The life-story of a fish? Answers on a scale, please!

In our next ‘Photo of the week’, we are exploring research investigating what information a fish scale can provide and how that can be utilised within ecological monitoring. The research is being led by BU’s Georgina Busst.

This scale is from a grayling, which belongs to the salmon family of fishes. There are many rings running around it – similar to that of a tree and just like trees fish grow seasonally. The seasonal growth is visible on their scales as rings are laid down closer together in winter, as fish grow much more slowly and are more spread apart in summer, as fish grow at a faster rate. You can see this pattern in this photo. The fish that this scale belongs to is 1 year old, approaching 2. You can tell this as the rings are closer together near the scale edge, indicating slower growth and therefore winter.

Scales are extremely valuable tools for fisheries ecologists as you can remove a few without harming the fish and you can collect lots of different information from them. Scales can be used not only to age fish, but to monitor their growth rates and relate this back to changes in the environment; reveal how many times a fish has spawned; how many years it has spent at sea; for DNA and genetic analysis and stable isotope analysis, which can reveal what the fish has eaten and what position it is in a food web. All that from a simple scale.

For more information about the project, email Georgina for further details.

This was an entry to BU’s first research photography competition and the entries for the next competition will be open shortly. For more details about the competition, please email research@bournemouth.ac.uk

This article was originally published on the BU Research website.