While water quality and pathogen surveillance has become more mainstream, it has been challenging for fish farmers to accurately monitor stress levels in their fish stock. Unfortunately, stress in fish can lead to many problems such as reduced feeding, slower growth, increased susceptibility to death and disease, and poorer meat quality.

To tackle this issue, a cross-disciplinary team of researchers from the Institute of Molecular & Cell Biology (IMCB) and Institute of Materials Research and Engineering (IMRE) and Republic Polytechnic, sought to characterize the stress response in our local barramundi species. Led by Principal Scientist Dr. Caroline Wee at IMCB, the team uncovered consistent dynamics of the stress hormone, cortisol, in blood plasma, mucus, and the surrounding water following handling stress. Each sample type showed a different time course of cortisol changes after stress. Importantly, water cortisol tracked plasma cortisol trends, although with a faster decline. These findings suggest that monitoring stress levels in fish through routine, non-invasive measurement of water cortisol could be a feasible tool to detect fluctuations in stress levels and identify early anomalies. Their collaborative study is now published in Aquaculture Reports. 

"Our next step is to explore the deployment of ultra-sensitive cortisol sensors, which our IMRE collaborators have developed, to on-farm settings, and use them to monitor other common stressful scenarios such as changes in water quality, stocking density, or even infection. We are excited to work with our industry and academic partners on these plans.”, said Dr. Wee.

In conclusion, these findings open up new avenues for developing more advanced and automated stress monitoring methods, transforming the aquaculture industry by improving fish welfare and promoting more sustainable aquaculture practices.

Link: https://www.sciencedirect.com/science/article/pii/S2352513424003119

Read more about Cortisol Aptasensor: https://www.mdpi.com/2218-273X/14/7/818