THE FLINDERSIAN AND PERONIAN PROVINCES
Alan J.K. Millar
Royal Botanic Gardens
Mrs Macquaries Rd
Sydney NSW 2000
The Flindersian and Peronian Biogeographic marine Provinces essentially encompass the
entire southern part of the Australian continent. From Geraldton on the West Australian
coast, along southern Australia and Tasmania in the south, and up to Brisbane in the east,
these two provinces account for the vast majority of the known marine algal species of
Australia and a substantial proportion of the world’s known genera and species. Unlike the
Dampierian Province, however, where there is scant knowledge of the marine algae from the
far north of the continent, the Flindersian and Peronian Provinces, but especially the
Flindersian, would have to be the best known of any comparably sized coastline anywhere in
the world.
The Flindersian Province
As with any biological boundary the exact limits of the Flindersian Province are not
precise, but essentially encompass the area of Australia from around Geraldton on the
Western Australian coast, across southern Australia including Tasmania and finish at or near
Cape Howe on the Victorian/NSW border. As John Huisman has noted in his chapter on the
northern Australian Dampierian Province, there is a large overlap of the Dampierian Province
and the Flindersain Province from Geraldton in the north to the south-west tip of the Western
Australian coast. Huisman has shown that a more realistic western boundary of the
Flindersian province is probably at Cape Leeuwin where the warm water current of that name
peters out.
Almost anything said about this Province is a result of the work of Professor Bryan
Womersley, presently of the Adelaide State Herbarium in South Australia. Some 50 years of
research has resulted in the five volume (six when it is completed) Marine Benthic Flora of
Southern Australia (Womersley 1984, 1987, 1994, 1996, 1998), which documents, describes
and illustrates approximately 1200 species of marine algae of the Flindersian Province. The
biogeographic results of this research have mostly been covered by Womersley (1990) and
show that this Province alone accounts for a staggering 43% of the world’s total number of
genera and 20% of its species. The percentages of the world’s genera peak with the red algal
family Ceramiaceae in which 55% occur in the Flindersian Province. Womersley (1990)
further divided the Flindersian Province into two main regions or subprovinces for which he
has accurate figures to suggest that the eastern-most of these, which extends from Kangaroo
Island to Cape Howe and includes South Australia, Victoria, and Tasmania, contains some
83% of the total Flindersian flora. Womersley & Edmonds (1958) and Womersley (1959,
1990) thought this region clearly demarcated enough to warrant its own name, the Maugean
Province. The western subprovince, which extends from Cape Leeuwin to Kangaroo Island
has approximately 60% of the species, while 45% are found throughout the entire Province.
In marked contrast to the western boundary of the Flindersian Province, there has
generally been consensus that the overlap in the east between the Flindersian and Peronian
Provinces is very much smaller. How small an overlap of marine algal species has never been
unequivocally tested until recently.
The Flindersian and Peronian Province boundary.
Our surveys of the subtidal marine algal flora from Gabo Island, which lies only a few
hundred metres off the tip of Cape Howe on the Victorian/New South Wales border, up to
Montague Island, which lies several nautical miles off the coast of Narooma in New South
Wales, have shown that the boundary between these two Provinces can be measured down to
almost a few hundred meters or at the most a few kilometres. The substantial promontory or
headland at Green Cape (which is situated 28 kilometres north of Cape Howe) has proved to
be an almost impenetrable barrier between the marine floras of southern and eastern
Australian. On the southern side of Green Cape, which is the northern side of Disaster Bay, a
diverse and luxuriant marine flora is found, which has a visibly large biomass, and almost
completely covers the seabed. On the north side of the Cape, however, a more turf algal
dominated marine flora exists (typical for most of NSW) in which the majority of the large
southern Australian species do not grow. While there are species known to be common to
eastern and southern Australia, perhaps the most spectacular display of this boundary would
be the presence of the cold temperate species, Durvillaea potatorum (Labillardière)
Areschoug (Bull Kelp), which only manages to get as far north as Tathra, some 50 kilometres
past Green Cape. The plants here never grow larger than about 50 cm long, with some as
small as 10 cm. The very tip of the Tathra headland is completely bare of Durvillaea, yet
within about 50-100m metres to the south, the first few small plants are found. At Green
Cape, the plants grow to their more normal lengths of 5-8 metres. Critical surveillance of this
stretch of the south eastern Australian coast has shown that this headland at Tathra is the
absolute northern limit of Durvillaea and that it is not seasonally affected. Of interest is the
knowledge that in the early 1940s, Durvillaea was a common inhabitant of the rocks around
the coast at Bermagui, which is 35 kilometres further north of Tathra (Valerie May and Isobel
Bennett pers. comm.). Since we now know that Durvillaea has a sharp northern limit in this
area, it would be interesting to ponder the possible effects of seawater temperature rises
spanning the past 60 years. Could it be that Durvillaea is inching its way south as the water
temperature rises?
The Peronian Province
Although publications of the marine benthic algal flora of NSW exist (Millar 1990,
Millar & Kraft 1993, 1994a, 1994b, Kraft 2000) and suggest to the casual observer that the
Peronian Province is well known, there are still massive stretches of coastline left completely
unexplored. Although this is also true for almost the entire length of the Great Australian
Bight in the Flindersian Province, the densely populated and relatively easily accessible NSW
coast has no such excuse. The province’s existence, however, is beyond dispute and is easily
the most clearly defined and perhaps most sharply demarcated of Australia’s five provinces.
As evidenced by the aforementioned comments regarding the southern limit, the northern
boundary (discussed below) of this province is equally stunning. The Peronian province is
equivalent to the political and geographical State of NSW and has an almost truly
North/South oriented coastline spanning 9o of Latitude, but a longitudinal span of only 3o.
Unlike the Flindersian province, the Peronian cannot be divided up so easily into
subprovinces and probably doesn’t deserve to be (the mainland coast at least). The entire
NSW coastline is essentially a transitional zone between the subtropical waters of Queensland
and the cold temperate waters of southern Australia. This region is affected mostly by the
East Australian Current, which starts it journey in the Coral Sea, passes Cape Byron at its
closest point on the eastern seaboard of Australia, then breaks up into anticyclonic eddies at
about Jervis Bay where it turns eastwards towards Lord Howe Island, picks up the northern
parts of the North Island of New Zealand, then hits Norfolk Island before heading north into
the South Equitorial Current (Jeffrey et al. 1990). While some species are restricted to the
north, and others similarly to the south of the NSW coast, continued collections from
unexplored areas are showing a very gradual change from north to south. Fifty-six species are
strictly endemic to the province and are included in Table 1.
Special mention must be made of Lord Howe Island and its relatedness to this province.
Although geopolitically part of NSW, marine biogeographically it is not. Its green algal
affinities lie with the tropical Indo-Pacific (Kraft 2000), its browns mostly with NSW (Millar
& Kraft 1994a), and its reds are very strongly reflective of the tropical-subtropical areas of the
Great Barrier Reef (Millar & Kraft 1993) to the north-west, and Norfolk Island (Millar 1999)
to the north east. Although some 1400 kilometres off the northern NSW coast, Norfolk Island
has enough species in common with the Peronian Province (46%) to be considered almost a
subprovince in itself. What could be argued without too much difficulty would be a
Norfolk/Lord Howe subprovince (the two share 45% of their species, Millar 1999), which
reflects a strong subtropical-tropical influence in the Peronian Province. Indeed they reflect a
real and substantial link between the Peronian and Solanderian Provinces.
The Peronian and Solanderian Province boundary
Although not as pronounced as the southern boundary of the Peronian Province, there
definitely seems to be a relatively rapid cut off in the north where the tropical Solanderian
Province starts. Through some freak of coincidence, the northern boundary of the Peronian
Province would appear to be almost right on the geopolitical border of Queensland and New
South Wales. It is at this point that many of the rocky headlands typical of the entire NSW
coast peter out and are replaced by Mangroves, saltmarshes and sandy bottomed estuaries.
The marine benthic algae, by their very nature, tend to grow only on solid rocky substrates
and the reefs and rocks of the Byron Bay region are clearly the northern NSW limit of many
of these habitats. North of Byron Bay, there are also few rocky intertidal platforms conducive
to algal growth. Even this eastern-most Cape of the Australian continent lacks any substantial
rocky intertidal platform. A few kilometres south, however, areas such as Lennox Head and
Ballina offer an array of subtidal and intertidal habits at which many, albethem turf algal,
species occur.
Similarly to the spectacular cut off of Durvillaea in the southern part of the Peronian
Province, so too is the northern most limit of the fucalean brown alga Hormosira banksii
(Turner) Decaisne. At almost the exact spot of the 29th southern parallel, Hormosira stops at
a rocky platform at Boulder Bay, just a few kilometres north of Ballina. This too seems a
temperature dependent species as it has not been confirmed from anywhere further north,
even where rocky intertidal platforms exist or its often more favoured habitat of saltmarshes
and Mangrove swamps, both areas being plentiful in south-eastern Queensland (Phillips &
Price 1997). Another interesting fact is that Hormosira occurs on an intertidal rock platform
some 1400 kilometres due east at Norfolk Island in the southern parts of the Coral Sea.
Sitting at precisely the same latitude, Norfolk’s resident Hormosira population is shrinking
according to anecdotal evidence. Furthermore, Millar & Kraft (1994a) have concluded that
populations of this species from Lord Howe Island, where it was known to exist in the 1930s
(Lucas 1935), have disappeared. Could this species also be suffering from seawater
temperature rises?
The Byron Bay region also appears to be the northern limit of another brown alga, Ecklonia
radiata (C.Agardh) J.Agardh, for although it has been recorded on several occasions from
south-eastern Queensland, Phillips & Price (1997) report that these are based on drift
specimens and that no authenticated vouchers of attached plants exist. Norfolk Island again
appears to hold some clues as to the distributional limits of this species for it is known to
occur on a deep (50 m) oceanic reef some 7 kilometres due east of the island (Millar 1999).
And almost as a direct link with Hormosira, Ecklonia too was known from Lord Howe Island
(Lucas 1935) but has since disappeared (Millar & Kraft 1994a).
Conclusion
While the Flindersian Province may well have a large overlap with the Dampierian Province
in the west of southern Australia, the eastern boundary is an extremely sharp one with the
Peronian Province and occurs at Green Cape (37o16’S) on the southern coast of NSW. The
political State of New South Wales appears to be the Peronian Province with the northern
boundary also representing the border between Queensland and NSW (28o10’S). The Islands
of Norfolk and Lord Howe possibly reflect a subprovince that links the Peronian Province
with the tropical Solanderian Province.
References
Jeffrey, S.W., Rochford, D.J., and Cresswell, G.R. 1990. Chapter 11.
Oceanography of the Australasian Region. In: Clayton, M.N. and King,
R.J. (Eds). Biology of Marine Plants. pp. 243-265 (Longman Cheshire, Melbourne.)
Kraft, G.T. 2000. The marine and estuarine green macroalgae (Chlorophyta) from Lord Howe
Island, southwestern Pacific. Australian Systematic Botany 13: (In press).
Lucas, A.H.S. 1935. The marine algae of Lord Howe Island. Proceedings of
the Linnean Society of New South Wales 60, 194-232, pls 5-9.
Millar, A.J.K. 1990. Marine red algae of the Coffs Harbour region,
northern New South Wales. Australian Systematic Botany 3, 293-593.
Millar, A.J.K. 1999. Marine benthic algae of Norfolk Island, South Pacific. Australian
Systematic Botany 12: 479-547.
Millar A.J.K. & Kraft G.T. 1993. Catalogue of marine and freshwater red algae
(Rhodophyta) of New South Wales, including Lord Howe Island, South-western
Pacific. Australian Systematic Botany 6: 1-90.
Millar A.J.K. & Kraft G.T. 1994a. Catalogue of marine brown algae
(Phaeophyta) of New South Wales, including Lord Howe Island, South-western
Pacific. Australian Systematic Botany 7: 1-46.
Millar A.J.K. & Kraft G.T. 1994b. Catalogue of marine benthic green algae
(Chlorophyta) of New South Wales, including Lord Howe Island, South-western
Pacific. Australian Systematic Botany 7: 419-453.
Phillips, J.A., and Price.I.R. 1997. A catalogue of Phaeophyta (brown algae)
from Queensland, Australia. Australian Systematic Botany 10, 683-721.
Womersley, H.B.S. 1959. The marine algae of Australia. Bot. Rev. 25,
545-614.
Womersley, H.B.S. 1984. The Marine Benthic Flora of Southern Australia. Part I. 329
pp. (Government Printer, Adelaide).
Womersley, H.B.S. 1987. The Marine Benthic Flora of Southern Australia. Part II. 484
pp. (Government Printer, Adelaide).
Womersley, H.B.S. 1990. Biogeography of Australasian marine macroalgae. In: Biology
of Marine Plants, Clayton, M.N. & King, R.J. (Eds) Ch. 16., pp. 367-381. (Longman
Cheshire, Melbourne).
Womersley, H.B.S. 1994. The Marine Benthic Flora of Southern Australia. Rhodophyta - Part
IIIA. 508 pp. (Australian Biological Resources Study, Canberra).
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IIIB. 392 pp. (Australian Biological Resources Study, Canberra).
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IIIC. 535 pp. (State Herbarium of South Australia, Adelaide).
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----------------------------------Table 1.
Acrosymphyton tenax Millar & Kraft
Amphiroa howensis Lucas
Anotrichium planatum Millar
Apoglossum unguiculescens Millar
Bangia simplex Lucas
Baldockia verticillata Millar
Beckerella pectinata (Gepp & Gepp) Fan & Papenfuss
Branchioglossum epiphyticum Millar & Wynne
Bostrychia tenella ssp. flagellifera (Post) King & Puttock
Botryocladia ebriosa Millar
Callithamnion arrawarricum Millar
Callithamnion korffense Millar
Ceramium lentiforme Millar
Ceramium setchellii Lucas
Curdiea crassa Millar
Dictyothamnion saltatum Millar
Dasya cernua Millar
Dasya fruticulosa Lucas
Dasya trichophora Millar
Dasya roslyniae Millar & Chidgey
Delesseria aemula Millar & Wynne
Erythrotrichia australis Levring
Eucheuma deformans Gabrielson & Kraft
Falkenbergia olens Lucas
Gelidium maidenii Lucas
Gigartina australis J.Agardh
Gracilaria halogenea Millar
Gymnogongrus irregularis Zanardini
Gymnophycus hapsiphorus Huisman & Kraft
Herposiphonia calva Millar
Halichrysis concrescens (J.Agardh) De Toni
Hypoglossum caloglossoides Wynne & Kraft
Haraldiophyllum sinuosum (Lucas) Millar
Kallymenia brachycystidea J.Agardh
Laurencia rigida J.Agardh
Liagora howensis Lucas
Melanthalia polydactylis J.Agardh
Meridiocolax bracteata Noble &
Meristotheca procumbens Gabrielson & Kraft
Nitophyllum delicatum Millar
Pachymenia prostrata J.Agardh
Patulophycus eclipes Millar & Wynne
Plocamium hamatum J.Agardh
Polysiphonia baxteri Lucas
Polysiphonia gelidii Zanardini
Predaea incraspeda Kraft
Predaea kraftiana Millar & Guiry
Reptataxis rhizophora (Lucas) Kraft
Sarcodia ciliata Zanardini
Scinaia howensis Huisman
Spermothamnion miniatum Huisman
Spirophycus acicularis Millar
Stenogramme phyllophoroides (J.Agardh) Millar
Valeriemaya geminata Millar & Wynne
Valeriemaya maculata Millar & Wynne
Vanvoorstia bennettiana (Harvey) Papenfuss (extinct)