I will be heading back out on survey ("tokt") on December 1st working from a floating dock near Tromsø to mark herring. But since my last excursion I've been at the office learning how to age fish using otoliths or scales. Right now I'm being taught about Norwegian Spring Spawning herring (the most economically valuable fish that we study). Thought I'd share some pictures.
|[A few scales from a particular area on the fish are removed when we do the normal sampling, |
and are cleaned before they are placed on the slides]
|[Cleaned scales going on the microscope slide]|
|[How the scales look under the microscope. This fish is 12 year old]|
|[7 year old fish]|