Category: Restoration

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Invertebrates

Nudibranch

If I really care about biodiversity and 95% of described species are invertebrates then I am spending too much time with birds. Tho based on a talk I heard at the Zoological Society we don’t know how to look after them yet. The things we do to protect birds also help the insects (removing rodents and wasps).

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Pohutukawa

Cloning Pohutukawa makes sense if you’re breeding them for a specific purpose. In my case erosion control. I just want Pohutukawa that are great at holding onto cliffs.

Pots

This cloned Pohutukawa worked. The one in the black pot had no rooting hormone and failed. This was my second try, the trick is to snip between the hard & soft wood.
This cloned Pohutukawa worked. The one in the black pot had no rooting hormone and failed. This was my second try, the trick is to snip between the hard & soft wood.

It’s growing slowly tho. While my seedlings are doing great.

About 400 trees, many of them ready for planting.
About 400 trees, many of them ready for planting.

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Browns Island Mussel Reefs

Or what is left of them! Even the oysters are swamped by mud from the Tamaki estuary. Wikipedia needs updating:

“The flatter areas to the west have very large part submerged mussel beds which extent out 100 m (328 ft) from the shore preventing easy landing”.

Now the exposed rocks are surrounded by thick mud.

Some green mussels in the large clumps. They were not often dominant.
Some green mussels in the large clumps. They were not often dominant.
Most of the solo green lipped mussels were around 9-10cm.
Most of the solo green lipped mussels were around 9-10cm.
At least 50% of the mussels were blue, of the mussel groups at least 80% of those individuals were blue.
At least 50% of the mussels were blue, of the mussel groups at least 80% of those individuals were blue.
The water was very dirty. It had not rained for at least a day or two.
The water was very dirty. It had not rained for at least a day or two.
This mussel and ambitious eleven armed starfish look like they are suffocating.
This mussel and ambitious eleven armed starfish look like they are suffocating.
Most mussels were above the low tide line. I know this a feature of blue mussels but why were the green mussel following suit? I made the same observation on the Mission Bay reefs.
Most mussels were above the low tide line. I know this a feature of blue mussels but why were the green mussel following suit? I made the same observation on the Mission Bay reefs.
Another example
Another example
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Mission Bay Mussel Reefs

I was very pleased to see so many green lipped mussels here. I thought it might be interesting to survey them as there size and abundance are good indicators for how a restored reef might manage this close to Auckland City.

Mission Bay Mussel Reefs


REEF 1 (huge composite photo)
Reef 1


REEF 2 (huge composite photo)
Reef 2

They look healthy to me.
They look healthy to me.
Northern end of Reef 2
Northern end of Reef 2

I saw the odd blue mussel, cats eye, kina, eleven arm, cushion star, asian tunicate and fanworm but green lipped mussels were by far the dominant species. There were only a few spots where oysters and barnacles were coming out on top.

Some of the seabed around the edges of the reef was littered with shells.
Some of the seabed around the edges of the reef was littered with shells.
But the shells quickly give way to sandy sediment.
But the shells quickly give way to sandy sediment.
This was typical
This was typical
These holes look to me like snapper are active in the area.
These holes look to me like snapper are active in the area.
These white fronted terns looked happy but the black backed seagull and variable oyster catchers were happier eating the mussels.
These white fronted terns looked happy but the black backed seagull and variable oyster catchers were happier eating the mussels.

Size
Most mussels were 7-8cm long. But there were a few around the 10cm mark. I think I was looking at two generations?

UPDATE: November 2016
The green lipped mussels have been heavily harvested. There are maybe 20-30 adults left across both reefs. Some juveniles amongst the remaining blue mussels. Rock oysters and blue mussels now the dominant species.

I was pleased to find the occasional juvenile green lipped mussel amongst the blue mussels.
I was pleased to find the occasional juvenile green lipped mussel amongst the blue mussels.
Rock oysters very dense in some places
Rock oysters very dense in some places
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Times

Oil While I was cleaning up this rusted oil barrel that had been dumped near a stream in Selwyn Bush decades ago, I thought about how “times have changed”. I guess all I need to do is make them change faster.

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A Dotterel Breeding habitat at Tahuna Torea

After the last count of 50 Pukeko at Point England I am considering trying to find a better breeding habitat on the Tamaki Estuary for the local Dotterel. Michael Taylor can’t recall Dotterel showing any interest in the tidal mudflats in the lagoon area at Tahuna Torea. I am wondering why, as this seems the perfect spot.

Here is a map showing the current state of the islands which are potential roosting/ nesting spots.
Here is a map showing the current state of the islands which are potential roosting/ nesting spots.

Mangroves and other vegetation would need to be cleared to give the birds a 270° view. Gwenda Pulham made the observation that there are no sand hoppers to feed chicks and I should read HANZAB. Which states “Usually feed on firm exposed mudflats, sand or stones; avoid soft sticky mud, e.g. near mangroves.”

But I have seen birds with sticky mud on their beaks. (Ambury park)
But I have seen birds with sticky mud on their beaks. (Ambury park)

So how sticky is too sticky?

This is what most of the mud looks like. Note crab holes and my average footstep depth of 2cm.
This is what most of the mud looks like. Note all the mud snails and my average footstep depth of 2cm.
The mud around the islands is higher and only covered 30 min either side of high tide. Note the extra crab holes.
The mud around the islands is higher and only covered 30 min either side of high tide. Note the extra crab holes.

The odd Pukeko and roosting Caspian Tern is seen on the flats, and occasionally a Banded Rail. But mostly it’s White Faced Herons and Pied Stilts.

If it has a 30% chance or working then I am keen to:

  • Clear dense vegetation from the islands.
  • Remove or trim a large amount of the mangroves.
  • Import shell.
  • Reinforce the islands.
  • Experiment with decoys.

UPDATE: May 2014: Experts think this is a long shot and that I have a better chance of dealing with the Pooks at Point England by poisoning them. But an even better idea is Chick Shelters!

UPDATE: March 2024: Well that worked after all!