What Water Conditions Bring Mahi-Mahi?
Last updated: 2026-09-26
Short answer
Mahi-mahi follow warm water. The records we own converge on a warm optimum in the high 20s°C, with catch rates dropping above roughly 29–30°C (Marín-Enríquez & Muhlia-Melo 2018; Zúñiga-Flores et al. 2008; Alejo-Plata). Most of that catch data came from commercial fishing, not rod and reel: tuna purse-seine sets in the eastern Pacific and longline sets off Colombia, with satellite-tagged fish agreeing on the same band. The one rod-and-reel record — the Cabo San Lucas sport fleet — found its best catch rates at 26–29°C, which brackets our peak rather than pinning it. Feeding itself is reported to slow below about 23°C and stop near 18°C (Hassler & Hogarth 1977, via Palko et al. 1982). There is no moon driver, and no chlorophyll driver — the evidence for each was too weak or too divided to include.
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 alone. There is no moon driver and no chlorophyll driver. Research chooses the driver; 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 temperature only. (Fixed dawn/dusk-overlap and night-baseline terms were removed in an earlier rebuild for the same reason.)
Chlorophyll — dropped, 2026-09-14. Chlorophyll matters somewhere in this fish's ecology, but the catch evidence does not agree with itself. One paper found most fish in clear water (“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); another found catch peaking in green 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); three more studies we own found no effect at all. The first paper also disagrees with itself between its raw fish counts and its own fitted models. And the chlorophyll value we can read for your spot is a modelled field, not the satellite measurement those papers used — nothing we own tells us how far apart the two are for the same water on the same day. There is no rod-and-reel study of chlorophyll and dolphinfish catch in anything we own. So we do not score it.
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: the open-access records we own converge on a warm optimum in the high 20s°C, a cold feeding cutoff (~18°C), and a decline above roughly 29–30°C. The exact optimum is region-dependent, and the sources below disagree about where inside that band it sits.
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 — this is where the fish were, not where they were caught)
The rod-and-reel record, and the tagged fish, both put the best water warmer than the two commercial curves above:
“In conclusion the distribution of the dolphinfish is directly affected by SST with the species more abundant at temperatures between 26 °C and 29 °C.” (Zúñiga-Flores, Ortega-García & Klett-Traulsen 2008, p.16 — three Cabo San Lucas sportfishing fleets, catch per trip; the only rod-and-reel catch-versus-temperature series we own)
“...spent 95% of their time in water between 25 and 29°C and displayed little variation in median temperature between distinct migratory regions (regional median temperature range = 27.0–27.9°C, overall median temperature = 27.5°C...)” (Schlenker et al. 2021, p.10 — nineteen satellite-tagged fish)
“The maximum and minimum SST values from quadrants where at least one dolphinfish was caught were 31.10° and 18.50°C.” (Marín-Enríquez & Muhlia-Melo 2018, p.13 — one survey quadrant's maximum, not a band)
The cited records place the best water in a warm range, but they do not pin one exact peak or measure a catch rate across the hottest part of our rating curve. Our chosen peak and curve endpoint stay private. The documented catch at 31.10°C above is one survey quadrant's maximum, not a broad catch band. An earlier version of this page called 30.5°C “the warmest water mahi are documented in”; that figure is a satellite-tag occupancy range, not a catch, and the claim has been corrected.
Calibrated: SST is required — with no temperature reading there is no Mahi score at all. Exact values are proprietary.
The best-water point is set by net, longline and satellite-tag records. The one rod-and-reel catch record we own agrees on the band but does not pin the point, and no study we own measures a catch rate in the hottest part of the curve — that stretch is an interpolation, and we say so rather than presenting it as measured.
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 data (Hammond 2008, Schlenker et al. 2021) is satellite-tag occupancy, which tells us where fish chose to be and not whether they bit. We use all of it as direction-of-effect evidence, not a promise that the exact range wins everywhere.
- The best-water point is set by commercial and satellite-tag records; the one rod-and-reel catch record we own brackets it at 26–29°C rather than pinning it. The checked catch studies leave the hotter-water response uncertain, so that part of the model is an interpolation rather than a measured catch effect.
- 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
- 2026-09-14: shifted the best-water point and warm fall-off to follow the cited rod-and-reel, satellite-tag, artisanal-fishery and laboratory evidence more closely. Corrected an older claim that 30.5°C was the warmest documented mahi water — that figure was a satellite-tag occupancy range, while the source above records a catch at 31.10°C in one survey quadrant. Dropped chlorophyll from the score.
- 2026-06-02: rebuilt Mahi to remove moon phase entirely (evidence too weak to weight honestly). At that time, the score used sea-surface temperature and a small, region-aware chlorophyll term; chlorophyll was later removed. Removed an unsupported hot-water anchor 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.