Why Fish Feed is Messing with Our Water Surveys

In the world of ecological studies, environmental DNA (eDNA) has become a go-to tool for understanding aquatic life. But here's the catch: it's not always accurate.

The Fish Feed Dilemma

Fish feed, used in aquaculture, can trick these surveys by showing up as false positives, like fish ghosts haunting the data. This is a big deal because it can mess up the results, especially near fish farms and processing plants.

The Research Findings

Researchers decided to dig deeper. They looked at three types of fish feed and found a whopping 51 fish species lurking in them. But here's the interesting part: DNA detected more species than RNA. This isn't just a small difference. It's significant. The same species showed up more often in water samples when using DNA than RNA.

The Significance

Now, why does this matter? Well, DNA seems to travel farther from its source than RNA. This means that in bays heavily used for aquaculture, RNA might be the better tool for accurate surveys. It's less likely to be contaminated by fish feed, giving a clearer picture of the actual fish population.

The RNA Advantage

But here's a thought: why isn't RNA used more often? It's less abundant in the environment and doesn't spread as easily as DNA. This makes it a more reliable option for ecological surveys in areas where fish feed contamination is a concern.