Observing a whole pen full of salmon at a fish farm will only tell you so much about their well-being. That's why Norwegian scientists have developed an implant that measures and records the vital signs of individual fish, who will serve as "sentinels."
Created by Eirik Svendsen and colleagues at the SINTEF Ocean research institute, the cylindrical device measures 47 mm long by 13 mm wide. It contains a battery, microcontroller and memory card, along with sensors that monitor blood oxygen content, heart rate, activity level, directional orientation and temperature.
The idea is that just a few salmon from each pen will get equipped with the implant, which is surgically inserted in the front part of the anesthetized fish's belly through a small incision. Once released back into the pen, those individuals will serve as "sentinel fish," providing a detailed picture of the well-being of both themselves and the pen population.
Svendsen tells us that for his current research, he is releasing the sentinels into a smaller pen within the larger overall pen, so they can be easily retrieved for implant extraction and data analysis.
While this may also be the best way to go moving forward, it's additionally possible that the fish could go right into the main pen. They would subsequently be identified at harvest via external markers such as fin tags, or by metal detectors which would detect the implants.
What's more, along with its use in traditional fish farming, the technology may also be utilized to assess the effects of new aquaculture techniques.
"It hasn’t previously been possible to gather all these types of data simultaneously," says Svendsen. "The implant offers us entirely new opportunities to address the requirements that new methods designed to improve fish welfare must be tested before they are used in practice."
Source: Norwegian SciTech News