Tag Archives: fish

Flying whale sharks

Short periods of flapping wings alternating with long, gliding descent helps birds preserve energy in flight. Now researchers have discovered that sharks and seals can use the same technique to glide through the ocean.

Adrian chasing down tags released from whale sharks at Ningaloo Reef. Credit: Steve Lindfield
Adrian chasing down tags released from Whale Sharks at the Ningaloo Reef. Credit: Steve Lindfield

Murdoch University’s Dr Adrian Gleiss led a team that attached accelerometers to whale sharks, white sharks, fur seals, and elephant seals.

They found that all four species performed the characteristic undulating flight of birds and bats, with periods of active, upwards propulsion alternating with slow, passive, gliding descents.

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A hot future for sharks

Dr Jodie Rummer, marine biologist, James Cook University, Townsville

2015 L'Oréal-UNESCO For Women in Science Fellow Jodie Rummer (Credit: L'Oréal Australia)Dr Jodie Rummer swims with sharks for her research. She is fascinated by fish and their ability to deliver oxygen to their muscles 20 to 50 times more efficiently than we can. Her global research into salmon, mackerel, hagfish, and now sharks explains why fish dominate the oceans, and has given her the opportunity to swim with sharks in the world’s largest shark sanctuary, in French Polynesia.

Her L’Oréal-UNESCO For Women in Science Fellowship will help her predict how sharks and other fish will cope with rapidly changing oceans. Some will be winners, some will be losers as the climate changes. That’s a problem not just for the oceans, but also for the communities that depend on fish for protein.

“Fish have been on the planet for hundreds of millions of years. It’s up to us to ensure they’re here for the next 100 million years,” she says.

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Live streaming for healthy waterways

Water sampling devices are keeping watch around the clock for toxic discharges into Melbourne’s creeks and stormwater drains, thanks to Victorian researchers at the Centre for Aquatic Pollution Identification and Management (CAPIM), based at the University of Melbourne.

Victorian researchers are developing real-time sensors of water quality. Credit: iStockphoto

And, they are also developing a new range of aquatic critter-containing sensors.

The Autonomous Live Animal Response Monitors (ALARM) will house live molluscs, insects or shrimps and transmit images and data to scientists via the web, in the ultimate test of a creek’s health. Continue reading Live streaming for healthy waterways

Virtual management of the world’s oceans

New computer models are challenging the conventional wisdom in marine science.

Virtual management of the world’s oceans
Beth Fulton’s fisheries models are used all over the world. Credit: Istockphoto
These models have revealed for example that: large populations of jellyfish and squid indicate a marine ecosystem in trouble; not all fish populations increase when fishing is reduced—some species actually decline; and, sharks and tuna can use jellyfish as junk food to see them through lean periods.

The models were developed by the 2007 Science Minister’s Life Scientist of the Year, Dr Beth Fulton, a senior research scientist at CSIRO Marine and Atmospheric Research in Hobart.
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Seeing fish through rocks

Dr Kate Trinajstic has used synchrotron light and CT scanning to see through rock, in the process discovering how ancient fish developed teeth, jaws and even a womb. Her work is increasing our understanding of how life on Earth evolved.

Seeing fish through rocks
The winner of the 2010 Malcolm McIntosh Prize for Physical Scientist of the Year, Kate Trinajstic. Credit: Ron D’Raine
About 380 million years ago in what is now the Kimberley Ranges in Western Australia, a vast barrier reef formed. In what would have been the inter-reef basins, large numbers of fish were buried relatively intact. Protective limestone balls formed around them and preserved them. When these balls are treated with acetic acid, the main component of vinegar, the surrounding rock dissolves, leaving only fossilised fish bones.

But in the course of studying hundreds of these dissolving balls, Kate began to see what looked like muscle fibres between the bones. She was eventually able to convince her colleagues that irreplaceable soft tissue detail was being lost in the acid treatments.
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Dinner for tuna

Sophie Bestley catching tuna. Credit: Thor Carter, CSIRO
Sophie Bestley catching tuna. Credit: Thor Carter, CSIRO

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.

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.

Understanding how Indigenous people value rivers

Long-necked turtles are a favoured food source for Aboriginal people in northern Australia’s Daly River region. Credit: CSIRO Darwin
Long-necked turtles are a favoured food source for Aboriginal people in northern Australia’s Daly River region. Credit: CSIRO Darwin

Indigenous people value rivers in many ways. Rivers provide bush foods and medicines, they are part of a culturally significant landscape, and have the potential to sustain future water-related businesses and employment.

So it’s important to know what impact changing river flow patterns and water allocations could have on Indigenous communities.

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Erosion and dams threaten barramundi and prawn fisheries

Barramundi caught at Shady Camp freshwater in Northern Territory. Credit: Marcus Finn
Barramundi caught at Shady Camp freshwater in Northern Territory. Credit: Marcus Finn

Kilometre-wide erosion gullies eating their way across Australia’s northern landscape are proving likely culprits as the main source of the sediments that are flushed into the Gulf of Carpentaria each year, possibly smothering prawn and barramundi breeding and rearing habitats.

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