Category: Conservation

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Pukunui egg decoys

A DOC ranger carefully candles a real Pukunui egg to check for signs of fertility. Photo Guy McDonald.

For the past few years, I’ve been supporting the campaign to raise awareness of the critically endangered Pukunui / Southern New Zealand Dotterel, and to see it recognised as New Zealand’s Bird of the Year. Unfortunately, the species is in a dire state and is on track for extinction within the next decade without urgent action.

Wanting to contribute in a meaningful way, I offered to produce decoy Pukunui eggs that the Department of Conservation (DOC) rangers could use to distract predators (primarily feral cats). However, DOC staff explained that decoy eggs would be most valuable during fertility checks, providing a substitute to keep adult birds settled on the nest while real eggs were removed for assessment. With only 12 nests found during the 2023/24 breeding season, it’s essential that each actively managed nest is as productive as possible. Ensuring birds aren’t incubating infertile eggs reduces wasted effort and limits their exposure to predators. Candling is only carried out when a bird has been sitting longer than the expected incubation period, suggesting the egg may not be viable.

Pukunui / Southern New Zealand dotterel nest. Photo Guy McDonald.

Using publicly available data on NZBirdsOnline, I 3D printed a set of six replica eggs, carefully matching the size, shape, and weight of real Pukunui eggs. Each egg was then airbrushed and speckled with acrylic paint to resemble the real thing as closely as possible. I also created custom protective cases for each egg to ensure they could be transported safely to Rakiura and carried in rangers’ backpacks during fieldwork.

Decoy pukunui eggs in protective cases. Photo Shaun Lee.

According to the rangers, the decoy eggs have been effective in keeping the birds settled during fertility checks, giving staff the time they need to carry out this crucial work without disrupting the breeding process.

A DOC ranger carefully candles a real Pukunui egg to check for signs of fertility. Photo Guy McDonald.

I’m proud to have volunteered my time to support the recovery of this remarkable species. You can help too by donating to the New Zealand Nature Fund.

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Ring net fishing in proposed protected areas

Trevally driving krill to the surface where they are predated by seabirds that are At Risk of extinction.

After a decade of consultation and compromise on the Hauraki Gulf / Tīkapa Moana Marine Protection Bill the government is proposing last minute changes to allow commercial ring net fishing in two areas. I have provided ministers analysis showing the proposal would compromise the objectives of the marine protection areas. I also asked Fisheries New Zealand for data on ring net fishing. They replied 49 working days later with a partial response, two days after the bill was debated in the house and I had complained to the Ombudsman.

The data provides factual information to support new arguments against the proposal to allow commercial ring net fishing in the proposed protection areas.

  1. Commercial ring net fishers in the Hauraki Gulf catch an average of $26,588 worth of fish in the proposed protected areas, which is only 6.8% of their total Gulf catch (averaging $366,213 annually). In weight, this equates to 17,616 kg or 12.5% of their total catch. This demonstrates that the proposed protected areas account for a small percentage of their overall income, especially considering these fishers also operate on Auckland’s west coast.
  2. The average annual catch from the proposed protected areas is 17,616 kg worth $26,588, which is small compared to the natural variability in catch outside these areas. For example, the catch outside protected areas fluctuates by 35,103 kg and $141,801 across years, far exceeding the potential loss from protection.
2019-20202020-20212021-20222022-2023Average
Inside protected areas (kgs)28,05123,1259,5759,71317,616
Outside protected areas (kgs)120,961119,841108,851143,954123,402
Inside protected areas ($)$28,383$47,838$16,280$13,852$26,588
Outside protected areas ($)$297,053$376,722$352,221$438,854$366,213
Commercial ring net fishing in proposed protected areas of the Hauraki Gulf

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Ten reasons why MPs should support Gulf protection bill

Snapper Goat Island

Recreational fishing lobbyists LegaSea are making a last ditch effort to stop the Hauraki Gulf / Tīkapa Moana Marine Protection Bill. Here are ten reasons why Scott Simpson and other MP’s should support the bill as it stands:

  1. Broad Public Support for Protection: There is overwhelming public support for marine protection. The bill will increase protection from 0.3% to 6%. 77% of the public want much more (30%) of the Gulf protected.

  2. eNGO Support for Increased Protection: Environmental groups have consistently asked for more protection than the bill currently provides, indicating that the bill is already a compromise aimed at balancing diverse interests​.

  3. Protection to Address Depletion and Habitat Damage: The bill addresses overfishing, habitat destruction, and declines in marine biodiversity in small areas. Lage scale bottom-impact fishing​ is being delt with through a different process.

  4. Scientific Evidence Supports High Protection Areas (HPAs): While recreational fishers claim there is no evidence to support HPAs, scientific studies worldwide demonstrate that protected areas are fantastic for restoring fish populations and biodiversity​.

  5. Minimal Economic Impact on Recreational Fishing: Recreational fishers will still have access to 87.4% of the Gulf for fishing. The HPAs cover a small portion, reducing the impact on fishing activities while promoting long-term marine ecosystem health​.

  6. Displacement Concerns Are Overstated: The limited fishing restrictions introduced by the bill are offset by gains in fish abundance in nearby areas, as larger, reproductively mature fish spill over into fished zones, ultimately benefiting fish stocks outside HPAs.

  7. Limited and Controlled Commercial Fishing: The bill may include ring-net fishing in two HPAs compromising their objectives. However, 10 high protection areas and the two marine reserve extensions will be unaffected by the amendment.

  8. Ecosystem Benefits for Seabirds and Marine Species: High Protection Areas will help protect seabird foraging grounds and marine ecosystems, which directly impacts terrestrial food webs and biodiversity on islands in the Gulf.

  9. Strong Legislative Foundations: The bill aligns with New Zealand’s marine protection obligations under international agreements, reflecting a responsible approach to safeguarding marine biodiversity while considering local cultural and socio-economic factors​.

  10. A Balanced Approach to Sustainable Use: This bill offers a compromise between no-fishing reserves and managed-use areas, establishing a multi-use marine park with regions for both recreational fishing and high protection. This approach meets both conservation and fishing community interests without entirely prohibiting either​.
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Oil spill trajectory modelling from the wreck of the RMS Niagara

RMS Niagara oil spill trajectory during summer conditions

I asked Maritime NZ for the oil spill trajectory modelling from the wreck of the RMS Niagara. I have uploaded it here for anyone interested.

Oil spill trajectory modelling from the wreck of the RMS Niagara

My layman’s notes below:

MNZ have kindly tried to explain it to me, but I don’t really understand why the 2016 modelling was only done with about 97 tonnes of oil (100 m³) when the Rena leaked 350 tonnes. The RMS Niagara could store more than 4,000 tonnes of oil and experts have estimated that there could be 1,400 tonnes remaining. This means the estimated volume of oil on individual beaches and the length of shoreline impacted could be dramatically worse.

The probability of oil contact with the shoreline increases by 10% if it happens in summer (This is tara iti / New Zealand fairy tern breeding season, we are down to nine breeding female left, note the Rena spill killed 2,000 birds). The impacts move a bit further south in winter.

It’s interesting to see the areas impacted. The spill expands outward from the wreck largely as you would expect, but there are interesting details. For example, it will be twice as bad at Goat Island than further up the coast at Mangawhai. If it’s going to be visible at the Mokohinau Islands in just a few hours, I think it might be a good idea to install a webcam there.

Harbours and bays are less impacted, but I wonder if this is an artefact of the modelling software. It definitely shows that even a 97-tonne spill will span a massive length of our coastline. For example, Waikato Regional Council also needs to be prepared.

I’d like a better understanding of the risk and the mentioned contingency plan. It would be helpful to run scenarios with different response times, gear, and methods; this may have already been done.

UPDATE: 10 Dec 2024. I asked Maritime NZ for costings for Stage 2 of the survey of the RMS Niagara wreck. Summary: The estimated cost for Stage 2 of the RMS Niagara wreck survey totals NZ$13.74 million, split into two parts. Part 1 involves a visual survey using a remotely operated vehicle (NZ$1.3 million). Part 2, requiring a dynamic positioning vessel due to proximity to submarine cables, includes hull cleaning, oil level measurement, and risk assessment (NZ$12.44 million). A moored vessel alternative for Part 2 costs NZ$4.5 million but is not recommended due to the risk to undersea cables. An additional NZ$500,000 is estimated for oil pollution response readiness during the survey.

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Turtles of Aotearoa

Turtles of Aotearoa 7 species of sea turtle in the world 5 recorded in New Zealand 2 more frequently seen here Nearest nest sites in Australia and New Caledonia Navigate using earths magnetic field Forage near the coast eating algae and sea slugs Threatened with extinction, dying here from marine plastic boat strike and fishing The regional subpopulation is expected to go extinct in 40-80 years Nest in Papua New Guinea, and Solomon Islands Forage offshore on jellies in the water Frequently caught by tuna fishers, with no efforts to reduce bycatch in leatherback hotspots Up to 1.5 m long Up to 2.7 m long Green sea turtles Leatherback sea turtles Loggerhead Green Leatherback Olive Ridley Hawksbill

After finding a green sea turtle in Devonport and reading about leatherback sea turtle bycatch I decided to do some research on what was going on with turtles in New Zealand. I made a graphic summary.

Turtles of Aotearoa 7 species of sea turtle in the world 5 recorded in New Zealand 2 more frequently seen here Nearest nest sites in Australia and New Caledonia Navigate using earths magnetic field Forage near the coast eating algae and sea slugs Threatened with extinction, dying here from marine plastic boat strike and fishing The regional subpopulation is expected to go extinct in 40-80 years Nest in Papua New Guinea, and Solomon Islands Forage offshore on jellies in the water Frequently caught by tuna fishers, with no efforts to reduce bycatch in leatherback hotspots Up to 1.5 m long Up to 2.7 m long Green sea turtles Leatherback sea turtles Loggerhead Green Leatherback Olive Ridley Hawksbill
Turtles of Aotearoa

Big thanks to Clinton Duffy for the review.

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Changes in reporting for inshore fishing boats with cameras

There is some confusion about the change in these numbers because of the way the data was reported. I made this graphic to also clear up that as of April 2024 there is no data that has been made public from the on-board cameras for commercial fishing vessels programme.

Data sources: Overview of the rollout of on-board cameras on commercial fishing vessels February 2024 Update at 1 April 2024: Progress on the rollout