Mahi‑mahi — Research & Methodology (v2)
Last updated: 2026-06-02
This page documents the variables we use for Mahi‑mahi (v2), 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 sea-surface temperature (the anchor) plus a small, region-aware chlorophyll term. There is no moon driver. Research chooses the drivers; we calibrate the curve 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.
Not used in the Mahi score
Moon phase — dropped. An earlier version of Mahi leaned on moon phase, but the evidence for it was a single offshore tournament summary — too weak and not replicated to weight honestly. Mahi is now driven by water conditions only. (Fixed dawn/dusk-overlap and night-baseline terms were removed in an earlier rebuild for the same reason.)
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.
Sea-surface temperature (the anchor)
Research-backed: multiple open-access studies converge on a warm optimum (~25–28°C), a cold feeding cutoff (~18°C), and a decline above ~28°C. The exact optimum is 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).” (p.4)
“Feeding decreased at temperatures below 23.0°C and ceased entirely at temperatures of about 18.3°C.” (Hassler & Hogarth 1977, via Palko 1982 p.16)
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)
Our temperature curve runs from the ~18°C feeding cutoff up to a peak near 26.5°C and ends at 30.5°C — the warmest water mahi are documented in. We do not score hotter water as if it were measured.
Chlorophyll (a small, region-aware term)
Research-backed: chlorophyll matters, but its best level depends on the local water mass — clear (oligotrophic) water and green (productive) water peak at different chlorophyll concentrations. So we read the local water and score it against its own type, instead of applying one global rule.
“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 — clear water)
“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 — green water)
Calibrated: SST is required — with no temperature reading there is no Mahi score. Chlorophyll is a small adjustment, gated by temperature so it can never lift cold water. Exact values are proprietary.
Limitations / Caveats
- Mahi in PrimeBite is an all-day rating, not an hourly bite chart.
- The two-sided temperature optimum curves are from the Eastern Pacific; Atlantic occupancy data (Hammond 2008) corroborates the same warm range. We use these as direction-of-effect evidence, not a promise that the exact range wins everywhere.
- Chlorophyll is a small, region-aware nudge — it reads clear vs green water locally and is gated by temperature, so it never rescues cold water.
- Mahi needs ocean data. At an inland or no-ocean spot there is no score — pick a coastal or offshore location.
- A higher rating means better predicted relative conditions than a lower one. It does not guarantee a catch.
Changelog
- 2026-06-02: rebuilt Mahi to remove moon phase entirely (evidence too weak to weight honestly). The score is now sea-surface temperature plus a small, region-aware chlorophyll term. Removed an unsupported 33°C temperature point so the curve ends at the warmest documented mahi water (30.5°C), and corrected the feeding-cutoff citation to Palko 1982 p.16 (Hassler & Hogarth 1977).
- 2026-03-30: earlier rebuild removed the fixed dawn/dusk-overlap and night-baseline terms.