The 2021 Togiak herring commercial harvest was sampled using the sampling application developed in 2020 to replace the previous sampling application which is obsolete and unsupported. The sampling app is located here:

S:/REG2/GBuck/Bristol Bay/Togiak Herring/2020 Togiak/herring_sampler_app.R

The current sampling app produces an individual .csv file for each slide of fish and giving that slide an individual session.id that includes a date/time stamp of when the sampling file was created. Once all sampling is completed, a scripted R loop is used to merge files into a ‘master.csv’ file. Age data was then added to the master.csv file. We then examine the purse seine ASL data by subdistrict (east to west)

library(ggplot2)
library(tidyverse)

master.asl <- read.csv("master2.csv", row.names = NULL)

temp <- master.asl %>%
  filter(age < 28) %>%
  filter(length < 500) %>%
  mutate(sample.date = as.Date(sample.date)) %>%
  mutate(catch.date = as.Date(catch.date))

#summary(master.asl)


ps.asl.plot <- temp %>%
  filter(gear == 5) %>%
  filter(subdistrict == 12 | subdistrict == 21)
  


ggplot(ps.asl.plot,aes(x = age)) +
  geom_histogram() +
  facet_grid(subdistrict ~ ., scales = "free")

No geograpnic differences are visually apparant to me betwwen harvest in the Hagemeister subdistrict (subdistrict = 21) west of Togiak Bay. and harvest in the Nunavachak subdistrict (subdistrict = 21) to the east of Togiak Bay. These two subdistricts contained 93% of the purse seine harvest in 2021.

ggplot(ps.asl.plot,aes(x = age)) +
  geom_histogram() +
  facet_grid(catch.date ~ ., scales = "free")

For the biomass calculation I used purse seine samples from the following catch dates:

1.pre-peak harvest: ASL catch date 5/5
2.peak survey: ASL catch dates 5/5-5/7
3.post-peak survey: ASL catch date 5/11

For the gillnet harvest I assign the following ASL data

1.harvest through 5/5/21: ASL catch date 5/5
2.harvest 5/6-5/7: ASL catch date 5/7
3.harvest 5/8-5/9: ASL catch date 5/8-5/9
4.harvest 5/10: ASL catch date 5/10
5.harvest 5/11-5/14: ASL catch date 5/11

Only 39 tons of gillnet harvest was taken and the single gillnet sample that was collected was applied to that harvest.