West Coast Groundfish Observer Program Manual, Part2 - NOAA

CHAPTER 6
Collecting Tags
Tags for fish other than salmon are usually externally located
on the dorsal surface or on the gill cover. Spaghetti tags are
the most common type of external tag but some fish may
have disc-shaped tags. If a tag is provided without the actual
fish, collect as much information as possible from the crew
member who gave you the tag including the tag collection date
and location.
Tagged salmon usually have internal coded wire tags or PIT
tags inserted into their snouts but some may have external disc
shaped tags on their dorsal fins. Coded wire tags are about 1
mm in length and have a distinct code, usually a series of
slashes at different intervals engraved on them. PIT tags are
electronically coded tags that require a reader to decipher.
Salmon tagged with coded-wire or PIT tags are identified by a
missing adipose fin. Neither type of snout tag can be
removed in the field, therefore, the entire snout must be
collected and returned.
Collect biological information from tagged fish using the
following procedure:
1. Remove the external tag or salmon snout. The
collection procedure for salmon snouts follows this
section.
2. Weigh the fish if possible.
3. Determine the sex of the fish.
• In the case of LIVE Pacific halibut, do NOT
attempt to sex the fish or remove the tag. Just
record the tag number and other pertinent data.
4. Measure the length of the fish.
6-34 1/30/2004