Algae discovery in Te Waikoropupū Springs sparks alarm in Golden Bay

Thursday, 14 November 2019

The appearance of green algae at the Te Waikoropupū Springs in Golden Bay has alarmed locals. The crystal clear springs are one of the region's biggest drawcards (video first published November 2019).

The discovery of green algae on the clear waters of Te Waikoropupū Springs has sparked alarm in Golden Bay.

Long-time resident Andrew Yuill, who regularly collects water samples for community conservation group Friends of Golden Bay, said he first noticed a patch of algae in Dancing Sands Spring about September 19.

'I just saw it out of the corner of my eye and I thought: 'It's not right',' Yuill said, adding it was the first time he'd seen such algal mats since he started taking water samples in early 2016.

An algal mat at the edge of Dancing Sands Spring.

Yuill estimated that initial patch of algae had since doubled in size. That patch and other algal mats were visible this week in Dancing Sands Spring and Main Spring when Stuff staff visited.

**READ MORE:

Algae on the water of Te Waikoropupū Springs.

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A visitor photographs Te Waikoropupū Springs, which contain some of the clearest water measured anywhere in the world.

* Fears for Te Waikoropupū Springs but council disputes nitrate trend

* Ngāti Tama will 'never stop fighting' until springs safeguarded**

Golden Bay resident Andrew Yuill says he first noticed a patch of algae about September 19 in the Dancing Sands Spring behind him.

Save Our Springs co-ordinator Kevin Moran said he was concerned the presence of algae might be a symptom of rising nitrate levels in the waters of Te Waikoropupū and he worried about the potential effects of those nitrates on the Arthur Marble Aquifer, which feeds the springs.

'The danger is that nitrate levels will kill the little creatures [stygofauna] in the aquifer and if that happens, we've got pea soup at Te Waikoropupū … we'll lose the clarity,' Moran on Tuesday told the Golden Bay Community Board as he urged council action over the nitrate levels.

Save Our Springs campaign co-ordinator Kevin Moran says Te Waikoropupū is a national treasure. To Māori, the springs are sacred. Ngāti Tama has long had the role of kaitiaki, or guardian, of the area.

Moran told the board members his major fear was that the springs could get lost in 'the paper chase' over changes to freshwater policy, which have been signalled by central Government.

'We'd like the assurance that Te Waikoropupū – this national treasure – will be at the top of the list,' he said.

Visitors this week at Main Spring where some algae has been growing in quiet patches of the waterway.

Yuill told the community board that data collected by Friends of Golden Bay showed the nitrate-nitrogen level in Main Spring had risen from 0.40mg/L in 2016 to 0.51-0.52mg/L for six successive results over September, October and into November.

'This is unacceptable, obviously,' Yuill said. 'We're starting to see weed mats growing there on the springs.'

Tasman District Council environmental information manager Rob Smith said while algae could respond to nitrate, it could also appear in spring and summer as a result of increased light and/or temperature.

However, while he understood it was 'not unique' to find some algae in the backwater areas, 'this is the first time we have heard reports of algae present there like this' in the springs, Smith said.

'We will certainly inquire further.'

Smith said a sample of the algae would be taken to determine its species. The algae might have already been present but only become noticeable because of its spread.

That reproduction could be sparked by rain washing nutrients into the waterway. Birds or the wind could also carry algae to different locations where it could build up if it had warmth, food and shelter.

'Anywhere there's habitat, there's algae,' Smith said.

Niwa freshwater ecologist and algae expert Dr Cathy Kilroy backed the call for a sample to be taken. A proliferation of algae in rivers and ponds was 'not that unusual' especially in spring when the light increased though it would be 'really nice to keep a watching eye on it' in Te Waikoropupū Springs.

The filamentous green algae Spirogyra was already present in the springs, Kilroy said.

Yuill and Ngāti Tama Ki Te Waipounamu Trust are joint applicants for a Water Conservation Order to protect the springs, the aquifer and associated water bodies. A hearing before a Special Tribunal closed in August 2018 and its recommendation report is awaited.

Council environment and planning manager Dennis Bush-King told the community board gathering the council was 'in a bit of a state of limbo' regarding recommendations from the Takaka Freshwater and Land Advisory Group – including protection for Te Waikoropupū Springs – until the results were released of that water conservation order application.

'We are legally obliged to give effect to the results of that order,' Bush-King said.