okenk
commented
1 year ago It does look like the combo survey might be catching more small fish, but that is also a big difference:
Closed brianlangseth-NOAA closed 1 year ago
okenk
commented
1 year ago It does look like the combo survey might be catching more small fish, but that is also a big difference:
Hastie mentioned this and so Im putting here to check. This is a lower priority at the moment.
Length-based selectivity of the two Triennial periods peaks around 50 cm, while the combo survey reaches an asymptote of 1 at around 15 cm! (fig.s 99-101) It isn't clear to me how/why that could/would reflect the true differences in ability of those surveys to catch canary of smaller sizes. Our survey does go a bit shallower, and is capable of sampling closer to rocks, but... (Maybe some of that is mesh size)
Combo selectivity for small fish is also higher than what was used for the non-trawl fleets, which appear to asymptote between 40 and 45 cm. That doesn't make a lot of sense to me, either. Perhaps there is something in the write-up