Logging threat fears for rare lobster

Experts fear a planned logging operation in Tasmania's north-west threatens the survival of the Tasmanian giant freshwater lobster.

A river system near Wynyard has been earmarked for logging by Forestry Tasmania, despite the area being known as one of the last strong holds of the vulnerable lobster.

The coupe is not listed for immediate protection under Tasmania's $276 million forest peace deal, but is being assessed for inclusion in future reserves of high conservation value forest.

Lobster expert Todd Walsh says sediment run-off from logging operations could decimate lobster populations and the area should be given immediate protection.

"Sediment covers their homes, which means the juvenile lobsters have nowhere to live, which means they're exposed to predators like platypus and blackfish."

"But also it covers up their food supply so they either starve to death or they get eaten; so sediment basically wipes them out."

Mr Walsh says the area is an important study site.

"This tributary runs into probably the most surveyed lobster spot on the planet, so there's been more lobsters surveyed and tagged downstream from this tributary than anywhere else.

"So it's probably the most important site that we've got," he said.

Meanwhile Forestry Tasmania has denied plans to log a key habitat of the giant freshwater lobster go against the spirit of the forest peace deal.

Ken Jefferys from Forestry Tasmania says it is harvesting the coupe to meet supply agreements, as it is required to do under the forest agreement.

"Only a few weeks ago we had to send a consignment from the south of the state to the north west with sawlogs to keep those mills operating, we are in a very constrained space, whenever you lock up more forests our capacity to reschedule, to adopt flexibility is significantly reduced."

http://www.abc.net.au/news/2011-11-09/20111109-logging-threat-fears-for-rare-lobster/3655276

Searching for the Tasmanian tiger in PNG

By:Joanna Egan | April-8-2011

IN DECEMBER 2010, the AG Society-sponsored adventurer Andrew Hughes headed into the wilderness in an attempt to see if the Tasmanian tiger, or thylacine - declared officially extinct in 1986 - continues to persist in any remote pockets (see video below) of Tasmania - and surprisingly, New Guinea.

Read more: http://www.australiangeographic.com.au/journal/search-for-the-tasmanian-tiger.htm

VIDEO: Highlights of Andrew Hughes' expedition to track the history of the Tasmanian tiger


(Via Kristin Edwards)

Warm weather sets lowland skink sex

SNOW skinks can base their gender on either genes or temperature. Which strategy they choose appears to depend on the weather.


Ido Pen of the University of Groningen in the Netherlands and colleagues studied two clans of snow skinks, Niveoscincus greeni, living at low or high altitude in the mountains of Tasmania, Australia. The team captured pregnant skinks from each clan and allowed half of each group to lie in the sun for 10 hours per day, while the others were restricted to 4 hours. When the skinks gave birth, the scientists sexed their offspring.

Litters born to the lowland clan had a greater proportion of females after long days in the sun, compared to short days. In contrast, the sex ratio of the highland litters remained equal (Nature, DOI: 10.1038/nature09512). This suggests that temperature drives the sex of low altitude litters, while genes determine gender further up the mountain.

Pen thinks climatic pressures are behind these different systems. At low altitudes, females born early under warm conditions have more time to grow large and produce offspring, so it is advantageous for these skinks' gender to be temperature-sensitive. At higher altitudes, however, erratic annual temperatures mean that the timing of birth may not affect reproduction rates, so the skinks rely on genes to produce a balanced sex ratio.

http://www.newscientist.com/article/mg20827844.300-warm-weather-sets-lowland-skink-sex.html

Warm weather sets lowland skink sex

SNOW skinks can base their gender on either genes or temperature. Which strategy they choose appears to depend on the weather.


Ido Pen of the University of Groningen in the Netherlands and colleagues studied two clans of snow skinks, Niveoscincus greeni, living at low or high altitude in the mountains of Tasmania, Australia. The team captured pregnant skinks from each clan and allowed half of each group to lie in the sun for 10 hours per day, while the others were restricted to 4 hours. When the skinks gave birth, the scientists sexed their offspring.

Litters born to the lowland clan had a greater proportion of females after long days in the sun, compared to short days. In contrast, the sex ratio of the highland litters remained equal (Nature, DOI: 10.1038/nature09512). This suggests that temperature drives the sex of low altitude litters, while genes determine gender further up the mountain.

Pen thinks climatic pressures are behind these different systems. At low altitudes, females born early under warm conditions have more time to grow large and produce offspring, so it is advantageous for these skinks' gender to be temperature-sensitive. At higher altitudes, however, erratic annual temperatures mean that the timing of birth may not affect reproduction rates, so the skinks rely on genes to produce a balanced sex ratio.

http://www.newscientist.com/article/mg20827844.300-warm-weather-sets-lowland-skink-sex.html