The Species Count That Disappeared Into a Notebook
NZTM coordinates in a trap survey aren't a nice-to-have. When you're running 12 trap sites across three waterbodies in the same catchment, the easting and northing are the only thing that unambiguously identifies where a specific catch record belongs. Site names change — locals call the same reach three different things, maps use a fourth — and GPS waypoints on the meter get overwritten. The NZTM Easting and NZTM Northing fields in this template are the persistent spatial anchor for every trap event, independent of what someone calls the reach that week.
The Fish Traps template was built for fish passage and population monitoring work in New Zealand freshwater systems. The NZTM coordinate system (New Zealand Transverse Mercator) makes that origin unambiguous.
What the Trap Check Actually Records
Each trap deployment generates one record: waterway name, site name, date and time, GPS location (device GPS plus manually entered NZTM coordinates for the survey database), trap type (fyke net, box trap, electric fishing stop net — whatever the method), habitat type, and riparian vegetation description.
Habitat type and riparian vegetation are open-text fields, not dropdowns. This is correct for a monitoring context where channel morphology and bank condition vary in ways that preset categories can't capture. The difference between "low gradient pool-riffle sequence with native kahikatea riparian fringe" and "modified concrete-lined drain with rank exotic pasture grasses to water's edge" is not two items in a list — it's ecological context that determines which species assemblage you'd expect to find and whether the riparian restoration plantings are working.
The template accommodates up to seven species per trap check, each with the same four fields: species name, number caught, minimum size, maximum size, and comments. For sites where kōaro, kākahi, brown trout, kōura, and shortfin eel might all turn up in the same event, this isn't overcapacity — it's barely adequate. The comments field per species is where you record spawning condition, unusual coloration, injury, or the fact that three of the shortfins were caught tangled in each other, which tells you something about trap density in that section of the channel.
What One Season of Survey Data Reveals
A season of trap monitoring across 15 sites, checked monthly from September through May, produces around 135 records. That's the minimum viable dataset for detecting presence/absence changes and crude abundance trends.
The min/max size fields per species are where the population structure information lives. A site that was producing shortfin eels with max sizes in the 600-700mm range two seasons ago and is now only producing individuals under 400mm has a cohort structure shift worth investigating. A single site visit won't show it. A database with consistent size-range records across multiple seasons will.
Filtering by Waterway lets you isolate all records from a single waterbody and look at species composition change over time. Filtering by Species (1) containing "kōaro" across all records shows you every trap event where kōaro were present — useful for mapping the upstream extent of kōaro distribution relative to any passage barriers in the catchment. The Site photos and Catch photos image fields attach the visual evidence to the record, not to a separate folder on someone's laptop where it will get renamed and become unidentifiable within a year.