FISH FAUNA OBSERVATIONS AT THE KERMADEC ISLAND GROUP (N.Z.)

By Sidney Lee Marsh 12 A Crisp Avenue, Pukekohe, South Auckland

INTRODUCTION

Situated 740-980 kilometres north-east of New Zealand, the Kermadec Islands lie between 29°13'S and 31°21'S, and between 177°50'W and 178°53'W. They consist of a chain of volcanic islands and rocks about 250 kilometres long running N.N.E., the closest rock being about 740 kilometres and Raoul Island 980 kilometres from New Zealand. The Kermadecs are a series of pinnacles on top of the Kermadec ridge forming four main groups of islands. From north to south these are:

i) Raoul Island (and the Herald Islets) - 29 km2 ii) Macauley Island - 3km2 hi) Curtis and Cheeseman Islands — <1 km2 iv) L'Esperance Rock Mean sea surface temperature varies between 17°C and 23°C in the vicinity of Raoul Island. The Kermadecs are influenced by tropical water to the north of the tropical convergence for part of the year; the convergence may be located at about 30-35°S in summer and about 23-25°S in winter. (Francis 1985). In July 1986 the 'Pegasus //'(skippered by Capt. E. Gosse) visited the Kermadec Island Group for 10 days as part of the first leg motoring up to the Kingdom of Tonga and the Fijian Islands. While in the vicinity I endeavoured to observe and also positively identify as many of the different species of fish as possible. However, due to the excessively rough conditions and high winds (at one stage gusts up to 70 knots) encountered over the first five days, the group of nine SCUBA divers were initially very restricted as to when and where they could dive (resulting in myself conducting only 14 SCUBA dives at eight different dive sites). Because of the great numbers of unfamiliar tropical, sub-tropical and previously unrecorded fishes found in the area, I opted for the method of recording the different fish species observed at the random dive sites on a slate, rather than using the transect method.

RESULTS

* Species also seen in the vicinity of Raoul Island. + Species further encountered at Minerva Reefs or 'Ata Island.

TANE 31, 1985-86 145 RAOUL ISLAND

Fig. 1. Location of dive sites, Kermadec Islands. Dive Site 1 — L'Esperance Rock (N/E side) An overcast day with little wind. A one to two metre swell was hammering the SW quarter of the rock face. SCUBA diving down through the 25 metres underwater visibility my buddy and I witnessed one 16 kilogram yellowtail kingfish (Seriola ialandi)* being hauled up to the boat caught on a trolled line. From 6 metres down to 25 metres several other kingfish (one individual approaching 50 kilograms) came in very close perhaps attracted by the food-like appearance of our SCUBA exhaust bubbles. Several hundred demoiselles (Chromis dispilus)* were milling about spread from the surface waters down to 30 metres where a sandy, gravelly terrace was studded and dominated by large stone monoliths and boulders which were for the most part totally devoid of any brown algal forests or extensive coralline growths. Also present in large numbers near the fringing white water margin, hundreds of blue maomao (Scorpis violaceus)* swam while scores of pink maomao (Caprodon longimanus)* intermingled with equal numbers of a drummer-like silvery-grey kyphosid, (Kyphosus bigibbus)*\ Two very striking "banana maomao", a yellow variety of the same fish, were also seen in amongst this plankton-feeding group of fishes.

Several golden snapper (Centroberyx assinus) and trevally (Psendo- caranx dentex)* were seen in mid-water along with one small mado

146 (Atypichtyhys latus)*. Nearer the rocky substrata at around 25 metres, a greyish-white angelfish*, (Parma) similar to black angelfish in most aspects except colour, hovered over their sporadically spread, territorial patches. A solitary male sandager's wrasse (Coris sandageri)*p\us several male and female green wrasse (Pseudolabrus inscriptus)* were seen as well as one dozen Lord Howe coral fish (Amphichaetodon howensis)* swimming in pairs and often singly. Loose schools of orange damselfish (Chrysiptera rapanui) congregated with juvenile demoiselles over the numerous bare rocky outcrops. Many painted moki (Cheilodactylus ephippium)* fossick• ed around the nooks and crannies and fissures occupied by some extremely large examples (averaging 50 cm long) of scorpionfish (Scorpaena cookii)*, similarly sized red cod (Lotella sp), and one speckled moray (Gymnothorax nubilus)*. On the gravelly sandy bottom at 30 metres a rocky overhang sheltered a 50 cm long yellow banded perch (Acanthistius cinctus)* and a 100 cm long spotted black grouper (Epinephalus daemelii)*+ sporting a uniform navy blue colour scheme. Both of these fish were extremely shy and could not be enticed any closer than 6 metres away. At the end of the dive my buddy and I were just boarding the boat when some curious dolphins came in close. We immediately plunged back in with full SCUBA equipment for a brief surface encounter with seven or eight defecating bottlenose dolphins (Tursiops truncatus) who soon lost interest and meandered away even after we tried dolphin kicking and using various sound attention-gaining methods (rapping knife against tank, vocal, etc.) in a vain attempt to lure them in closer to us.

Dive Site 2 — Stella Passage — Curtis Island Curtis Island is a live volcanic cone smoking and smelling very sulphuric. Before entering the water here, a 10 kilogram yellow-tail kingfish was pulled up on a line, tagged and released. An overcast sky accompanied the bitterly cold, strong southerly winds that limited our party to only two SCUBA dives in this area. A sandy, gravel bottom at 18 metres was strewn with boulders of various sizes (football to room size), many of which were haphazardly stacked up, one on top of another. Due to heavy swells stirring up the sandy bottom, underwater visibility was a poor 10 metres. Diving here I encountered large schools of mado and demoiselles but not so many blue maomao or "drummer" as were seen at L'Esperance Rock. Green wrasse and sandager's wrasse were relatively common as were the greyish-white angelfish, notchhead marblefish (Aplodactylus etheridgi)*, scorpionfish, red banded perch (Ellerkeldie sp)*, gold ribbon grouper (Aulacocephalus temmincki)*, golden snapper, black-spot goat fish (Parupeneus signatus)*, trevally, yellow banded perch and some

147 large (75 cm in length) bluefish (Girella cyanea)*. En masse, big eye (Pempheris analis)*, crowded the sheltered undersides of ledges an< dark caverns, while around one such location (a small area covering approximately 10 m2), 10 painted moki sheltered and browsed. Other fish seen on this dive were: a pair of Lord Howe coralfish, one small red mullet (Upeneichthys lineatus)*, one male yaldwins triple-fin (Tripterigion sp), a few black angelfish (Parma alboscapularis)* displaying a prominent white ear spot in most cases, one clown toado (Canthigaster callisternus)*, one toadstool grouper (Trachypoma macracanthus)*, one mosaic moray (Enchelycore ramosus)*, one blue knifefish (Labracoglossus nitida) and two lionfish (Pterois volitans)*'.

I encountered four spotted black grouper at this site as well. One 40 kilogram individual remained in the vicinity of the anchor and warp. This fish was very curious but at the same time very wary and shy — he remained a uniform navy blue colour and didn't approach within seven or eight metres of the divers. Nearly 100 metres away another fish of similar size was seen by another diver to be hovering rapturously within five metres of my prostrate form totally engrossed in writing on an underwater slate. (I was unaware of its presence at the time!) Finally, a little further on from this location (possibly 20 metres) two other spotted black grouper were lying passively just outside their lair — a large boulder, supported by three or four other rocks, forming a dark protective shelter. The largest grouper was estimated to be 60-70 kilograms in weight. This fish sported a black/grey/white mottled colouration and allowed four divers to approach within touching distance. However, after some gentle strokes along the length of its body, this majestic creature slowly finned over to the confines of its lair, and from there peered back at the divers for the remainder of the dive.

Dive Site 3 — Denham Bay (South-West Face) Raoul Island Appalling weather conditions, high winds and vicious squalls caused a large swell to run into the Bay stirring up sediment and reducing underwater visibility to 7 metres. Large numbers of lionfish hovered in pairs, or just by themselves, close to pock-marked rockfaces and shady underhangs. In one small hole jostling each other side by side was a yellow banded perch, a painted moki, and a Lord Howe coralfish. Crimson cleaner fish (Suezichthys sp.) were also seen for the first time. Throughout this dive red banded perch were seen resting and surveying their domains without moving from their little separate home ranges. Dive Site 4 — Meyer Island (Western Side) Raoul Island At the time gusting winds (up to 70 knots) and horrendous ocean swells made this the only feasible anchorage for 'Pegasus IF over a 48

148 hour period. Surges crashing into the south-eastern face of the nearby Napier Island sprayed white water 15 metres into the air. Over a period of one week we were to dive this location four separate times. At around mid-morning on the first day a few divers descended down the anchor warp through the fluctuating 4 metre underwater visibility (the poor visibility was attributed to the stirred-up sandy bottom of the surf-pounded beaches of nearby Raoul Island). My buddy and I encountered a very gradual sloping bed of sand at 20 metres. Closer to Meyer Island itself, rocky pinnacles guided us to scoured-out ravines winding deep into the substrata. Sporadically strewn car-sized boulders and deep fissures yielded many different vertebrates. Hundreds of clown toado, mainly juveniles at around 5 cm in length, hugged the bottom near the mouth of ravines. Two turtles (Ertmochelys imdricata and Caretta caretta) approaching 180 cm in length were surprised resting/sleeping on the sand; upon noticing our presence these monsters quickly departed. All told we had four such encounters with turtles over the next three days, culminating in some pretty exciting turtle-riding during one night dive here. Sheltering in a crack at 15 metres a fish I initially took to be a painted moki, proved upon closer inspection to be a magpie morwong (Cheilodactylus vittatus). Also identified for the first time on subsequent dives (as underwater visibility slowly increased to 30 metres) were elegant wrasse (Anampses elegans), one brown/lime shaded irridescent spotted boxfish (Ostracion cubicus) plus numerous mimic blennies (Plagiotremus tapeinosoma) swimming about, eel-like, in open water. These small fish 6-8 cm long) were seen at all depths; in surface waters right down to 20 metres. Occasionally one individual, with its sharp small teeth bared, would dart in for a sample of our wetsuits. Rainbow fish (Suezichthys sp) and three or four finely spotted leather jackets (Thamnaconus analis) and two 30 cm long red/white/black mottled hawkfish (Cirrhitus splendens)+ were added to the list offish seen in this area as were two 30 cm long red mullet.

During the day, in the darker recesses — spacious caverns and jutting overhangs (and at night foraging over a sandy bottom in 20 metres of water) four or five 60 cm long striped boarfish (Evistias acuirostris)+ hovered, unconcerned by our nearby scrutinising gaze. On this side of Meyer Island three or four spotted black grouper were found beneath overhands over the sand. These fish averaged 100 cm in length and were sporting their dark, uniform colouration, and would not let us touch them. As a point of interest, under one large boulder sheltered three yellow banded perch — one of which was a massive 55 cm long specimen, a 60 cm long scorpionfish, and a 100 cm long bright yellow flutemouth (Aulostamus chinensis)+ keeping company with a graceful, lavishly

149 decorated lion fish. On the final dive at this site, circulating in amongst hundreds of milling kahawai (Arripis trutta), blue maomao and "drummer" were no less than 13 "banana maomao", a colour-variant of the "drummer" including one yellow and white, splotched hybrid plus one yellow and black, splotched hybrid.

Dive Site 5 — Boat Cove, Raoul Island Our party dived this site twice. From three metres sloping down to over 20 metres a sandy bottom was dotted with small rocks and boulders. At this location the surrounding precipitous cliffs offer partial protection to small vessels on an otherwise exposed rocky coastline. Near the solid stone landing, down at six metres my buddy and I discovered under one ledge (lm2 area) seven lion fish together. Two or three finely spotted leather jackets and a loose school of kahawai with a yellowtail kingfish were prowling in mid-water, while on one rock near the bottom perched a hawk fish and occupying the dark confines of large cracks and caverns were dozens of big eyes. One pretty limegreen wrasse (Thalassoma sp) about 20 cm long, shyly hung about until the dive ended.

Dive Site 6 — Milne Islet, Raoul Island Diving down on the seaward side here four divers swam about through an intermixed school comprised of sizable kahawai averaging 50 cm in length, a solitary yellowtail kingfish, drummer, one banana maomao, and many smaller densely packed, sprat-like fish. Limited to only 10 minutes on the gravel/rocky bottom at 30 metres, a 100 cm long spotted black grouper estimated to be approximately 40 kilograms in weight, took up most of my attention for the duration of this dive. In an attempt to lure it in close I proceeded to industriously tumble over small boulders and inspect their undersides — basically ignoring the fish by not acknowledging its presence. This approach worked and for a good five minutes this grouper (displaying a mottled colouration) hovered and gaped at me from arms-length distance. With my air supply dwindling I ventured two strokes along his side before the fish meandered off to investigate some other SCUBA divers and I initiated an ascent for the surface. NB: Two other divers reported seeing two yellow and black long-snouted butterfly fish (Forcipiger flavissimus)\

Dive Site 7 — Fishing Rock, Raoul Island One hundred metres out from the landing I went over the side for a quick 20 minute look. At six metres, a broad sandy expanse sloped up to

150 the pebble beaches running along the northern coastline of Raoul Island. Only two adult trevally were seen plus one 20 cm long box fish (Arothron sp.).

Dive Site 8 — Napier Island, Raoul Island A slow moving anti-cyclone enabled us to dive here before departing north-bound. As a direct result of the more favourable weather conditions, underwater visibility improved dramatically to around 25-30 metres for our two dives around this islet. The first dive was around the north-eastern face where I finned along a vertical drop-off, for the most part devoid of any growth except for small isolated clumps of coral. Looking out into the deep blue water, silvery-grey "drummer", one banana maomao and about one dozen pink maomao maintained station against a slight current while close by flighty bluefish streaked past. One speckled moray was occupying a crack at 20 metres, and not far away was a Spanish lobster (Arctites antipodum). As well, one 120 cm long spotted black grouper was seen lurking in 35 metres of water, plus divers also reported seeing a 150 cm long ocean sunfish (Mola mola) at 15 metres. The second dive was spent mainly around 30 metres depth just off the south-western face. Several yellowtail kingfish swept in close by here while vast shoals of pink maomao silvery-grey "drummer", banana maomao* blue maomao, demoiselles and blue fish milled and swirled about at all depths. For the first time we saw two female red pigfish (Bodianus vulpinus) both around 45 cm in length and one crested blenny (Tarablennius laticlavius). N.B: Just around the corner here, further to the south, five divers had a close encounter with four or possibly five spotted black grouper on a sandy bottom at 20 metres. One diver offered a dead kahawai to one nearby individual but the 'peace-offering' was rejected. Meanwhile another grouper quickly moved in, gulped the whole thing down and swam around for some time, periodically chomping at the kahawai tail still protruding from its mouth. This behaviour was apparently infec• tious as soon all the groupers began to madly mill about. During this incident, one or two divers physically touched grouper.

DISCUSSION

On this trip, of the 50 different fish species positively identified at the Kermadec Islands, an extremely large percentage (86%) have been previously recorded as being seen, at one time or another, occupying niches around the North and South Islands. (Ayling and Cox 1982). Although there is a strong tropical coral reef/sub-tropical element in

151 these species there is no real connection (or link) with the fish species found in the closest, northern situated neighbouring reef systems and Islands (those of the Tongan group) (Pers.obs.) This could be due to the tropical convergence being situated somewhere between New Zealand's Kermadec Islands and Tongan territory. Six hundred and ten kilometres north of Raoul Island lies the reef system of South Minerva, from there North Minerva (a further 37 kilometres) and 370 kilometres north-east of here — 'Ata Island. Despite the short distances (relative to the immensity of the Pacific Ocean) involved, from the closest Tongan territories to the Kermadec Islands, there were only seven species (14%) observed on this expedition, that were common to both New Zealand waters and the closest reefs and islands belonging to the Kingdom of Tonga.

ACKNOWLEDGEMENTS

First and foremost I thank Capt. Eric Gosse for his effort under arduous conditions in safely piloting our group of divers from New Zealand to Tonga — no mean task! To my Tongan buddy on most of the Kermadec dives, Ian Swanson, and my sister in law, Marie Marsh who kindly typed up my notes, I am most grateful. Finally I thank Michael Morris and Dr. Roger Grace for their help and guidance in preparing this manuscript.

REFERENCES

Ayling, A. & Cox, G.J. 1982: 'Collins guide to the sea fishes of New Zealand'. Collins. 343p. Francis, M.P. 1985: 'The Kermadec Islands, a marine reserve proposal'. Internal report no. 29, unpublished. Fisheries research division, New Zealand Ministry of Agriculture and Fisheries. 33p.

152 APPENDIX. Species list of fish fauna observed during the expedition's 10 day stop-over at the Kermadec Island Group in July 1986. Listed in the order they appear in the text. Kingfish (Seriola lalandi) Demoiselle (Chromis dispilus) Blue Mao Mao Scorpis violaceus) Pink Mao Mao (Caprodon longimanus) Silvery-grey perch (Kyphosus bigibbus) Banana Mao Mao (Kyphosus bigibbus) Golden Snapper (Centroberyx affinis) Trevally (Pseudicaranx dentex) Mado (Atypichthys latus) Greyish-white Angelfish (Parma sp) Sandagers Wrasse (Coris sandageri) Green Wrasse (Pseudolabrus inscriptus) Lord Howe Coral Fish (Amphicheatodon howensis) Orange Damselfish (Chrysiptera rapanui) Painted Moki (Cheilodactylus ephippium) Scorpionfish (Scorpaena cookii) Red Cod (Lotella sp) Speckled Moray (Gymnothorax nubilus) Yellow Banded Perch (Acanthistius cinctus) Spotted Black Grouper (Epinephalus daemelii) Notch-head Marblefish (Aplodactylus etheridgi) Red Banded Perch (Ellerkeldie sp.) Gold Ribbon Grouper (Aulacocephalus temmincki) Black-spot Goatfish (Parupeneus signatus) Bluefish (Girella cyanea) Big Eyes (Pempheris analis) Red Mullet (Upeneichthys lineatus) Yaldwins Triplefin (Tripterygion sp.) Black Angelfish (Parma alboscapularis) Clown Toado (Canthigaster callisternus) Toadstool Grouper (Trachypoma macracanthus) Mosaic Moray (Enchelypoma ramosus) Blue Knifefish (Labracoglossus nitida) Lionfish (Pterois volitans) Crimson Cleanerfish (Suezichthys sp.) Magpie Morwong (Cheilodactylus vittatus) Elegant Wrasse (Anampses elegans) Boxfish (Ostracion cubicus) Mimic Blenny (Plagiotremus tapeinosoma) Rainbow Fish (Suezichthys sp.) Leatherjacket (Thamnaconus analis) Hawkfish (Cirrhitus splendens) Striped Boarfish (Evistias acutirostris) Flutemouth (Aulostomus chinensis) Kahawai (Arripis trutta) Wrasse (Thalassoma sp.) Long-snouted Butterfly Fish (Forcipiger flarissimus) (Arothron sp.) Boxfish (Mola mola) Ocean Sunfish (Bodianus vulpinus) Red Pigfish (Tarablennius laticlavius) Crested Blenny

153