I have spent a fair bit of time thinking about how citizen scientists can measure the health of their local streams using Macroinvertebrate Community Index (WIMP & SHMAK) and the index of biotic integrity (IBI) for New Zealand fish. The great thing about using stream life to measure stream health is that the animals act as 24/7 sensors that measure any of the countless pollutants that harm life. The problem with it is that finding and more importantly identifying species involves disrupting them.

eDNA (environmental DNA) sampling solves this by measuring the presence of stream life base on the tiny fragments all life constantly erode into water. Wilderlab have set up a testing system with relatively cheap kits available for citizen scientists. I found it easy to use on my local stream (which is very degraded). I am really excited about this technology, especially as the price comes down and results are benchmarked against existing stream health Indices.

Feeding our plastic legacy

It’s nearly one week into the Covid 19 lockdown. Council were not able to retrieve dying and dead birds from the pond at Tahuna Torea. The birds have been dying from avian botulism which paralyse them (its a horrible way to go). I took a pied stilt to the vet but it did not make it and cleaned up other dead and dying geese and mallards.

While I was there I noticed a lot of trash that had become exposed, as the water was the lowest it’s been in at least 10 years. Going back to pick it up I found it was mostly bread bags taken to the pond to feed the birds. I understand the commonly known reasons for not feeding birds. But I had no idea how much plastic goes into the water as byproduct of the practice. Light can not penetrate the dark pond waters and the plastic doesn’t break down. Sediment settles on top and where ever I dug into the dried mud I found plastic.

I’ll spend a few more hours gathering it but I’ll never get it all. I’m sure other ponds are similar if not worse. As long as we keep selling bread in plastic, bird feeding will be contributing to our plastic legacy.

UPDATE: 5 April

After removing three black sacks of dead birds and soft plastics I was rewarded with seeing this secretive bird feeding right where I had been cleaning up 😀

Spotless Crake

UPDATE: 12 April

So far I have retrieved two geese, four mallards, one juvenile black-backed gull and four black sacks full of plastic, mostly bread bags.

Don’t buy a water storage solution from Bailey Tanks.

Bailey Tanks make their water storage tanks from plastic which comes into the business as small pellets. Since August 2017 I have seen these plastic pellets coming out of their business at 36 Ash Rd, Wiri and into the local stream where it flows into the Manuaku Harbour. I have been regularly reporting the pollution to Auckland Council who have been asking the business to clean up their act, they were fined $750 on the in May 2017 however the plastic keeps coming out.

Bailey Tanks stormwater outlet (August 2017)
You can see the small plastic pellets littering their yard from the street (9 Feb 2020 Council job number INR60232011).
Plastic pellets (nurdles) at stormwater pipe exiting the Bailey Tanks (9 May 2019 Council Job number #8260221120).

Today (22 February 2020) I thought I would go and see if the rain would increase the amount of plastic washing to the stream. Pallets were coming but I was horrified to see the surface of the water covered in a fine plastic powder which they also use to make their products. Council job number 8260232660.

I took a sample home to have a better look at these micro plastics close up.
This is the path the pollution takes from the stormwater outlet to Puhinui Creek and then the Manukau Harbour. Map constructed using data from Auckland Councils Geomaps service.

Industrial pollution is usually event based, where a business has accidentally spills something and creates a pollution incident. This kind of slow leak is much worse, I hate to think how much plastic this company has dumped into the Manukau Harbour where it poisons our wildlife.

Newsroom reporter Farah Hancock investigated the site after the February 2020 incident and reported on it.

UPDATE: 24 May 2020

A new pipe has been installed upstream and was flowing clear when I visited at 3pm today.
But the old pipe continues to leak plastic. It took 20 minutes to log the incident with Auckland Council (Job number 8100624496) during which time I counted 18 plastic pellets exiting the pipe. I said I would wait for the officer (to show them the pollution) but I got a text back saying they will not visit until tomorrow.

I followed up on the the job number above (8100624496) to find out that officers did not visit the site to investigate the incident. I requested a site visit with officers but they refused.


The site was the cleanest I had ever seen, the business is clearly trying to clean up their act which is great. (Just one plastic pellet sighted). It’s a shame that they just cant stop leaking plastic tho. Check out the tiny bits of plastic powder in this video. Council RM Incident 8620239074, INR60239074.


The population of any given species needs to be strong enough to handle destructive natural and made made events. Without this resilience one event can wipe a species of the face of the planet forever. In New Zealand our rarest endemic breeding bird is the New Zealand fairy tern. With a population of only 40 birds this is the breakdown for the 2017-18 season.

  • 3-4 of last seasons surviving chicks which are too young to breed
  • 1 menopausal female
  • 1-2 ‘engaged’ couples who behave like they are breeding but do not lay eggs
  • 11-14 unpartnered males (the population is short on females)
  • 20 breeding birds (10 pairs)
  • It’s a fragile population with too many males (1:2 ratio). The other major concern is that during breeding season 80% of the population is on the same 40km stretch of coast. Here is where the breeding happened in 2017-18:

    East coast:
    Waipu 2
    Mangawhai 5
    Pakiri 1

    West coast:
    Papakanui 2

    The fragility is particularly exposed when we think about the threat of an oil spill from the RMS Niagara. This wreck is a time bomb just off the coast from this critical breeding habitat. Even a small amount of the submerged oil could easily cover the fairy terns breeding grounds for weeks, starving the birds to death in a matter of days.

    Forestry and water quality

    When I first heard about erosion in the Hunua Ranges causing havoc for Auckland’s water supply I wondered if it was because of recent deforestation. Drone footage shot by Watercare confirmed that theory for me (see stills below from this video). It seems strange media are not talking about it. To me it looks like just another case of our water being compromised for private profit.

    A little bird told me Watercare own the land and were in the midst of replanting it with natives – it would be good to know the full details. I will email them.

    (2,089-72 = 2017) So sometime in 2017 they decided to start harvesting. But the wood in the pictures looks at least months old. My guess is the harvesting that caused the contamination was done in 2016 for private profit. Hard to tell from the information received. Awaiting a report with interest.