Creelcurve: Fisheries Lab

Support

Creelcurve is an offline iPhone and iPad field-record and calculation aid. No sign-in or subscription is required.

Start a clean survey

1. Open the Survey options menu and choose Survey Library.
2. Use the plus button to create a blank survey, or duplicate the worked sample to preserve its structure.
3. Enter a survey title, waterbody, target species, protocol, lead observer, and date.
4. Add catch observations and matching station effort before interpreting CPUE.

Why CPUE says “By Gear”

Effort measured in seconds, net-hours, hauls, and angler-hours is not directly interchangeable. When a survey contains more than one effort unit, Creelcurve intentionally withholds a single combined CPUE and shows gear-specific and station-specific indices in Stations.

Export a field packet

Tap the share icon in the toolbar. Creelcurve creates a multi-page PDF report, a fish-record CSV, and an effort-record CSV, then opens the iOS share sheet. Choose Files to retain a local copy or another destination approved by your organization.

Backups and device changes

Survey records live in Creelcurve’s private app container. Before deleting the app or changing devices, export the PDF and CSV field packet for each survey. Creelcurve does not operate a cloud-sync service.

Calculation limits

The app displays method boundaries alongside PSD/RSD, Chapman mark-recapture, catch-curve, and weight-length screens. Always apply the responsible agency’s species thresholds, sampling design, gear corrections, handling requirements, and permitting rules.

Report a problem

Email support@shadowfetch.com with the device model, iOS or iPadOS version, the screen involved, and the steps that led to the issue. Do not attach sensitive field data unless you are authorized to share it.