Tag Archives: sharks

Aussie sharks still at risk from industrial fishing, despite protections

Macquarie University’s Professor Rob Harcourt urges Oceania-wide action to safeguard several species.

Sharks in Australian waters are well protected but are at risk as soon as they leave them, a new international study reveals.

The North Atlantic blue shark shares much of its territory with longline fishing fleets. Credit: Neil Hammerschlag

The study compiled by 150 scientists around the world – including 26 with ties to Australia – has found that even in the most remote parts of the world’s oceans migratory sharks are in severe danger from commercial fishing fleets, new research reveals.

In a paper published in the journal Nature, more than 150 scientists, including Professor Rob Harcourt from the Department of Biological Sciences at Australia’s Macquarie University, report that the sharks – which include iconic species such as the shortfin mako (Isurus oxyrinchus)  and the great white (Carcharodon carcharias) – congregate in food-rich areas that are also prime hunting grounds for commercial longline fishing fleets.

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Warming oceans will affect sharks’ brains

By Macquarie University

Rising ocean temperatures due to climate change will not only be felt by smaller organisms like coral, but will also impact apex predators, according to new research.

The study from the Macquarie University Fish Lab found that increasing water temperature by just 3ºC altered the behaviour of hatchling sharks.

Baby sharks incubated at temperatures predicted by the end of the century had very different turn preferences compared to sharks reared in present day water temperatures.

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Protecting surfers from shark attacks

Macquarie University researchers discovered that most sharks are colour blind, and used that knowledge to create patented wetsuit camouflage designs that are now on the market. Now the team is looking at how sharks perceive surfboards.

Associate Professor Nathan Hart, his students and collaborators are taking a new look at the sensory world of sharks. Using a range of physiological, genetic and behavioural methods, they have obtained the clearest view yet of how sharks, including notorious predators such the great white shark, see the world around them. 

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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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Blood reveals Great Barrier Reef sharks as homebodies

Small Australian sharks have been exposed as bigger homebodies than previously thought, in a study that took an existing chemical tracking technique and made it work for Great Barrier Reef sharks.

Dr Sam Munroe in the field
Dr Sam Munroe working in the field, Cleveland Bay, Queensland

The study found that the travel history of the Australian sharpnose shark was written in their blood—with chemical ‘fin-prints’ showing they tended to stay within smaller areas than previously believed.

“Small-bodied sharks that are both predator and prey, such as the Australian sharpnose, may be particularly important links between food webs,” says lead researcher Dr Sam Munroe, who studied the sharks while at James Cook University in Townsville.

“Information on their movements can improve our understanding of how the ecosystems function, while also helping us predict species most at risk from the impacts of a changing environment.”

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Starving cancer and other stories

Prostate cancers are made up of hungry, growing cells. Now we’ve discovered how to cut off their food supply thanks to a study published in Cancer Research and supported by Movember. More below. Also Australian science discoveries you may have missed from the past week. Heart cells growing in a test-tube – Melbourne How birds [...]