In 2009 the Mercury newspaper and the Tasmanian Department of Primary Industries, Water and Environment produced the landmark education resource Tasmania: SOS (Saving our Species). In support of this new package, the newspaper published a series of articles featuring a selection of Tasmania's threatened species and these are reproduced below in text format.
Rare lichen takes years to recover from fire
Maugean skate a murky mystery
By: DANIEL GLEDHILL
AUSTRALIAN scientists are finding new species of fish at a faster rate than ever before.
Sharks and rays are no exception, with nearly 100 new Australian species described in the past two years.
The maugean skate (Zearaja maugeana) was discovered in the late 1980s and is found only in Bathurst and Macquarie harbours in western Tasmania.
The waters of these estuaries are stained dark brown from the tannin washing out of the surrounding buttongrass plains, reducing light penetration even at shallow depths.
Bathurst Harbour is a remote 40km2 basin in the Tasmanian Wilderness World Heritage Area and is separated from the ocean by the 12km long Bathurst Channel. The limited light penetration has produced an unusual habitat resembling those found in deep offshore waters.
One of the few skates known to live in estuarine habitats, the maugean skate is medium-sized, reaching about 80cm in length. It
occurs mainly in depths of less than 10m, but has a body shape resembling deep-water species found on the continental slope.
Little is known of its biology or life history, but it is likely to feed on invertebrates burrowed in mud and sand. Despite numerous surveys, only a few specimens have been collected.
This species is listed as endangered by the Australian Government's Environment and Biodiversity Conservation Act; by the Tasmanian Government's Threatened Species Protection Act; and the IUCN Red List of Threatened Species due to its restricted geographic range and apparently small population.
Gill-netting poses a real threat and could drastically reduce or eliminate the small population in Macquarie Harbour.
Two other species - one occurring off New Zealand, the other off South America - are the closest relatives to the maugean skate. They are likely to have shared a common ancestor millions of years ago in the seas of Gondwana, a supercontinent including the land masses of South America, Antarctica, New Zealand and Australia.
Scientists at the CSIRO are continuing investigations into the evolutionary history of Australian fishes, including the maugean skate.
This includes the use of genetic techniques to determine how closely it is related to relatives in New Zealand and South America.
A greater understanding of the history of this skate will shed further light on how some elements of the Australian fauna were derived.
* Daniel Gledhill is an ichthyologist with the CSIRO's Wealth from Oceans Flagship. (published in the Mercury newspaper, Hobart, on August 18, 2009.)
Heath a true cliff-hanger
There's no sting in this tail
By: CLARE HAWKINS
THE smallest of our threatened species are often the ones most easily ignored, yet they can be just as vulnerable.
Sixty-three per cent of all threatened animal species listed by the Tasmanian Government are classed as invertebrates - that's 119 species, including butterflies, crayfish, snails, spiders and seastars.
Pseudoscorpions occur around the world and are uniformly tiny - the largest known is only 6mm long.
As the name suggests, they aren't really scorpions and they don't sting, but their pincers make them look a little scorpion-like.
The Mole Creek Cave pseudoscorpion (Pseudotyrannochthonius typhlus) is classified as rare. It is 2.8mm long and, like many small species, is known only from a very small area, which makes it especially vulnerable.
This species is found only in the Mole Creek karst system in central northern Tasmania. While it has been documented in 10 caves within this system, only 12 specimens have ever been found. This is despite some wide-scale surveying by characteristically several sharp-eyed cave biologists.
Caves are such stable places that it may be difficult to imagine how anyone could affect the fauna that live in them.
However, not all the caves where the Mole Creek Cave pseudoscorpion occurs are protected, and some activities can act at a distance.
Quarrying, land clearance and changes to drainage and water nutrient levels can all affect conditions in caves.
Trampling of individual pseudoscorpions and their cave habitat by visitors could also be a problem for the species.
We have a poor idea of exactly how these threats might affect this elusive species because so little is known about it and how it can survive at such apparently low numbers.
Biologists estimate there are more giant pandas in the wild than endangered Tasmanian Mole Creek pseudoscorpions.
* Dr Clare Hawkins is a senior zoologist at the Department of Primary Industries, Parks, Water and Environment. (published in the Mercury newspaper, Hobart, on August 20, 2009.)
Cushion plant in fast decline
By: JENNIE WHINAM
* Dr Jennie Whinam is a senior ecologist at the Department of Primary Industries, Parks, Water and Environment. (published in the Mercury newspaper, Hobart, on August 21, 2009.)
Tassie quolls in a spot of bother
Blue grass plays a haunting theme
By: WENDY POTTS
THE Midlands and lower Derwent Valley are the only places to find the endangered blue wallabygrass (Austrodanthonia popinensis).
Most of the habitat for this tufted grass has long since been converted for agriculture or housing.
Native grasslands are now considered to be threatened vegetation communities.
Like many of our threatened grassland species, Austrodanthonia popinensis now mostly occurs along roadsides.
It is quite palatable and doesn't thrive in remaining native grasslands that are grazed by sheep and cattle.
However, these species of grass generally require open conditions with gaps of bare ground for successful recruitment from seed.
Roadside slashing at the right time of year will generally provide the right conditions to allow populations to regenerate and expand.
In the past these species would have relied on fire and browsing by native animals to provide recruitment gaps.
Austrodanthonia popinensis does not occur in any formal reserves and it is at risk from further losses of its grassland habitat, overgrazing, competition from weeds and inappropriate management of roadside occurrences.
Roadsides should be slashed before or after the plants have flowered and set seed, and care should be taken when spraying weeds to avoid damaging the grass.
Weeds will also spread where there are gaps of bare ground.
Find out more about this plant in its note sheet and soon-to-be-published listing statement, under "Austrodanthonia popinensis'' in the Department of Primary Industries, Parks, Water and Environment's threatened species list at www.dpipwe.tas.gov.au/threatenedspecieslists
* Dr Wendy Potts is a senior botanist at the Department of Primary Industries, Parks, Water and Environment. (published in the Mercury newspaper, Hobart, on August 25, 2009.)
Island running out of petrel
By: RACHAEL ALDERMAN
SUB-ANTARCTIC Macquarie Island is an oasis for seabirds. It is home to more than one million penguins, rare albatross species and a diversity of burrow-nesting seabirds.
Nine species of burrowing petrel, including the sooty shearwater, fairy prion and grey petrel, breed in burrows and cavities all over Macquarie Island, from low coastal slopes to the high plateau areas.
Nesting is seasonal and a single egg is laid, with both sexes sharing the incubation.
After hatching, the downy young are attended by parents for the first one to two weeks, then left unattended in the burrow while parents forage for cephalopods, crustaceans and fish. Once able to fly, many species leave the island for the non-breeding season.
Most species are active after dark to reduce the risk of predation. As such they can be difficult to locate and to estimate numbers.
Burrowing petrels are particularly susceptible to threatening processes since most species are long-lived, have delayed maturity and produce only a single egg, which is not replaced even if it fails after laying.
The main threats to burrow-nesting seabirds on Macquarie Island are feral pests introduced by sealers and shipwrecks.
The weka, or woodhen, was introduced probably as a food source about 1880 and was widespread by 1890. Being omnivorous, it preyed on burrow-nesting seabirds until it was eradicated in 1989.
Cats were the most voracious predator of burrowing petrels until they too were eradicated in 2000 after an intensive trapping and shooting program.
With the removal of cats, several species of burrowing petrel that had previously been extinct on the island have begun to return, including the grey petrel, soft-plumaged petrel and cape petrel - but they exist only in very low numbers.
The greatest threats to the recovering populations are rabbits and rats. Rabbit grazing destabilises nesting slopes and exposes burrow entrances, making them more susceptible to predation from skuas.
Rats also eat small chicks and eggs. Some species are known to occur only on offshore rock stacks where rats are absent.
A comprehensive eradication plan to target rabbits, rats and mice is scheduled for winter next year.
Hopefully the petrel populations will continue to grow and we will see colonisation and recolonisation by new species.
* Rachael Alderman is a seabird biologist at the Department of Primary Industries, Parks, Water and Environment. (published in the Mercury newspaper, Hobart, on August 26, 2009.)
Orchid set to rise from the ashes
By: WENDY POTTS
THE endangered sagg spider-orchid (Caladenia saggicola) is a ground orchid that was thought to exist only in a small community of up to 200 plants on private land near the Hobart Airport.
Three plants were recently found in a small reserve at Dodges Ferry, and it is likely that much of the original habitat for the species has now been lost.
The species is at risk because of its low numbers.
As its seedlings can establish in patches of bare ground, particularly if recently burnt, an ecological burning program is being implemented to provide the appropriate disturbance conditions to allow the main population to increase.
This population has also been fenced to reduce the impact of grazing rabbits.
The Dodges Ferry population is at risk because of its proximity to housing.
Caladenia saggicola is one of 18 threatened Caladenia species in Tasmania, 10 of which are spider-orchids.
While many spider-orchids are pollinated by male native wasps that attempt to mate with part of the flower because the shape and scent of flowers mimic those of female wasps, Caladenia saggicola produces scents that attract insect pollinators that are looking for a feed.
Like other Caladenia species, plants of Caladenia
saggicola die back to underground tubers after flowering.
The species can only be identified during its brief flowering period from September until October, though plants may not emerge or flower in times of drought, and prolonged drought may lead to the death of tubers. This makes Caladenia saggicola sensitive to the impacts of climate change.
You can find out more about this plant in its listing statement, under Caladenia saggicola, in the Department of Primary Industries, Parks, Water and Environment threatened species list: www.dpipwe.tas.gov.au/threatenedspecieslists
* Dr Wendy Potts is a senior botanist at the Department of Primary Industries, Parks, Water and Environment. (published in the Mercury newspaper, Hobart, on August 27, 2009.)
Vulnerable little shrimp still a great survivor
By: MICHAEL DRIESSEN
THOUGH listed as rare and only 12mm long, Hickman's pygmy mountain shrimp (Allanaspides hickmani) is a great survivor.
This tiny tan-coloured, almost transparent crustacean has changed very little from fossilised relatives that lived more than 250 million years ago and it is regarded as a living fossil.
The closely related and much larger mountain shrimp, or Anaspides, is familiar to many people as it is commonly observed in tarns and streams of western Tasmania.
Hickman's pygmy mountain shrimp can be found in just one tiny area of the planet - 3km2 of buttongrass moorland near lakes Gordon and Pedder in South-West Tasmania.
Most of its original habitat was flooded in the early 1970s for hydro-electric power generation.
It lives in surface pools and in the subterranean burrows of freshwater crayfish that open into these pools.
Crayfish burrows are important habitat for Hickman's pygmy mountain shrimp because surface pools often dry up over summer. The waters in these pools are tannin-stained, low in nutrients and highly acidic.
The shrimp feeds on detritus and can live for up to 14 months.
Mating starts in late autumn and eggs can be laid all year long, with most hatching in summer. Juveniles are about 2mm long at hatching and grow at about 1.3mm per month until they mature at about 7mm.
There appears to be no immediate threat to Hickman's pygmy mountain shrimp, but its small population makes it vulnerable to one-off events such as a wildfire combined with drought.
Perhaps the greatest concern is the potential impact of climate change. The climate in the South-West appears to be marginal for the formation of peats that support buttongrass moorland. A rise in mean annual temperatures could potentially cause these peats to degrade.
* Michael Driessen is a senior zoologist at the Department of Primary Industries, Parks, Water and Environment. (published in the Mercury newspaper, Hobart, on August 28, 2009.)
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