Mahi‑mahi — Research & Methodology (v1)
Last updated: 2026-03-30
This page documents the variables we use for Mahi‑mahi (v1), the open-access URLs behind each driver, verbatim quotes, and what is research-backed vs calibrated. We keep proprietary calibration details private.
How it works (overview)
Mahi is an offshore all-day rating built from moon phase plus a capped ocean block (SST and optional chlorophyll). The live rebuild removed the old overlap and night-baseline assumptions. Research chooses the drivers; we calibrate weights and caps so the output maps to 1.0–5.0. Exact 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
Research-backed: an open-access offshore tournament summary reports Dolphinfish (Mahi‑mahi) catch-rate peak at First Quarter.
Source (open PDF): NC Sea Grant — Hook, Line & Science (Winter 2020)
“Scientists found a relationship between catch rates and lunar phase for 5 of the 8 species as shown here…
Dolphinfish first quarter” (PDF p.2)
Calibrated: Mahi now uses its own smooth First-Quarter curve. It still peaks at First Quarter, but the fade after First Quarter and the late-cycle recovery back toward New Moon are calibrated product choices.
Excluded from the live score
The live Mahi rebuild does not use a fixed dawn/dusk overlap bonus or a fixed night baseline anymore. Those terms were removed because they were not strong enough to keep as live score drivers.
Environmental variables (verification)
This section documents what the papers say (verbatim quotes with page pointers). How we map that into a stable rating uses proprietary thresholds and caps.
Oceanography (SST + chlorophyll‑a)
Research-backed: multiple open-access studies show SST and chlorophyll-a covary with dolphinfish/mahi CPUE/habitat, but ranges are region-dependent.
SST anchors:
Marín‑Enríquez & Muhlia‑Melo 2018 (PDF)
“...dolphinfish preferred warm waters (24–28°C)...” (PDF p.1)
Martínez Arias et al. 2022 (PDF)
“Higher values of CPUE occurred in temperatures between 25.5 and 27.5 ºC. Above 27.5 °C and below 25.5 °C, CPUE decreases.” (PDF p.5)
“...are generally restricted by the 20°C isotherm (Gibbs and Collette 1959).” (PDF p.4)
Hammond 2008 (SEDAR document page)
“Dolphinfish were shown to utilize ocean waters with temperatures ranging from 16.0 to 30.5°C.” (cached PDF p.3 / printed p.2)
“...tolerated temperatures from 15°C to 29°C but would stop feeding at 18°C (Hassler and Hogarth 1977).” (cached PDF p.87 / printed p.75)
Chlorophyll anchors:
“...low concentrations of chlorophyll‑a (<0.02 mg/m3) ...” (Marín‑Enríquez & Muhlia‑Melo 2018, PDF p.1)
“82.90% of total fish... was caught in waters with concentrations of chl‑a between 0.05 and 0.25 mg/m3...” (Marín‑Enríquez & Muhlia‑Melo 2018, PDF p.5)
“Higher values of CPUE occurred in places where Chl‑a varied between 0.5 and 2.2 mg/m3. Below and above these values respectively, CPUE decreased.” (Martínez Arias et al. 2022, PDF p.5)
Calibrated: SST is required (if missing, ocean is neutral). We apply a cold-water gate so CHL does not cancel cold penalties below a set threshold, and an ocean cap; exact values are proprietary.
Limitations / Caveats
- Mahi in PrimeBite is an all-day rating, not an hourly bite chart.
- The moon-phase evidence comes from an open-access offshore tournament summary, so we treat the exact curve shape as a calibrated product choice.
- SST and chlorophyll studies are region-specific. We use them as conservative direction-of-effect evidence, not as a promise that the same exact range wins everywhere.
- If SST is missing, the ocean block stays neutral. If water is cold, chlorophyll does not cancel that cold-water miss.
- A higher rating means better predicted relative conditions than a lower one. It does not guarantee a catch.
Changelog
- 2026-03-30: rebuilt live Mahi model to remove the old fixed overlap and night-baseline assumptions; live score now uses moon phase, SST, and chlorophyll only.
- 2026-03-30: refreshed the public Mahi citation trail with corrected Young and Hammond page references and added this limitations/changelog package.