Source: Department of Conservation
Last summer Sam Fisher spent a week in one of the most beautiful places in Aotearoa. Sam chatted to us about the sacred lakes in Nelson Lakes National Park and the latest measures to keep them safe from a new, invisible threat.
I was previously working in IT but switched to conservation. Early midlife crisis career change you ask? Something like that. I completed the ranger training programme earlier this year and was lucky enough to have my summer placement with the Nelson Lakes team.
As part of my placement, I got to be hut warden at Blue Lake Hut for a week.
Yeah, it’s a magic spot
Rotomairewhenua / Blue Lake is nestled amongst the 2,000m peaks of the Nelson Lakes National Park, sitting at about 1,200m above sea level. It takes 2 days to get there, a tramp that takes you through vast valleys and over high mountain passes. It’s a journey into the remote heart of the park.
Look at the photos and see how stunning it is there! Rotomairewhenua has the clearest freshwater in the world with a visibility of around 70 metres underwater. Incredible.
I was super fortunate with the weather when I was up there. It’s such a beautiful backdrop and you get some amazing reflections off the lake.
The bonus of being the warden is that you get the place to yourself for a good chunk of the day (after the cleaning is done of course!), while the trampers are moving through. Standing up there on a clear day, it’s something else to see. Everything is blue – blue sky and blue lake on a bluebird day.
The birds are stunning too – you’ve got rifleman hanging out all around around the lake. You can just sit back and listen to them and see if you can see them. They’re one of my favourite birds to spot because they’re always around there.
Life in the past lane
I’ve heard stories from older volunteers who spent time at Blue Lake Hut decades ago, that they used to dare each other to get in the lake because it’s so numbingly cold! Others used to use it and Rotopōhueroa / Lake Constance for washing or as a water supply.
I think people were hanging on to those memories, but today we know it’s not appropriate to do that. Times have changed, as have our practices.
We’ve wised up to respecting the culture
The lakes are now called by their original names on maps. So we have Rotomairewhenua / Blue Lake and Rotopōhueroa / Lake Constance on all the maps. This acknowledges the long history and high cultural significance that they have for Māori, particularly Ngāti Apa ki te Rā Tō iwi.
The lakes are tapu (sacred) and are not to be touched. This is to uphold their mauri (life force) and purity.
We show respect for the lakes and for the iwi by never touching the water. That means no swimming, filling drink bottles or washing clothes.
Staying out of the water keeps these special lakes safe
The other message I tried to get across in my hut talks was about the serious threat of invasive algae getting into these lakes. Two microscopic algae – lindavia and didymo – are already present down the hill in Lakes Rotoiti, Rotoroa and Tennyson.
Lindavia produces lake snow, a really ugly snot-like slime that hangs below the surface of the water. Didymo coats rocks with a gross white material that looks like wet toilet paper. They would both really stuff up the lakes and headwaters of the rivers.
It could only take one person to wander into the lake with wet boots or togs on – even if they’d swum in Lake Rotoiti a few days ago. Or splash a drop of contaminated water from their drink bottle. That one innocent action could infect the lakes with invasive algae and spoil them forever.
Once the algae are there, there’s no way to get rid of them – no going back. It would destroy the visual and cultural significance and go against everything we’ve agreed to do in terms of protecting the environment for everyone, including Māori.
Talking to trampers and Te Araroa walkers, it seemed like the two-pronged approach to caring for the lakes – the cultural significance and the biosecurity – was well received and respected.
Alternative water available – you can cool off in the stream
Getting up to Blue Lake Hut is a big walk for sure. As a tramper I know it’s really, really nice to be able to have a refreshing dip at the end of the day.
Because you can’t swim in the lake, we’ve provided an alternative.
I made a track down to a stream where people can go. It’s just 5 minutes away and is all signposted before you get to the hut. It’s freezing cold but a great option on a hot day. The stream does turn into a pretty steep river just downstream, so we ask people to take a bit of care.
There are also those wet days when the hut is full of dripping wet gear and the fire’s going – then it’s more like a free sauna in there!
New cleaning stations
This summer we’re putting in cleaning stations near the main access points at Coldwater, Lakehead and Sabine Huts. It’s an extra step to reduce the chance of lindavia and didymo getting into our pristine rivers and alpine lakes.
As I said, those nasties have already got into the bigger, more accessible lakes – Rotoiti, Rotoroa and Tennyson. Lindavia arrived about 4 years ago so we’ve really had to tighten up our biosecurity to keep it out of the rest of the park.
The cleaning stations are pretty simple. There’s a tank with pre-made 10% detergent solution, a sink and a bucket underneath to hold the used solution. I’ve literally just finished painting them – DOC green of course!
Everyone needs to clean all their gear that’s wet or damp from any river or lake water. So it’s stop, soak and wait for 10 minutes. This is the Check, Clean, Dry method that people have probably heard of, and yeah, it does work to kill those microscopic algae.
Most people know how important it is to use the cleaning stations in the upper North Island to protect kauri, so I think people will embrace this way of protecting our lakes too.
You just need to allow ten extra minutes to do the right thing. The cleaning stations are all near huts where people often stop to make a cuppa or have a snack anyway, so we’re anticipating that it won’t be much of a hassle.
For now and for the future
We’ve got a totally unique environment with the lakes and mountains up there. It’s got to be for everyone forever, not just for me today.
I sometimes ask people how they’d want to leave it for their kids, and their kid’s kids. I don’t have any kids (keeping well clear of that!) but do have plenty of nieces and nephews. I’d hate for them to come here and not get to see the same pristine environment I got to see.
So finally, on behalf of the team here at Nelson Lakes, we really welcome you to come and experience this amazing part of the world. And we trust that you’ll follow our simple rules to keep it that way for everyone who comes after us.
Read more about how you can help prevent the spread of lindavia
