In a paper published in Conservation Physiology, CTBCC's Deb Bower, along with co-authors from a variety of institutions, investigates salinity tolerance in Australian freshwater turtles.

High amounts of salt in brackish water can be a challenge to freshwater species, such as turtles.

This study aimed to indentify the tolerance of two freshwater turtles, Emydura macquarii and Chelodina expansa, to high salt content waters.

Interestingly, both species reduced feeding when exposed to 15% salt water compared to in freshwater (0‰), suggesting behavioural adaptations to decrease intake of salt.

The researchers suggest that this osmoregulatory behaviour may allow for persistence of turtles in regions affected by salinization; however, growth rates and body condition may be affected in the long term.

Salinization, due to rising sea levels and other factors, is a threatening process for many species. Although these turtles have mechanisms to survive temporarily in saline waters, the authorsstate that it is likely that sustained salinization of waterways will exceed their short- to medium-term capacity to survive increased salt levels, making salinization a potentially key threatening process for these freshwater reptiles.

Read the full paper here. https://academic.oup.com/conphys/article/4/1/cow042/2404592/Salinity-tolerances-of-two-Australian-freshwater