Black Marlin — Research & Methodology (v1)
Last updated: 2026-03-30
This page explains the public Black Marlin model story: what PrimeBite uses, what the research supports, and what the limits are. We do not publish the exact numeric tuning or any reproduction-ready recipe.
How it works (overview)
Black Marlin is an offshore all-day rating built from three live drivers: moon phase, GBR-timed seasonality, and SST. PrimeBite does not show Major/Minor moon-position windows for Black Marlin, and the old overlap term is no longer part of the live score.
Research chooses the drivers and the direction of the story. PrimeBite calibrates the exact curve shape, thresholds, and weights so the score stays stable on a 1.0-5.0 scale. Those exact numeric tuning values are proprietary.
Variables (what's research-backed vs calibrated)
Research-backed means the driver/pattern/mechanism is supported by open-access sources. Calibrated means we chose the exact curve shape/thresholds/weights/caps to produce a stable 1.0–5.0 score and to avoid overclaiming from region- or gear-specific studies.
Moon phase (quarter phases / “half-moons”)
Research-backed (GBR diaries): higher CPUE during half-moons and ~30–40% lower during new or full moons.
Pepperell et al. 2025 (open access): DOI • PDF • cached PDF p.7 / p.13
“Moon phase had a non-linear relationship with higher CPUE during a half moon and approximately 30%–40% lower during new or full moons (Fig. 7e).”
Calibrated: the exact curve shape is not claimed as the paper’s exact effect size.
Seasonality (GBR timing)
Research-backed: a GBR spawning aggregation forms in Oct–Nov; the charter season is Sep–Dec with peak CPUE Oct–Nov.
Domeier & Speare 2012 (open access): PLOS ONE full text
Pepperell et al. 2025 (open access): PDF • cached PDF p.11
Calibrated: PrimeBite uses a mild off-season drag plus a stronger Sep-Dec run, but the exact month-to-month values are proprietary and GBR timing is applied globally as a modeling choice.
Environmental variables (verification)
This section documents what the papers say (verbatim quotes) and then shows how PrimeBite maps that into a stable rating (calibrated thresholds + caps).
SST (SST-only ocean block)
Setyadji & Fahmi 2020 (open access): DOI • PDF • cached PDF p.6 / p.7
“In this study, high CPUE occurred between 29–31°C...”
“... SST and SSH were statistically significant when incorporated into the models, but it allegedly wasn’t the main driver...”
Calibrated: PrimeBite uses SST as a smaller ocean covariate, treats missing SST as neutral, and keeps the exact thresholds and caps private.
Limitations / caveats
- The strongest moon-phase and seasonality evidence is GBR-specific, but PrimeBite currently uses one global Black Marlin profile.
- SST support comes from a different fishery and region, so PrimeBite keeps the SST block smaller than the moon driver.
- SSH appears in the literature, but it is not a live scored PrimeBite variable yet.
- If SST is missing, PrimeBite keeps the ocean block neutral instead of guessing.
Sources
- Pepperell et al. 2025 — ICES Journal of Marine Science
- Domeier & Speare 2012 — PLOS ONE
- Setyadji & Fahmi 2020 — Indonesian Fisheries Research Journal
Changelog
- 2026-03-30: removed the unsupported overlap term from the live Black Marlin score and rebuilt the remaining 3-driver model.
- 2026-03-30: updated the public page so it now matches the live driver set and current disclosure standard.