The Thelma Biotel Acoustic Salinity Transmitter measures the salinity and temperature of the water. The tag can be attached externally to a fish or another specimen, or it can be anchored close to, or in the vicinity of an acoustic receiver for the purpose of logging salinity and temperature in the water. The transmitter can be delivered in two sizes, 9 mm and 13 mm, and with two types of sensors: one for fresh water and one for brackish/salt water. The salt water version can be used to estimate salinity. The transmitter measures conductivity and temperature values with a certain interval (typically minutes) and transmits acoustically the values. Thelma Biotel can also offer a custom adapted solution where the transmitter also transmits a statistically and coded value with information about what water quality (combination of conductivity and temperature) the transmitter has been exposed to during the last 48 hours (for example). For more information, contact Thelma Biotel.

Example of Application

During chemical treatment of Gyrodactylus salaris in salmon rivers, there is a risk that infected fish can hide in a well or supply of ground water and thus escape from the chemicals. The
conductivity transmitter is designed to monitor in what water qualities the fish stay, before, during and after the treatment. Ground water supplies will typically have 2-3 times higher conductivity than the river main stream, and also a different temperature. The figure below shows an initial conductivity measurement that was performed close to the river bank where ground water of high conductivity was mixed with river water of low conductivity. The Acoustic Conductivity and Temperature Transmitter is expected to provide valuable information about fish behavior during such treatment.