Confirm that we use correction factors for Gulf of St. Lawrence South?

[zoekitchel]

According to this publication, there is a change in gear and vessel in the GSL-S survey in 1985 and then a change in vessel in 1992. This publication describes correction factors. I don't see any mention of these correction factors on OceanAdapt (either in Metadata or in compile.R). Does anyone know if the original data we get from DFO website (publicly available here) includes these correction factors?

Benoît, H.P. and D.P. Swain. 2003. Standardizing the southern Gulf of St. Lawrence
bottom-trawl survey time series: adjusting for changes in research vessel, gear and
survey protocol. Can. Tech. Rep. Fish. Aquat. Sci. no. 2505: iv + 95 pp.

"Bottom-trawl surveys have been conducted annually in the southern Gulf of St. Lawrence
during the month of September since 1971. These surveys provide a time series of
information on the abundance, size-composition and distribution of more than 70 species
of marine and diadromous fish and over 40 marine invertebrate taxa. However, most
research activities utilizing these data are contingent on continuity of the time series for
each taxon. This means avoiding or correcting for any systematic changes in catchability
of these taxa to the survey. During the 33 year history of this survey there have been
changes in sampling gear and research vessels, as well as changes in the time of day in
which scientific fishing took place. These are all factors that are known to affect
catchability and for which corrections should be made to ensure inter-annual
comparability of catches. In this report we document such corrections for changes in
catchability and also provide a summary of other corrections or considerations that
should be taken into account when analysing the southern Gulf of St. Lawrence survey
data. "

[zoekitchel]

Similar case with GSL North, from this publication. Again, this is not described in the GSL North metadata or in compile.R. I don't know where we got these raw datafiles, but, do they include the corrections automatically?

"This combined series was developed
following a comparative study between the two vessel-gear tandems (1990-2005: CCGS
Alfred Needler – URI 81’/114’ trawl; 2004-2012: CCGS Teleost – Campelen 1800 trawl) to
establish specific correction factors for about twenty species caught (Bourdages et al.
2007). This resulted in adjustment of Needler catches into Teleost equivalent catches.
Note that the distinction between the two redfish species, Sebastes fasciatus and S.
mentella, is based on the analysis of the soft anal fin rays count and the depth of capture
of individuals (H. Bourdages, DFO Mont-Joli, pers. comm.)."

[mpinsky]

I do not know, and I don't see any mention about it on the GSL-South website. I believe we'd need to contact the data providers to know.

When we worked with DFO to add these regions to OceanAdapt, they pointed us to the websites but did not tell us to use the correction factors. I don't know if this was their oversight or if the factors have already been applied.