Author: Shaun

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Pāpaka

An open letter to the Minister for Oceans and Fisheries.

Hon David Parker
Minister for Oceans and Fisheries
d.parker@ministers.govt.nz

11 May 2022

Tēnā koe Minister Parker

Pāpaka / Paddle Crabs (Ovalipes catharus) are native to New Zealand. There are 10 commercial fishery areas with nearly all the catch on the East coast of the North Island. The commercial catch has been in decline for two decades with no changes to the Total Allowable Commercial Catch (TACC). The TACC is about ten times larger than the recreational and customary catch. The main fisheries (PAD 1, 2, 3, 7, 8) look like they may have collapsed, the TACC for these fisheries total 590 tonnes, landings in the 2019-20 season were only 19.2 tonnes (3% of the TACC).

I disagree that the fishery is only lightly exploited (FNZ 2021).

Commercial paddle crab landings (tonnes)

Please research the current population. If you don’t have the resources to do this then I recommend you:

  1. Dramatically reduce the TACC for Pāpaka to allow the species to recover.
  2. Reduce the daily bag limit from 50 to 5.
  3. Ban the use of nets in estuaries which kill Pāpaka and other declining species as bycatch.

Thank you

References

FNZ 2021. PADDLE CRABS (PAD) https://fs.fish.govt.nz/Doc/25060/55%20PAD%202021.pdf.ashx

UPDATE 19 August

Response from Hon David Parker.

The response leaves catch limits incredibly high (765 tonnes for commercial) despite acknowledging that commercial take is incredibly low. The minister assumes that the population is healthy but provides no data to justify the decision.

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Kayak diving

I figured out how to dive from my kayak this summer. It’s been really fun with lots of advantages including:

  • Less swimming effort for shore dives
  • Lower emissions than diving from a boat
  • Some locations are easier for me to access via kayak
  • Less drama / hassle than a boat

At first I tried towing my kayak to the water with my tank onboard. The C-Tug SandTrakz Cart Kayak Trolley is great but not designed to carry so much weight. Even without the tank I have broken one of the straps. I now carry my tank and BCD while towing the kayak with everything else onboard including my weights.

The other thing I find very useful is these stainless steel D-Eye Swivel Snap Hooks. The anchor, wheels and camera all get clipped on so nothing falls off. Even though I have clips for my paddle I tie it on as I really dont want my paddle gone when I resurface.

I found putting the BCD on in the kayak too hard so I just do that in the water, it has its own little rope & clip so it does not float away. I also 3D printed a fitting to get a little dive flag going but it should be bigger.

I love having more gear closer when shore diving, including my phone, dry keys and something warm to eat as soon as I get out of the water :D. I’m sure my set up will evolve over time (I need a slightly heavier anchor for soft substrates) but I’m really happy with this and plan to do lots more.

Extra photos by Kirk Tucker

Update August 2024

With the C-Tug Double Up Bar (four wheels!) I can now take everything down to the beach in one trip. I’m not quite strong enough to get it back up the steepest bit of sand in one trip and I take the dive tank back up separately.

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A small kūtai reference bed

One of the interesting challenges associated with kūtai / mussel reef restoration in the Hauraki Gulf Marine Park (HGMP) is the lack of a reference bed.

The last natural soft sediment kūtai bed left in the HGMP is in an estuary and recovering after being wiped out by a storm in 2015. This means our best reference beds are those under or adjacent to kūtai farms or previously restored. Myself and other divers have helped look for a natural bed in The Noises group of islands which still has old kūtai growing on rocks. On the first of April (to celebrate the tipa / scallop closure which will temporarily protect the seafloor around the Noises from dredging for the first time ever!) I went for a dive / snorkel with Sue Neureuter who wanted to show me kūtai recruiting on shell near the base of some rocks. It was disappointing to see large losses the kūtai growing on the rocks due to a devastating combination of recreational harvest and this summers cyclone impact. The kina barrens were shocking and the area dearly needs protection. However we did find some recruits. The juveniles look very cosey in the old shell showing how dead shell still provides many ecosystem benefits, possibly including a suitable recruitment substrate. There is not much primary recruitment substrate around (kelp) but I did see some beautiful christmas tree hydroids.

Juvenile kūtai growing in adult shell

I was most excited to find a small c4mx4m bed of kūtai growing on soft sediment. I lifted kūtai up at the edge of the bed and they were only attached to each other and some dead shell. I don’t know if the kūtai recruited on to the shell hash here or if they came off the rocks and built up over several years. Some of the kūtai were old and large but most were closer to 9cm long. I did not measure any. I took some photos and spent two minutes doing some photogrammetry on part of the bed using this process I also took a sample of the shell hash.

The bed was remarkable because:

  • the kūtai sat at a very similar depth in the shell hash compared to softer sediments
  • the bed was lacking any signs of bio deposits from the kūtai (I have seen this once before at Marsden Point but thought it was just due to really high current which there is not here)
  • the bed had less colonial epifauna than restored beds
  • the bed showed no signs of clumping which is a very important feature of established beds
  • the bed had some young ecklonia radiata growing in it (I should have lifted one up to see what it was attached to)
  • the portion of the bed I mapped contains some >10 cooks turban suggesting shell is or was swept into the area

Let me know if you notice anything else unusual. If the Noises kūtai were protected and able to regenerate it would help us learn a lot about kūtai restoration.

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A fish decoy for my camera

I do wide angle macro photography underwater which helps me take great photos in yuck conditions. However it’s not so good for bigger fish who tend to not get that close. I tried 3D printing a little decoy for the end of my camera to see if it changed fish behaviour.

3D printed fish decoy that uses the laowa probe lens as an eye

I have only used it once but so far:

  • Bigeye (which the decoy design was based on, were not even a little interested).
  • Triplefins are not longer swimming under my lens (thats useful) but might be a bit more timid.
  • Red moki seem really curious, I’m sure they are doing a ‘double take’.

I’ll adjust my decoy a bit and do some more tests.

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Breath of the Gulf

Movement of larvae has been modelled in the Hauraki Gulf / Tīkapa Moana / Te Moananui-ā-Toi. It’s beautiful to watch and I wish I could share it with you. No matter where the larvae start off they pulse north south with tidal rhythms that make it look like the Gulf is breathing. Depending on the swell, wind direction and currents they drift for 10’s of kilometres in all directions connecting east, west, north and south.

In this video I have tried to visualise what I saw and felt looking at the modelling work. I have used our six tiny marine reserves because they make a disproportionate contribution to breathing life in to the Gulf.

If you want to know about shellfish larvae in the Gulf I recommend this blog post.

UPDATE: I found a video with a biophysical larvae modeling from Auckland University scientists it’s at 1:10:50 here.

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An underwater time machine for Waiheke Island

On an ordinary part of our coastline in 1975 our first marine reserve was created. The Cape Rodney-Okakari Point Marine Reserve at Leigh was difficult taking 13 years to overcome all the objections from fishers. 47 years on what have we learnt?

We now know the sacrifices those fishers made has been paid back a hundred fold. The reserve is home to large fish which make a disproportionate contribution to the Gulf Tāmure / Snapper population. It takes thirty six 30cm Tāmure / Snapper to make the same amount of eggs as one 70cm Tāmure / Snapper. Adult Tāmure / Snapper within the reserve at Leigh were estimated to contribute 10.6% of newly settled juveniles to the surrounding 400km2 area, with no decreasing trend up to 40km away. The commercial value of the nursey has been estimated at $1,490,000 per annum. That’s a huge contribution and it makes you wonder how bad things would be without the reserve, what’s worse we might not even know how bad it had gotten.

The marine reserve at Leigh was designed to act as a benchmark, a view of what an unimpacted ecosystem would look like. It’s the best place to experience marine wildlife. The fish are big and abundant, the water is alive and exciting. Putting your head underwater is like looking back in time when the ocean was healthier.

With every passing generation we lose memories of abundance and diversity. When I wonder if I saw more seahorses as a child I can’t be sure. This is the value of having a reference point to measure marine health.

Our marine scientists now understand edge effects, population source & sink dynamics and the connections between geology, habitat and biodiversity. They understand how intact ecosystems are more resilient to pollution and change. At 2,350ha the new Waiheke marine reserve is four times the size of the Leigh marine reserve (547ha). I think it will out perform the Leigh marine reserve and deliver our best chance of experiencing an intact marine ecosystem in the inner Gulf. It could be a benchmark, the gold standard to which we measure other changes we make.

There will be many additional benefits for the Waiheke marine ecosystem like protecting against overfishing and improving the resilience in the face of climate change and pollution. But it’s the reserves function as an experience of unimpacted ecosystem, a window back in time, not just to 1975 but further back before human impact, that’s what we hope to discover.

But this time machine won’t happen without your support. Please visit https://www.doc.govt.nz/waihekeproposal/ and let the decision makers know what excites you about the proposal.

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Panmure bridge gull colony

My unrequested report to Auckland Transport (AT) following the completion of a new bridge (part of the AMETI / Auckland Manukau Eastern Transport Initiative) above a colony of native Tarāpunga / Red-billed gulls.

In response AT commissioned this report from BECA. It has a few errors (southern black-backed gull dont nest in the area but white-fronted tern do) but I mostly agree with it. They missed opportunities to point out that more research should be done on light impacts and the possibilities for shielding.

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New Zealand’s crazy fishing rules

With the government reviewing the Wildlife Act 1953 I got to thinking about our wild fish. The rules are pretty crazy.

I definitely think its time for a review.

Link to high res portrait version of this diagram.