PAPERS AND PROCEEDINGS OF THE HOYAL SOCIETY OF TAI::3MANIA. Vo,LUME 94

NOTES ON THE INTERTIDAL ECOLOGY OF TRIAL HARBOUR, .

By

E. R. GUILER Department of Zoology, University of Tasmania.

(With 3 plates)

1. Introduction. 2. DESCRIPTION OF THE TRIAL HARBOUR 2. Description of Area. AREA 3. Methods and Nomenclature. Trial Harbour, latitude 41 0 59' S., consists of 4. The Physical Environment. a reef extending a few chains out to sea in a north­ 5. Ecology of the Reef. westerly direction and some smaller reefs along the coast with boulder beaches. The roadstead is 6. Notes on nearby Areas. narrow. 7. Discussion. To the north of Trial Harbour the coastline 8. Acknowledgements. consists of rocky cliffs trending generally in a 9. References. north-westerly direction. The cliffs are only feebly incised by watercourses and there are few boulder ABSTRACT beaches. To the south of Trial Harbour there are three low rocky headlands interspaced by beaches. A description is given on the zonation and general The beaches are composed of yellow quartzose ecology of a reef on the exposed West Coast of rcunded grit fragments forming a rather soft gritty Tasmania. The reef shows the unusual feature sand. The hard packing of sand found on many of a Hormosira-Corallina belt on an exposed coast. ocean beaches is lacking here. There was evidence A white of Lithothamnion which is con­ in November, 1956, of a very considerable removal sidered to be characteristic of cold water con­ by marine agencies of sand from one beach to the ditions occurs there. The scarcity of littorines and south of Trial Harbour. At one end of the beach barnacles is attributed to local factors. a vertical bank seven feet in height had been cut in the grit, indicating that this quantity of sub­ 1. INTRODUCTION stratum had been removed fairly recently. The This paper is the eleventh of a series on the sand scouring experienced by intertidal organisms intertidal and is the first must be intense. to describe the major features of an intertidal To the south beyond the furthest of the head­ region on the West Coast of Tasmania. This coast­ lands mentioned above, the shoreline continues for line is very rugged and is readily accessi:ble at only 15 miles to as , a four places. The most southerly accessible place, sand surf beach penetrated near its northern end West Strahan, is a region of sandy beach and is by the Little . thus outside the scope of this present series of papers. The north-westerly part of the coast is fairly readily accessible but is situated a con­ 3. METHODS AND NOMENCLATURE siderable distance from . An attempt was The area was examined during three periods, made to examine the shore at Pieman Heads, a namely January, 1951, November, 1956 and Feb­ difficult place to reach, but bad weather defeated ruary, 1957. During the first of these visits the my object. The site of the present study, Trial weather encountered was so bad that little work Harbour, latitude 41 0 59' S. longitude 141 0 10' E., beyond a preliminary survey could be undertaken, is accessible by motor track from . Visits but better success was obtained on the later visits. were made to the harbour in January, 1951, The collections were sorted and I am indebted to November, 1956, and February, 1957 and February, Mr. R. C. Kershaw and Miss Hope Macpherson 1958. Trial Harbour is named for the brig" Trial" for identifying the and to Dr. Dora P. which used the "port" for the first time in 1881. Henry for naming the Cirripedia. The algae were During the mining boom the region became the identified from University Herbarium material. site of the town of Remine and a jetty was erected. Little remains of either structure today. The place The nomenclature used is that of Stephenson is well named since clouds of sandfiies. mosquitos and Stephenson (1949) and GuileI' (953). and frequent very rapid changes of weather make The author of each species is only quoted in the working there a real trial. text the first time that species appears.

57 58 INTERTIDAL ECOLOGY OF TRIAL HARBOUR

4. PHYSICAl, ENVnWNMENT In Tasmania, where much of the coastline con­ sists of dolerite which does not form wave cut (a,) Climatic factors. platforms of any extent, large reefs such as this are uncommon. The largest platforms I have seen (1) Rainfall.-The Trial Harbour area is shown are at South Cape Bay where the reef extends over by the Weather Bureau (1936) to be in an area of 50" to 60" annual precipitat.ion. This rainfall 100 feet from the base of the cliffs. is seasonal with more than 5" occurring each Fresh water enters the harbour near the reef month during the period April to October, inclusive. where the Serpentine Creek pours into the sea, at times of flood the volume of water carried There is no meteorological station maintained at by Creek is not great but even then it is Trial Harbour or in its vicinity so there are no d.oubtful if it could have a profound effect on the records of temperatures, relative humidity or other fa.una and 1'101'a because it enters the Harbour at a climatic data. However, the Meteorological Office deep water channel which is sti.rred by (947) shows the region as a mean monthly wave action. Biologlcally, as be seen temperature range from 20°C. 6,6°C, there is little evidence of the fresh water having any efIects on the and There are (b) Sea temperatures. several other sources of fresh ranging from There are no sea temperatures available from to creeks between Trial Harbour and the Trial Harbour but the Meteorological Office shoVl but as at Trial Harbour, they do not the West Coast of Tasmania as having a maximum have any apparent effect on the fauna or fiora of the shore, All these creeks carry brown button­ monthly sea temperature in March of HL8"C. and grass water. a minimum of 9.4° in September.

(e) Wind and Swell. 5. ECOLOGY OF THE REI~F The prevailing wind at Trial Harbour is westerly The reef, as noted above. is remarkably uniform tG north-westerly with the latter the sectOl' in the level nature of its sUl:faee and as a result. of strongest winds. The winds Force 7 mest of it falls in one characteristic faunal and (Beaufort Scale) 10% of the ubservations 11ora] belt. The exceptions to this are at the recorded by the Office ( . The of the reef. whether exposed to the full of swell is prevailing south-westerly to with wave action or not. on some slightly elevated rocks swell occurring some 10% of the time and a at the wave sheltered end of the reef and on a swell being the usual type of sea en­ small raised ridge at the seaward exposed end of countered. Days or no s\vell are rare. All of these the reef. records were compiled ships oIT the coast and The ,',Dnation seen on the rocks at the sheltered may not 1'o11ect on the shore. POI' end of the reef is- example, strong north to east, Le. offshore winds coll1rrLna deaden the effect 01 swell and reduce very diemenensis and materially t.he amount of wave action en the shore, Briefly, to sum up the physical environment, Horrnosira lJanksii (Turn.) Decaisne + Trial Harbour experiences a considerable range Corallina sp. of temperatures, both air and sea, and has a heavy There are no further belts below this level rainfall. Rough seas together v/ith heavy to because the InfralitcraJ f"inge and the lower moderate swells are liable to occur at any time of the l\tIidlittoral are replaced by ponds. of during the year and gales are frequent. the reef. however. falls into this mixed HOT1nosira­ Corallina belt. In November the Iiorrnosira plants (d) Geology. were all small and obviously young growths. The November visit showed a well developed belt Waterhouse (1916) describes the ge010gy of the below lornen- area in detail. The coastline to the north of Trial. tarius together Harbour consists of a red granite with some meta~ with Sol. and sedimentary rocks near the harbour a few this algal metamorphic rocks exist to the south of belt as a permanent feature of the zonation as the Harbour and form small headlands. The reef an these species are noted for the seas(.'nal nature at Trial Harbour is composed of serpentine which of their presence on the shore and in February when fresh. is a very darlr. blue but on the reef they were absent. it is soft in texture and coloured a light greenish 'Waterhouse eonsiders that the freshest reef (a) The Chamaesipho belt. are a light brown colour. The reef is pene­ In sun shaded places the lower of the trate by veins or aragonite and contains magnetite. Chamaesipho belt have a population Ga/eolaria Wave action has worn the reef down to a very caespitosa (Lam.), This worm never reaches the Ul1i'form level with a ridge at one point near the status of a belt forming species. but it is common seaward edge, There are extensive deep gullies in situations similar to that described above. worn in the edges of the reef and at low tide the The Chamaesipho belt does not support a well 'Seneral reef surface has ponds which are usually developed fauna or flora. There are no lichens or fairly shallow 00 cms. approx. depth). The reef algae at this level on the shore. The absence of 1s entirely covered at high tide or during periods lichens is undoubtedly due to the fact that the of rough seas. rocks do not reach sufficiently far above the inter- E. R. GUlLER 59 tidal region for the Supralittoral lichens to and the chiton Sypharochiion maugeanus Iredale appear. The absence, rather surprisingly, of the and May. The latter species is especially common littorinid, L'ittorina unijasciata; (Gray), can be in clefts and in ponds. attributed to the same cause. Most of the species encountered are cryptic in habit. One of the most (c) The lIormosira-Corallina belt. interesting of these is the small mussel Modiolus pulex Lam. which is characteristically surrounded Most of the reef falls into this belt which con­ by sand which clings to the shell. These tinues as far as the algal belt at the seaward edge mussels, approximately 2 mm. in length live of the reef. The continuity of the belt is broken cracks in the rock and although very numerous, by ponds, some of which are of considerable size are most inconspicuous. but mostly of shallow depth, being less than one metre deep at low water. 'The other species found in the barnacle belt are the gastropods Subninella und1tlata (Solander), The ponds contain a similar lYlelanerita meZanotragus (Smith), Lepsithais described above, namely Ecldonia, and vinosa (Lam.), Fossarina sp.? Petterd, Corallina with the addition of Phyllospora comosa Siphonaria diemenensis (Quoy , JYlont- (La;bill.) Kutz., Laurencia botryoides (Turn.) Gail., jortula rugosa (Quoy and Galm.), the mussel Codium fragile (Sur.J Hariot, Corallina pilulijera Modiolus pulex and the chiton Sypharochiton Post & Rupr. An interesting feature of these and May. All of these above is the presence in them of small plants of favour sun shaded cJ]stis pyrijera (L.l Ag. This species is is scarce in this belt, found living in offshore beds and is not a young Cellana solida a species of the intertidal zone. However, belt. petterdi (Ten.-Woods) and some of the small plants living in the ponds are Conacmea subundulata (Angas) also are found in never exposed to the air and so cannot be con­ the Chamaesipho belt as well as Siphonari(£ ,zonata. sidered as intertidal in nature, other larger plants living in the big ponds are exposed for considerable Charnaesipho belt occurs at the seaward edge of periods at low water and so can be considered to be the platform where there is a ridge of rock elevated intertidal in nature (Plate n. Hormosira banksii above the general shelf level. This belt is occurs around the edges of all of the All by Notoacmaea mayi, Lepsithats vinosa, of these algae are of equal ecological with unijasciata, L. praetennissa, Permanent the exception of Codium which is scarce. this belt have a sandy mud bottom with ,'ill.nn,ln~ua The fauna of the deeper ponds is poor. This Is undulata, Dicathais textiliosa, and the in large measure due to the absence of the stones Pleurobranchus rnaculatus (Quay and OIl the bottom of the ponds to provide shelter Miss Nielson, who identified this species for me, a cryptic or semi-cryptic fauna. There are assures me that the do not fit Quay large boulders which undoubtedly shelter some and Gaimard's but that they belong but they are too large or too solidly to the species as P. rnaculatus. embedded to move. A further factor, probably the most important, which discourages the development (b) The Siphonaria b~U. of a large fauna is the nature of the bottom of the The dominant species is S. cliemenensis together ponds. The bottom is of sand which is moved with the small sand surrounded mussel of the about considerably gales and must move Charnaesipho belt, Modiolus 1Julex. Ulva lactuca to some extent during normal period of the and Scytosiphon lomcntarius are common in day when the shore is covered by the sea. There restricted areas which have a small amount of is no infauna in the sando water retained on them at low tideo However. these The starfish, Patiriella calenr (Lam.) is locally growths are seasonal, being absent; from tile reef very common in ponds. In some places up to 100 in l"ebruary, The lower part of the SiphonaTia belt individuals can be collected in an area of about is charaderized a rich growth of one square metre, It is numerous in + U/va +- with Colpomenia places where there is some drift This species Ponds in this belt contain Subninella unduZata, is very variable in colour and the number of srnall of Ecklonia rad'lata (Ag.) ,1. Ag., a few animals found each day also varies very COll- sp" and a sparse population of Entero­ On 6th November, there were on sun sheltered damp situations. A many in the ponds but on following this belt contained a large number the species was uncommono did large orange reveal the hiding places of the By ColpoTflenia the 8th, the starfish had returned and were radiata, cuvieri, plenty of them in the ponds. (Schmic\L) , Other species found in the deeper ponds are Below a large Dicathias textiliosa (Lam.) Sulminellu und711ata, a Botryllus sp" orange in colour, a deep plum Austrocochlea (Chlorodiloma) odontis (Woods), coloured Botrylloides, a purple IAthothamnion and lineo/ata (LamJ, Aplysia tasmanica a bright orange-red calcareous Bryozoan. (Teno-Woods), Notohaliotis ruber (Leach), Bembi­ Other species found on the rocks in this belt are dum nanum (Lam.), Lepsithais vinosa, Montjortula the limpets Notoacmea petterdi (Ten.-Woods), rugosa (Quay & GaimJ, Siphon aria tasmanica, S. Conacmea subundulata (Angas), a species of diemenensis, Patellanax chapmani (Ten.-Woods) Chiazacrnea, the pulmonate Siphonaria tasmanica and Sypharochiton maugeanus. Some of these (Ten.-Woods). the therid Ioepsithais vinosa (LamJ species are of particular interest, particularly 60 INTERTIDAL ECOLOGY OF TRIAL HARBOUR

Aplysia tasrnanica. This species was very sporadic The barnacle belt at the seaward edge is popu­ in occurrence and was represented by juvenil;; lated by gastropods. but there are no other species individuals which were attached by the posterior of barnacles present in this belt. Notoacmea mayi ends of their foot to Laurencia plants. One small (May), Lepsithais vinosa (Lam.), Littorina unijas­ plant harboured seven juvenile Aplysia. The data, L. pmetermissa (May), Modiolus pulex and ftssurellid lVIontjortula rugosa was particularly Patel/aida latistrigata 'Angas). are the other numerous on the reef. In other parts of Tasmania species found in the barnacle belt. this species is not very common. The Austrornytilus belt is populated by lVIoni· The carnivorous gastropod, Corninella lin eo lata, jortuia rugosa (Quay & Gaim.) and by chltons, was very numerous in the shallow ponds. Corninella Sypharochiton rnaugeanus (Iredale & May). A few always could be found by killing and crushing any Catophraqm,us are found at this level but other species of , whereupon Corninella all small in size. The anemone, Actinia would come out of hiding in the sand to feed on (Parq') is found in clefts in the mussel belt to·· the dead animal. The individuals of Corninella gether with Galeo/aria. These two species "re not live buried in the sand and make their found living together. The patelliform way over the sand using the of the dead Patel/oida latistrigata, Notoacmaea ",",'UJrU7.n,.ur. aeimal as a guide. Two varieties of C. lineolata Patellanax chapmani are found in the were found---that with continuous lines around myttlus belt. the shell and that with the lines broken. The Catophragmus belt has the The ponds towards the wave exposed end of the fauna as that given above for the reef have the same flora excepL that Laurencia belt but with the flssureHid lVIont/orilL/a T7.lqosa botY!JoiCles becomes more scarce. lVIacrocystis becoming very much more numerous. purijera becomes larger and the plants more One of the strill:ing features of the mixed algal numerous but a requirement for this species is a and the Lithophyllum, belt is that there are no pool of several metres extent. Lessonia corrugata other than small species such as Lucas appears in these ponds, pods, on or inside the weeds. The nry"",'t." Shallow p::mds of less than 10 cms. depth in tht.' fauna extends further down the shore HonnosiTu-Corallina belt do not usually support seen in the Sarcophycus belt. a varied algal flora. Generally spealdng the only The Ltthophyllum belt is populated aJga present is JIormosira though Coral/ina mayor Cellana solida, a white encrusttng may not also be present. Patiriella e:rigua (Lam.) Laurencia botryoides, Ulva, COTallina and a few occurs sporadically throughout these ponds, plants, the chiton Plaxiphora Those parts of the reefs which are not submerged a Galeolaria caes- a poor largely of the the thaid Dicathais species, maugecmus, calcar (I,am.J. caespitosa diemenensis. a turf in some places The seaward of the reef is exposed to heavy wave action this factor becomes of greater' TheSarcophyclts belt is the most obvious feature ImparLance in determining the zonal pattern. A ot the Intertidal region but it is very poor in fauna smaJI ridge near the edge of the reef is sufficiently and flora. The ascidian Pyura stolanijera (Heller) elevated above the general level of the reef to show i3 found attached to the rocks around the holdfasts the zonation in an almost unbroken sequence from of the large alga and some clusters formed by the Charnaesipho belt down to the Infralittoral Modiolus pulex. The latter species often has fringe. The zonation is Charnaesipho columna, numbers of Kellia anstralis (Lam.) around Austromytilu8 TOstmtus (Dunker), Catophragmus byssus strands. Poneroplax albiCla is scarce and polyrnems Darwin, mixed algal belt, .lAthophyllurn there are a few Cellana solida. Iridaea sP. ? austra­ hyperellum Foslie, Sarcophycus potatorum (Labill.) lasica occurs between the plants and all of the roek Kutz, which is not occupied by these speCies is encrusted This zonation is not necessarily present over aU by a pink LUhotharnnion sp., which is relieved by of the exposed edge of the reef. Catophmgmus is some blaek patches of Isactis. Corallin a pilulijera rather patchy in distri'bution, preferring places and Lithophyllurn hyperellurn are also found in the where there are rounded fingers of the reef SaTcophycus belt but are conflned to the upper extending out to sea so that surf and broken limit of the region. A large button shaped, dark water passes over the rock. Similarly, the mussels green coloured alga, Codium spongiosurn Harv., are patchy in distribution and are not found on forms a prominent feature of this belt. This Codiurn the most exposed situations. The gullies extending species is scarce to rare on the shore but it forms into the reef show a reduction in the number and such a vivid splash of green in the prevailing pink size of Sarcophycus plants in direct proportion to of Lithothamnion that a false impression of its the distance from the edge of the reef and even­ numbers could easily be gained. Small limpets live tually Sarcophycus becomes absent and is replaced in the upper part of the SaTcophycus belt, these by PhyllospoTa as the dominant Infralittoral fringe being Patelloida victoTiana (Singleton), PateUanax alga. lVIacTOcystis often occurs in these gullies. The peronii (Blainville) and P. squamijera (Reeve) and mixed algal and Lithophyllurn belts in November the chiton Poneropla.'E alb ida (Blainville). were richly populated by Ulva lactuca, and a mixed The sheltered north eastern side of the reef, Scytosiphon belt was found on the shore above the although having SaTcophycus in the Infrauttoral Infralittoral fringe in places with submaximal fringe, shows the decreased strength of the wave exposure. action in the belt found in the Midlittoral. The E. R. GUILER 61

Horrnosira-Corallina belt extends to the edge of the together with the orange anemone Anthothoe sp. reef and is replaced by a mixed algal belt with The ponds at highest levels on the shore frequently Laurencia often predominating and forming a turf. support a large Horrnosira population. The edges On the sheltered edge of the reef where there is of the ponds have a few Cellana living just out of broken water Cato1Jhragmus is more numerous the water. than on the exposed side. One particularly noticeable feature of this part of the coast is the size of the holdfasts of Sarco­ 6. NOTES ON NEARBY AREAS phyclls, one particularly large disc being over 30 ems. in width. In most places there are individuals The rocky areas to the south of Trial Harbour of Pyura stolonijera scattered around the holdfasts are all situated in close proximity to sandy beaches oi this alga. and on account of the very heavy sand scouring experienced in these places there is often a poverty of life on the rocks. The "cut and fill" of sand in these beaches is very great. approximately 7. DISCUSSION seven feet of beach removal being noted in December, 1956. The rocks immediately beside the The Trial Harbour area, although situated on a beaches are smooth and polished by the sand and very exposed part of the coastline, does not exhibit there is no permanent animal or plant life on them features which can be considered to be typical of with the exception of a few roving forms, such as strong wave action. The absence of a well developed Littorina or Austrocochlea living high on the shore, Littorina belt is one such feature. Other features the latter being found in more sheltered places, are the absence of a well developed barnacle belt The mussel Austrornytillls is apparently least and the development of an Hormosira-Corallina affected by wave action and sand action, being association on the reef. However, these features can often found in sheets covering the rocks at a level all be attributed to two local factors, namely the about the lower Midlittoral. Other species which development of a reef extending for some distance provide competition at this level for the mussels are oU-shore and the absence of cliffs or rocks. This absent but as the sand scouring diminishes these reef greatly reduces the wave action which is put in an appearance, the last to do so encountered at about high water level and this has SaTcophycus. In some instances the rocky had the effect of reducing the spray upon which to the South of Trial Harbour show a the Littorines depend for their food and moisture. zonation of Littorina, Chamaesipho, BTachyodontes Further, the absence of any cliffs suitable for (perhaps with Catophmgrnlls) , Sarcophycus. colonization by the species which habitually live To the north of Trial Harbour, the coast on the upper part of the shore naturally results stretches for some miles as cliffs interspaced with in the absence of these species. small boulder beaches. These, where it is possible The reef being at almost the same level from to carry out examination, show a typical exposed seaward edge to the land is colonized almost coast zonation-namely, Littorina L, Chthamalns, entirely by the species which are able to success­ Catophragmus, Corallines (including fully live at that tidal level. On an exposed coast and finally Sarcophyc·us. In many one might expect a mixed Corallina-Patelloid small mussel is found forming a dense barnacle belt as at, 1'01' example Eaglehawk Neck growth on the rocks at the bottom of the Chamac,· (Guiler, 1952). However, the reef at Trial Harbour sipho belt, especially in places where the surface is of such an extent and apparently has reduced of the rock is uneven, e.g., at a place known locally the wave action to such a degree that Horrrwsira as Ladder Hole. is able to survive on the exposed coast, although Cellana solida and the anemone Actinia tene­ J-Ionnosira is normally a species of more sheltered /Jrosa are both found on the wave sheltered side habitat. of boulders. Galeolaria caespitosa Is also found on the wave sheltered side of rocks but it is The presence of M elaneTita melano[ragus on the most common in places which are sheltered from coast near Trial Harbour is of interest. This species the full force of the waves wherD there is broken was found at the Fieman Heads, some 40 miles water. In these situations it forms encrustations further to the north but it is absent from the south not more than 2,5 ems. in thickness. coast at South Cape Bay (Guiler, 19[)4). 1V1elanerita occurs very commonly along the north coast Other species found very commonly in this part (Kershaw, 1956 and Guiler, Serventy & Willis, 1958) or the coast are Dicathais "baileyana, Poneroplax and it is also found at Freycinet Peninsula on the aZbida, Lithophyllum hyperellwn, Modiolus pulex, East coast. I did not record Melanerita at Eagle­ and CatophTagml1s polymerus. The latter is very hawk Neck in 1952 but in February and April, 1957 common in some, but not b.Y any means all, places I found several individuals on the sheltered side ,"hich suner wave action plus surf, It is absent of Fossil Island at the Neck. The speeies can from many situations which appear suitable to it. definitely be classified as rare at Eaglehawk. I did Ponds in this region support a fauna which is not find any specimens at Fortescue Bay, about few in species but large in numbers. Melanerita seven miles further south, in December, 1956. It melanotragus is one of the most common pond can be said that Eaglehawk Neck probably rep­ dwelling species. Cominella lineolata, Austro­ resents the southern limit of this species. The cochlea obtusa constricta, A.UstTocochlea odontis southern limit on the west coast must remain a (Wood) . Bembiciurn nanum (Lam.), Sypharochiton matter for some speculation until examinations can maugeanlls, Patiriella exigua are all common be carried out in this inaccessible area. 62 INTERTIDAL ECOLOGY OF TRIAL HARBOUR

One o'f the features of the south and west coasts Pherson 1dentified the Molluscs and Miss B. Nielson, is a prominent white Lithothamnion which lives Tasmanian Museum identified the tectibranch for characteristically in the Infralittoral fringe around me. To these people I extend my thanks. the holdfasts of Sarcophycus. I have seen this species in Safety Cove near Port Arthur and Cribb (954) records the species from Port Arthur. I 9. REFERENCES. have seen it at Fortescue Bay but it is not common GRIBB, A. B., 1954.--The algal of Port Arthur, Tas­ at Eaglehawk Neck. It does not occur on the north mania. Pap. Roy. Soc. Ta.m., 88, 1954, pP. 144. coast or on the northern part of the East coast. GUILER, E. R., 1953-.-Intertidal classification in Tasmania. J. It is very common on the south coast at South Ecol. 41, PP. 381-386. Cape Bay and also at Trial Harbour. It would -----, 1952.-The intertidal ecology of the Eaglehawk appear that this Lithothamnion is indicative of Neck area. Pap. Roy. Soc. Ta.m., 19511 (1952), pp. 13-29. cold conditions and does not penetrate far into , 1954.~The intertidal zonation at two places in Australian waters. Southern Tasmania. Pap. Roy. Soc. Tasm., 88, 105-118. The absence of the southern Bull Kelp Durvillea -----, SERVENTY, D. L., AND WILLIS, J. C., 1958.­ (Cham.) Hariot is worthy of comment. Fisher Island. Pap. Ray. Soc. Tasm., 9'1, 19'58, pp. 165-184. Although much of the drift weed on the shore, KERSHAW, R. C., 1957.-Notes on the intertidal fauna of the particularly to the north of Trial Harbour, is West Head, North Tasmania, Vict. Nat. 12, 1957, pp. Durvillea this material has been carried in the 137-141. sea for a considerllible time since large barnacles, I'I1ETEOROLOGICA,L OFFICE, 1947.-Monthly meteorological oharts Lepas australis Darwin, are found attached to the of Western Pacific Ocean. H.M.S.O. London, 1947. weed. STEPHENSON, T. A. AND STEPHENSON, A., 1949.·-The universal features of zonation between tidemarks on rocky coasts. 8. ACKNOWLEDGMENTS J. Ecol. 37, pp. 289-305. I am grateful to Mr. D. P. Alexander for assis­ WATERHOUSE, L. L., 1916.-'The South Heemskirk Tin Field, tance during the field work and to Mr. T. McMahon Dept. Mines TaB. Gml. Surv. Bull. 21, 19'16" pp. 1-450. for the photographs upon which the plates are WEATHER BUREAU, 1936.-Results of rainfall observations made based. Mr. R. C. Kershaw and Miss Hope Mc- in Tasmania. Melbourne, 1936. PAPERS AND PROCEEDINGS OF THE ROYAL SOCIETY OF TASMANIA, VO,LUME 94

P.LATE I.-The reef looking south. The channel in the foreground is occupied by Macrocystis. (Photo T. McMahon).

F 62. PAPERS AND PROCEEDINGS OF THm ROYAL SOCIETY OF TASMANIA, Vo,LUME 94

P.LATE II.-Sarcophycus and the Lithothamnion belt at the seaward edge of the reef. (Photo T. McMahon). PAPERS AND PROCEEnINu:S OF THE ROYAL SOCIE;'!Y Of" TASMANIA. VO,LtJME 94

PLATE Ill.-Horm·osira 0 n the surface of the reef.