MLSSA

Newsletter

AUGUST 2001

No. 280

"Understanding, enjoying & caring for our oceans"


 

Next Meeting 15/8/01

The next meeting is the August General Meeting which will be held at the Conservation Centre, 120 Wakefield Street on Wednesday 15th August commencing at 7.30pm.

 

Our speaker for the evening will be John Hill MP, the opposition spokesman for the Environment. He will be discussing the Labor view of the problems associated with the Environment and will answer questions put to him by members. With an election to be held soon and the possibility of a change of government, this is your opportunity to make your views known in a small group.


 

Contents

Soft, Transparent, Floating Jelly Things (stfj’s)

Some Interesting Mapsites

Nicolas Baudin Onboard "Le Geographe" In 1802

Tiny Town Takes "Tidy Town" Trophy

Seahorse, Hippocampus ramulosus/Les Minquiers

A Seadragon’s Tale


 

2002 Calendar

The 2002 calendar should be available at the August General Meeting. The Committee has determined a sale price of A$10.00, which is a considerable reduction on this year.

Members will be able to purchase personal copies at a discount price of A$8.00.

We ask members to take an initial 25 copies to purchase or sell and hope everyone will ask for more later.

If commercial enterprises wish to sell on our behalf then please put them in touch with me.

Philip Hall


 

Soft, Transparent, Floating Jelly Things (stfj’s)

At various times of the year, our coastal waters become inundated with stfj’s of various kinds. Between them they consist of two phyla. I have always been a little confused about these stfj’s, I knew what they were, but was often a little fuzzy on their relationship to each other, so I guess I’m writing this partially to do a little revision for myself and as a reference for all of you.

As I’m sure you have all experienced, common names for organisms can cause much confusion and often do not accurately delineate one or other organism. So in Australia we have a fairly large number of organisms that are generically called ‘jellies’ but as mentioned before actually belong to two different phyla and falling into at least four different classes.

The largest contingent belong to the Phylum Cnidaria (silent C). The thing about the Cnidaria is that all the organisms in this group have virtually the same life cycle (at a very basic level) with both medusoid and hydroid stages. What separates jellies from animals like hydroids, anemones and corals (which are all cnidarians) is that hydroids, anemones and corals all live mainly in the hydroid form, attached to a substrate for the majority of their life. Whereas jellies spend the main portion of their life as a medusa – they are basically upside down anemones, if you like. The bell (main body) is equivalent to the column of an anemone, they both have a mouth in the middle of the body (a one-way system) with digestive organs and gonads inside the body. Both kinds of organism also have tentacles with stinging cells for catching prey.

The traditional ‘jellyfish’ belong to two classes: Class Scyphozoa and Class Cubozoa. As you can probably tell, the Cubozoa consist of the box jellies (‘cubo-’), which are typically box-shaped, with often only four tentacles, one each trailing from each ‘corner’ of the bell. There is only one species listed in Edgar’s ‘Australian Marine Life’ as having been recorded in southern temperate waters, Carybdea rastoni Haacke, which is also widespread in the Indo-West Pacific region. The Cubozoa are most famous for the sea wasp (Chironex fleckeri) that ‘terrorises’ swimmers off Australia’s tropical beaches each summer. It is most dangerous for two reasons: 1) it has very long tentacles (up to 3m) that are seemingly invisible, and 2) it carries an extremely strong toxin in those tentacles. The toxin is a large molecular weight protein that attacks the cardiovascular system, so victims often die of respiratory failure.

The Scyphozoa contain the classical jellies with long tentacles or large oral arms. This group is largely unclassified, with unknown specimens being collected every year. Only about 200 species have been officially classified, but there are many more awaiting discovery. The translucent bell and numerous long, thin tentacles trailing underneath it can identify these traditional jellies underwater. They are usually not completely transparent, with often a little colour inside the bell. There are some species, that belong to the Order Rhizostomeae, that have large oral arms under the bell. Those species so far recorded in southern Australian waters have bells 35-50 cm in diameter, so they are not easy to miss. They appear to be bulky and quite solid, as opposed to the traditional jellies, which appear to be quite fragile.

Also in the Cnidaria are two other groups that need mentioning. In the Class Hydrozoa are two orders that contain pelagic stfj’s. Most of us are familiar with the poisonous Portugese man o’ war (Physalia physalia Linnaeus) that belongs to the Order Siphonophora. Organisms in this order are colonies of hydroids that live together to create what looks like a single organism. Within the body of the man o’ war are individual hydroid polyps that are specialised for feeding, defence, float production and reproduction. This organism is easily recognisable by its blue-purple colour and its ‘sail’ – a vertical vane that is used as a sail to push it along by the wind, as it lives in the surface layer of the ocean; it’s alternative name is ‘by-the-wind-sailor’. The toxin in its long, frilly tentacles is also proteinaceous and can deliver an extremely painful sting. The traditional remedy is to apply vinegar or water after removal of the tentacles, but this can encourage further envenomation of the stings, so according to Edgar current practice is to apply cold packs for pain relief. If the pain does not subside after approximately 15 minutes, monitor vital signs and seek medical advice. As an interesting aside, on a recent IMAX film about the sea scientists, hundreds of metres down in a deep sea submersible off California, discovered a siphonophore that was ‘as long as a football field’. The individual hydroid polyps were joined together in a chain.

The other groups of stfj’s that most people are not aware of is the Order Limnomedusae. This group consists of both marine and freshwater hydrozoans with four to six radial canals and tentacles arranged in sets around the margin of the saucer-shaped bell. I have never heard of this group before and am now keen to see one. Edgar cites two species that come into southern Australian waters, Olindias phosphorica Delle Chiaje and O. singularis Browne. The only species that would come into SA waters would be O. singularis. They both have a maximum medusae diameter of 35 mm, so they are not huge, but from the pictures in Edgar’s book they look exquisite. I believe they would be quite easily mistaken for traditional jellies.

The other group of stfj’s are the comb jellies. Most of us would be able to tell one of these from a traditional jelly, as they have quite a different structure, but for the uninitiated I shall explain the differences. The comb jellies belong to a completely different group, Phylum Ctenophora (silent C). Only a few years ago the Cnidaria and Ctenophora were grouped together as the Coelenterata, but science finally made up its mind to separate the groups completely.

Ctenophores are exclusively marine, lack stinging cells (hence their separation from the Cnidaria) and most of the 100 or so species are transparent, free-swimming animals. Comb jellies are characterised by their shape, which is usually ovoid, and by the presence of eight rows of fused cilia that run vertically down the long axis of the animal. In the UK, I was taught that their colloquial name was ‘sea gooseberry’ because of their uncanny resemblance in shape. The beating cilia often appear irridescent and make these small and otherwise fairly boring creatures quite a joy to watch. According to Edgar, they are the largest animals to use cilia for locomotion. They usually have a pair of long tentacles that are invisible to us and are used for prey capture, but with a lack of stinging cells they rely on sticky cells on the tentacles that grip on contact. They eat large zooplankton such as crustaceans and even small fish.

The largest species known in southern Australia is Leucothea sp. that has a bell height up to 90 mm.

There are times during summer when comb jellies come in their hundreds of thousands to our shallow coastal waters and swimmers happily play about in the water ignorant of the stfj’s brushing against their bodies. When I have been snorkelling with these creatures in such abundance I think it is an incredible and beautiful site and of course they are completely harmless.

To quickly summarise, jelly organisms fall into four groups in two phyla:

I hope you are a little more enlightened and can now talk as if you know what you are saying. Enjoy the stfj’s.

Alex Gaut


 

Some Interesting Mapsites

I have visited many of these sites and found them quite fascinating. I cannot vouch for the validity of the entire set however. Give them a go, you may be surprised what you learn!!

http://www.whereis.com.au

http://geography.about.com/science/geography/cs

http://www.nationalgeographic.com

http://earth.jsc.nasa.gov

http://geography.about.com

http://www.odci.gov/cia/publications/factbook

Philip Hall

 


Nicolas Baudin Onboard "Le Geographe" In 1802

Nicolas Baudin was charting South Australia’s shores at the same time as the English explorer Captain Matthew Flinders in 1802. Baudin was a French Admiral in command of two ships, "Le Geographe" and "Le Naturaliste". The two vessels were conducting an around-the-world scientific expedition.

Baudin named Geographe Bay in WA after his ship of the same name when he discovered the bay in 1801.

Captain Flinders was sailing east on the brig "Investigator" whilst Baudin was sailing west onboard "Le Geographe". The two captains met off of the area of the mouth of the River Murray on 8th April 1802 before continuing their respective journeys. Flinders had already charted Spencer Gulf and Gulf of St Vincent. He had also already named Cape Jervis before it was sighted by Baudin’s expedition who chose to call it Cape Fleurieu in honour of Count M. de Fleurieu.

The Count was the French Navy Minister, Charles Pierre Claret, who had financed Baudin’s expedition. Some say that Baudin also applied the Fleurieu name to the peninsula that ends at Cape Jervis. It seems, however, that the name of the Fleurieu Peninsula only became official in 1911 when a grandnephew of Baudin visited the area.

The Fleurieu name has also been applied to one of the islands in the Hunter Group in Bass Strait off the northwest coast of Tasmania, although that island is now known as Hunter Island.

Although Flinders, as already mentioned, had already named Spencer Gulf and Gulf of St Vincent, it seems that Nicolas Baudin named a location on the west coast of Yorke Peninsula ‘Cape St Vincent de Paule’ in the region to the south of Fishermans Bay. Baudin’s expedition would also have named Spencer Gulf as ‘Golfe Bonaparte’ after General Napoleon Bonaparte and the Gulf of St Vincent as ‘Golfe Josephine’ after Napoleon’s wife, at the time, Josephine. There is a Joseph Bonaparte Gulf in the Timor Sea west of Darwin named after Napoloeon’s brother Joseph, King of Naples and Spain.

Other men that sailed with Nicolas Baudin were Henri and Louis de Freycinet, Peron and Lesueur. The Freycinet Peninsula, National Park and Mount Freycinet in Tasmania are all named after Louis or Henri de Freycinet. Baudin placed Louis de Freycinet in charge of the "Casuarina" from which de Freycinet mapped Spencer Gulf, Kangaroo Island and Tasmania.

The French scientist and explorer Francois Peron was sailing with Baudin. Peron had fought in the revolutionary army on Rhine but was wounded and taken prisoner. He had apparently lost one of his eyes by the time that he was released in 1794. He then studied medicine and joined Baudin’s scientific expedition. He is credited with being the first man to write from first hand experience a true account of Tasmanian Aborigines.

He collected many biological specimens during the voyage and classified them later on. He wrote one volume on the history of the voyage (Voy. Austr. 1807?) before he died in 1810. His work was then completed by Louis de Freycinet prior to his own death in 1842.

Charles Lesueur was an artist on the expedition by Baudin. He seems to have continued Francois Peron’s work by describing some marine fish species (together with Peron) after Peron’s death.

It seems that there was another Baudin onboard "Le Geographe" with Nicolas Baudin. Charles Baudin des Ardennes had sailed as a junior officer on "Le Geographe" under Baudin but the two were not related. The young Baudin later became an Admiral despite having his shattered right arm amputated in 1807 whilst he was a Lieutenant. The arm was amputated at Port Louis where Matthew Flinders paid him a visit.

Nicolas Baudin was so ill in Timor on the journey home that he put Henri de Freycinet in charge of "Le Geographe" for the journey to Isle de France (Mauritius). In September 1803 Baudin died at Mauritius and another officer was placed in charge of the "Geographe" for the remaining distance home to France.

Steve Reynolds

 


Tiny Town Takes "Tidy Town" Trophy

Congratulations to the people of Port Vincent on SA’s Yorke Peninsula. The town (pop. 460) has won a major Australian Tidy Towns award. Port Vincent took out the 2001 award for Excellence in Environmental Education. The town had used several initiatives that focused on the marine environment, their school grounds and involvement with the local community. The title of the town’s theme was "From Farm to Foreshore". The National awards were held in Brisbane on 7th April.

Steve Reynolds


 

The following items are taken from the British Marine Life Study Society Torpedo Magazines.

2 April 2001
A Swanage lobster fisherman has just caught his second Seahorse, Hippocampus ramulosus, this week - the first was smooth, the second very fluffy! Seahorses have been reported from Weymouth Bay and the Fleet in Dorset and there are anecdotal reports of seahorses from Studland eelgrass beds, but about 20 years ago.

Report by Peter Tinsley, Dorset Wildlife Trust

 

 

Torpedo 61 July 2001

 

Les Minquiers, Southernmost tip of British Isles, area exposed at low water is awesome, reef is over 12 by 6 miles, June 10th, population one!


 

A Seadragon’s Tale

"Have you got a Leafy Seadragon?"

This is a frequently asked question in the Marine Laboratory at Hallett Cove School where senior students help junior school children to learn from marine life in the "habitats" of a 2000 litre viewing wall.

Now that the Leafy Seadragon is the official marine emblem for South Australia it has taken some of the focus from the charismatic megafauna like Right Whales, Great White Sharks, Sea Lions and Dolphins. In the process, concepts like "Leafy Seadragon Friendly Catchment Programme" are helping young South Australians to do things that help the marine environment. Landlubbers of all ages can appreciate that if we can get it right for Seadragons then we are probably on track for their habitat and the worms and other sea life that do not evoke such fascination and friendly feelings. Seadragons are masters of camouflage and most of us will go a lifetime without seeing one. And some would say…. "So what?"

A stretch limo version of a seahorse with weed like appendages and a relatively short life span is an unlikely beastie to motivate and amaze the masses. And yet the Seadragon exhibit at The Seattle Aquarium was runner up to the Microsoft funded "Experience Music" as the best tourism initiative for the year 2000 in Bill Gate’s adopted home state of Washington, USA. Voronica Whitney-Robinson is responsible for the Seadragons at The Seattle Aquarium and she was in Australia for a week in March 2001 to observe Leafy Seadragons in their natural environment….the coastal waters of South Australia.

Our first dive was at Rapid Bay near Cape Jervis where 12 minutes from entry, not one but four Seadragons were using the jetty piles to minimise the rush of an out going tide. Visibility had been affected by stormy weather so our cameras were left with the vehicle. A chance meeting with Pierre Constant under the water, a few wavy gestures and a 100 metre swim back to the northern section of the jetty and we got "the picture". There is a probability that the Seadragons in the photos are the parents or close relatives of the award winning Seadragons in Seattle. For Voronica, it was the closing of a loop because she knew that the Dragons that "flew" to Seattle before she came to Australia were collected under permit as eggs from a brooding male at Rapid Bay in January 2001. As Rapid Bay is about the only place in the world where divers have a degree of certainty to see Leafy Seadragons from a jetty, the eggs that were sourced in January could be the last of their kind.

It’s important to note that wild caught Seadragons do not fair well in captivity. Often they are doomed by pressure on their vital organs as gas in their swim bladder expands during the slowest of ascents in a few metres of water. The unrelenting flash of cameras and the confines of an aquarium can stress and kill wild caught animals even when they survive transfer from the ocean. Getting it wrong can be costly to public aquariums and drive the black market trade that is around all things of value. The concern for the security of the wild population of Seadragons at Rapid Bay is fair and it has got to the point where photographic identicards are being considered for divers to keep a watch on the animals that are resident at the jetty.

The South Australian Government has given total protection to Leafy Seadragons and initiatives are in place to afford the same status to Weedy Seadragons. Only one institution has reportedly bred Leafy Seadragons in captivity so the entire world is supplied from wild stock or captive raised animals that are taken at birth from the brood sacks of a pregnant male. Males hatch about two hundred or more eggs, sometimes twice in a season between October and February. After receiving the eggs from a female, the male incubates the eggs for about 46 days and the miniature replicas are about 3 cm long. They retain part of their yolk sack at this time and after their pug shaped snout unrolls, they can be observed feeding on tiny plankton within an hour of birth.

Growing at about 3-4 mm per day and slowing to 4 to 6mm per week hatchlings can be ready for public display within three months and the survival of captive raised specimens is much better than those in the wild. We saw Seadragon enemy number one on the north coast of Kangaroo Island. It is the blue throated wrasse, a wily, hyena like fish that hangs back from a brooding male and grabs the newborn Seadragons as they hatch and sometimes from the male’s tail before they hatch. Perhaps it could be argued that the natural predators of Seadragons are not so much the enemy as our increasing fascination and interest in these weird creatures.

Jim Thiselton is a guardian for the Seadragons of Kangaroo Island. He hosts divers and film makers from all over the world to experience the animals that he has recorded with hieroglyphics in his log book. One Seadragon that we were introduced to was no stranger to divers after seven years of regular contact and Jim carefully inspected the ol’dragon for parasites and other discomforts as one would do for a good friend. The north coast Seadragons have "addresses" and Jim calls in on them all. He has a knowledge of the day that eggs were transferred from "mum" to "dad", the day that individuals were born and where the young dragons grew up in the hidden forests of kelp. The scientific literature does not document the detail that must be in Jim’s head and, for now, Jim’s ecotourism operation is affording the Seadragons of Kangaroo Island a higher level of protection than state law that is in place to do the same.

South Australia is the only State in Australia without a venue like The Sydney Aquarium or an Underwater World. Non divers can watch the graceful movement of Leafy Seadragons in Western Australia, Melbourne, Sydney, the Sunshine Coast, Singapore, Seattle, Chicago, New England, California, Texas, Europe and elsewhere around the world. Non divers cannot see a living Seadragon in South Australia where they are the official mascot for a biodiversity that is more than a match for the Great Barrier Reef. South Australian children learn about sea life in books, from video, the Internet and the beach and most of them grow up without a real connection or an understanding of just how special our cool southern waters are.

Voronica’s visit to South Australia has highlighted for me the interest that the international community has in our dragons. Pierre Constant was at Rapid Bay and Kangaroo Island on a fact finding mission. He is a photographer, writer, publisher, adventurer and when he wasn’t focussed on our Seadragons he was organising the details for an expedition that he will lead to come back and see them. This is significant when you learn that Pierre has led expeditions to dive around the Galapagos Islands and deserted atolls of the Pacific.

Once upon a time Seadragons were a hidden secret and now the world has caught up with them. Breeding them in a captive environment remains a mystery and with the international effort to understand the species, that problem will soon be solved. Does the replica Seadragon at the South Australian Museum continue to be our only permanent exhibition of this fascinating species? Should they remain a reward for those who can afford the luxury to scuba dive and observe them in the wild? Do we direct families and travellers to view a South Australian marine icon as an exotic in some interstate or international aquarium? Do we deny a permit to collect eggs from brooding males in the wild to the Victorian school teacher who supplies the world with captive raised dragons?

It is an adaptation from the wisdom of an African tribal elder called Baba Dioum that has become my guide with these questions.

In the end we will conserve only what we love.

We will love only what we understand.

We will understand only what we can learn.

For now, Leafy Seadragons are out there. As their numbers are affected by the things that landlubbers do, I believe that landlubbers need to make connections with the sea life that is unseen, unloved, unknown and under valued. I believe that South Australia needs a marine interpretive centre where these connections can be made. Magic Mountain is at the centre of South Australia’s premier tourism precinct at Glenelg. It may be bulldozed and replaced with a place for "edutainment" by the sea. I believe that it is the best site that South Australia has for a world class marine life awareness venue. Both the State Government and the Holdfast Shores consortium is supportive of this idea. So the question and the problem is:

"Do South Australians want a world class marine interpretive centre and where do we find 10 million dollars to make it happen?"

Tony Isaacson

Teacher of Marine Studies at Hallett Cove School

Proponent for a Marine Interpretive Centre at Holdfast Shores -Glenelg SA

Member: Australian Marine Education Alliance (AMEA)

Marine Education Society of Australasia (MESA)


 

 

 

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