What is threatening the purity of Rotomairewhenua, New Zealand's clearest lake?

An invasive microscopic alga known as 'lake snot' (Lindavia) is threatening the purity of Rotomairewhenua due to increased visitor activity.

How does tourism impact the Blue Lake in Nelson Lakes National Park?

Increased tourism boosts the lake's popularity but also raises the risk of hikers unknowingly spreading invasive species like 'lake snot' on their gear.

What cultural significance does Rotomairewhenua hold for the Ngāti Apa?

Rotomairewhenua is a sacred site for the Ngāti Apa iwi, historically used for spiritual cleansing rituals and holding deep cultural and spiritual importance.

Home / Environment / Hikers' Boots Threaten 'World's Clearest Lake'

Hikers' Boots Threaten 'World's Clearest Lake'

30 Nov

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Summary

A microscopic alga known as 'lake snot' threatens the purity of Rotomairewhenua.
Increased tourism puts the visually clear freshwater lake at risk of contamination.
Biosecurity measures and visitor education aim to protect the sacred lake.

Hikers' Boots Threaten 'World's Clearest Lake'

Nestled in New Zealand's Nelson Lakes National Park, Rotomairewhenua, or the Blue Lake, is celebrated for its unparalleled water clarity, allowing visibility of up to 80 meters. This natural wonder, sacred to the Ngāti Apa Māori iwi, is now at risk due to its growing popularity. Conservationists and the Ngāti Apa fear that increased visitor numbers could lead to the introduction of the invasive alga Lindavia, commonly known as 'lake snot.'

The spread of Lindavia, which excretes a slime that can obscure the water's clarity, is a primary concern. Scientists believe humans are the main vector for this organism, easily transmitted via contaminated boots or water bottles. Its presence, even in small amounts, could irrevocably alter the lake's ecosystem and mar its visually pristine state, which has drawn significant attention through social media.