The raging bushfires and intense drought that has plagued the Australian continent for several months have taken a heavy toll on wildlife, particularly in the state of New South Wales. The images of burned koalas and kangaroos are chilling, but they are not the only species that are suffering.
In the streams of the permanently wet Gondwana rainforests, along with other stream catchments in platypus habitat of New South Wales, climate change enhanced drought and bushfire has decimated aquatic habitat to the point where many now fear the local extinction of the species.
According to Aussie Ark, the “platypus' distribution range is throughout the entire fire ground on the east coast of Australia, including the Manning catchment, and the species is suffering from the effects of fire, and catastrophic effects of drought, climate change as well as the unregulated pumping of water from rivers”.
Staggering numbers of deaths to this species are now estimated to be in the “thousands if not tens of thousands”.
With recent heavy rains, the scorched forest floor, full of ash, actually repels water absorption rather than soaking into the soil. — the remaining unique ancients now face another threat; silt from the wildfires is flowing into streams, killing the animals in their burrows and their food supply along dried up river banks.
x xYouTube VideoFrom the UNSW newsroom:
xPublished in the international scientific journal Biological Conservation this month, the study examined the potentially devastating combination of threats to platypus populations, including water resource development, land clearing, climate change and increasingly severe periods of drought.
Lead author Dr Gilad Bino, a researcher at the UNSW Centre for Ecosystem Science, said action must be taken now to prevent the platypus from disappearing from our waterways.
“There is an urgent need for a national risk assessment for the platypus to assess its conservation status, evaluate risks and impacts, and prioritise management in order to minimise any risk of extinction,” Dr Bino said.
Alarmingly, the study estimated that under current climate conditions and due to land clearing and fragmentation by dams, platypus numbers almost halved, leading to the extinction of local populations across about 40 per cent of the species’ range, reflecting ongoing declines since European colonisation.
Under predicted climate change, the losses forecast were far greater because of increases in extreme drought frequencies and duration, such as the current dry spell.
Dr Bino added: “These dangers further expose the platypus to even worse local extinctions with no capacity to repopulate areas.”
The platypus “is suffering from the effects of fire, and catastrophic effects of drought, climate change as well as the unregulated pumping of water from rivers.â€ÂWhat’s the NSW gov doing? No assessment of loss, no recovery plan. #nswpol#bushfirecrisishttps://t.co/cgxbqcMDO7
— Kate Washington MP (@KateRWashington) January 16, 2020
ABC news summarizes the UNSW Centre for Ecosystem Science presser and study.
Conservation organisation Aussie Ark has witnessed a significant drop in platypus number in the Greater Barrington region of New South Wales.
Aussie Ark president Tim Faulkner says the drought has had the biggest impact on the animals.
"In our region, they're all dead, they're gone — I can't find them," he said.
"They don't go into hibernation”.
snip
"The platypus that we did rescue, we had two die the next day.
"Their bellies are empty and they're all riddled with E. coli and a greater diversity of bacteria than that.
"Platypus are a Gondwanan dinosaur species — they are monotremes, egg-laying mammals, some of the oldest lineages of mammals on earth.
"They've been in this constant east coast temperate environment, largely unchanged, for millions of years.
"To see it now … a cesspit that's bacteria ridden and lifeless … certainly in our area — and this must be so wide spread — they're gone."
Sad news, even sadder is the fact that the Australian government just doesn’t care enough to protect Australian wildlife from not only climate change, but other human activities such as habitat fragmentation, dam building and land clearing.
x xYouTube VideoTuesday, Jan 21, 2020 · 2:21:22 PM +00:00 · PakaloloFrom the Guardian on silt poisoning platypus habitat.
Generally, bushfire ash comprises organic carbon and inorganic elements such as nitrogen, phosphorous and metals such as copper, mercury and zinc.
Sediment rushing into waterways can also contain large amounts of soil, since fire has consumed the vegetation that once bound the soil together and prevented erosion.
And carcinogenic chemicals– found in soil and ash in higher amounts following bushfires – can contaminate streams and reservoirs over the first year after the fire.
x xYouTube VideoImmediately following the bushfires, we expect to see an increase in streamflow when it rains, because burnt soil repels, not absorbs, water.
When vast amounts of carbon are present in a waterway, such as when carbon-loaded sediments and debris wash in, bacteria rapidly consumes the water’s oxygen. The remaining oxygen levels can fall below what most invertebrates and fishcan tolerate. These high sediment loads can also suffocate aquatic animals with a fine layer of silt which coats their gills and other breathing structures.These high sediment loads can also suffocate aquatic animals with a fine layer of silt which coats their gills and other breathing structures.
Habitats are also at risk. When sediment is suspended in the river and light can’t penetrate, suitable fish habitat is diminished. The murkier water also means there’s less opportunity for aquatic plants and algae to photosynthesise (turn sunshine to energy).
What’s more, many of Australia’s waterbugs, the keystone of river food webs, need pools with litter and debris for cover. They rely on slime on the surface of rocks and snags that contain algae, fungi and bacteria for food.
But heavy rain following fire can lead to pools and the spaces between cobbles to fill with silt, causing the waterbugs to starve and lose their homes.
This is bad news for fish, too. Any bug-eating fish that manage to avoid dying from a lack of oxygen can be faced with an immediate food shortage.