West Coast Groundfish Observer Program Manual, Part2 - NOAA

CHAPTER 6
Sexing Fish
Data Collection Guidelines
1. Collect sexes from tagged fish.
Figure 6- 3: Sexing Fish
2. Collect sexes when otoliths are taken.
3. Collect sexes from salmon when scales or snouts are
taken.
4. Collect sexes when taking lengths from dead high
priority rockfish.
DO NOT sex fish in the following situations:
1. When the fish are being discarded alive. This is
common in the Live Fish and Dory Fleet fisheries.
2. When the fish is a hardy species that is likely to survive
being discarded. Lingcod, sablefish and Pacific halibut
are considered to be hardy species and should not be
sexed unless they are dead and tagged.
3. When the fish is tagged but the vessel is retaining the
fish and sexing it would damage the product (some
vessel may still allow you to sex it, but usually not).
Preparing to Sex Fish
Roundfish, sablefish, rockfish, flatfish and salmon are all sexed
slightly differently due to variations in anatomy (See Figures
6-3 and 6-4). Attention should be paid to the cut necessary to
locate the gonads, the location of the gonads within the body
cavity and the physical description of the gonads.
6-16 1/30/2004