distinguished, typified by station 4. In the intertidal facies, the numbers of Nucula hartvigiana are generally lower, Chione stutchburyi usually becomes dominant, the subtidal crab Halicarcinus varius is replaced by H. whitei, and Zeacumantus lutulentus becomes common. The whelk Cominella glandi• formis is almost exclusively intertidal, and the wedge shell Macomona liliana is sometimes important, although not encountered in significant numbers at Great Mercury Island. An interesting member of this community is the small semelid bivalve Theora lubrica. This bivalve is a recent arrival to New Zealand from South East Asia, and has become well established in shallow water muddy substrates (Climo in press). This record is a further extension of its known range. The biotope of this community is rare on the offshore islands, and, particularly with respect to the intertidal facies, this community is not usually well-developed away from the mainland harbours. Where this community is well-developed in larger harbours on the mainland, considerable subdivision is possible.

2. Tawera spissa community Stations: 9,10,1 1,16,18,28,31,34. Marginal station: 17. Biotope Sediment: Sand or muddy sand with a variable amount of shell. Depth: Mainly 5 to 20 metres.

"0 Energy: Moderate to low. Characterising species No. of stations % occurrence Tawera spissa 9 100 Associated species Cominella quoyana 9 100 Polychaetes 9 100 Halicarcinus varius 7 78 Cominella adspersa 6 67 Neoguraleus sinclairi 6 67 Hermit crabs 5 56 Echinocardium cordatum 5 56 Ischnochiton maorianus 5 56 Anthochiton stangeri 4 44 Zegalerus tenuis 4 44 Maoritomella albula 3 33 Alpheus sp. 3 33

This community is well-developed on the sloping seabed south of Huruhi Harbour, in a strip parallel to the shoreline. The Tawera spissa here are fairly uniform in size, ranging from 15 to 20mm long. In the densest part of the bed (station 11), the density of Tawera spissa is estimated at between five and six thousand per square metre. The sediment is probably at the fine end of the range of sediment grades occupied by well-developed T. spissa communities.

3. Caryocorbula zelandica - Pleuromeris zelandica community Stations: 20,21,22,27,29,30,32,33. Marginal stations: 12,13,25. Biotope Sediment: Muddy fine to medium sand, sometimes shelly. Depth: 20 to 30 metres and probably deeper. Energy: Low. Characterising species No. of stations % occurrence Caryocorbula zelandica 6 55 Pleuromeris zelandica 6 55 Associated species Polychaetes 11 100 Sponges 7 64 Hermit crabs 7 64 Diplodonta zelandica 6 55 Nucula nitidula 6 55 Echinocardium cordatum 6 55 Bryozoa 5 45 Cominella quoyana 4 36 Notocallista multistriata 4 36 "Amphiura" sp. 3 27 Pupa kirki 3 27 Zeacolpus pagoda 3 27

91 Amphipod (large) 3 27 Balanoglossus australiensis 3 27

This community contains a relatively large number of species, but no particular species is especially abundant. The choice of characterising species was fairly arbitrary, since an examination of the data could equally well justify the association being termed the Diplodonta zelandica - Nucula nitidula com• munity. It is in fact most likely a facies of a "Nemocardium" community (see discussion later). The marginal stations have quantities of red algae attached to shells. Station 27 has an unusually high number of hermit crabs (31). It is not clear, however, whether this sample represents a high density of hermit crabs over a large area, or just a small localised pocket of hermits aggregated for food or other purposes.

4. Paphies subtriangulatum community Stations: 5,6,7,8. Biotope Sediment: Medium to fine sand. Depth: Intertidal to about 2 metres. Energy: Moderate to high. Characterising species No. of stations % occurrence Paphies subtriangulatum 0 0 Associated species Amalda australis 2 50 Soletellina nitida 1 25

The tuatua (Paphies subtriangulatum) was found on the beach on the eastern boundary of the study area. Because of the natural variability in abundance and distribution of the tuatua on clean, semi-exposed beaches of this type, it is not surprising that the dredge samples were inadequate to accurately represent this community. Amalda australis is probably a more stable member of the community, and may be preferable as a characterising species.

5. Pupa kirki - Pectinaria australis community Stations: 15,36. Biotope Sediment: Medium to fine sand. Depth: 5 to 15 metres. Energy: Low. Characterising species No. of stations % occurrence Pupa kirki 2 100 Pectinaria australis 2 100 Associated species Echinocardium cordatum 2 100 Polychaetes 2 100 Cominella quoyana 1 50

92 Myadora striata 1 50 Pervicacia tristis 1 50 Hermit crabs 1 50 Astropecten polyacanthus 1 50

This community covers only a very small area at Great Mercury Island, but can be separated from the other communities because a similar community is known to occur more extensively elsewhere (Grace and Whitten 1974). The high numbers of Pupa kirki (18 at station 36, 10 at station 15), and the few additional species, separate this community from those surrounding it.

6. Tawera spissa - Venericardia purpurata community (poorly sampled) Stations: 14,23,24,26. Bio tope Sediment: Course sand to shell gravel. Depth: 3 to 1 5 metres. Energy: Moderate to high. Characterising species No. of stations % occurrence Tawera spissa 2 50 Venericardia purpurata 1 25 Associated species Polychaetes 4 100 Bryozoa 3 75 Caryocorbula zelandica 2 50 Zegalerus tenuis 2 50 Balanoglossus australiensis 2 50 Astropecten polyacanthus 2 50 "Rhodoliths" 2 50 Cominella quoyana 1 25 Diplodonta striatula 1 25 Gari stangeri 1 25 Glycymeris laticostata 1 25 Epigonichthys hectori 1 25

This community was poorly sampled, partly because of the small number of stations, and partly because it is difficult to get a good bite with the dredge in very shelly sediments. It is likely that the larger infaunal bivalves were not adequately sampled. A scuba-dive off the outside of the outermost of the Sisters revealed a good bed of Glycymeris laticostata together with a number of the species listed above, on a steeply sloping shell gravel substrate. Occasional Pecten novaezelandiae and Atrina zelandica were also noted in the area. The inefficient operation of the dredge in very coarse sediments probably biases the results so that a higher proportion of epifauna to infauna is recorded than actually occurs on the seabed. Large numbers of "rhodoliths" were picked up by the dredge at station 26 (see earlier discussion).

93 7. Ecklonia radiata - Carpophyllum spp. community. The rocky bottom areas fringing the hard shorelines support underwater "forests" of Ecklonia radiata, often mixed with Carpophyllum flexuosum, especially in more sheltered areas. Carpophyllum plumosum is often present in very shallow water but quickly gives way to E. radiata in deeper water. Very low-relief areas are usually devoid of large algae. Underwater observations were made at 8 rocky bottom stations (A to H) indicated in Fig. 1., and these are discussed briefly below. As an example of this community a cross section of the underwater profile at station B is illustrated in Fig. 4. A. A boulder beach on the shore gives way subtidally to a shallow, low-relief rock flat, supporting a field of coralline turf with numerous urchins (Evechinus chloroticus). Occasional upstanding rocks are covered with dense growths of E. radiata, apparently inaccessible to the algae-grazing urchins. B. (Fig. 4) Well-rounded boulders on the semi-exposed shore continue subtidally, sloping fairly steeply to the fine sand bottom at about 6m depth. A narrow zone of Xiphophora chondrophylla at low water level gives way to a shallow band of coralline turf on small boulders, with occasional plants of C. plumosum. A dense bed of lm tall E. radiata extends from lm depth to 3m. Mixed E. radiata and C. flexuosum continue to the sand. This area appears to be devoid of E. chloroticus. Much of the E. radiata at this station is in poor condition, with the thallus partly degenerated, and in some cases missing altogether. This condition of E. radiata was noted also at Red Mercury Island, (Grace 1972), and is discussed by Don (1975). C. This is similar to station B., but has a wider coralline turf flat with common E. chloroticus. Cystophora retroflexa and small E. radiata plants occur on larger

30 METRES

Fig. 4. Diagrammatic profile of rocky bottom station B.

94 rocks in the coralline zone together with occasional plants of C. plumosum. The main algal bed consists of mixed E. radiata and C. flexuosum, extending to the sand at 4m depth. Very few E. radiata plants are damaged compared with those at station B. D. This shallow reef of low-relief solid rock and boulder rubble supports small amounts of E. radiata and C. retroflexa around the edges, where the reef drops off steeply into deeper water. Most of the reef itself is covered with old holdfasts of E. radiata, indicating the existence of a former dense kelp bed. Until a few years ago, E. radiata was visible on the surface here at low tide, advertising the presence of the reef (local information). Very few E. chloroticus are present on the rock. E. Low-relief reefs with dense beds of E. radiata are separated from the rocky shore by a shallow flat rock platform. Parts of this platform have a thin veneer of sand, and both rock and sand support a blue-green filamentous alga. Carpophyllum plumosum dominates the very shallow rocks on shore, with Pterocladia capillacea and X. chondrophylla also present. Juvenile crayfish (Jasus edwardsi) are common in crevices on the reefs. F. A dense bed of E. radiata covers the rock slope from below the intertidal zone of Hormosira banksii to the sand at 5m depth. Small crayfish can be found in holes beneath the kelp canopy. G. Similar to station F., but a little shallower. Some E. radiata plants show signs of damage as at station B. H. The western side of the small island drops off nearly vertically to a shell-gravel slope at about 20m depth. The underwater rock cliff is covered with a dense bed of/?, radiata.

DISCUSSION AND CONCLUSIONS Comparison with other areas in New Zealand Descriptions of New Zealand intertidal life are given in Morton and Miller (1973). Sublittoral soft-bottom faunas have been investigated by McKnight (1969), who worked with nearly 600 samples from the New Zealand continental shelf. He recognised several groups of communities. In an analysis such as the Great Mercury Island one, correlation with any one of McKnight's individual communities is sometimes difficult, as fewer samples were used, and the inshore environment sampled is more variable than the continental shelf. Some communities recognised at Great Mercury Island can, however, be compared with McKnight's groups of communities and in these cases a tentative correlation with one or more of his individual communities is given.

I. Zostera muelleri - Nucula hartvigiana community Best known from sheltered harbour flats on the mainland, this community can be subdivided into a number of associations ranging from the intertidal to the shallow sublittoral. A subtidal occurrence of this community was recorded from Slipper Island by Grace and Whitten (1974). The community and its variations are discussed more fully by Morton and Miller (1973).

<>5 2. Tawera spissa community Widespread on the continental shelf, communities with Tawera spissa as a dominant species have been classified by McKnight (1969) into several types. It is difficult to assign this Great Mercury Island example directly into any one of the associations suggested by McKnight, but the best fit appears to be his Tawera spissa - Venericardia purpurata community. Venericardia purpurata, however, was not common in any of the Great Mercury Island samples, consistent with McKnight's suggestion that T. spissa tends to be dominant in shallow areas. A similar community was described from Slipper Island by Grace and Whitten (1974), although this occurred on a coarser substrate and in shallower depths than the present example. Other parallels, also occurring on generally coarser substrates, are found in the Tawera - Glycymeris formation in the Auckland Harbour (Powell 1937), the Tawera - Dosinia community at the entrance to the Whangateau Harbour (Grace 1972a), Tawera beds at Whangarei Heads (Morton and Miller 1973), and Tawera beds at Mimiwhangata (Ballantine etal 1973).

3. Caryocorbula zelandica Pleuromeris zelandica community Close parallels with other benthic communities in New Zealand are difficult to maintain, but affinities clearly lie with the "Amphiura" and the "Nemocardium" communities listed by McKnight (1969). Of particular rele• vance are McKnight's Amphiura rosea - Dosinia greyi community, Nemo• cardium pulchellum - Venericardia purpurata community, and the Nemocardium pulchellum - Pleuromeris zelandica community, all of which have affinities with the Great Mercury Island example, in terms of species composition, depth, and substrate, but differing in terms of percentage occurrence of particular species. Great Mercury Island is geographically close to McKnight's NZOI stations C789 (assigned to the Nemocardium pulchellum - Venericardia purpurata community) and C792 to C794 (assigned to the Nemocardium pulchellum - Pleuromeris zelandica community). If a parallel is to be maintained, it may be best to consider the Caryocorbula zelandica - Pleuromeris zelandica community as an inshore or shallow water variation of one of McKnight's "Nemocardium" communities, despite the very low occurrence of N. pulchellum in the Great Mercury Island samples (one specimen at station 32). The abundance of hermit crabs at station 27, together with the relative scarcity of other fauna, suggest that this station may have similarities with the hermit crab community listed by McKnight (1969).

4. Paphies subtriangulatum community The tuatua (Paphies subtriangulatum) occurs on open sandy beaches throughout New Zealand and is noted for an inherent variation in population densities. This soft shore community is probably one of the most difficult to sample quantitatively, because of low faunal densities and a high degree of variation. This community is described more fully from other areas of New Zealand by Knox (1969) and Morton and Miller (1973).

96 5. Pupa kirki - Pectinaria australis community The occurrence of this community at Great Mercury Island appears to indicate a fragment or poor development of a community which was recognised at Slipper Island by Grace and Whitten (1974). The Myadora boltoni Scalpomactra scalpellum community at Slipper Island had similar depth and substrate characteristics, and many similarities in species composition to the Pupa kirki - Pectinaria australis community recognised at Great Mercury Island. Grace and Whitten (1974) suggested that their M. boltoni - S. scalpellum community may be a shallow water variation of the Scalpomactra scalpellum - Maorimactra ordinaria community of McKnight (1969).

6. Tawera spissa - Venericardia purpurata community Although poorly sampled, this appears to be a more typical development of the T. spissa - V. purpurata community of McKnight (1969) than is the T. spissa community discussed earlier. The coarse substrate, and the presence of other species normally associated with T. spissa in coarse substrates, tend to separate this community from the T. spissa community discussed above. On geographical grounds alone, it is difficult to justify separating these two communities at Great Mercury Island. They appear to be different developments of the same community. The earlier discussion of parallels to the T. spissa community is also relevant here.

7. Ecklonia radiata - Carpophyllum spp. community This community, or variations of it, is widespread on rocky bottoms off much of the hard shoreline of New Zealand, particularly in the north. Discussions of various aspects of subtidal E. radiata beds are given by Ayling (1975a, b), Bergquist (1960), Doak (1971), Don (1975), Dromgoole (1964a, b), Grace (1972b), Grace and Whitten (1974) and Morton and Miller (1973).

ACKNOWLEDGEMENTS The authors wish to thank Mr Richard Willan for identification of some molluscs, Mr D.A. Saies for the loan of the outboard motor and Mr Steve Durney for the loan of a particularly useful dredge rope.

REFERENCES Ayling, A.M. 1975a: Habitat: coastal kelp forests. N.Z. Nature Heritage 21: 579-83. Ayling, A.M. 1975b: Offshore kelp forests. N.Z. Nature Heritage 22: 605-609. Ballantine, W.J., Grace, R.V. and Doak, W.T. 1973: "Mimiwhangata Marine Report." Limited circulation report for New Zealand Breweries Ltd. 98pp. Bergquist, P.L. 1960: The marine algal ecology of some islands of the Hauraki Gulf. Proc. N.Z. Ecol. Soc. 7: 4345. Climo, F.M. (in press): The occurrence of Theora (Endopleura) lubrica Gould, 1861 (Mollusca: Bivalvia: Semelidae) in New Zealand. Poirieria. Doak, W.T. 1971: "Beneath New Zealand Seas." Reed, Wellington. 113pp. Don, G.L. 1975: "The effects of grazing by Evechinus chloroticus (Val.) on populations of Ecklonia radiata (Ag.)." MSc thesis, University of Auckland. 80pp.

97 Dromgoole, F.I. 1964a: The ecology of the sublittoral boulder beaches at Little Barrier Island. Tane 10: 70-78. Dromgoole, F.I. 1964b: The depredation of Ecklonia radiata beds by the sea urchin Evechinus chloroticus. Tane 10: 120-22. Grace, R.V. 1972a: "The Benthic Ecology of the Entrance to the Whangateau Harbour, Northland, New Zealand." PhD thesis, University of Auckland. 205pp. Grace, R.V. 1972b: Sublittoral zonation of dominant organisms at Red Mercury Island, north-eastern New Zealand. Tane 18: 57-66. Grace, R.V. and Whitten, R.F. 1974: Benthic communities west of Slipper Island, north-eastern New Zealand. Tane 20: 4-20, Knox, G.A. 1969: Beaches. Chapter 32 In Knox, G.A. (ed.), "The Natural History of Canterbury." Reed, Auckland. 620pp. McKnight, D.G. 1969: Infaunal benthic communities of the New Zealand continental shelf. N.Z. Jl mar. Freshwat. Res. 3: 409-44. Morton, J.E. and Miller, M.C. 1973: "The New Zealand Sea Shore." 2nd edition. Collins, London. 653pp. Powell, A.W.B. 1937: Animal communities of the sea-bottom in Auckland and Manukau Harbours. Trans. R. Soc. N.Z. 66: 354-401.

APPENDIX 1. Station data. *Key to sediment code: m = muddy sand, fs = fine sand, ms = medium sand, cs = coarse sand, sg = shell gravel. fNo. of species. For this purpose all species of sponges and all species of polychaetes are grouped together. **> & i— ( m ( m volum e volum e STATIO N STATIO N Sediment * Residu e Residu e Sediment * 1 II) in 500 13 19 9 Is 100 10 2 10 ni 800 15 20 10 m 500 13 3 10 m 100 10 21 10 in 600 13 4 10 in ? 100 9 22 9 in 700 7 5 9 Is 5 1 23 8 cs 800 7 6 9 ms 50 3 24 7 cs 800 7 7 9 fs 40 2 25 8 111 200 10 8 9 fs 20 2 26 8 sg 2000 19 9 4 fs 150 9 27 9 III 400 7 10 9 ins 700 12 28 9 III 200 21 11 6 in 1000 11 29 8 m 500 12 12 2 ms 100 12 30 7 m 350 9 13 10 fs 700 12 31 8 ms ? 200 13 14 8 cs 300 12 32 7 m 200 13 15 8 ms 30 6 33 8 in 200 8 16 9 ms 150 12 34 7 m 700 16 17 10 ms 900 15 35 10 in 150 18 18 8 m 800 16 36 10 fs 30 5

98 APPENDIX 2. Species counts. Note: for each species, the station at which that species occurs is given, followed in brackets by the number of individuals occurring in the sample.

ALGAE Caulerpa hypnoides 25,27,28 Unidentified blue-green filamentous 31 Unidentified small red algae 11,12,13,25,31 Coralline "rhodoliths" 23,26,28 Coralline turf 14,28 ANGIOSPERMS Zostera muelleri 1,3,4,9,10,19 PORIFERA Aplysilla violacea 32(1) Aplysilla sp. 30(1) Ciocalypta sp. 11(D,20(1) Sycon sp. 12(2),26(1) small red 28(2),29(2),30(2) others 20(1),21(5),22(1) COELENTERATA Anthopleura aureoradiata 4(74) Culicia rubeola 21(1) Flabellum rubrum 20(1),21(1) NEMERTEA black 13(1),34(1) 13(1),34(1) orange 28(1) BRYOZOA 1,12,14,20,21,23,25,26,28(2),30(1), PHORON1DA 17(1),35(1) SIPUNCULOIDEA 21(1),26(1),28(1) POLYCHAETA Axiothella australis 5(tubes),7(tubes),8(rubes) Boccardia polybranchia l(tubes),2(tubes),3(tubes),31(tubes),35(tubes) Hydroides norvegicus 2(5),9(13),10(7),11(20),12(30),14(13),16(1), 17(6),18(18),23(4),25(10),26(1),28(3),30(3), 31(14),34(14) Owenia fusiformis 10(5),12(C) ,20(3),21(1),22(1),25(13),27(1), 28(4),29(1),30(5),32(2),33(1) Pectinaria australis 1(1),3(1),13(5),15(1),16(1),17(1),18(1), 20(1),27(4),30(1),32(1),35(1),36(10) Spirobranchus sp. 26(1) Unidentified 1(5),2(9),3(17),4(3),5(1),6(10),7(9),8(2), 9(6),10(12),13(8),14(2),15(7),16(2),17(18), 18(11),19(22),20(9),21(20),22(3),23(3),24(12), 25(3),26(5),27(10),28(36),29(2),30(7),31(5), 32(6),33(5),34(7),35(32),36(4) AMPHINEURA Amaurochiton glaucus 2(2) Anthochiton stangeri 1(1),2(1),10(1),11(2),18(3),26(3),28(5),30(2) Ischnochiton maorianus 1(3),10(1),17(8),18(3),28(1),34(2) Notoplax cuneata 14(2) Terenochiton inquinatus 2(1),10(1),17(1) Unidentified 11(4),14(1),18(2)

99 GASTROPODA Amalda australis 7(1),8(1),34(2) A. novaezelandiae 27(1),31(2) Antisolarium egenum 23(1) Buccinulum lineum 26(1) Bursatella glaucus 9(2) Cominella adspersa 2(1),3(1),10(5),11(1),16(2),17(2),18(1),

19(1))28(3),31(2),34(1) C. glandiformis 3(D,4(13) C. quoyana 9(1), 10(6), 11(8), 12(1), 15(0,16(2), 17(8), 18(14),19(2),22(1),24(1),25(2),28(8),31(10), 32(1),34(6),35(2) Emarginula striatula 32(1) Epitonium phillipinarum 12(1) Lunella smaragda 2(1) Lyroseila chathamensis 18(1) Maoricolpus roseus 17(1),21(3),26(1) Maoritomella albula 16(2),17(1),34(1) Marginella pygmaea 18(1) Murexsul octagonus 28(1) Neoguraleus sinclairi 1(2),2(2),9(1),10(1),16(1),17(2),19(14),31(3), 34(1),35(2) N. tenebrosus 11(1) N. sp. 4(2) Penion adusta 11(1) Pervicacia tristis 15(2),16(1) Philine angasi 18(1),24(1),25(1),34(1) Philinopsis taronga 33(1) Pupa kirki 13(1),15(10),16(1),29(1),31(1),33(2),34(1),36(18) Vermetidae 26(30) Xymene ambiguus 18(2) Zeacolpus pagoda 13(1),24(1),29(1),31(1),33(2) Zeacumantus lutulentus 4(19) Zegalerus tenuis 11(3),14(1),17(2),18(2),23(1),27(1),34(1),35(1) BIVALVIA Anomia walteri 31(1) Atrina zelandica 3(D,35(1) Barbatia novaezelandiae 26(1) Cardita aoteana 26(1) Caryocorbula zelandica 12(1),13(1),14(1),20(1),24(5),25(1),28(2), 29(3),30(4),32(1) Chione stutchburyi 2(21),3(1),4(128) Diplodonta striatula 14(1) D. zelandica 19(1),20(1),27(2),29(2),30(2),32(2),33(3),35(1) Dosina zelandica 1(4) Gari stangeri 14(1),28(1) Glycymeris laticostata 26(1) Hiatella arctica 20(1) Leptomya retiaria 1(1),2(1),35(1) Limaria orientalis 13(2),35(1) Limatula maoria 14(1) Macomona liliana 6(0,35(2)

100 Myadora striata 13(1),36(1) Nemocardium pulchellum 32(1) Notocallista multistriata 13(2),21(2),22(1),32(1) Nucula hartvigiana 1(125),2(500),3(32),4(39),17(8),34(1),35(35) N. nitidula 12(1),13(7),22(2),25(6),27(1),32(1) Nuculana bellula 20(1) Pleuromeris zelandica 13(1),21(1),25(1),29(3),30(1),33(3),34(1) Scalpomactra scalpellum 25(1) Soletellina nitida 6(3),13(1) Tawera spissa 9(9),10(63),11(350),14(1),16(58),17(2),18(164), 23(1),28(15),31(26),34(94),35(3) Tellinella eugonia 12(1),33(1) Theora lubrica 1(1),3(1) Venericardia purpurata 24(1),26(1),28(8) Zenatia acinaces 22(1) CRUSTACEA Cyclasterope zelandica 19(1),29(1) Balanus trigonus 1(2),2(3),12(1),28(1),31(1) Unidentified Amphipoda 20(1),21(1),29(1) Isocladus armatus 4(2),19(1) Alpheus sp. 1(1),3(2),9(2),26(1),28(2),31(1),35(1) Callianassa filholi 32(1) Pontophilus australis 9(2),35(1) Unidentified Galatheid 26(1) Unidentified hermit crabs 2(1),9(4),11(1),12(2),15(1),16(3),18(3), 21(2),22(1),25(3),26(2),27(31),28(1),30(2), 32(1),35(1) Ebalia laevis 18(1) Halicarcinus varius 1(5),2(5),3(10),9(3),10(1),16(1),17(2),18(1), 19(11),25(1),28(2),34(3),35(7) H. whitei 4(5) Hemiplax hirtipes 3(1) Liocarcinus corrugatus 2(1),26(1),28(1),31(1),35(1) Paramithrax minor 10(1),19(2),26(4),29(1) Petalomera wilsoni 26(1) ECHINODERMATA Ocnus calcarea 26(11) Unidentified Holothurian 10(1) Echinocardium cordatum 2(1),10(2),13(2),15(3),16(2),17(1),18(1),19(1), 20(1),27(4),30(1),31(1),32(5),33(2),36(1) Astropecten polyacanthus 14(2),16(1),23(1),36(1) Amphipholis squamata 35(1) Amphiura sp. 1(1),20(2),21(3),29(1) CHORDATA Balanoglossus australiensis 14(4),20(1),21(2),24(1),28(3),29(3) Saccoglossus sp. 28(2) Unidentified simple Ascidian 12(1) Didemnum candidum 12(3) Unidentified compound Ascidian 32(1) Epigonichthys hectori 23(1) Trachelochismus sp. 34(1)

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