Friday January 13, 2012
As lunchtime approaches, Patrick may be thinking about what’s for lunch, but at the moment he’s trying to figure out how we’re going to fit more salmon heads into our freezer. All fall, we have been collecting the heads of salmon that have died naturally and washed up on our fish counting weirs. We collect the heads from these salmon because their otoliths (ear bones) can be extracted and analyzed to provide valuable information about the fish’s life history. If the head came off a fish without an adipose fin, it may contain a coded-wire-tag (CWT) indicating its hatchery of origin, and where and when it was released from the hatchery. Let’s just say, it might be a good day to avoid the fish tacos.