fishing fisheries research river herring

How To Catch Hard-to-Catch Fish?

Some fish are really hard to catch, but scientists need to study these hard-to-catch fish too. How do they do it?


Figure 1 – Video showing the pound net that I use to catch river herring for my research. The net allows fish to swim safely and freely inside of the impoundment until I return to check the net. This design allows researchers to safely release any non-target species caught and minimizes stress on the targeted fish.

Many of us are familiar with how to catch fish. You bait up a hook with something the fish likes to eat and you throw it in the water. Well, what if the fish you want to catch is more of a filter feeder than a predator, like the river herring that I study? In that case, you would normally use some sort of net to scoop them up. But what if the fish you are trying to catch have very good eyesight and can see your net coming in addition to being really strong swimmers? They simply outrun your net when they see you coming. In order to get detailed information about fish like this, you have to be able to capture them. To capture these hard-to-catch fish, we borrow ancient Chinese technology to build a trap net. The shape of the net capitalizes on the fact that these fish are such strong swimmers by continuously directing them away from the opening of the net, preventing their escape. Bonus: it is probably the most environmentally friendly fishing method, reducing injury, mortality, and bycatch. We heart our fish!

Figure 2 – A beautiful, well preserved ancient Chinese heart-shaped pound net. Many years later, cutting-edge fisheries science still starts with the same concepts utilized by ancient peoples long ago. Source: Wikipedia Commons

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