Aquaculture (fish farming) is often viewed as a way to meet the growing demand for seafood while taking pressure off of wild populations. With some species and some farms, that’s exactly how it works. With others, fish farming can be incredibly harmful to the environment and can alter the nutritional value of the fish.
One of the biggest problems with fish farming is disease, which can be caused by improper feeding, stress from extreme or toxic conditions, or attack by disease organisms, which can happen internally or externally. In open-ocean farms, there is a risk of spreading disease to wild populations; in on-shore farms disease can spread rapidly, which means that preventing disease is much easier (and cheaper) than treating it. This leads farmers to use preventative antibiotics, which can be bad for the fish and for the humans consuming that fish.
In Denmark, 75 percent of antibiotics used in fish farms are used to treated fish with enteric redmouth disease, which is harmless to humans but reduces fish wellbeing and increases mortality. Fish in the Danish production industry are vaccinated against this disease, but that hasn’t solved the problem.
Researchers at the University of Copenhagen studied rainbow trout (Oncorhynchus mykiss) using 3D scans to learn how the fish get infected with the bacterium in order to help develop a more effective vaccine. The OPT scanner (Optical Projection Tomography) is a rare piece of technology that allowed the researchers to monitor the infection “with unparalleled precision.”
You can see what the 3D scan looks like in the following video clip:
“The research findings are presumably the first of their kind and the scanning images exceed our wildest dreams,” project leader Martin Raida of the Department of Veterinary Disease Biology said in a news release. The team found that the bacterium infects the fish via a specific cell type found in the gills and its presence can be registered in the blood stream a mere 60 seconds later.
The researchers hope that this knowledge will help in the creation of a more effective vaccine against enteric redmouth disease, which would lessen the amount of antibiotics used in the fish farming industry.
Copyright © 2014 by Marine Science Today, a publication of Marine Science Today LLC.