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.
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.
Local fishermen in Indonesia are catching less fish. Whatever the reason, it is a significant problem for those who live on small islands in particular, as fish make up about 90 per cent of the protein they eat.
A team of Indonesian and Australian social scientists is looking at how communities adapt to these changes.
Dr Jodie Rummer, marine biologist, James Cook University, Townsville
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.
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.
And, they are also developing a new range of aquatic critter-containing sensors.
New computer models are challenging the conventional wisdom in marine science.
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.
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.
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. Continue reading Seeing fish through rocks→
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.
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.
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.