marine science


Australian researchers have revealed a new pattern of ocean circulation which will change our understanding of marine events.

Research at the University of Melbourne and the Bureau of Meteorology has overturned conventional ideas of ocean circulation. [click to continue…]

Samurai of the sea

9 June 2011

in 2011

SawfishWhat sawfish really do with their saw

Scientists thought that sawfish used their saw to probe the sea bottom for food.  But a Cairns researcher has found that these large (5 metres or more) and endangered fish actually use the saw to locate and dismember free-swimming fish – using a sixth sense that detects electric fields. She’s in Melbourne this week as a winner of Fresh Science. [click to continue…]

A biotechnologist from the South Australian Research and Development Institute has taken using “everything but the pig’s squeal” to new lengths. Through clever recycling of pig waste, Andrew Ward has been able to produce feed for aquaculture, water for irrigation, and methane for energy. His ‘waste food chain’ can be applied to breweries, wineries and any system producing organic waste. [click to continue…]

NickFindanis_single pulse  of synthetic jet

Researchers at the University of New South Wales have improved the aerodynamics of aircraft by putting rows of tiny synthetic jets along the wings of aeroplanes —much like the suck and blow jets octopuses use to move through the water.

The models tested demonstrated smoothing of the air flow over the wing section. This would infer a faster and smoother ride on aeroplanes.

If adapted to aircraft this would potentially mean less fuel and ultimately less cost. [click to continue…]

Bore hole through ice. Credit: Mike Craven Australian Antarctic Division (AAD)Researchers at Geoscience Australia have unravelled the development of a unique seafloor community thriving in complete darkness below the giant ice sheets of Antarctica.

The community beneath the Amery Ice Shelf in Antarctica is 100 km from open water and hidden from view by ice half a kilometre thick. This ecosystem has developed very slowly over the past 9000 years, since the end of the last glaciation.

Today it is home to animals such as sponges and bryozoans fed by plankton carried in on the current. [click to continue…]

tropical_rock_lobster2A team of Queensland researchers have discovered that lobsters, prawns and other crustaceans have evolved a unique way of making colours: making the complex patterns appreciated by biologists and connoisseurs of seafood.

Their work will help with conservation, aquaculture and may even lead to a new food colourant. And all the colours come from just one molecule.

The colour of seafood is directly linked to its acceptability as food. Highly coloured lobsters and prawns attract a premium price. And for the crustaceans themselves, it’s a matter of survival. [click to continue…]

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Sophie Bestley catching tuna, photo credit Adam Watkins

Sophie Bestley catching tuna, photo credit Thor Carter, CSIRO

Issued on World Oceans Day

Southern bluefin tuna can’t even have a quiet snack without CSIRO researchers knowing. They’ve developed a way of tracking when the tuna feed and also where, at what depth, and the temperature of the surrounding water.

It’s the first time anyone has been able to observe the long term feeding habits of migratory fishes directly and the information is transforming our understanding of these highly sought after ‘Porsches of the sea’.

Dr Sophie Bestley and her colleagues at CSIRO’s Wealth from Oceans National Research Flagship surgically implant miniaturised electronic “data-storage” tags into juvenile fishes off the coast of southern Australia. [click to continue…]

The world’s fastest growing abalone—the tropical donkey’s ear abalone, Haliotis asinina—can be bred to grow rapidly and reliably for aquaculture, Queensland biologists have found. And that makes it potentially a high value alternative crop for struggling prawn farmers. [click to continue…]

Certain small reef fish use wing-like fins to ‘fly’ underwater, allowing them to cruise at speeds equivalent to tuna, a team of Australian and US researchers has found. The design of the fins has drawn the attention of underwater submersible designers and the US Office of Naval Research.   

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 Bluefin tuna use three times as much oxygen as other fish their size, making them more difficult to culture. That’s just part of the valuable information uncovered by University of Adelaide PhD student, Quinn Fitzgibbon and his colleagues in a study where they monitored live tuna swimming inside a 350-tonne “waterbed”.

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Warfare between bacteria could provide an environmentally friendly solution to biofouling, according to Dhana Rao and her colleagues at the University of NSW.

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How sea slugs fall in love

14 August 2007

in 2007

Scott Cummins and his colleagues at The University of Queensland have uncovered a potent mix of chemicals which acts like a cross between Chanel No 5 and Viagra-but only if you are a sea slug.

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Fish make omega-3 from noxious weed

Australian scientists have found that fish fed oil extracted from one of Australia’s most damaging noxious weeds, Patterson’s curse, produce health-giving omega-3 oils for human consumption. [click to continue…]

The Australian lungfish-one of the world’s oldest fishes and related to our ancient ancestors-may have been viewing rivers in technicolour long before dinosaurs roamed the Earth.

Recent work by postgraduate student Helena Bailes at the University of Queensland has found these unusual fish have genes for five different forms of visual pigment in their eyes. Humans only have three.

Night and day (colour) vision are controlled by different light sensing cells known respectively as rods and cones. Humans have a single type of rod and three types of cone, each containing a different pigment gene tuned to red, green and blue wavelengths. Lungfish possess two additional pigments that were lost in mammals, Bailes says. They are tuned to longer wavelengths than in most other fish.

“Lungfish are very large, slow-moving fish, so vision was always assumed to be of little importance” she says. “This work may change that theory.”

Lungfish are ‘living fossils’ unchanged for over 100 million years. The Australian species (Neoceratodus forsteri) is the most primitive of the living lungfishes. It is a threatened species protected from fishing which lives in only a handful of rivers in south east Queensland.

“The only way to find out how the first creatures on land saw the world is to look at their closest living relative: the Australian lungfish,” Bailes says.

The photoreceptive cells, which house the visual pigments, are bigger in lungfish than for any other animal with a backbone. This probably makes them more sensitive to light.

“We keep discovering ways in which these animals are quite different from other fish,” Helena Bailes says. “Their eyes seem designed to optimise both sensitivity and colour vision with large cells containing different visual pigments.”

She now is hoping that behavioural research can find out how these fish are using their eyes for colour vision in the wild.

“We may then learn what Queensland rivers look like to some of their oldest inhabitants, before those inhabitants are wiped out,” Bailes says.

Helena is one of 13 Fresh Scientists who are presenting their research to the public for the first time thanks to Fresh Science, a national program sponsored by the Federal and Victorian Governments. One of the Fresh Scientists will win a trip to the UK courtesy of the British Council to present his or her work to the Royal Institution.

Helena working in her laboratory Composite image, clockwise from top: Helena in the lab, Australian lungfish, retinal photoreceptors of lungfish, a retinal ganglion cell leading from the eye to the brain in lungfish Australian lungfish

Box jellyfish are capable of moving several kilometres a day, but seem to stay within a relatively short stretch of beachfront. Those are some to the initial findings of a young researcher in North Queensland, who is undertaking the first detailed study of the movements of the potentially lethal animals.

Matt Gordon of the Tropical Australian Stinger Research Unit at James Cook University in Cairns is using the latest ultrasonic technology to track the jellyfish. He aims to make Australia’s tropical beaches safer by developing a computer model capable of predicting where and when they will occur.

“There are several long held theories regarding where box jellyfish are found and why they move from one area to another,” Gordon says. “But until now there has been limited evidence to support them.

“For instance, as early as the 1960s it was suggested that box jellyfish swim up creeks towards the end of the season to reproduce. But until we followed a large, sexually mature individual up an estuary near Tully in April of this year, there was no hard data on this.”  

In order to record their movement patterns, each box jellyfish is fitted internally with an ultrasonic tag using a type of surgical glue called Histoacryl. Each tag emits a unique signal that can be heard underwater using a hydrophone. It is now possible to track the movement patterns 24 hours a day, 7 days a week using new submersible ultrasonic receivers developed in the US.

By collecting data from four different locations, Matt Gordon intends to develop a model that can be applied throughout the tropics. It is anticipated that such a model will be of benefit to local councils and the tourism industry by allowing stinger enclosures, tourist attractions and resorts to be placed in safer areas.

Matt is one of 13 Fresh Scientists presenting their research to the public for the first time thanks to Fresh Science, a national program hosted by the State Library of Victoria. One of the Fresh Scientists will win a trip to the UK courtesy of the British Council to present his or her work to the Royal Institution.

Hitchhiking pests uncovered

31 August 2004

in 2004

A test for  toxic algae could help save our coastal waters from attack by invading pests

Coastal waters around the world are threatened by invaders lurking in the ballast water of cargo ships.

A new global agreement will require ships to meet strict regulations to ensure they do not harbour any unwanted invaders. New technologies are therefore needed for treating ballast water on board. But which treatments will work? Some of the most dangerous algae can play dead.

CSIRO researcher Monique Binet has developed a new method for determining which ballast water treatment works, and which doesn’t. Her test will do in one day what previously took up to six months.

 “Ballast water is essential to balance the ship’s cargo,” says Monique, one of the Fresh Science winners for 2004. “But some 15,000 species are hitchhiking lifts around the world with the water each week.”

“A particularly notorious type of algae are the toxic dinoflagellates which are capable of poisoning shellfish. These poisoned shellfish can be lethal if eaten by humans. Several international organisations have suggested that these algae should be one of the benchmarks used to assess new treatment technologies.”

“The trouble is that these are tough critters. The dinoflagellates form dormant cysts which can survive for years in the ballast tanks. So testing the different treatment technologies relies on the ability to distinguish between live and dead cysts.”

Until now this has meant painstaking hours of microscopic examination, followed by a wait for up to 26 weeks to see if the cysts germinate into live, swimming algae.

And that’s where the new method developed by Monique and her colleagues at CSIRO’s Centre for Environmental Contaminants Research (CECR) comes in.

“Using a technique called flow cytometry, we can now analyse each and every cyst for its size, structure and fluorescence. Based on these characteristics and the use of a DNA stain, we can tell which cysts will germinate into live cells in a matter of minutes” says Monique.

“The trick was first washing the cysts for 24 hours to remove their mucous coatings, and selecting the right staining conditions, so we can now determine cyst viability within 1 day, instead of the conventional 3-26 weeks.”

The research has attracted interest from around the world with Monique presenting at conferences in Germany and New Zealand.

Monique now plans to apply this method to other species of toxic dinoflagellates as well as other micro-organisms that hitch a ride in the ballast water tanks. Enabling the rapid assessment of ballast water will help prevent these pests from spreading any further.

 
As found in the sediment of ballast water tanks – the dinoflagellate Alexandrium catenella in its resting cyst form with surrounding mucous.  The dinoflagellate after a wash. The surrounding mucous has been removed allowing it to be analysed with flow cytometry   
   
The dinoflagellate in its motile form, a cell chain. This can bloom into red tides