Are Sea Trout Being Counted as Salmon on the River Maine

Inland Fisheries Ireland (IFI) publishes two key sets of data every year: the Annual Fish Counter Summary Report and the Status of Irish Salmon Stocks with Catch Advice. When these reports are compared side by side, some important inconsistencies emerge — particularly for the River Maine in County Kerry.


County Donegal


The Counter Data

According to IFI’s 2024 Fish Counter Report, the River Maine recorded:

SpeciesCount
Spring salmon129
Grilse (1SW salmon)1,250
Late summer salmon245
Sea trout31*

*Sea trout figure is marked unverified.

On the surface, this suggests a very strong grilse run — one of the highest in the country.

The Problem

This doesn’t add up for three reasons:

1. IFI’s Own Description of the River Maine

IFI describes the Maine as a river that “gets a good run and sizeable sea trout all through the season.” If that’s the case, why does the counter only show 31 sea trout compared to 1,250 grilse?

2. Known Counter Limitations

IFI openly admits in multiple reports that their counters struggle to distinguish salmon from sea trout. For example:

  • Kerry Blackwater: “doesn’t count many sea trout as it has been configured to count salmon as accurately as possible.”

  • Inagh (Derryclare): sea trout often bypass the counter entirely.

  • Owenboliska: trout runs can be missed depending on water release conditions.

Counters rely on fish size thresholds and electrical resistance — but large sea trout and small grilse overlap in size. Misclassification is inevitable.

3. Mismatch with National Trends

The Status of Irish Salmon Stocks 2024 report highlights that grilse numbers have been in long-term decline, with 2023 being the lowest on record and only a “minor increase” in 2024.

Yet, the Maine counter shows an improbably large run of 1,250 grilse.

Graph: National Grilse Trend vs. River Maine 2024

| Year  | National Trend | Maine Counter |
|-------|----------------|---------------|
| 2023  | Lowest on record | N/A         |
| 2024  | Minor increase   | 1,250 grilse|

This discrepancy points to possible misclassification.

The Commercial Angle

Castlemaine Harbour (into which the Maine flows) is one of the few remaining systems with a commercial salmon fishery. If grilse numbers are inflated by misclassified sea trout, it creates the appearance of a healthy salmon stock. That, in turn, provides justification to keep the commercial nets open.

In reality, the true salmon stock may be much weaker.

Independent Evidence

  • Video proof: Local anglers have recorded clear footage of sea trout being caught and released on the River Maine. This confirms their presence in numbers far greater than the 31 fish reported by IFI’s counter.

  • Catch statistics: IFI’s own national data show the Castlemaine/Laune system accounts for a large share of Ireland’s sea trout catches. Yet these do not appear reflected in Maine counter figures.

Table: Castlemaine/Laune vs Maine Counter (2024)

SourceSea Trout Recorded
Castlemaine/Laune system (rod catches)Among Ireland’s highest
Maine counter (IFI, 2024)31 (unverified)

Conclusion

The evidence points strongly toward misclassification of sea trout as grilse in IFI’s counter data on the River Maine. This raises serious concerns about the accuracy of salmon stock assessments — and the decisions to maintain commercial fisheries in Castlemaine.

By inflating grilse numbers, IFI risks overstating the health of salmon stocks and underplaying the importance of protecting vital sea trout runs.

Next steps:

  • Push for release of River Maine-specific sea trout catch records from IFI’s tagging/logbook scheme.

  • Demand greater transparency in how counters distinguish between species.

  • Ensure that stock advice integrates sea trout data rather than disregarding it.

The future of both salmon and sea trout in the Castlemaine system depends on it.

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