Our Scientists – From Coast to Coast to Coast – Stephen Wischniowski
Transcript
My name is Stephen Wischniowski. I'm the program manager for the sclerochronology lab or more commonly known as the age lab and essentially we provide internal services to our clients at DFO, those being Salmon, ground fish, pelagics, and shellfish.
Essentially what we do is they collect structures for us in the field, they bring them into the lab, and we determine how old those structures are.
For different species we use different techniques and different structures so for salmon for instance we'll use scales, herring also, we'll use scales, that's a pelagic species that we age.
Most commonly for ground fish we'll use otoliths which is an ear bone located inside the head of the fish. And we prepare them by breaking them in half, putting them over an alcohol burner, and baking them to a point where they change colours.
This enhances the seasonal growth and this is what we interpret as age. We count these annual rings so it's very similar to a tree that's cut in half, you see all the growth rings, essentially that's the same thing.
So the fundamental principal of this lab is to produce age estimates to go into stock assessment and harvest policies to ensure that we aren't over harvesting any one particular species and ensure the sustainability of those species.
- Date modified: