Visitors are being advised to clean their footwear prior to exploring the 'most crystal-clear lake globally'.
In the heart of New Zealand, nestled within the wilderness, lies Rotomairewhenua, a sub-alpine lake that was first discovered by the Maori tribe, Ngāti Apa. They named it "the lake of peaceful lands" and used it as a sacred site for cleansing the bones of the deceased, believing it would secure their spirits a safe journey to Hawaiki.
This extraordinary lake gained international fame a decade ago when scientists discovered its "exceptional optical purity," boasting a visibility of between 70 and 80 meters, making it one of the clearest freshwater lakes globally. The stunning landscape and crystal-clear waters have since then been popularized on social media, attracting tourists during New Zealand's summer months (December to March).
However, with the increasing popularity comes a concern from conservationists and Ngāti Apa. Their primary fear revolves around the spread of Lindavia, a microscopic alga known as "lake snow" or "lake snot," which thrives in the lake's downstream areas such as Lakes Rotoiti, Rotoroa, and Tennyson. This invasive species could potentially make its way up the trail on hikers' boots or in their water bottles, posing a threat to the lake's exceptional clarity and purity.
Lindavia made its way to New Zealand probably via fishing gear in the early 2000s. This alien alga is not known to be toxic for humans but can still cause nuisances. It produces long viscous strands of mucilage, which, when concentrated, can become a nuisance, clogging up fishing lines, boat filters, or hydroelectric power systems. In the case of Rotomairewhenua, this film of slime could possibly impact the lake's remarkable clarity.
The team of Phil Novis, a senior research scientist specializing in algae at the government-owned environmental institute Landcare Research, has emphasized that every speck of the invasive alga could drastically alter a lake's ecology. According to his research, Lyndavia is only present in lakes that are easily accessible to humans, deepening the concerns of the Ngāti Apa tribe and the conservationists.
If Lindavia were to infest Rotomairewhenua, it could lead to severe consequences, jeopardizing the lake's water quality and overall health. This would undoubtedly be a devastating turn of events for Ngāti Apa, who hold the lake in high cultural and spiritual significance. Since they no longer use it for ancient ceremonies, the pristine lake remains a symbol of their identity, a connection to their ancestral traditions.
In an effort to preserve Rotomairewhenua's purity and exceptional clarity, the New Zealand Department of Conservation, Ngāti Apa ki te Rā Tō Trust, and the Te Araroa Trust have been working together to introduce biosecurity measures along the trail. They have installed cleaning stations at huts and have been urging visitors not to touch the water. Signs and educational videos on the Te Araroa trail app remind hikers of the biosecurity risks and the lake's cultural significance.
During the peak tourist season, a warden stationed at the lake educates hikers about the lake's biosecurity risks and cultural importance. So far, it appears that visitors are adhering to the guidelines, ensuring that the pristine lake remains untouched and its unique qualities preserved for future generations.
To prevent the spread of Lindavia, following some simple guidelines can make a significant difference. Make use of cleaning stations, avoid contamination, ensure that all your gear is completely dry before swimming or taking water from other lakes, and respect access restrictions. By following these guidelines, visitors can help maintain the lake's ecological integrity and preserve its cultural significance.
References:[1] Department of Conservation[2] New Zealand Geographic[3] Stuff.co.nz[4] Te Ara - The Encyclopedia of New Zealand[5] Landcare Research
Visitors to Rotomairewhenua during New Zealand's summer months are urged to adhere to biosecurity measures to protect the lake's exceptional clarity and purity, as the introduction of invasive species like Lindavia could lead to severe consequences for the lake's water quality and cultural significance. Following simple guidelines, such as using cleaning stations and avoiding contamination, can help preserve the lake for future generations.
The increasing popularity of Rotomairewhenua has raised concerns about the spread of invasive algae like Lindavia, which could potentially impact the lake's remarkable clarity, posing a threat to its exceptional optical purity and cultural significance for the Maori tribe, Ngāti Apa.
