This project plan outlines a two-event mark recapture experiment on Arctic grayling Thymallus arcticus in Beaver and Nome Creeks. Sampling will be conducted in 36 river kilometers (rkm) of the mostly road-accessible portion of Nome Creek and in the 44 rkm floatable portion of Nome Creek to the confluence of Beaver and Wickersham Creeks during July 2023. This follows a 2-year radiotelemetry study on Arctic grayling in the Beaver Creek drainage, where information acquired on life history such as migration timing, seasonal habitat preferences, and distribution has informed the timing, index area, and future data analyses for this mark-recapture experiment. The marking event will occur in early July, where three 2-person crews will sample a total of 6 rkm each day (i.e., 2 rkm per crew) and deploy approximately 1,000 Floy tags in Arctic grayling ≥250 mm FL. The recapture event will occur in late July, where Arctic grayling will be captured throughout the index area using the same methodologies employed during the first event and fish will be examined for tags. The population estimates acquired in 2023 will be compared to the last assessment conducted in 2000
The Operational Plan associated with this study can be found at
https://www.adfg.alaska.gov/FedAidPDFs/ROP.SF.3F.2023.07.pdf
This folder contains all raw data associated with fish marking and recapture, reformatted as .csv files: mark_float.csv, mark_hike.csv, recap_float.csv, and recap_hike.csv. These data are read into R and additional data manipulation and error correction is performed in script.
Two additional files are included: site_boundaries.csv gives the starting and ending coordinates of all sampling reaches, and beaver_cr_rivernetwork_op.Rdata is an R workspace file that allows import of the rivernetwork associated with the sampling area, formatted for use with the riverdist package.
1_BCMR_data.R loads all data and performs all data manipulation and reformatting and error correction.
2_BCMR_assumptions.R performs all statistical tests and checks to validate the mark-recapture assumptions.
3_BCMR_estimates.R produces output relevant to estimation of abundance and length composition.
This folder was created to house figures and tables generated by R, and is currently empty.
This Markdown file writes a Word document summarizing the results of assumption validation and estimation of abundance and length composition.