Discovering Otago’s Oldest Dusky Galaxiid at Waipori Station
Waipori Station, nestled near Lake Mahinerangi in Otago, is home to a remarkable group of native freshwater fish found only in the small tributaries of the Waipori River. Among them is Gladys, a dusky galaxias who is believed to be the oldest recorded galaxiid in the Otago Region.
Preserving Endangered Species
With only 25 known populations, dusky galaxias are highly sensitive to environmental changes, such as stock access to streams, reduction of native vegetation, land development, forest harvesting, and predatory brown trout. Unfortunately, Aotearoa has lost 25% of its known dusky galaxias populations over the past decade, making conservation efforts more critical than ever. The rare freshwater fish species is classified as ‘Nationally Endangered.’
Meet Gladys: The Record-Breaking Galaxiid
Gladys, officially known as ‘Green Tag V93,’ was first discovered and tagged by Otago Regional Council’s Team Leader of Biodiversity, Pete Ravenscroft in 2004. When Ravenscroft returned to Burnt Creek in May 2024, he found Gladys still thriving in her original pool. At 28 years old (equivalent to 108 in fish years) and measuring 157 mm in length, Gladys is not only the oldest but also the longest dusky galaxias ever measured. Gladys’ pool is further safeguarded by several large downstream waterfalls, which act as natural barriers to predatory brown trout, ensuring the continued survival of this endangered species. Recent eDNA testing conducted in 2023 at Burnt Creek confirmed the continued presence of these elusive fish species, a testament to the sediment-free waters at Burnt Creek.
Protecting Our Natural Heritage
Unlike migratory whitebait, non-migratory galaxiid species like the dusky galaxias live their entire lives in the stream where they hatched. Over millennia, these populations have been isolated by geological events such as earthquakes and glacial movements, evolving into distinct species. The Burnt Creek catchment, located in the tussock-covered Lammerlaw/Lammermoor ranges, provides an ideal habitat with tannin-stained water, a schist bed, vegetated bank margins, and excellent water quality.
Commitment to Conservation
The discovery of Otago’s oldest dusky galaxias Gladys and her companions underscores the importance of protecting our natural assets for future generations. Pāmu’s ongoing efforts at Waipori Station exemplify our dedication to protecting waterways and biodiversity on-farm. As stewards of the land, we remain committed to maintaining and enhancing the health of our waterways and the diverse species that call them home.
