Comparable effort
Gear-specific and station-specific indices prevent seconds, net-hours, hauls, and angler-hours from being collapsed into a misleading total.
Offline fisheries field lab
Creelcurve
Record catch and effort, keep incompatible gear units separate, inspect size structure, screen population inputs, and hand off a reviewable field packet.
Built around field context
Creelcurve keeps measurements, station effort, protocol context, analysis limits, and the next action together. It works without an account, advertising, analytics SDK, or network service.
Length structure
Live bins, PSD and RSD screens, and a fitted weight-length relationship update from the entered fish record.
Population inputs
Chapman mark-recapture and catch-curve screens keep their assumptions beside the result and remain editable in the field.
Local survey library
Create, duplicate, switch, and retain multiple surveys on the device without signing in or syncing to a server.
Readiness checks
Local consistency checks flag invalid measurements, unmatched stations, mixed-gear stations, missing protocol context, and impossible recapture totals.
Reviewable exports
Share a multi-page PDF field packet plus separate catch and effort CSV files through the iOS share sheet.
The actual app in use
The station workspace below is captured directly from the current iPad build.
Method boundary
Creelcurve is a field-record and calculation aid. Species thresholds, sampling design, permits, animal handling, gear corrections, and management conclusions remain the responsibility of the qualified user and applicable agency.