Lake Fidler facts for kids
Quick facts for kids Lake Fidler |
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 Lake Fidler
Location in Tasmania
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| Location | South West Tasmania |
| Coordinates | 42°30′31″S 145°40′37″E / 42.50861°S 145.67694°E |
| Type | Meromictic |
| Basin countries | Australia |
| Designation | Tasmanian Wilderness World Heritage Area |
Lake Fidler is a special lake located right next to the Gordon River in Tasmania, Australia. It's part of the amazing Tasmanian Wilderness World Heritage Area.
What makes Lake Fidler unique is that it's a meromictic lake. This means it has layers of water that don't mix together. The top layer is fresh water, and underneath is a layer of salty water that has very little oxygen. Scientists D. A. Hodgson and Professor Peter Tyler first discovered these interesting lakes in the Gordon River area.
Why Lake Fidler is Special
Lake Fidler is a meromictic lake, which means its water layers stay separate. Imagine a cake with different layers that don't blend. The top layer of Lake Fidler is fresh water, while the bottom layer is salty and has almost no oxygen. This creates a very unique environment.
How Human Activity Affected the Lake
For a long time, the Gordon River would naturally bring salt water into Lake Fidler during certain times of the year. This helped keep the salty bottom layer healthy. However, when a hydro-electric power plant was built on the Gordon River, it changed how much fresh water flowed into the lake.
These changes meant less salt water could get into Lake Fidler. Because of this, the deep, salty layer of the lake started to shrink. This was a problem because that salty, oxygen-poor layer is an important part of the lake's natural balance.
Helping Lake Fidler: A Special Recharge Project
To help Lake Fidler, a company called Hydro Tasmania got permission from the Australian government in 2004 to "recharge" the lake. This meant adding salt water back into it.
They used a large tugboat to bring about 1.4 million litres (that's about 370,000 US gallons) of salt water from the sea. The water was brought in smaller amounts, about 100,000 litres (26,000 US gallons) at a time. This sea water was then carefully released into the lake through a special tool called a diffuser. The diffuser made sure the new salt water settled into the bottom layer without mixing with the fresh water on top.
This project was finished in April 2005, and it worked! The salty layer in Lake Fidler was restored. However, scientists noted that if the lake doesn't get enough natural salt water again, this special recharging process might need to be repeated in about 10 to 15 years.
