Recent freshwater fish surveys in the Maungatua Block have shown positive results, with native galaxiid populations still present, reproducing and generally healthy. Expert freshwater fish consultant Richard Allibone carried out the surveys in December 2025 and February 2026. The surveys focused on streams connected to Crystal Creek, Munros Dam Stream and a tributary of Lake Mahinerangi. The main purpose was to assess whether known native galaxiid populations were still present, how healthy they appeared and whether their habitats had expanded or contracted.
Dusky galaxias
In Crystal Creek, dusky galaxias (pictured) were found at all four of the sites assessed, while in Munros Dam Stream, they were found only in the main refuge area. This more limited distribution is likely due to the presence of brook char (aka brook trout), which can predate on native galaxiids.
Across Crystal Creek and Munros Dam Stream, 104 Dusky galaxias were caught, with sizes ranging from 47mm to 137mm. This size range is a positive sign, as it shows the population includes both younger and older fish and is not limited to a single age group.
Eldon’s galaxias and fish density
In the Lake Mahinerangi tributary, 36 Eldon’s galaxias were caught, ranging from 51mm to 128mm.
Catch rates were fairly similar across the occupied sites, suggesting stable fish density in a suitable habitat.
This study confirmed that both Dusky galaxias and Eldon’s galaxias populations are still present in the same general stream reaches where they were first mapped in 2015 to 2016. The assessment also identified some small extensions within the known range of Dusky galaxias, especially downstream in Crystals Creek and in one Munros Dam tributary. The Eldon’s galaxias populations appear stable, and the size range of fish caught suggests they are also healthy.
Finally, the survey shows that the native fish populations still exist and are doing well at most of the sites visited, which suggests that forest management activities are not harming the aquatic ecosystem.