MARINE LIFE SOCIETY OF SOUTH AUSTRALIA
Are you interested in any aspect of
marine life? Do you want to learn or understand more about the underwater
world? Do you want to campaign against the pollution of our oceans and
the destruction of reefs and seagrass beds? If so, our Society (MLSSA)
caters for people just like you.
Our motto is "--- understanding,
enjoying and caring for our oceans ---". These few words summarise
our member's motives. Members seek to understand our ocean, derive enjoyment
from observations of marine life and are committed to its protection.
Become a Society member and enjoy contact
with others with similar interests. Our members include divers, marine
aquarists and naturalists. Our aim is to promote a better understanding
of our marine environment.
Our activities include:-
-Studying our local marine environment
Established in 1976, MLSSA holds monthly
meetings and field trips. We produce various informative and educational
publications including a monthly Newsletter and an annual Journal. Our
library is a source of helpful information for marine enthusiasts.
Through our affiliation with other organisations
(i.e. Conservation Council of SA and the Scuba Divers Federation of SA)
we are kept up to date with relevant issues of interest. MLSSA also has
close ties with appropriate Government organisations, e.g. various museums,
universities and libraries.
Everyone is welcome to attend our General
Meetings which are usually held on the third Wednesday of every month (except
December) at the Conservation Centre, 120 Wakefield Street, Adelaide.
You can also join our Society. We have
subscription levels for students, individuals, families and organisations.
We invite you to complete the membership subscription form later in this
Journal and send it with your payment to MLSSA.
The postal address of the Society is :-
120 WAKEFIELD STREET,
The MLSSA logo features a Leafy Seadragon
which is unique to southern Australian waters. The Leafy is South Australia's
only totally protected fish. Its beauty surpasses that of any creature
found in tropical waters and, once seen by divers, is amongst the most
remembered of their diving experiences. We believe that the Leafy Seadragon
symbolises our Society's involvement in the marine environment.
This is the 15th Journal to be published since the first edition in October 1979. They were originally known as the MARIA Journals until the formation of our present Society.
This year we have again covered a wide range of topics, with articles submitted by both professional scientists and laypersons. We thank them all for the considerable amount of work, and thought, they have put into their task.
The selection contains detailed studies of fish, fish families, egg cases, shells, dinoflagelates and of the Biodiversity contained in South Australian waters.
The dinoflagelate study is the second in a series of three studies we are publishing which were conducted by MLSSA member, Jean Cannon.
The Scorpionfish family comes under scrutiny and so does the Dusky Morwong in the second of the present series of articles by past member, Evan John.
The dangers in the exploitation of marine creatures gains a detailed analysis in an article written by Tony Flaherty of the Marine and Coastal Community Network.
We hope you enjoy the1997 MLSSA Journal.
This is the MLSSA Journal, an official
publication of the Marine Life Society Of South Australia Inc.
Our Society is active in trying to protect
our marine environment and this Journal mainly contains articles about
Copyright - The MLSSA Journal is a publication
of the Marine Life Society of South Australia Inc. and is copyright 1997.
The contents may not be reproduced without prior permission of the Society
or the copyright holder.
Disclaimer - The opinions expressed
by authors of material published in this Journal are not necessarily those
of the Society.
Contributions should be mailed to MLSSA,
at 120 Wakefield Street, Adelaide SA 5000.
Although every care will be taken with
contributions, no responsibility will be assumed for any loss or damage
The act of mailing or otherwise submitting
a manuscript shall constitute a warranty by the contributor that the material
is original, and is in no way an infringement upon the rights of others.
It shall also be an affirmation of the
fact that the material is submitted for publication subject for revision
as is deemed necessary by the editor to meet the requirements of publication.
The Paper Nautilus Argonauta (spp)
Nautilus Nautilus (spp)
Philip Hall ©
Early in 1996 MLSSA member Phill McPeake was clambering over some boulders at the waters edge at Pt Moorowie on Yorke Peninsula, South Australia. Wedged between two large rocks he came across a Paper Nautilus. It was an exquisite specimen.
I was fascinated by the extraordinary beauty of the find and decided that as I did not know very much about this creature I would see what I could find out.
Information on the Paper Nautilus is
very scant and usually many years old, some of it dating back to Minoan
times! Information on the Chambered Nautilus begins with fossil records
and very little recent research has been done. The main body of data was
compiled in the years prior to 1902.
The Paper Nautilus, or Argonaut, is a pelagic cousin of the octopus. It belongs in the Cephalopod Class of the Mollusc Phylum. Two species are found in South Australian waters, with Argonauta nodosa being more common than Argonauta argo. The egg cases of the female are highly prized by collectors and also as souvenirs, by visitors and locals alike.
This creature has been well known for centuries. The earliest pictures come from the Mediterranean region. The earliest representations of the Paper Nautilus A. argo, are found in a fresco of molluscs from the Minoan culture on the island of Crete. In later times, Aristotle (384 - 322 BC), depicted the Paper Nautilus as resting on its back, two arms raised as a sail, the others being used as steering oars. This delightful scene was believed to be accurate for many years. Later, the great English poet Byron called the creature, "the Ocean Mab, the fairy of the sea".
It has already been mentioned that individuals are being found washed up on South Australian beaches with increasing frequency, but mass strandings are rare. One mass stranding was recorded by Luke Jansons and Tomas George, of Pt Vincent Primary School on Yorke Peninsula SA. They recorded, using survey forms, that of the hundreds of Nautilus washed ashore at Pt Vincent and along the nearby coastline, up to 300 were stranded in the first two weeks of August 1995 alone. These strandings along the coast they then mapped. They turned the details of these finds, and of the creature itself, into a project that was eventually entered in the "Earthworm Awards". Some of the Argonauts had been kept alive in an aquarium and were filmed and studied. Studying them in a tank was also the aim, in 1979, of MARIA (the predecessor to MLSSA) member Chris Illert. However this apparently was never achieved.
Live creatures found on the seashore are usually very stressed. This is from contact with the bottom in shallow water, and the higher temperature in the Gulfs compared with the open ocean. Another contributory factor is that they have haemocyanin in solution in their blood instead of haemoglobin. This fails to carry oxygen to the muscles very efficiently and thus they tire very quickly when handled, increasing their stress level. The animals also have both a gill heart and a systemic heart. The latter is inefficient in the delivery of oxygen.
A further reason for their general failure to survive in the local waters, is the presence of a greater number of predators.
The creature is not contained in a shell as many believe, but the female lives in an egg case she produces. This case averages approximately 250 mm in diameter. The largest found in South Australia was at Henley Beach and its maximum diameter measures 10.5 inches (266 mm). The male is very much smaller than the female, at about three centimetres long (30 mm), and has no shell or case. His only apparent function in life is to fertilise the female.
As a member of the octopus order it has eight arms, with two rows of suckers. In the female two of the arms hold the case over the body as it is not attached by muscles.
The animal has a slender body with a narrow head and arms of unequal length. The body colour is white, flecked with closely set small brown dots. It has an iridescent, silvery sheen which is common to all of the pelagic octopoda. The dorsal arms of the female are laterally en- larged membranes. These large, shell-secreting flaps, cover the entire case like a web. The female constructs the egg case, beginning the task as soon as she emerges from the egg sac. She continues enlarging the case until maturity. At this stage they are flexible, transparent and parchment-like. When the creature leaves it or dies, it becomes white and brittle. Specimens from New Zealand and Tasmania have been reported to be almost ochre yellow rather than white.
Each arm makes half a case, and a double keel forms where the two halves join. Along the keels are rows of knobs, called tubercules. The tubercules, or nodules, can be white or speckled from reddish brown to purple in colour. Ribs on either side of the case terminate in the tubercules. In A. argo the lateral ribs are not interrupted by these tubercles. The exterior ridges appear as grooves inside the case. Some cases have ear-like lateral extensions and are known as "eared cases" but these are not considered to belong to a distinctive species.
The female will occasionally leave the case, but if deprived for a long period will die. She will not create a new one. Evidence that the case can be repaired comes from the South Australian Museum where it is reported that some cases have been patched with reversed pieces from the same case. Further observations of this mending of cases were recorded from the Pt Vincent cases.
Observations of A. argo have shown that their eyes can pick a change in light intensity, eg if a swimmer casts a shadow, and in an aquarium at night they will follow a torch beam. Their ability to learn simple routines, however, has not been demonstrated.
The range of both species is from Queensland to Western Australia with many observations from the vicinity of Kangaroo Island. They seem to be worldwide in warm seas. A. nodosa has been observed to spawn off Montagu Island NSW whilst live specimens of A. argo have been seen off Lord Howe Island, NSW. Most sightings have been in Spring and early Summer.
Hectocotylus was the generic name Cuvier (1829) gave to the organism he found in the mantle of Argonauta and he supposed it to be a parasitic worm. In fact it is the tip of the male copulatory organ which breaks off and is left in the pallial cavity of the female. This is the tip of the third left arm. The female mates only once and after the eggs hatch she soon dies. The eggs do not hatch together as there are at least three stages in the one case. The spongy egg mass of up to 1000 eggs is contained inconspicuously in the apical spirals of the shell-like egg case. As the eggs grow larger they force the mother from the case and the young can be released. At the end of her life the female drifts or swims to the shallows, into sea-grass, onto reefs and sand flats and dies.
Aquarium observations have shown that there is air in the egg case which keeps the animal suspended in mid-water, but it is not clear how it is regulated. The creature has been observed to depths of 50 metres, but frequently moves to the surface.
As a member of the Order Octopoda, the creatures have the ability to change colour and eject ink. Strong chromatophore changes have been observed in specimens from Pt Vincent, whilst others have described it as being only a blush. It can also emit a considerable amount of ink. Another main defence against enemies seems to be the web covering the egg case. It can be withdrawn producing a silvery flash which may deter predators.
Feeding seems to be a rather hit and miss affair as the animal does not hunt food but seems to just bump into it by chance. The fourth arm sweeps the case if it is touched and any food collected is placed in the mouth.
Collected cases vary in size. Exceptional specimens reach a maximum diameter of approximately 365 mm, but the average seems to be about 250 mm in diameter.
Whilst only A. nodosa and A.
argo drift into South Australian waters, at least two further
species are known in northern Australia. These are Argonauta hians and
Argonauta böettgeri, both less colourful and smaller than those
we find here.
The following list details the individual differences between probable species.
Unfortunately there is little descriptive data for some of the following proposed species. A. compressa, A. maxima, A. argus and A. americana may be variations of A. argo. A. cornuta, A. nouryi and A. pacifica may be variations of A. boettegeri.
Argonauta nodosa Solander, 1786
The commonest find in SA waters but it is still uncommon. The largest reported specimen is 14.5 inches (365 mm) with a maximum diameter of 6 inches (150 mm).
The two keels are relatively wider apart
and nodules much stouter and more widely spaced than A. argo.
Argonauta argo Linnaeus, 1758 = A. compressus Blainville = A. maxima Gault
A. argo is more elongate in lateral view than A. nodosa and has more ribs which are also smaller. They bifurcate and are tubercular only at the keel edge. There are 60 small tubercles on each side compared to half this number on A. nodosa of the same size.
The cases generally measure up to eight inches (203 mm). In 1854 the largest ever case was asserted by Dr A. A. Gould to be 11.75 ins (298 mm)x 7.5 ins (191 mm), but this measurement is disputed, and it has been claimed to be only 10 3/8 ins (263 mm). The case was presented by the family of T.H. Perkins to the Boston Society of Natural History at a cost then of $ 500 (US).
In 1936 large numbers of A. argo
were sighted in the Northern Adriatic. Several specimens have also
been recovered from Florida beaches. A. argo is a rarer find in
SA than A. nodosa.
Dall - a synonym for A. argo
Argonauta argus - possibly A. argo Voss, 1977
The male was described to be about 1
cm in size with the female up to 20 cm. The case was described as a brood
chamber, and was boat-shaped and paper thin. The creatures were found in
Argonauta hians Solander, 1786
This species is called Hian's Paper Nautilus or the Brown Paper nautilus and is relatively rare. The case is brownish with darker brown knobs which are sometimes absent, or it may be cream to light sepia in colour. It is much smaller, rounded and fatter than A. nodosa. It is conspicuously ribbed, with widely spaced radiating ribs ending at the periphery in large, sometimes spiny, knobs. The ribs are alternately long and short at every second rib, terminating in a tubercle on the keel. There are 15 to 18 tubercles each side.
The case grows to between 50 mm (2 ins)
and 90 mm (3.5 ins). Live specimens have been seen off Lord Howe Island,
NSW. The eggs are reported to be pink to whitish in colour.
Argonauta böettgeri Böttger, Maltzan (1881)
This is similar to A. hians but has more ribs which unite in twos and threes halfway across the shell. The tubercles on the keel are very prominent, double the size of those on A. hians. The case is ochre-yellow and more deeply shaded on the first or curled part. The case is finely granulated and is on average 2 inches (50 mm) in diameter.
These are rare finds, and on one specimen
the top of the tubercle on the keel was open, probably due to damage, but
possibly to allow the easy exit of juveniles.
Argonauta cornuta Conrad
Argonauta nouryi Lorois
Argonauta pacifica Dall
Argonauta oryzata Mensch
Pearly or Chambered Nautilus
Nautilus remains have been found in London clay. The animals were large predators in the seas of the Ordovician period, 450 million years ago. Three thousand five hundred different species once existed. A later arrival, the Ammonites, are also fossil relatives of today's Pearly Nautilus, and these squid-like animals appeared during the Devonian period, approximately 380 million years ago, dying out along with the dinosaurs at the end of the Cretaceous period 65 million years ago. The shell of the Ammonite was chambered and constructed in a similar way to that of its living relative, with today's creatures being a link with the past.
The Nautilus was studied extensively in England, France, Germany and Holland in the 19th Century and it was the name given by Jules Verne to the submarine in the novel "20,000 Leagues Under the Sea". A further literary reference is to be found in the poem called "The Chambered Nautilus" by the American poet Oliver Wendell Holmes (see Appendix). This was written in 1885, and demonstrates the confusion between the Paper and Chambered Nautilus at that time. It also shows how the erroneous picture by Aristotle, of the Paper Nautilus raising its web-like arms as sails so as to scud before the wind over the ocean, was still accepted in the latter years of the last Century. Even up to 1978 The Concise Oxford Dictionary described the Paper Nautilus as having "webbed sail-like arms".
Willey (1902) studied the Pearly Nautilus on and about the island of New Britain around the start of the century. He attempted to breed and rear some Nautili in rock pools and specially made basketwork cages. Sacking was used to provide an egg deposition surface around the pools and cages. Sacking also prevented the entry of conger eels, which were observed to attack the helpless creatures, into the rock pool areas. He had no success as the eggs were either infertile or became "addled" in about two weeks. His results, and a detailed anatomical study of the Nautilus, were published, "Zoological Results of the Years 1895/6/7, Cambridge University Press", 1902.
A further anatomical study was compiled in 1900 by Lawrence Edmonds Griffin in his published account, "Memoirs of the National Academy of Sciences, Vol.VIII, 5th Memoir, Washington Government Printing Office". This work was a summary of the then known information and drew heavily on the work done by Dr Willey. Both of these studies contain finely detailed drawings of the internal and external structures of the creature.
In recent times Mike deGruy and Dr Bruce Carlson studied the breeding of the Chambered Nautilus in an aquarium. "Addled" eggs that were discarded eventually hatched viable young after a period of approximately nine months.
Originally discovered in Indonesian
waters in 1705, they are found in several places around the Western Pacific.
Many have been reported around Fiji, New Caledonia, The Philippines, the
northern reefs of the Great Barrier Reef system, in Malaysian waters and
around the Palau Islands. Around Australia they seem to have a range from
Queensland to the Northern Territory. One living specimen was found at
Foul Bay on York Peninsula SA in 1911, and was probably carried south by
ocean currents. They vary in size but mainly seem to have a maximum diameter
of 15 to 20 centimetres. Nautilus pompilius is the most common of
the four generally recognised species. They are more primitive than other
cephalopods which have internal shells.
The nautilus has a thin, two-layered shell, which is spirally coiled and chambered, mother-of-pearl lined, and pressure resistant. Willey found a pearl inside one. It was a specimen measuring 15 mm by 11 mm and weighing 3690 mg. The partitions, called septa, grow at an estimated rate of one every few weeks, to a final count of 38 chambers, with the creature occupying the last chamber. At maturity the septa also become thicker, and there is a black border on the inside of the final chamber, which is smaller than the preceding one. The outer porcellaneous surface is light coloured and ornamented with zebra-like red/brown stripes radiating from the umbilical region but not extending to the broadest part of the body whorl. The inner is of a delicate pearly nacreous substance.
A tube called the siphuncle extends through a central hole in the coils. The nautilus is not attached by the siphuncle to the shell. It remains in the shell by muscle pressure. The fluid containing chambers are filled with gas via the tube walls to let the creature control buoyancy by regulating the ratio of gas to liquid, and it also allows for the adjustment of fluid in the chambers as the creature grows.
The nautilus has many more arms than an octopus, and these are arranged in two circles. The outer 38 are prehensile whilst the inner 24 in the male, and 48-52 in the female, are oval. These tentacles are the nautiloid equivalent of feet and hands and enable the creature to "smell" and "taste" food. These arms bear no suckers but are nevertheless adhesive, and have chemically sensitive "taste buds" to "sniff" out prey. Once food has been detected the tentacles spread out and the creature finds the prey by combining the signals from the tentacles with directional information provided by its rhinophores, two small tube-like organs positioned just below the eyes. When it reaches the prey the arms are able to extend to about twice the diameter of its body. The arms do not help the animal to crawl, but two trailing tentacles do help the nautilus to follow the contours of the seabed it is traversing. The male has a spadix organ of four modified tentacles for copulation. These tentacles have a retractable extension called a cirrus. The mantle is transparent in the living creature. There appears, from the observations of Dr Willey, to be an excess of males which are larger than the female. The nautilus can pull in all the tentacles, and drop a leathery hood (like a trapdoor), for protection.
The creature uses the muscular funnel to jet horizontally in reverse, the normal swimming method, as the funnel is aimed forward. The funnel has two separate lobes and water is ejected by the contraction of funnel muscles and also by the withdrawal of the body into its shell. The funnel is not fused into a tube as the lower edges curl around each other, and within the funnel is a tongue-like fleshy process acting as a valve. Water is sucked in through a passage behind each eye, firstly to bring oxygen to the gills. There are four gills (tetrabranchiata) arranged as two pairs, instead of two gills only as in other cephalopods. It can dive to 2000 ft during the day, which is more than 300 fathoms or 600 metres, in order to rest on the ocean bottom.
The beak-like jaws are strong enough to crush shells and there is a radula with eleven longitudinal rows of teeth. It eats algae, fish, crabs, shrimp and other invertebrates. It has simple grooved and stalked eyes without lenses, operating on the principal of the pinhole camera. There is no ink sac or pigment in the skin. The brain is composed of three pairs of ganglia. There is only one oviduct (right). The eggs are large (40 mm) and are contained in an envelope. They are shed singly, with up to ten eggs laid, at intervals of nearly two weeks.
The creature has many enemies. Beak marks on some shells suggest attacks by other nautili. They are sometimes attacked by sharks and conger eels, and are often taken for food and used as bait by humans. Their shells are highly prized as ornaments and for sale to tourists.
The Pearly Nautilus usually frequents
the deeper waters where the temperature is only a little above freezing.
When specimens are kept in an aquarium this must be taken into account.
Live creatures may be observed at the Waikiki Aquarium on Honolulu.
list details the individual differences between probable species.
Unfortunately there is little descriptive data for some of these creatures.
N. repurtus, N. stenomphalus, N.
ambiguus, N. alumnus, N. perforatus, N. marginalis and N. moretoni
may be variations of N. pompilius, whilst N. umbilicatus,
N. perforatus and N. texturatus may be variations of N. scrobiculatus.
Nautilus belauensis Saunders, 1981
This has a larger mature-sized shell
than N. pompilius.
Nautilus macromphalus Sowerby, 1849
Large numbers of these creatures have
been caught by research teams off Indo-Pacific reefs. The umbilicus5
is described as being deep with varying width. It is subperforate, of 2½
whorls, and the walls are concave and narrow towards the interior. The
colour is like N. pompilius.
Nautilus pompilius Linnaeus, 1758
This species is the most widely found.
It has no indentation at the side of the shell. It is bilaterally symmetrical,
with a large aperture and has a variable umbilicus5 which is
imperforate. It is light-coloured and ornamented with zebra-like red/brown
stripes radiating from the umbilical region.
Nautilus repurtus Iredale, 1944
This is possibly a sub-species of N.
pompilius or it may be a synonym for N. pompilius. Specimens
described as being a Western Australian form of N. pompilius have
been found at Albany, Cottesloe and on Rottnest Island. One shell containing
a live creature was found at Foul Bay SA, in 1911.
Nautilus stenomphalus Sowerby, 1849
This is an extreme variety. It is reported
to have a narrow perforate umbilicus, and the colour is like N. pompilius.
Nautilus ambiguus Sowerby, 1849
This is possibly a synonym for N.
pompilius, but the authenticity is dubious.
Nautilus alumnus Iredale, 1944
This is possibly a synonym for N.
Nautilus perforatus Willey, 1896 Conrad, 1849
May be a variety of N. pompilius or a synonym. (Willey)
May be a variety of N. scrobiculatus
or a synonym. (Conrad)
Nautilus marginalis Willey 1896
May be a variety of N. pompilius
or a synonym.
Nautilus moretoni Willey
May be a variety of N. pompilius
or a synonym.
Nautilus scrobiculatus Lightfoot, 1786
The shell is compressed and is occasionally
found with an obsolete ridge near the periphery. It is rougher and striated,
(both concentric and radiated), than N. pompilius, and the colour
is creamy white, ornate on the umbilical half of the last whorl with orange/brown
streaks. There is a light zone before the umbilicus and the umbilical patch
is almost black. The umbilicus has 2½ whorls and is deep, broad
Nautilus umbilicatus Lister
May be a synonym for N. scrobiculatus.
It has a very wide perforate umbilicus.
Nautilus texturatus Gould, 1857
May be a synonym for N. scrobiculatus.
I wish to thank Dr S. Shepherd of the
South Australian Research and Development Institute, Dr W. Ziedler of the
South Australian Museum and Mr E. John, Senior Science Master at Westminster
School, for taking the time to read and suggest amendments or corrections
to this document.
This is the ship of pearl, which, poets feign,
Sails the unshadowed main,--
The venturous bark that flings
On the sweet summer wind its purpled wings
In gulfs enchanted, where the Siren sings,
And coral reefs lie bare,
Where the cold sea-maids rise to sun
their streaming hair.
Its webs of living gauze no more unfurl;
Wrecked is the ship of pearl!
And every chambered cell,
Where its dim dreaming life was wont to dwell,
As the frail tenant shaped his growing shell,
Before thee lies revealed,--
Its irised ceiling rent, its sunless
Year after year beheld the silent toil
That spread his lustrous coil;
Still, as the spiral grew,
He left the past year's dwelling for new,
Stole with soft steps its shining archway through,
Built up its idle door,
Stretched in his last-found home, and
knew the old no more.
Thanks for the heavenly message brought by thee,
Child of the wandering sea,
Cast from her lap, forlorn!
From thy dead lips a clearer note is born
Than ever Triton blew from wreathèd horn!
While on mine ear it rings,
Through the deep caves of thought I
hear a voice that sings --
Build thee more stately mansions, O my soul,
As the swift seasons roll!
Leave thy low-vaulted past!
Let each new temple, nobler than the last,
Shut thee from heaven with a dome more vast,
Till thou at length art free,
Leaving thine outgrown shell by life's
Oliver Wendell Holmes
& ENDEMISM IN SOUTH AUSTRALIA
Dr Karen Edyvane
South Australian Research & Development Institute (Aquatic Sciences)
PO Box 120, Henley Beach, South Australia.
The marine and estuarine waters of South
Australia represent some of the most unique and biologically diverse waters
to be found in Australia and the world. This uniqueness and diversity is
due primarily to the richness and endemism of the marine temperate fauna
and flora of southern Australia and also, the geographical location and
physical characteristics of South Australia's coastal environment. Compared
to other regions of temperate Australia, South Australia has a wide range
of coastal landforms and marine habitats and also, a variety of oceanographic
conditions, including a high degree of variability in sea temperatures.
Of particular significance are the two large, sheltered tidal gulf ecosystems
of Gulf St Vincent and Spencer Gulf, which provide habitat for some of
the largest temperate, mangrove, seagrass and tidal saltmarsh communities
in Australia. In addition, the marine fauna and flora of South Australia
include both the typical cold temperate biota of Tasmania, Victoria and
southern New South Wales and the transitional warm to cool temperate biota
of southern Western Australia. These factors have combined to produce a
rich diversity of organisms and communities along the South Australian
coast, which in many instances is unparalleled, both in Australia and at
a global level.
Evolution of Australia's
Many of the same factors which have
made Australia's terrestrial fauna and flora, unique and biologically diverse,
have also resulted in some of the highest levels of biodiversity and endemicity
in marine biota in the world. These factors include the long period of
geological isolation; the large continental landmass of Australia, particularly
the extensive continental shelf; the long east-west, ice-free extent of
the southern coastline (ie. the longest stretch of south facing coastline
in the Southern Hemisphere); and also the characteristic low nutrient status
of the Australia's coastal waters have all contributed significantly to
the biological diversity of Australia's marine environments. Low nutrient
regimes generally promote biological diversity and co-evolutionary strategies
to rapidly harvest, utilise and recycle limited nutrient resources. In
temperate Australia, the long period of geological isolation has been particularly
important in producing very high levels of marine endemism. While the marine
flora and fauna of tropical Australia and the Indo-Pacific mixed some 20
million years ago (when the continental plates of Australia and Southeast
Asia collided), the marine biota of southern temperate Australia has remained
isolated for over 65 million years - resulting in some of the highest levels
of endemism in the world.
The `Unique South'
- Marine Biodiversity in
Along the southern coast of Australia, South Australia falls within a major marine biogeographic region, known as the Flindersian Province, which extends from southwest Western Australia to southern New South Wales and includes the waters of Victoria and Tasmania Within this broad region, the coastal waters of South Australia waters contain both the warm to cool temperate biota of southern Western Australia and also the cold temperate biota of Victoria, Tasmania and southern New South Wales. This cold temperate element (west of Robe, South Australia) has been recognised by some biogeographers as a distinct subprovince of the Flindersian - the Maugean Subprovince. In many ways, South Australia is at the heart of the `Unique South', as it's marine biota encompasses these two distinctive regions within a region of very high biodiversity and endemism.
The marine biota of the southern temperate coast of Australia, as mentioned above, has some of the highest levels of marine biodiversity and endemism in Australia, and the world. This is particularly the case for the marine flora and also invertebrate taxa such as bryozoans, ascidians, nudibranchs, molluscs and echinoderms. Within he Flindersian Province, approximately 1,155 species of macroalgae, 22 species of seagrasses, 600 species of fish, 110 species of echinoderms and 189 species of ascidians have been recorded. Of these, approximately 85% of fish species, 95% of molluscs and 90% of echinoderms are endemic. In contrast, approximately 13%, 10% and 13% of fish, mollusc and echinoderms, respectively, are endemic in the tropical regions of Australia. Similarly, the marine macrofloral diversity and endemism in the temperate regions of Australia is among the highest in the world. The richness of the temperate macroalgal flora (ie. 1,155 species) is 50-80% greater than for other comparable regions around he world, with approximately 800 species and over 75% endemism recorded in the red algae alone. The level of temperate species biodiversity in macroalgae is approximately three times the level recorded in the tropical regions of Australia, where approximately 200 - 400 species of macroalgae have been described.
Similarly, Australia's waters also contain
the highest level of species diversity and endemism for seagrasses in the
world, with the greatest levels of speciation and endemism in temperate
waters, where 22 species have been recorded (cf. to 15 species in tropical
waters). In the family of seagrass commonly called "Tapeweed"
or Posidonia species, southern Australia has recorded the greatest
number of species in the world. Within temperate Australian waters, the
seagrass meadows of the southern coast of Western Australia (9,000 sq.km),
and Spencer Gulf (3,700 sq.km) and Gulf St Vincent (1,530 sq.km), comprise
the largest (and most diverse) temperate seagrass ecosystems in Australia
and the world. In contrast, seagrass abundance (and diversity) is low in
temperate south-eastern Australia, where the high energy coastline restricts
seagrass to estuaries and protected bays. For instance, seagrass occupies
approximately 500 sq.km in coastal Tasmanian waters, 150 sq.km in the waters
of New South Wales and 100 sq.km in Victorian waters.
Rocky Cliffs to Mangrove Shores
- South Australia's Coastal
South Australia itself has over 3,700
kilometres of coastline (including Kangaroo Island, but excluding the offshore
islands) which extend from the cool temperate waters of the 12-14oC),
to the transitional warm temperate waters of the Bight region in the west
of the state (where annual sea temperatures fluctuate from 16-20oC).
In the sheltered gulf systems of South Australia (ie. Gulf St.Vincent and
Spencer Gulf), fluctuations in annual sea temperatures are even greater.
In Spencer Gulf sea temperatures fluctuate from 14oC in winter
to 25oC in summer. This is in contrast to the south-east of
South Australia, where a summer "upwelling" of cooler water maintains
fairly uniform year-round sea temperatures of 12-14oC. The cooler
nutrient-rich waters of the upwelling contribute directly to the considerable
productivity of this region, which has seen the development of major commercial
fisheries, such as lobster and abalone in this area. This coastal upwelling
represents the only significant upwelling along the whole of the southern
Australian coastline. In addition, the localised periodic coldwater nutrient-rich
upwellings in the eastern Great Australian Bight, and also the seasonal
influence of the warmer Leeuwin Current, have also contributed to the significant
marine biodiversity and productivity of South Australian waters. In particular,
the warm waters of the Leeuwin Current are thought to be responsible for
the dispersal of many tropical pelagic marine organisms from the warm waters
of the northwest of Australia to the southern coast of Australia.
The coastline of South Australia is
also characterised by a wide range of marine habitats; from the rough-water
rocky shores and sandy beaches of the south-east and west coast, to the
extensive calm-water mudflats, seagrass and mangrove habitats of the gulf
regions. Sandy beaches and rocky shores dominate South Australia's coast
occupying approximately 59% and 33% of the coastline. These habitats are
particularly common in the swell-dominated oceanic regions of South Australia,
which for the most part face the full force of the Southern Ocean, and
as such, experience some of the highest wave energies in Australia. On
rocky shores, steeply sloping, ancient Precambrian granites or gneisses
dominate wave-exposed capes and promontories. Between these areas, on surf-beaten
coasts, particularly on the west coast of South Australia, limestone cliffs
derived from ancient consolidated sand dunes (and up to 90 metres high
along the Nullarbor Cliffs) occur over hundreds of kilometres of coast.
In contrast the sheltered mangrove habitats occupy 8% of the coastal habitat
of South Australia. The gulf systems of Gulf St Vincent and Spencer Gulf
together represent one of the largest, sheltered coastal ecosystems to
be found anywhere in temperate Australia.
Offshore, the wide, swell-dominated,
open shelf waters off South Australia, particularly the Otway region of
southeastern South Australia (ie. Lacepede and Bonney Shelf) and Great
Australian Bight (ie. Eucla Platform), have allowed some of the largest
modern, cool-water, open shelf accumulations of carbonate sediments in
the world. Export of sediment from land to the wide continental shelf is
low because of South Australia's low continental relief and predominantly
arid climate. Together with the cold water upwelling ocean waters, these
shelf conditions have resulted in luxuriant growths of carbonate-producing
bryozoans and coralline algae, together with sponges, molluscs, asteroids,
benthic and some planktonic foraminifera. These organisms form the basis
for the accumulation of Holocene sediments, which generally contain a high
proportion of bryozoans. In open coastal areas, like the Great Australian
Bight, winds and persistent southwest swells, erode and rework these carbonate
sediments and supply much of the sediment for extensive beach and dunal
systems which dominate these regions.
The large sheltered gulf ecosystems
of South Australia are of particular ecological significance. They are
habitat for some of the largest areas of temperate seagrass, mangrove and
tidal saltmarsh communities in Australia. The extensive meadows of seagrass
within the gulf ecosystems provide an essential habitat for marine organisms
and form the basis for much of the state's commercial and recreational
fisheries. The Grey Mangrove, Avicennia marina var. resinifera,
found in the upper intertidal area on sandy mud flats, is the only species
of mangrove found along the temperate southern Australian coast. In South
Australia it reaches it's maximum abundance, covering a total area of 230
km2, due principally to the extent of sheltered habitats within
the gulf ecosystems. Likewise, extensive areas of salt-tolerant coastal
samphire communities, including plants such as Sarcocornia and Halosarcia
(relatives of the more familiar saltbush) also occur in South Australia.
These communities form extensive zones in the upper intertidal to supratidal
level, adjacent to the mangrove forests.
This remarkable biological diversity
is not restricted to marine flora. South Australia also has the richest
assemblage of ascidians or "sea-squirts" in the world, with over
200 described species. Many of these species have been recorded near the
offshore islands of the Great Australian Bight region and among the extensive
limestone cave systems of western Eyre Peninsula. Other marine invertebrates
such as nudibranchs or "sea-slugs" are also very well represented
in South Australia, with over 500 recorded species. The Investigator Strait
- Backstairs Passage region is home to a wide range of lesser known invertebrate
groups, including ancient brachyopods (or "lamp shells"), rare
free-living corals and bryozoans. Bryozoans (or 'lace corals') reach their
greatest species diversity in temperate southern Australia, particularly
in South Australia, due to the wide continental shelf, where they form
a major component of the shelf sediments. In this respect, bryozoans are
the temperate equivalents of the hermatypic corals of the tropical environments
Not only do the temperate marine environments of South Australia contain very high levels of marine biodiversity and endemism, but our waters are also becoming increasingly recognised as an area of global conservation significance for many species of rare and endangered marine mammals, particularly in the Great Australian Bight. For this reason there is a clear imperative to establish marine conservation management frameworks which can protect the key conservation values of our marine environment, and also can provide for the human use, particularly along some of the more populated sections of our coastal environment.
The Great Australian Bight region itself is now recognised as an area of global conservation significance for the Southern Right Whale (Eubalaena australis) - a species formally recognised as both 'endangered' (under the Commonwealth Endangered Species Protection Act 1992) and 'vulnerable to extinction' (by the World Conservation Union and the International Union for the Conservation of Nature). While Southern Right Whales each year regularly visit coastal bays and inlets around South Australia, specific areas such as the Head of the Great Australian Bight represent one of the most significant habitats for the breeding and calving of Southern Right Whales in the world. Estimates currently put the world population at around 1,500 to 3,000 individuals, with an Australian population of approximately 400-600.
The Great Australian Bight region is also recognised as a significant seasonal habitat for many other species of rare and endangered marine mammals. At least 17 species of cetaceans have been recorded including migratory species such as Blue Whales, Sperm Whales, Minke Whales Humpbacks and Rorquals. Frequent sightings of Sperm Whales and Beaked Whales may be related to the known squid populations off the Ceduna canyons and near the edge of the continental shelf. Killer Whales have also been recorded and their presence is probably related to the abundance of pinnipeds along the western Eyre Peninsula.
Three species of seals or pinnipeds breed in South Australian waters: the rare Australian Sea Lion (Neophoca cinerea), and the New Zealand Fur Seal (Arctocephalus forsteri), and the Australian Fur Seal (Arctocephalus pusillus doriferus). The Australian populations of the New Zealand Fur Seal are limited in their distribution to southern Tasmania and the Great Australian Bight, and are found on the islands of Recherche Archipelago (WA), eastwards to Kangaroo Island (SA). The Australian Sea Lion, which is endemic to Australia, is presently limited to the offshore islands of Western and South Australia, from the Houtman Abrolhos to the islands of Recherche Archipelago (WA), and from Nuyts Archipelago to Kangaroo Island (SA). Breeding populations of the Australian Fur Seal, which also breeds in South Australia, are confined to south-eastern Australia, including Tasmania.
The Australian Sea Lion is one Australia's most endangered marine mammals and one of the rarest and most endangered pinnipeds in the world and is endemic to Australia. The species is recognised as `rare' under South Australian legislation; a `Special Protected Species' in Western Australia; and `rare' by the IUCN. Prior to seal-hunting, this species occurred along the whole of the southern coastline, but is now confined to the waters of South Australia and Western Australia. The estimated world population for this species is 10,000 - 12,000 individuals, with estimated population sizes of 7 500 sea lions in South Australia and 3 100 in Western Australia. This makes makes long-term management and conservation of this species a particular responsibility and obligation for South Australia. Major breeding areas for sea lions in Australia include the offshore islands off the south coast of Western Australia and western South Australia. Of particular significance is the recent discovery of numerous small breeding colonies along the Nullarbor Cliffs in the Great Australian Bight.
Major breeding areas for sea lions in Australia include the south coast of Western Australia and western South Australia. Major breeding areas in South Australia include the Pages, Dangerous Reef and Seal Bay, Kangaroo Island. Point Labatt on western Eyre Peninsula was, until recently, the only and largest recorded mainland breeding site for this species in the world. In South Australia, Australian Sea Lions have been recorded on a total of 69 offshore islands and reefs and three mainland sites. A total of 18 offshore islands, particularly off the Eyre Peninsula, support breeding populations of sea lions and a further 18 islands have been identified as possible breeding sites. In Western Australia a total of 13 islands support breeding colonies and a further 16 islands have been identified as possible breeding sites.
Although most of the world population of the New Zealand Fur Seal occurs in New Zealand, there are a few colonies in Australia. Breeding colonies occur on the islands off the southern coast of Western Australia, on islands at the entrance to Spencer Gulf (South Australia), and on Kangaroo Island. South Australian waters contain approximately 22,600 individuals (or 83% of the total Australian population for this species). Together, the fur seals from the Neptune Islands comprise almost 13,800 seals and represent approximately 61% of the estimated South Australian population or 51% of the total Australian population for this species. Within the Great Australian Bight, the islands of the Nuyts Archipelago have smaller, but nevertheless important, colonies of fur seals (and sea lions).
Other rare or endangered species which
also dominate in South Australian waters include the rare Leafy Sea Dragon
(Phycodurus eques), an ornately camouflaged sea horse which evades
predators by blending in with the leafy fronds of surrounding kelp plants;
and the well-known White Shark (Carcharodon carcharias), whose abundance
in South Australian waters has led to South Australia's prominence as one
of the key sites in the world for scientific research and filming of this
Marine Conservation Management
"The first rule of intelligent tinkering is to save all the parts..." (Aldo Leopold)
In recent years the South Australian Research and Development Institute (SARDI), with assistance from the SA Herbarium and SA Museum, have been undertaking one of the most comprehensive marine mapping and biodiversity programs ever undertaken in Australia. Remote sensing techniques, systematic marine surveys and the documentation and analysis of the wide range of species, habitats and ecosystems along our coasts, is providing information that will be fundamental not only for marine biodiversity conservation in South Australia, but also, the sustainable management of fisheries, aquaculture, tourism and many other coastal and marine uses. To this end, identifying the wide range of habitats and ecosystems will enable the full range of South Australia's biodiversity to be fully represented in a reserves system - while defining the boundaries of these ecosystems will enable us to identify our "marine catchments". While the boundaries of these marine catchments may not be as sharp as on land - an analogous range of environmental and physical factors (ie. oceanography, bathymetry, geology, and exposure) combine to produce a unique range of marine flora and fauna within them.
While the establishment of an ecologically representative system of Marine Protected Areas (ie. Marine Parks and Aquatic Reserves) is important for marine biodiversity conservation - equally important is the recognition that integrated planning and management, ie. "integrated catchment management", is essential for the sustainable management of our marine environments. This is because ocean currents and tides ensure that virtually all marine activities have the potential to affect one another. In this respect, "off-reserve management" and the need for catchment management is more important under the sea than on land.
South Australia's diverse marine and
coastal ecosystems and their resources are of immense ecological, cultural
and economic importance to South Australians. In the long-term, the success
of a comprehensive marine conservation program will depend on a coordinated
and integrated approach to the management of marine ecosystems and their
resources. This will be essential for both the protection and conservation
of South Australia's marine heritage, and also the economic welfare of
the State's aquatic resource base. The challenge, however, will continue
to be raising the consciousness and awareness among South Australians of
their diverse marine ecosystems - and the need to protect and conserve
some of the most unique species, habitats and environments in the world.
Growth In Culture Of The Toxic Dinoflagellate
Alexandrium minutum From The Port River
JEAN A. CANNON
Department of Botany, The University of Adelaide, G.P.O Box 498,
Adelaide, South Australia, 5001.
Blooms of the toxic dinoflagellate,
Alexandrium minutum, occur in the Port River, Adelaide, South Australia,
in the vicinity of a sewage effluent outfall. The conditions which promote
vegetative growth of A. minutum have been studied using log phase
clonal cultures isolated from these blooms. Vegetative growth (mean doubling
time 2.2 - 3.3 days) was optimal at 20°C and a light intensity of 100
µE m-2s-1. Cultures survived at low cell densities
for 60 days in the dark. There were no significant differences in growth
due to salinity. Soil extract was more important than either minerals or
vitamins in enhancing growth. The addition of nitrate and phosphate significantly
increased vegetative growth. Maximum cell densities in culture were very
similar to those found in situ in the main dock area of the
river, but not as high as those found in sheltered embayments.
The Port River in South Australia is
an estuarine system which drains much of Adelaide's stormwater. It receives
30-40 million litres per day sewage effluent in the shallow, upper reaches;
it also receives one-way tidal flow from a man made marine lake. Site details
are described elsewhere [1, 2]. The toxic dinoflagellate Alexandrium
minutum is one of the most common species of phytoplankton in
the Port River; its biology there is summarised in Figure 1. Germination
of its cysts in the shallow, upper reaches of the Port River results in
vegetative cell appearance . There are two situations in which a rapid
increase in cell numbers (or outbreak) occurs. The first type is the formation
of a subsurface bloom in the shallow, upper reaches of the river.
The unusual one-way tidal flow  distributes this narrow band of bloom
throughout the dock area. The second outbreak type occurs when the water
column is stable . This results in a surface bloom with cell densities
of 106 or 107 cells L-1 in the upper 3
- 4 m, with a rapid increase in cell numbers in the river. The conditions
promoting the first outbreak are the subject of this paper, and important
to any development of management strategies. These subsurface blooms, not
visible from the surface, are large blooms with all the problems associated
with visible blooms.
Materials And Methods
The growth of Alexandrium minutum
in culture was tested across a series of light, temperature, salinity
and nutrient regimes. Clonal cultures isolated from blooms in the Port
River were grown in GPM medium of Loeblich . The effect of temperature
on growth was examined at 12º, 16º, 20º and 25ºC, and
26‰ and 50 µE m-2 s-1 irradiance. The effect
of irradiance at 0, 14, 20, 25, 50, and 100 µE m-2 s-1
was examined at 16ºC and 26‰ salinity. The effect of salinity
(21, 26, 31.5 and 35 ‰) on growth was examined at 16ºC and 50 µE
m-2 s-1 . The initial cell density was 8.8 x105
cells L-1 with four replicates for each treatment. Cultures
were incubated on a 12:12 LD cycle, the different light levels achieved
by use of clear perspex cubes of approximately 30 cm covered by either
aluminium foil (dark) or varying densities of shade cloth.
Salinities were obtained by varying the proportions of filtered Port River
water (35 ‰) and demineralized water, with nutrients added in the usual
proportions for GPM medium. Standard procedures were used in counting cells.
In the first experimental series (salinity, temperature and
light irradiance), cells were counted at five to seven day intervals for
60 days. In experiments testing the effect of nutrients on growth, cells
were counted for 34 days. The latter series tested the effect of three
combinations of N and P on the vegetative growth of Alexandriun minutum:
0.2 mg N L-1 + 0.35 mg P L-1; 0.4 mg N L-1
+ 0.70 mg P L-1, and 0.6 mg N L-1 + 1.05 mg
P L-1. These media also contained minerals, vitamins and soil
extract. The effect of these three components, solely and without addition
of N + P, was also examined. Oceanic water was used for this experimental
series and the soil extract prepared from a Port River bank sample. These
cultures were incubated at 26‰ salinity, 16ºC and 50 µE m-2
s-1 on a 12:12 hour LD cycle. A one way analysis of variance
for each experiment tested the effect of temperature, light or salinity
on cell abundance.
The optimal growth conditions
for Alexandrium minutum were 100µEm-2s-1 and
16°C. There were no significant differences in vegetative growth rates
due to salinity (at 0.05 probability). Vegetative growth rates, as mean
doubling time in days, under the various treatments are listed in Table
1. The maximum cell densities in culture (2.2 x 108 cells L
-1 ) were comparable to those in the main dock area,
but lower than in the sheltered embayments . The effects of temperature,
light and salinity are graphed in Figures 2-5.
Alexandrium minutum showed optimal growth in culture at 100 µE m-2s-1 and 16° C, was tolerant of salinity between 21 - 35‰, and its growth significantly increased with nutrients. The temperature range in spring and autumn when A. minutum blooms in the Port River is 14 - 19°C. Its blooms typically develop from mixed blooms in which another species has been dominant . Work in progress indicates that A. minutum does not compete well in mixed cultures at warmer temperatures., and that shading is an important factor in this. In the Port River, subsurface dinoflagellate blooms are found at a depth of 3 - 4 m for nine months of the year, with Alexandrium minutum the dominant species in spring and autumn. When the water column is stable the blooms ascend towards the surface and high cell densities are found in the upper 4 m. Vertical migration has been reported for Port River dinoflagellates . Dinoflagellates require higher irradiances than other phytoplanktonic groups; subsurface blooms form in narrow bands ca. 1 m thick because of self shading effects . Temperature is important, both because of its direct affects on metabolic rates and indirect affect on the vertical stability of the water. In winter (9 - 10°C), very few dinoflagellates are present in the Port River. Nutrient levels found where the blooms occur are 0.43 mg/L oxidised nitrogen and 0.55mg/L total phosphate, levels comparable to the concentrations which promoted rapid vegetative growth in culture. Most photosynthetic dinoflagellates also need external organic compounds: usually the vitamins B12, biotin and thiamine. Other substances found in soil extracts are sometimes required in small amounts presumably as catalysts . Vitamins may be introduced in land runoff or produced in situ by bacteria and other algae . In this study, soil extract increased growth of Alexandrium minutum, but not significantly.
Similar studies with other species, e.g. Gymnodinium catenatum, demonstrated optimal growth occurred in culture under similar conditions . The mean doubling time of 2.2-3.3 days (under optimal conditions) for A. minutum was a little faster than the 3-4 days cited for G. catenatum. The conditions which result in maximum excystment may not be those which promote rapid growth; a time lag may occur between excystment and maximal cell division . Dinoflagellates have relatively low growth rates. Taylor  reports that it is not uncommon for a bloom to take weeks to develop. Gymnodinium catenatum in Tasmania was confined to humus-laden rivers, its blooms being more extensive in years with heavy rainfall.
The seasonal timing and abundance of
resting cyst germination did not appear to be linked, in contrast to findings
for Alexandrium tamarense [8-10] and Gymnodinium breve 
which showed a close link between cyst germination and bloom events. In
the Port River, this latter link occurs for Alexandrium minutum. Optimal
conditions for excystment of Alexandrium minutum are 14 to 21‰ and
16°C, conditions which occur near the sewage effluent outfall in spring
and autumn . Nutrient concentrations were not important for excystment.
These conditions differ a little from those which are optimal for rapid
vegetative growth in culture. Large bloom events are triggered when heavy
rainfall combines with the low salinity effluent to increase the germination
of cysts in the upper reaches of the river. Rapid vegetative growth occurs
in the high nutrient water when followed by calm, sunny weather. Thus,
sewage effluent appears to play a dual role, both in the germination of
cysts and in the first outbreak forming subsurface blooms. Management strategies
for this river require removal of this effluent.
This study was funded by the Port Adelaide
Industrial Land Committee and The University of Adelaide. I wish to thank
Dr. A. Cheshire of The University of Adelaide's
Department of Botany for encouragement and assistance with analysis of
data and Dr. S. Blackburn and Dr. G. Hallegraeff of CSIRO, Hobart for helpful
1. J.A. Cannon in: Toxic Phytoplankton
Blooms in the Sea, T.J.Smayda and Y. Shimizu, eds. (Elsevier, New York
2. J.A. Cannon in: Toxic Marine Phytoplankton,
E. Granéli et al., eds. (Elsevier, New York, 1990)
3. A.R. Loeblich, III, J. Phycol. 11:
4. F.J.R. Taylor in: Biology of Dinoflagellates,
F.J.R.Taylor, ed. (Blackwell Scientific Publications 1987) pp 399-502.
5 S.A. Blackburn, G.M. Hallegraeff,
and C.J. Bolch. J. Phycol. 25: 577-590. (1989).
6. G. Gaines and M. Elbrächter
in: The Biology of Dinoflagellates, F.J.R.Taylor, ed. (Blackwell Scientific
Publications , Oxford, 1997). pp. 224-268.
7. D.G. Swift in: Physiological Ecology
of Phytoplankton, I.Morris, ed. (Blackwell Scientific Publications, Oxford,1980).
8. D.M. Anderson, J.Phycol. 16,
9. D.M. Anderson, S.W. Chisholm and
C.J. Watras, Mar. Biol. 79, 179-189 (1983).
10. D.M. Anderson, and F.M.M. Morel,
Estuar. Coastal Mar. Sci. 8, 279-293 (1979).
A Study Of Anatomical And Lifestyle Diversity Within The Fish Order
Sharon L. Drabsch,
School of Biological Sciences, Finders University of South Australia.
The order Scorpaeniformes includes both the frequently encountered fish varieties such as scorpionfish, gurnards, stonefish and flatheads, and rarely seen, unusual varieties such as the velvetfish, prowfish, pigfish and blobfish. Gross morphology varies substantially between the distinctive families of this order.
Due to a lack of information available (to me) on comparative internal anatomy, the anatomical features considered in this study were restricted to external characteristics. Flinders University's marine aquaria collection included some Gymnapistes marmoratus (Soldierfish) and juvenile flathead. Hence, the behaviour and functional anatomy of these species were studied first hand. For other species, behaviour and functional anatomy were proposed from photographs and comments found in the literature.
The anatomical features considered were:
*fin types, shape and structure
*size and position of eyes and mouth
*teeth, scales, spines and the lateral line
*specific gravity and colouration.
The lifestyle factors studied and related to anatomy include:
*specific habitat of the fish (benthos or pelagic zone; rocky, sandy or reef ocean floor; water depth)
*food and feeding strategies
*protection from predators
*ventilation of the gills
*use of fins.
A bony ridge (suborbital stay), that runs lengthwise below the eye from the third suborbital bone to the preopercle, is used to assign the 29 families of fish to the order Scorpaeniformes (Gomon et al, 1994). Hence, this characterisic is considered to be ancestral. This study concentrates on the nine families that occur in southern Australian waters (Gommon et al, 1994).
Most Scorpaeniforme species are benthic (sea floor) dwellers of the neritic (continental shelf) zone, and are found in rocky, sandy or reef areas of all but the coldest oceans. They are ambush predators of small crustaceans and fish. Their habit of burying themselves in the sand or hiding amongst rocks, weed or coral, plus cryptic colouration, shape and stillness, serve to avoid detection by both prey (so that prey will come within "striking distance") and predators. The eyes, which are large in most species, are positioned dorsally on the sides of the head (may protrude above the dorsal profile). This would serve to improve upward vision for detection of prey and predators; species that bury themselves in the sand, as observed in Platycephalidae (flatheads), may have only their eyes exposed. The terminal mouth is often large and angled upwards, with small, numerous teeth, which would serve in the capture of prey swimming above.
Body shape in the families Aploactinidae (velvetfish), Gnathanacanthidae (red velvetfish) and Pataecidae (prow- and indian-fish) is compressed, ie. flattened from side to side, to varying degrees. Along with a strong resemblance to seaweed, this indicates a benthopelagic (free swimming near the sea floor) lifestyle. In Platycephalidae, the body and especially the head, is depressed ie. wide, which suits a benthic, burying fish. In all families, the body usually tapers posteriorly, from rather thick and/or deep anteriorally to a shallow caudal peduncle.
The dorsal fin of most velvet-, prow- and indian-fish is long and continuous, which serves to aid in disguise. The three-fin velvetfish has a dorsal fin in three distintly separate sections. In Scorpaenidae (scorpionfish), Triglidae (gurnards) and Gnathanacanthidae, the dorsal fin is deeply notched into two sections, and serves as protection against predators, as the anterior dorsal fin section spines are strong and venomous, with the ends not joined by membrane. Platycephalidae have two separate dorsal fins.
Pectoral fins are large, with considerable range of movement in scorpionfish. Gurnards have very large pectoral fins which fan out horizontally, and often have colourful markings that would serve to warn potential predators of the fish's toxicity (poisonous spines). Some gurnards have a large dark spot on each pectoral fin or on the anterior dorsal fin which may resemble a large eye, hence acting to deter predators. The lower pectoral rays of gurnards and some scorpionfish are thickened and unbranched which would make them more robust. Scorpionfish use their pectoral, ventral and to a lesser extent, anal and caudal fins, to prop themselves up on the substrate, and erect the dorsal fin in defence when threatened. In gurnards, the lower pectoral rays are also unconnected and agile, and are used for "walking" along the seafloor. Flatheads use their moderately small pectoral fins and long ventral fins to bury themselves in sand.
Caudal fins of Scorpaeniformes are usually rounded, a shape that is probably more robust and hence less likely to be damaged by the rocks and substrate that this order lives amongst. Anal fins usually resemble the posterior caudal fin or section. Prowfishes do not have ventral fins (Gommon et al, 1994).
Flatheads, scorpionfish and gurnards can flatten all of their fins against the body (caudal fin folds to lie straight out from the body, along/under the substrate) to aid in hiding. In the observed soldierfish and flatheads, all fins except the caudal (tail) fin were flattened against the body when swimming fast. G. marmoratus used all fins to aid in manoeuvring when swimming slowly or maintaining a suspended position in the water. The pectoral fins generate lift when angled slightly downwards posteriorally.
Scale coverage varies, from absent in many families, to restricted to the lateral line, to small and covering most or all of the body. The lateral line scales are usually larger than adjacent scales, probably reflecting their modification as an opening to the water for the sensory pits. The lateral line is straight in all species, but faint in the scale-less fish. Spines are common on the suborbital stay, opercula and other areas of the head, especially in scorpionfish.
With the mouth held slightly open and opercula movement slight, ventilation of the gills was barely perceptible in the observed fish, which would act as a further aid to avoid detection. The observed fish tended to sink when swimming ceased, which indicates negative buoyancy. This would help the fish return to, and maintain, its position on the bottom, even when currents or waves are acting to suspend or move the fish. This is supported by Aleev (1969) who listed the specific gravity and buoyancy of many fish species including Scorpaena porcus (family Scorpaenidae). He found this species to have a specific gravity of 1.07, which gave the fish a buoyancy of -0.06 after taking into account the specific gravity of the water in which the fish was caught (1.01). Wedging in amongst rocks, coral or burying would aid in maintaining a position on he bottom also. Pelagic fish are expected to be neutrally bouyant, to aid in maintaining their position in the water column.
Colouration functions mostly in camouflage, with the rocky and reef area benthic fish having patches to match the substrate, and sandy area fish being generally of lighter colour with small spots. Camouflage in G. marmoratus included a brown-black stripe running across the top of the head and down the face over the eyes, making even the eyes difficult to detect. The benthopelagic fish are shaped and coloured to resemble the seaweed or rocks that they inhabit. As previously mentioned, bright warning colouration is present in some species (gurnards). When feeling threatened, the colouration is displayed by fanning out the coloured fins. When waiting for prey to approach, the colourful fins can be folded in to avoid detection by the prey. Sexual dimorphism was not observed in any Scorpaeniforme species, but differences in colouration between juveniles and adults, or individuals from different areas was evident in a number species.
Correlations between form and function were evident in the diverse species of the order Scorpaeniformes. Most species are benthic and not equipped for active hunting or fleeing quickly from predators. Thus, they tend to have camouflaging shape, features, colour and behaviour that blend in with the environment, to prevent detection by both prey and predators. Venomous and non-venomous spines on most of the benthic species, with warning colouration in some that can be displayed when threatened or vulnerable, would also protect the fish from predation. Fin morphology also depends upon lifestyle, with the benthic fish having strong, large and agile lower fins for support on or amongst rocks or coral, or for burying into sand. The benthopelagic fish have fins that aided in disguise amongst seaweed. Buoyancy tended to help maintain the fish in its particular habitat, with benthic species being negatively buoyant. Hence, these fish exhibit many distinct anatomical and behavioural adaptations that can be attributed to lifestyle.
*Aleev, Y.U. (1969) Function and
gross morphology in fish. Keter Press, Jerusalem.
*Gommon, M.F. (1994) The fishes of
Australia's south coast. State Print, Adelaide.
The Sketches of the fish are by Sharon
The Dusky Morwong or Strongfish
HEAD OF SCIENCE
Most people diving or snorkelling on reefs, drop-offs or jetty piles around the southern coasts of Australia, and especially spearfishers in the past, will have seen these rather slow moving, yet graceful fish. Unlike its relative, the Blue Morwong, Dusky Morwong are found in relatively shallow water of up to about 20 metres, both amongst the sea grass beds and on rocky reefs, often resting on the bottom. It is this habit, combined with their size, which makes them an easy target for young spearfishers, and in conjunction with gill netting practices, stocks of the Dusky Morwong have been heavily depleted.
The Dusky Morwong belongs to the Cheilodactylidae Family, a group known collectively as the Morwongs, and which includes the Magpie Perch (Goniistius vizonarius), The Jackass Fish, (Nemadactylus macropterus), and the Blue Morwong (Nemadactylus valenciennesi).
There are a number of structural features which characterize these fish. The lower rays of the pectoral fin are unbranched and thickened. The body is fairly long and shallow, and compressed, with a very shallow caudal peduncle (the stalk or base of the tail). The caudal fin is forked and has pointed tips. The dorsal fin is continuous, with a distinct notch between the taller spinous and the smaller soft sections. On the head, there are neither bony knobs or scales on the snout or in front of the eyes. The mouth is relatively small and does not reach back to below the eyes. The lips are thick and fleshy, and there are bands of small pointed teeth on both jaws. The pectoral fin is long with the lower six rays thickened and unbranched and projecting a short distance beyond the pectoral membrane.
Body colour varies with age. Whereas adults are a uniform silver grey, juveniles and immature morwongs have spots scattered on the body, dark bars across the operculum, and six or seven broad oblique bars on the upper body parts.
The Dusky Morwong has a number of local names - some complimentary, and some not, often relating to the taste of the dark, strong-smelling flesh of large adults - butterfish, shitfish, strongfish. Aboriginal names are also applied - nunda and tillywurti.
Many people confuse the Dusky Morwong with the Jackass Fish, and sometimes Morwong flesh has been sold as sea bream or silver bream. The flesh of the young Dusky Morwong is white and tasty - they feed on molluscs, worms, and crustaceans such as prawns.
Their habitats are the shallow coastal waters between Sydney and Lancelin (W.A.), as well as the Bass Strait coast of Tasmania.
Who, as a diver, can ever forget the sight of stationary Dusky Morwong resting on or near the bottom, watching the diver's every move, and not moving off until the last minute. They seem to have a sense of presence when underwater flash bulbs go off, and are much photographed fish.
It is also said that they seem to have a great affection for their "mates", as they have been observed staying near and nuzzling a speared and dead swimming partner, unaware that the spear has ended that friendship.
The Dusky Morwong is quite a large,
docile and yet graceful fish. It is gratifying to know that our spearfishing
laws in South Australia are going a long way to protecting the species,
and hopefully numbers will gradually increase to more population-viable
Our slide collection of South Australian marine fish species has increased by 30 slides since our 1997 Journal. These slides are listed in this issue for your interest. A few of the slides listed in the previous Journal are being repeated in this issue because the details have been changed. This list then, when combined with the previous list, provides readers with the details of all the 123 fish slides in our Photo Index.
We have now begun to expand our Photo Index to include common marine invertebrates and algae. A number of slides of invertebrates are being worked on at present and will be presented in a later issue.
The Index has been used often recently for talks, presentations and displays, etc.. All slides are being reproduced on our webpage on the Internet. Narratives for each slide will be added to the webpage so that it will become an educational site.
We are indebted to Society member David Muirhead who has taken all but one of the new fish and invertebrate slides. The other slide came from a friend of David's.
Other Society members are participating in the Index by selecting slides, identifying species, getting the slides on to our webpage, writing narratives, etc..
The Index is only made possible by the generous assistance of Duckpond who are helping with the duplication of slides.
Two sets of slides make up the Index.
There is a Master Set and a Working Set.
Photo Index Officer 1997-8
Exploitation of Marine Flora and Fauna
by Tony Flaherty
with extracts from correspondence with Peter McGlone, Threatened Species Network Tasmania,
and Dr Amanda Vincent of McGill
When people think about the use of wildlife and the environment they often think about things they are familiar with. Typically many people don't think beyond the shoreline when it comes to plants and animals and threatening processes. In the marine environment it is very difficult for us to fully appreciate the environment and where organisms fit into it. On land we can sit back and look through to the horizon, and explore and study its plants and animals with relative ease. Once we get underwater, we cannot usually see beyond five to thirty metres, it is hard to visualise a seascape. As individuals even if we venture beneath the waters, we can only really see small pieces of it, and studying even its more common inhabitants can be difficult.
One of the questions we could ask is about how we deal with marine organisms when it comes to exploiting them? Legally we rarely treat native marine fish as "wildlife". Most are covered by laws or regulations that only relate to their exploitation as food. However relatively few species are actually fished commercially. It is only relatively recently that fisheries managers have looked towards a more holistic means of managing both the fish stocks and their habitat.
On the land legislators and managers have thought differently. Most native, terrestrial, vertebrate wildlife is protected under some form of national or state legislation and there is usually some form of federal legislation regarding export. Whilst typically an exemption or permit is needed to take native birds, reptiles or mammals, and plants in most states, this is not the case with native marine fish.
It is only recently that an Australian marine fish, the Spotted Handfish (Brachionichthys hirsutus) has been declared endangered. This set something of a precedent for the listing of marine fish in Australia.
This small fish has a restricted distribution in the Tasmanian Derwent River and bays. The handfish is at risk because of its small population size, and its habit of laying its eggs on the sea floor. Tasmanian researchers fear that the North Pacific Seastar (Asterias amurensis), may be a culprit in the decline of the Spotted Handfish. The seastar is thought to have been introduced by foreign ships in ballast water. Its numbers have risen rapidly in the Derwent estuary and there is concern that Pacific Seastars may be consuming the eggs of the handfish. Just as on land feral pests can impact on our native species. As a species becomes rare there is also the added risk that it will be targeted by specialist collectors for the aquarium trade or even for scientific collections.
Recently the Federal Environment Minister Robert Hill announced that the Commonwealth will introduce important export restriction measures of some of Australia's unique syngnathid fish, the seahorses, seadragons and pipefish.
For several years a number of national and international organisations have campaigned for the protection of syngnathid fish under the Commonwealth Wildlife Protection Act by removing them from Schedule 4. Wildlife on this list, which includes marine fish, are basically exempt from export restrictions. Removing them from the schedule will actually increase protection by placing an obligation for assessments and monitoring of the export trade.
This can be seen as an extremely timely and enlightened initiative. Hopefully this leading initiative will also encourage the state fisheries agencies to initiate stronger protection measures. Strong precautionary measures are required to regulate the numbers of seahorses, seadragons and pipefish taken from Australian waters and facilitate monitoring, documentation and further research.
Leading global seahorse expert, Dr Amanda Vincent has stated there is a need to develop precautionary legislative frameworks for seahorses and other syngnathid fish at the state and federal level. The growing gap between demand and supply in nearby Asian nations makes it inevitable that Australian Syngnathids will come under increasing pressure.
Dr Vincent commented: "Australia has prime responsibility for the conservation of seahorses because about one third of the world's seahorse species occur in their waters". Dr Vincent believes that Australia is unusual among seahorse-rich nations, because it has both the legislative and legal ability to control the trade of seahorses properly and because few or no people currently depend on the trade. Thus Australia offers a potential buffer against the eventual disappearance of seahorse populations and species.
Internationally, the members of the Species Survival Commission of the International Union for the Conservation of Nature (IUCN) have included the Spotted Handfish, and a number of other marine fish species on its Red List of Threatened Animals. A number of these are found in Australian waters, including Great White Shark (Charcharodon carcharias), Bluntnose Sixgill Shark (Hexanchus griseus), Southern Bluefin Tuna (Thunnus maccoyii ), Big bellied Seahorse (Hippocampus abdomonalis), White's Seahorse (Hippocampus whitei) and Robust or Gunther's Pipehorse (Solegnathus robustus).
While much research is conducted on fish in Australia, most of this research is with commercial species. Consequently, very little is known of the lives of even the most common, non-commercial species.
With regards to marine invertebrates and plants, there is limited knowledge of the species and often even less management. Over two hundred taxa of Australian molluscs such as cowries, coneshells and tritons are considered vulnerable (Jones & Kaly). World wide, many shellfish are targeted for the trade in shells as collector's items and tourist curios.
In the marine environment, the benefits of listing individual species as "protected" may be limited if it is not carried out in conjunction with adequate habitat protection such as no-take marine reserves, where threatening processes can be excluded or controlled.
Many marine organisms are naturally rare or have a low local abundance (although not all rare species are necessarily endangered). Just as on land, our seas have many variables and micro-habitats that determine where certain plants and animals can live - water temperature, salinity, light, bottom type, currents, and nutrients. So if pollution or other habitat impacts occur, some species may not simply be able to move to another patch of sea.
World wide there is concern over the
decline of marine ecosystems such as coral reefs, seagrass and kelp communities,
sheltered bays and estuaries. Some of our giant kelp communities (such
as Macrocystis) may be susceptible to forest die back possibly due to siltation
and rising ocean temperatures.
A CASE STUDY
Exploitation of Syngnathid Fish
There is a growing concern for the protection of seahorses, pipefish and seadragons (called Syngnathid fish) in Australian waters. These fish are threatened globally by habitat destruction and are also the target of a growing trade for aquarium fish and Asian medicines. International trade for syngnathids involves more than twenty countries worldwide, with the taking of seahorses for Traditional Chinese Medicine estimated at 20 million animals each year.
Many of these fish stay in the same small area, and stay with the same partner, particularly when breeding. Seahorse populations for most species tend to be low, although some areas may support many animals at certain times. Seahorses will probably be slow to recolonise areas from which they have been removed.(Vincent 1996).
As virtually nothing is known about the status of these fish in Australian waters, a precautionary approach must be maintained if these species are to be exploited from Australian waters. Most state governments fail to monitor the commercial exploitation of such fish. Even if fisheries departments knew the level of fishing, there is little information available on stock levels and likely impacts of fishing on which to adequately assess its sustainability.
If culturing of the species is to be undertaken, there must also be mechanisms or formal processes for export and marketing established to ensure that wild stock are not over-exploited, and that any exploitation can be assessed and monitored.
Tasmanian fisheries managers have recognised that commercial harvesting of such species has the potential to significantly reduce a local population. Such an impact could lead to "commercial extinction" (where the animal is no longer able to be exploited) and perhaps the failure of the remaining fish to reproduce successfully. (DPIF Policy Document & Fishery Development Plan for the Tasmanian Marine Aquarium Fishery).
With the apparent increased demand in
commercialisation of species there would appear to be an urgent need for
the Commonwealth and State fisheries managers to adopt a policy document
and fishery development plan on marine aquarium and fisheries to supply
Traditional Chinese Medicines (TCM).
It is hoped such initiatives would incorporate strategies to:
Leading Australian conservation agencies have asked for increased regulation of the trade in fish species following Dr Amanda Vincent's report on the International Trade in Seahorses, (Traffic Oceania and World Wide Fund for Nature, 1996). Whilst there is anecdotal evidence of a large trade in seahorses in Australia, no government other than Tasmania appears to regulate the catch or ecological impact of this trade.
There is a need to develop precautionary legislative frameworks for seahorses and other Syngnathids at the state level. The growing gap between demand and supply in nearby Asian nations makes it inevitable that Australian Syngnathids will come under increasing pressure.
However even if aquaculture of seahorses in Australia is successful it may be of little help in reducing the problem of seahorse decline in other countries. Overseas, as other food fish stocks have declined, poorer fishing communities have switched to harvest seahorses to supplement their incomes. However the high tech methods of culturing that may be developed in Australia will be of limited use in these communities.
With at least 11 species of seahorse
occurring in Australia, there is a great opportunity to lead the way in
controlling and monitoring syngnathid exploitation.
Lack Of Export Controls
Peter McGlone, the Tasmanian Coordinator of the National Threatened Species Network has been trying to encourage the adoption of export controls for syngnathid fish.
In 1992 a proposal by the Commonwealth Government's Australian Nature Conservation Agency was submitted to protect all syngnathid species under the Wildlife Protection Act 1982. Protection under the Wildlife Protection Act 1992 is the absolute minimum required of the Commonwealth to ensure the survival of our exported wildlife species. This is not a total ban and responsible traders and fishers that show their activities to be sustainable have nothing to fear. Removal from Schedule 4 of the Act is the sensible safeguard against a possible expansion of the trade in Australian species, illegal traders and lack of action by state or territory governments.
As mentioned, the Spotted Handfish has set a precedent in Australia with its listing as an endangered marine fish. As an endangered species, it can no longer be exempt under the Wildlife Protection (Regulation of Imports and Exports) Act 1982. As discussed most recently the recent rescheduling of syngnathid fish sets a precedent in managing the export of a marine fish.
The Importance of Commonwealth Intervention
Firstly, the protection by the Commonwealth Government is critical as not all state and territory fishing authorities may implement controls under state laws.
Secondly, even if these controls were implemented, the level of monitoring and policing for minor fisheries in most states is generally ineffective and exploitation would be likely to continue unchecked. The level of monitoring is inadequate in many states.
Thirdly, even if all states provided
strong protection there will be illegal take and controlling the export
of illegally taken wildlife is the responsibility of the Commonwealth.
This policing role can only be undertaken if species are protected under
the Wildlife Protection Act.
Schedules Of The Wildlife Protection Act
Here, very simply, is an explanation
of the relevant differences between the four key schedules of the Wildlife
Protection Regulation of Imports and Exports) Act 1982. This is provided
by Jon Bryan and Peter McGlone.
Live native Australian vertebrate animals: import/export permit granted only for:-
- inter zoo transfer; or
- prescribed scientific research. Other than live native Australian vertebrate animals: import/export permit granted only:-
- for inter zoo transfer; or
- for prescribed scientific research;
- where the specimen is, or is derived from, a live animal that was bred in captivity.
Live native Australian vertebrate animals: import/export permit granted only:-
- for inter zoo transfer; or
- for prescribed scientific research;
- when it satisfies criteria in section 16 as a household pet.
Other than live native Australian vertebrate animals: import of export permit granted only:-
- for inter zoo transfer;
- for prescribed scientific research;
- the specimen is, or is derived from, a live animal that was bred in captivity;
- the specimen is, or is derived from, an animal specimen that was taken in accordance with an approved management program.
Animals: import/export permit granted only:-
- for inter zoo transfer;
- for prescribed scientific research.
Species exempt from the Act.
Our knowledge of our seas and oceans
is still extremely limited. Even more limited is our knowledge of how to
conserve and manage marine habitats. Globally, we have a poor record of
managing marine fisheries, particularly in recent years with the rapid
increase in mechanisation and technology. In the marine environment, our
management is usually limited to managing the fishers or other extractors
rather than the actual stocks or habitat. Typically the levels of exploitation
of a new marine resource are greater than our ability to research the biology
of the species, let alone the ecosystem it is a part of.
A Solution? Marine Protected Areas
Protecting an individual species can offer a short-term solution by raising awareness or minimising direct impact on that organism. However the long term solution must be the management of human activities and the protection of habitat.
The loss of habitat has been one of the most significant factors affecting our marine environment and its fisheries. With more and more people there is increasing pressure on our coasts and marine life. One of the ways we can manage and conserve our marine environments is through the creation of marine protected areas. These can protect many different types of marine environments and their plants and animals.
Marine protected areas can protect fish from human disturbance in important nursery areas, to help them spawn and grow. They can protect special creatures and plants that may live in or use certain areas, or simply save parts of an ecosystems from disturbance and impact. They can also provide unspoilt natural places for people to visit and offer areas for education and research.
Many marine researchers feel there is a need to have large areas managed and protected throughout all of the major types of marine ecosystems or bio-regions in Australia. There is a growing public awareness of the need to ensure our marine environments are adequately protected and conserved.
On land, the historic, rapid development of agriculture and industry has lead to many of our unique landscapes being altered or lost. We have a great opportunity not to repeat the process in our seas. With the rapid development of marine industries we need to ensure that our unique "seascapes" are conserved, and that developments that may impact on them are managed in an environmentally sound way.
Marine conservation is still in its
infancy. In Australia, just as our terrestrial fauna and flora is unique,
so too is our marine wildlife. The "Precautionary Principle"
is a concept often discussed but rarely implemented. Over fifty years ago
the pioneering American forester and conservationist Aldo Leopold voiced
that that the first rule of intelligent tinkering is saving all the parts.
On land we have a National Parks system that was built primarily on the
leftovers of exploitation, land clearance and degradation. In the sea we
have the great opportunity to start saving all the parts, by establishing
effective management and creating a representative system of marine protected
References and Further Reading
Allen, T. 1996, Marine Protected Areas, coming in from the cold in Southern Temperate Australia, Case Studies In Biodiversity and Ecologically Sustainable Development, Australian Association for Environmental Education.
Garson, Dr M. 1997, "Marine Resources : Cure-all or Lose All" in Nature Australia, Australian Museum, Autumn.
Jones G.P. & Kaly U.L. 1996, Conservation of rare, threatened and endemic marine species in Australia, in The Marine Environment, Technical Annex 1, The State of the Marine Environment Report for Australia, Department of Sport And Territories.
International Union for the Conservation of Nature, 1996 IUCN Red List of Threatened Animals.
Our Sea, Our Future, the major findings of The State of the Marine Environment Report for Australia, 1996, Department of Sport And Territories.
Sant G. and Hayes E. editors. 1996, The Oceania Region's Harvest, Trade and Management of Sharks and Other Cartilaginous Fish, an Overview, Traffic Oceania.
Shark News, the Newsletter of the IUCN Shark Specialist Group, available by paid subscription or donation contact IUCN Shark Specialist Group, The Nature Conservation Bureau Lt,
Tasmanian Dept. Primary Industries Fisheries. 1996, Policy Document & Fishery Development Plan for the Tasmanian Marine Aquarium Fishery.
Vincent, Dr A. 1996 The International Trade in Seahorses, Traffic International, World Wide Fund for Nature.
"Waves" Newsletter, The Marine
& Coastal Community Network, (contact your MCCN state coordinator).
Some Marine Fish Species found in
Australian waters that have recently been listed on 1996 IUCN Red List
of Threatened Species.
Great White Shark, (Charcharodon
carcharias). Protected in NSW and Tasmanian waters, commercial catch
prohibited in SA, vulnerable status recognised and protected status enacted
in South Africa, Florida and California, recently listed on IUCN Red List.
Vulnerable due to declines in extent of occurrence world wide and decline
in habitat, and actual levels of exploitation and by-catch. Reduction of
up to 80% estimated over next ten years. (Sarah Fowler, IUCN Shark Specialist
Bluntnose Sixgill Shark, (Hexanchus
griseus). Recently listed on IUCN Red List as Vulnerable, open oceanic
species recorded from some Australian sites.
Southern Bluefin Tuna, (Thunnus
maccoyii ). Population reduced, and levels of exploitation.
Spotted Handfish, (Brachionichthys
hirsutus). Population reduced, decline in area of occupancy, quality
of habitat, actual or potential levels of exploitation, effects of introduced
Big-Bellied Seahorse, (Hippocampus
abdomonalis). Recently listed as Vulnerable on Red List, with expected
reduction of 80% in the next ten years due to actual and potential levels
of exploitation, (Vincent)
White's Seahorse, (Hippocampus
whitei). More a warm water species, occurs rarely in SA, recently listed
on IUCN Red Listing, Vulnerable.
Robust or Gunther's Pipehorse,
(Solegnathus robustus). Endemic to Southern Australia, recently
listed on IUCN Red List as Vulnerable due to exploitation, with possible
reduction of 80% in the next ten years due to actual and potential levels
of exploitation. (Vincent)
Note While not yet listed by the IUCN
the Grey Nurse Shark, (Carcharias taurus) has undergone severe
depletion in numbers in eastern Australia, protected in NSW, listed as
Vulnerable by Aust. Soc. for Fish Biology.
Whale Shark, (Rhincodon typus).
Weedy Seadragon, (Phllopteryx
taeniolatus). Endemic to southern Australia.
Leafy Seadragon, (Phycodorus
eques). Endemic to southern Australian waters.
Short-headed or Shortsnout Seahorse, (Hippocampus breviceps). Endemic to Southern Australia.
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