Posted by Daniel Nyqvist | Vinterekologi

The stream aquaria with ice cover.

The Lab and Stream, a project that “strives to bridge the gap between anglers and academics”, has written about NRRV:s lab research on winter ecoology of brown trout:

“I think that one of the reasons that people are fascinated with fish is that they are hard to observe. Fish live in a world that is difficult to visit and largely mysterious to us air breathers, even though that world might be only a few feet underneath your boat or dock. While the underwater world might seem like an alternate dimension, the under ice world is even more distant from people’s understanding. Anyone that has stood on a frozen lake has wondered what is going on underneath them, but under ice behavior is notoriously hard to study because it’s cold and dark down there.

A cool new study by researchers from Sweden and Norway has shed some light on what trout are doing under the ice. They built stream channels in the lab that had a window on one side (to observe the fish) and added ice cover to the top of the channels to simulate a frozen river environment. In each channel they added 4 brown trout and observed their feeding and swimming behaviour…”

Read the full article at

Johan Watz led the experiment described and focoused his PhD on the winter ecololgy of salmonids. Read his thesis here. Links to the papers included are available in this blog post.

Leave a Reply

Your email address will not be published. Required fields are marked *