Restate fork lengths as total lengths — convert_fork_lengths • peskas.kenya.data.pipeline

KEFS records each fish on the length type the enumerator measured: mostly total length, but fork length for tunas, mackerels, jacks and some snappers. Everything downstream reads length_cm as total length, and the size views compare it with FishBase lengths at maturity that coasts::enrich_taxa() restates as total length. So fork lengths are restated here, per fish and before summarise_priority_lengths() averages them, with the same POPLL fits: TL = intercept + slope * FL, from coasts::get_tl_conversions().

Usage

convert_fork_lengths(
  priority_df = NULL,
  taxa_mapping = NULL,
  version = "latest"
)

Arguments

priority_df: Long priority-species data from reshape_priority_species().
taxa_mapping: Airtable taxa mapping for the KEFS form, with survey_label, alpha3_code and scientific_name.
version: FishBase / SeaLifeBase release. Keep it the release coasts::enrich_taxa() reads, so both sides of the size comparison use the same fits.

Value

priority_df, with converted fish carrying length_type = "total_length".

Details

A species with no fork-length fit keeps its fork lengths, and the step logs a warning naming it. Carapace (lobsters, crabs) and mantle (octopus, squid) lengths are left as measured: they are the standard measures for those animals, and none of the lobsters, crabs, octopus or squid KEFS measures has a length at maturity to compare against (2026-09).