Explore size data from different sources

[marcnadon]

Explore size compositions from: 1) Bfish fishing 2) Bfish camera 3) FRS - 1 fish trips

Explore the diffrence in mean lengths from: 1) Bfish fishing 2) Bfish camera 3) FRS - 1 fish trips 4) FRS - 1-5 fish trips 5) FRS - 1-10 fish trips 6) FRS - all trips

[MOshima-PIFSC]

Size compositions from BFISH fishing, BFISH camera, and FRS 1-fish trips are fairly different. The 1-fish trips and camera data are skewed towards larger fish. Both BFISH datasets were filtered to only include fish above 29 cm (to match with the index). Also, research fishing and camera compositions are pretty distinct so this may require splitting the BFISH index into 2 gear-specific indices in the future.

When comparing the mean lengths over time in FRS data, 1-fish trips had consistently higher mean lengths than trips with more than 1 individual. As you include trips with more fish, mean length decreases, although mean lengths for trips with a max of 10 fish is pretty similar to mean lengths when including all the trips.

When comparing the different FRS trips with BFISH camera and research fishing data, research fishing data is most similar to FRS_all (all trips) in the first 4 years but after 2020 the mean length drops dramatically. I currently don't have the meta-data to investigate this much further (is it due to sampling area fished?) but can ask Ben for more information.

[MOshima-PIFSC]

Also comparing UFA to BFISH camera and fishing length comps, UFA matches pretty well with BFISH fishing.

[marcnadon]

@MOshima-PIFSC, could you add the yearly camera vs fishing BFIsh size structure graphs you showed before? It would be good to see how much the 2021-2023 resfish lower sizes skewed the overall distribution previously showed.

[MOshima-PIFSC]