Lake Eyre

• Category: Inland Aquatic Biomes.
• Geographic Location: Australia.
• Summary: A desert lake that is most often dry, Lake Eyre is home to hardy species with special adaptations.

Officially known as Kati Thanda–Lake Eyre, Lake Eyre is located in the deserts of Australia and holds the title of being Australia’s largest salt lake. Lake Eyre provides an extremely unique habitat for its inhabitants, as the lake does not always contain water. On average, the lake has water every two to three years, and on a very irregular basis, making it difficult for most plants and animals to survive. Historically, the lake rarely fills up, and since the 1860s, the lake has been at capacity four times, the most recent being in 2025. Mostly, the lake is a string of water holes, leaving very little water to support its inhabitants. Only the hardiest species of plants and animals are able to survive in this environment. The small populations of flora and fauna that do call Lake Eyre home have learned to adapt and thrive in this unusual environment, and they have created a complex ecosystem in the process.

Geography and Climate

Lake Eyre is located in the northern part of South Australia. The lake is generally flat, with the lowest portion about 50 feet (15 meters) below sea level. The lake is surrounded by sandy and stony desert, and the climate is arid to semi-arid, when it rains. During the year, the temperature fluctuates from 70 degrees F (21 degrees C) in July, the coolest time of year, to 99 degrees F (37 degrees C) in January, the area’s summer.

Lake Eyre receives about 5 inches (127 millimeters) of rainfall per year, which is about three times less than the world average rainfall. The lake’s evaporation rate is about three times higher than the world average, with the evaporation rate exceeding 140 inches (3,556 millimeters) per year. When filled, Lake Eyre is Australia’s largest saline lake, containing a 15-inch (38-centimeter) thick salt crust on the lake’s floor.

Lake Eyre is divided into two parts, north and south, connected by the Goyder Channel. The northern part of the lake is 90 miles (145 kilometers) long and 47 miles (76 kilometers) wide, while Lake Eyre South is 40 miles (64 kilometers) long and 14 miles (23 kilometers) wide. The combined volume of both parts is 19 cubic miles (79 cubic kilometers).

The lake’s basin overlies the Great Artesian Basin, one of the largest underground aquifer basins in the world; the Great Artesian Basin’s mound springs are a crucial water source for the biome. During excessive rainfall, the Lake Eyre tributaries—Cooper Creek, Diamantina River, and Georgina River—will feed the lake, but only in very small amounts. Most of the moisture is lost to evaporation prior to reaching Lake Eyre.

Biota

Since European colonists first documented the lake in 1840, it has rarely filled. The first recorded filling was in 1949, and before that, it was thought to be permanently dry. As it fills irregularly, the lake cannot be relied upon to sustain most plants and animals. As a result, the lake is home to a few aquatic plants, mainly diatoms, green algae, and blue-green algae.

Surprisingly, about 20 species of fish live in the lake. During dry periods, these fish survive in water holes, some of which are extremely small, but the largest are up to 12 miles (19 kilometers) long. These water holes have an average temperature of 95 degrees F (35 degrees C) or higher for days at a time, and are high in salt, making it possible for only the hardiest species to survive.

These fish, which include six species of goby as well as the bony bream, spangled perch, rainbowfish, and silver tandan, have adapted. Many have evolved into smaller versions of their species, enabling them to thrive in small spaces for long periods of time. They can thrive in the harsh conditions and are able to live by consuming the lake’s few algae species for food. Their reproductive cycles are adjusted to match the lake’s flood years.

There are some invasive species in the lake area, including crayfish, lobsters, shrimp, and crabs. All of these species have had to adapt, as well; the crabs that now live in the lake can survive long periods with little or no water and dwell in the desert sand. During flood years, the environment can drastically change, and several species of nomadic birds will make the lake home during flood years; these species include the black swan, Australian pelican, cormorants, silver gull, and pink-eared duck. These birds rely on the fish as well as the invasive species for food sources and use the lake as breeding grounds.

Environmental changes such as rising temperatures from global warming could alter the composition of Lake Eyre, with desert plants filling in the dry riverbeds instead of water. Extended dry spells could endanger the species that have adapted to the river’s current cycle, as hardy as they may be. If, however, rainfall increases enough to counter evaporation, then aquatic activity would spring to life in the altered life cycles of the river region’s inhabitants. Associated shifts in habitats beyond the lake could alter species distribution in ways that would impact all of the Lake Eyre life forms.

Bibliography

Cockayne, Bernie. “Climate Change Effects on Waterhole Persistence in Rivers of the Lake Eryre Basin, Australia.” Journal of Arid Environments, vol. 187, Apr. 2021, doi:10.1016/j.jaridenv.2020.104428. Accessed 3 Jan. 2026.

Cohen, Tim J., et al. “Late Quaternary Climate Change in Australia’s Arid Interior: Evidence from Kati Thanda–Lake Eyre.” Quaternary Science Reviews, vol. 292, 2022, p. 107635. doi:10.1016/j.quascirev.2022.107635. Accessed 3 Jan. 2026.

Kerezsy, Adam. Desert Fishing Lessons. UWA Publishing, 2011.

Kotwicki, Vincent. Floods of Lake Eyre. Engineering and Water Supply Department, 1986.

McMahon, Thomas A., et al. Hydrology of Lake Eyre Basin. Sinclair Knight Merz, 2005.

Measham, Thomas G., and Lynn Brake, editors. People, Communities, and Economics of the Lake Eyre Basin. Desert Knowledge Cooperative Research Centre, 2009, www.nintione.com.au/resource/DKCRC-Report-45-People-communities-and-economies-of-the-Lake-Eyre-Basin.pdf. Accessed 3 Jan. 2026.

“Rare Flood Event Transforms Spectacular Kati Thanda-Lake Eyre into Outback Oasis.” Government of South Australia, Department of Environment and Water, 14 May 2025, www.environment.sa.gov.au/news-hub/news/articles/2025/05/rare-flood-event-transforms-spectacular-kati-thanda-lake-eyre-into-outback-oasis. Accessed 3 Jan. 2026.

Timms, Brian V. “The Biology of the Saline Lakes of Central and Eastern Inland of Australia: A Review With Special Reference to Their Biogeographical Affinities.” Hydrobiologia, vol. 576, no. 1, 2007, doi:10.1007/s10750-006-0290-1. Accessed 3 Jan. 2026.