how to access IPHC data?

[iantaylor-NOAA]

The International Pacific Halibut Commission conducts an annual set line survey described at https://www.iphc.int/research/fishery-independent-setline-survey-fiss/ with a data portal at https://www.iphc.int/research/fishery-independent-setline-survey-fiss/ which allows you to download the data.

@CindyTribuzio-NOAA shared some info by email about the IPHC survey and gave permission for me to extract here:

The AFSC had been generating design based estimators from the FISS survey data, which we no longer do because of the changes to the FISS survey design. But, as part of that, I worked with AKFIN to annually pull the data from the IPHC portal and clean it up into a more user friendly format. We have the raw (akfin.iphc.fiss........) and cleaned up survey data (akfin.afsc_host.fiss.......) available in AKFIN.

My question is how do you go about querying IPHC data? And what processing steps do you do?

The AKFIN copy of the IPHC data is news to me. @gertsevv and I have used IPHC data in past assessments for Spiny Dogfish, Longnose Skate and Big Skate, but at least in the past there was missing information in the files on the data portal about the number of hooks examined for non-halibut species that was necessary for creating an index, so we got data directly from IPHC staff. I will happily learn more about the AKFIN version of these data in the future.

With regard to the 2025 Yelloweye Rockfish update conducted by this class, from what I understand, WDFW has been leading the effort on analyzing the yelloweye data from IPHC and may be able to provide a standardized index to the class.

The figure below is copied from the Wetzel, C.R.. 2024. Summary of available data to support U.S. West Coast groundfish stock
assessments. Pacific Fishery Management Council, Portland, Oregon. 211 p. https://www.pcouncil.org/documents/2024/05/f-3-attachment-2.pdf/. In the months ahead, the subset of folks working on yelloweye will surely be in contact with WDFW about this index and can transfer this discussion to the future yelloweye github repo or start a new one if they want.

[CindyTribuzio-NOAA]

Thanks Ian!

Yes, the data in the portal are imperfect and I have found errors occasionally in the non-halibut data for Alaska! I am much less familiar with the West Coast and BC data, but can see where there could be gaps in the information.

For those unfamiliar with the FISS data, the IPHC survey generally does not count all of the non-halibut that are caught. The have a semi-standardized subsampling rate of about 20%, where they count everything on the first 20 hooks out of a 100 hook skate (5-6 skates per station). The raw FISS data from the IPHC data portal includes fields for "HooksFished", "HooksObserved", and "SubSample". The SubSample is a binary flag where 0 = all hooks were observed and 1 = 20% of hooks were observed for non-halibut. To account for some of the variability in sampling rate, the AKFIN processing steps calculate the number of effective and ineffective total and observed hooks for each station.