Aquaculture challenges from climate change

 Australian native freshwater species, fisheries, government, research
Jun 092014
 

ABC NewsOriginal story at ABC News

The CSIRO has told a world aquaculture conference in Adelaide the industry already is facing challenges from climate change.
Barramundi - Rising water temperatures are a challenge for fish farming.

Barramundi – Rising water temperatures are a challenge for fish farming.

The fast-growing industry generates more than $1 billion annually for the Australian economy and CSIRO research scientist Alistair Hobday says aquaculture operators have been making a strong impression in the international marketplace.

“I think aquaculture operators in Australia are very sophisticated, they grow high-value products that go to international markets as well as our domestic markets and I think they’re well set up for coping with these changes,” he said.

But Dr Hobday says aquaculture operators will need to find ways to adapt to rising temperatures.

“We’ve seen cases around Australia where warming waters that have been unusually warm have led to declines in salmon production, have led to declining oxygen in tuna pens,” he said.

The CSIRO says temperatures have risen by one degree Celsius in the past century in Australia, but by more than two degrees in the south-east and south-west of the nation. Continue reading »

‘Novelty’ crocodiles new home at Cairns golf course

 Australian native freshwater species, Interest, waterways/wetlands, wildlife
Jun 062014
 

Original story at ABC News

You would be happy with a double eagle on the golf course, but a pair of crocs is enough to make any player choke.
Two crocodiles have been moved to a golf course near Cairns. Photo: Sukree Sukplang/Reuters

Two crocodiles have been moved to a golf course near Cairns. Photo: Sukree Sukplang/Reuters

Two crocodiles, both about a metre long, have taken up residence at a Yorkeys Knob golf club near the far north Queensland city of Cairns.

But Half Moon Bay Golf Course manager Greg Ferry reckons they are more of a novelty than a threat.

“A few of the golfers are mentioning there’s a few other hazards around,” he said.

“They aren’t really much of a danger at the moment, they’re a bit of a joke and people are interested in having a look at them.”

The pair, who live in separate lakes on the club’s grounds, come within about 15 metres of a couple of the holes on the course.

Warning signs are dotted around the place and rangers are monitoring the reptiles to ensure they do not pose a danger to golfers. Continue reading »

New crayfish traps will save platypus from drowning

 Australian native freshwater species, community, research, threatened species, waterways/wetlands, wildlife
Jun 052014
 
The platypus is vulnerable to opera house traps set to catch crayfish.

The platypus is vulnerable to opera house traps set to catch crayfish.

Original story at Wildlife Extra

The Australian Platypus Conservancy (APC) has been carrying out trials on a new design of a type of crayfish trap called an opera house trap. Opera house traps are widely sold in Australia to deploy in rivers to catch crayfish for eating. Unfortunately, these same rivers are populated by air-breathing platypus that cannot escape from the traps once they have entered them and so drown. The new design is fitted with a circular escape hatch in the roof, through which platypus can find their way back out. The research, funded by the Taronga Conservation Society, involved 34 adults and 24 juvenile platypus to establish how easily the animals found the escape holes.

Of the four animals tested during daylight hours, all escaped within one minute of being introduced to a trap. At night, 63 per cent of tested animals managed to find their own way out within one minute and 19 per cent in 1-2 minutes. All exited via the escape hatch in the roof. Given that a platypus can hold its breath for approximately two and a half minutes when active, these findings suggest that a large proportion of wild platypus are likely to escape from a modified trap before they drown. Continue reading »

BCC Pest Fishing Stats

 Australian native freshwater species, Club News, community, education, Field Trips, government, pest species
Jun 022014
 

If you didn’t make it along to the BCC Pest Fish Education Event you missed a fantastic morning out. The water might have been too cool for the Tilapia to bite but there were lots of other fish being reeled in. We were all impressed with the variety of native fish in the lake despite invasions from African Tilapia, American Gambusia and North Queensland Barred Grunter. There might have been a few fish that went back without being tallied but we did our best to count everything that came in – checkout the stats below. The barbless hooks provided by BCC ensured fish were able to be returned to the water in good condition. I still haven’t found out who managed to land gambusia while line-fishing…

BCC Pest Fishing Day at Forest Lake. Photo: Leo Lee

BCC Pest Fishing Day at Forest Lake. Photo: Leo Lee

Continue reading »

Jungle Perch with a Frog in its Throat

 Australian native freshwater species, fisheries, Interest
May 232014
 

Original story by Daniel Meers, The Cairns Post

TALK about having a frog in your throat! A North Queensland angler was left stunned after he found a live green tree frog sitting inside the throat of a jungle perch he caught on the weekend.

SURPRISE: Angus James caught a Jungle Perch in North Queensland and when he removed the hook he found a frog inside it's mouth, Photo: Angus James

SURPRISE: Angus James caught a Jungle Perch in North Queensland and when he removed the hook he found a frog inside it’s mouth. Photo: Angus James

Angus James began unhooking the fish to throw back in the water when he saw the frog, who leapt over his head to freedom. Continue reading »

Sleepy cod threat to Queensland’s western rivers

 Australian native freshwater species, pest species, research, waterways/wetlands
May 192014
 

Original story by Brian Williams, The Courier Mail

SCIENTISTS fear a fish species introduced to Queensland’s iconic western rivers could become another environmental pest.
Although sleepy cod is a native species found on the eastern fall of the Great Dividing Range, it risks upsetting the ecological balance in the western rivers.

Although sleepy cod (Oxyeleotris lineolata) is a native species found on the eastern fall of the Great Dividing Range, it risks upsetting the ecological balance in the western rivers.

Sleepy cod have been found in the Thomson River from Windorah north to Longreach and are likely to be in the Barcoo.

The cod is a native species but found naturally only on the eastern fall of the Great Dividing Range, from Rockhampton north and into the Gulf of Carpentaria. Continue reading »

Monster feral goldfish in the Vasse River WA

 Australian native freshwater species, pest species, research, waterways/wetlands
May 172014
 

Original story by Paige Taylor, The Australian

ACOUSTIC tags used to track great white sharks off the West Australian coast have been put to use on a menacing population of giant goldfish in the Western Australia’s southwest.
A 2kg Goldfish from the Vasse River, south of Perth.

A 2kg Goldfish from the Vasse River, south of Perth.

The former pets and their offspring, some 40cm in length and weighing 2kg, are among invasive feral fish entering the southwest waterways, where for the first time unique local fish are outnumbered by alien species. Continue reading »

Tarpon / Oxeye Herring (Megalops cyprinoides), Finniss River, NT

 Australian native freshwater species, Field Trips, waterways/wetlands
May 152014
 

By Greg Wallis (pseudechis) at YouTube

The Tarpon or Ox-eye Herring (Megalops cyprinoides) is a common fish found in the rivers and coastal areas of northern Australia. It is also found through much of the tropics from east Africa, across the Indian Ocean to South-east Asia. It is also commonly referred to as the Indo-Pacific Tarpon outside of Australian waters.The Tarpon/Oxeye Herring from Australian waters should not be confused with the much larger Atlantic Tarpon (Megalops atlanticus) from the americas. The fish at the end of the video is a Black Catfish (Neosilurus ater).

Although the Oxeye Herring can grow to well over a metre, it is more commonly seen up to around 50 cm. Larger fish are normally found in marine waters.

The tarpon can often be seen flashing and “gulping” air at the waters surface; it can tolerate low oxygen levels in the water due to it’s ability to supplement it’s oxygen supply via air that is gulped into it’s modified swim bladder.

Tarpon are highly regarded as a sportfish because of their fighting ability on light tackle. They are often observed actively feeding on the surface of tropical billabongs in the early morning and late afternoon where they are easily caught on flies and lures although they are regarded as poor eating because of the large number of fine bones.

For more information on Oxeye Herring see the Fishes of Australia website at:

http://www.fishesofaustralia.net.au/h…

CAAB Taxon Code: 37054001

www.gregwallis.com

Barramundi (Lates calcarifer), Finniss River, Northern Territory

 Australian native freshwater species, Field Trips, fisheries, waterways/wetlands
May 072014
 

By Greg Wallis (pseudechis) at YouTube

The Barramundi or Giant Perch (Lates calcarifer) is an iconic fish from the freshwater billabongs, estuaries and coastline of northern Australia. Growing to 180cm and 60kg in size, these fish are a formidable predator.

Hatchling Barramundi are almost entirely males and spend their first year around mangroves and floodplain lagoons before moving further upstream into freshwater. At around 3 — 5 years of age and 60 — 80 cms the fish change sex and become female and move downstream to the tidal river mouths to breed.

Generally speaking it’s not a good idea to swim in natural waterways where Barramundi occur. Because they migrate from upstream freshwater areas down to the mouths of the rivers and back again, if you see Barramundi in a swimming hole it means that there are no substantial barriers downstream impeding their movement up from the coast, which also means Saltwater Crocodiles will have no problems in also accessing the area!

Barramundi are highly prized by fisherman both for their eating and fighting qualities. They are a very important food source for Aboriginal people and are regularly depicted in bark paintings and rock art.

For more information on Barramundi see the Fishes of Australia website

http://www.fishesofaustralia.net.au/h…

CAAB Taxon Code: 37310006

www.greg wallis.com

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