Author: Shaun

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Surveying a kuakua / large dog cockle shell drift

I was stoked to stumble across this kuakua shell drift North West of Waiheke Island. It adds a lot of complexity to the seafloor and is fun to explore because of the biodiversity it hosts. I imagined it was one large drift that I could map by attempting to swim around it at slack tide. To do this I dragged a float on the surface with my son’s phone attached. The phone was using MapMyRun as I am very familiar with the app. A plastic container was screwed to the float to hold the phone which was encased in two plastic bags, the lid of the container was also taped to the float). I had a friend on the surface follow me in a small boat with a Garmin Explorer Plus (this also helped with safety and was essential to help me get back to the boat against the current).

Edge of the kuakua shell drift

The bed is dominated by kuakua but also included large long trough shells (Oxyperas elongatum) and tipa / scallop shells further out. I used these large shells as the edge of the drift rather than the smaller shells. It was tempting to use the high contrast line created by dark red algae growing on undisturbed (but often smaller tawera spissa) shells which contrasted with the white shell hash. I took my phone to record marine life, logged on iNaturalist.nz. Many of the sponges were hard to identify as I was not using a dive light and the warm colours are missing.

The time stamps on my photos and the length of the dive on my dive computer were useful but the timestamps on the individual tracking points on the Garmin were essential to identify the dive path. This is because I needed to remove tracking points generated:

  1. Before the dive from boat movement
  2. While I drifted during my safety stop
  3. After the dive while being towed back to my boat

Although I ran out of air before I could get around the whole drift (44minute dive) the tracking data gives a sense for the size of the drift. By joining the start and endpoints the track roughly made a four sided shape for which I could calculate the area (16,813m2 or 0.017km2) by dividing it into two triangles and applying Heron’s Formula.

There were some small gaps in the drift and I’m sure the habitat exits outside the area I tried to circle, I felt like it was more dense in the NW where there was also more tipa shell. I’d like to make a little drop camera to get a better sense for the seafloor habitats surrounding the surveyed area. I would also like to try doing some photogrammetry showing the diversity in the drift , to do this I need to build a cage for my GoPro that I can attach lights to.

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New Zealand’s dairy industry

New Zealand dairy industry

Environmental reports and main stream media are often critical of different aspects of the New Zealand dairy industry. Here I summarise them together in one graphic. View at higher resolution by clicking on the image below.

Graphic summary of the New Zealand’s dairy industries impacts.

References – resources for further reading on the impacts of New Zealand’s dairy industry.

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Map of dog prohibited area at Tahuna Torea Nature Reserve

Map of dog prohibited area at Tahuna Torea Nature Reserve

Like many locals I regularly ask people to not walk their dog at Tahuna Torea Nature Reserve. Sometimes dog walkers push back and say they are allowed to walk their dogs on the beach or around the top of the track. To make it clear here is the wording from the Auckland Council website:

“Dogs are prohibited at all times in Tahuna Torea Nature Reserve. This covers all park areas and associated beach and foreshore areas from the public walkway between 24 and 26 Vista Cresent to its boundary on West Tamaki and Tahaki Roads.”

Here is a map to visually explain the area.

To map the “beach and foreshore areas”, I projected the boundaries perpendicular to the starting points on land, down to the low tide line. Mean Low Water Springs (MLWS) has been visually estimated.

Update March 2024

Roberta Reserve also excludes dogs on the foreshore and playground. There is an exemption for the area in the water of the stream mouth seaward side of the bridge on Roberta Reserve.

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LegaSea’s displacement argument

LegaSea are asking their supporters to object to the Hauraki Gulf Marine Protection Bill due to concern’s about displacement.

“We do not believe the proposed protection measures go far enough to restore fish abundance and biodiversity in the Hauraki Gulf. Marine protection and fisheries management controls need to go hand-in-hand, otherwise all we will do is shift current fishing effort into our neighbour’s waters. We want 100% of the Hauraki Gulf seafloor protected from destructive, mobile fishing methods including bottom trawling, Danish seining and dredging. And, we want Ahu Moana, a joint iwi/hapū and community driven solution to resolve local depletion issues.” (Full email published here).

If we forget about the many non-fishing benefits of marine protection, then also forget about the fisheries benefits of marine protection (nursery and spillover) then forget about the fisheries plan which aims to rebuild stocks including Ahua Moana we are left with LegSea’s naïve argument over a limited amount of fish. Does it stand up?

No, the recreational losses for all species fished in the HPAs total 293 tonnes, the proposed commercial reductions from the corridors will total between 632-1017 tonnes.

Update January 2024. Marine scientists at the University of Auckland have done some excellent work looking at the displacement argument.

Math + references:

Calculating the weight of recreational catch lost to HPAs

Recreational fishers harvested 2,068 tonnes of snapper from the HGMP in 2017/18 fishing year. 9.58% of the recreational fishing effort is in the proposed High Protection Areas. The HPAs will reduce recreational fisheries catch of snapper by 198 tonnes. 

Recreational fishers harvested 517 tonnes of kahawai from the HGMP in 2017/18 fishing year. 9.58% of the recreational fishing effort is in the proposed High Protection Areas. The HPAs will reduce recreational fisheries catch of kahawai by 50 tonnes. 

– https://www.doc.govt.nz/globalassets/documents/getting-involved/consultations/2022/revitalising-the-gulf-2223/stage2-revit-gulf-economic-impact-assessment.pdf

These two species represent 82% of the fish (by weight) caught in the Gulf in the 2017/18 fishing year. 

– https://gulfjournal.org.nz/wp-content/uploads/2020/02/State-of-our-Gulf-2020.pdf

Recreational catch in the HPAs for the 2017/18 fishing year = 248 + 18% (45) = 293 tonnes. 

Calculating the weight of commercial catch lost to trawl corridors

Option 1 would result in an estimated reduction in landings of approximately 632 tonnes of fish per year. Option 4 would result in an estimated reduction in landings of approximately 1017 tonnes of fish per year.

– https://www.mpi.govt.nz/dmsdocument/58729-Discussion-document-Bottom-Fishing-Access-Zones-in-the-Hauraki-Gulf-Marine-Park

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Submissions on the protections proposed by Revitalising the Gulf

I spent a few days going through the 7,550 submissions on protections proposed by Revitalising the Gulf. I’m estimating 77%-90% of the submissions were positive about the protection proposals. However huge numbers concerned about the continuation of bottom impact fishing outside the protected areas and cultural take inside them. So there is a general need for more protection. This level of public support for marine protection can be expected and can be seen in Polling from the Hauraki Gulf Form, Submissions on the recent Waiheke Marine Reserve Proposal and the Live Ocean Barometer 2023.

Most of the names were redacted from the submissions but the organisation names were left public. Here are the names of the organisations that made significant submissions.

OPPOSED PARTIALLY SUPPORT SUPPORT
Legasea
2xs Charters / Balmain Boating Services
Alan Seasprite Charters
CRA 2 Rock Lobster Management Co
Dr Hook Charters
Fisheries Inshore NZ
Kina Industry Council
Mercury Bay Game Fishing Club
NZ Rock Lobster Industry Council
New Zealand Charter Boat Association
New Zealand Sport Fishing Council
Paua Industry Council
Princess Carol Charters
Provider Adventures Ltd
Sea Urchin NZ Ltd
Seahawk Fishing Charters
Slipper Island Residents Association
Snap Attack
Specialty & Emerging Fisheries Group
Tairua Adventures Ltd / Artisan Fishing Co
Te Ohu Kaimoana
Te Ra Charters
The New Zealand Angling & Casting Association
Whitianga / Coromandel Peninsula Commercial Fisherman’s Association		 Aldermen Islands Marine Reserve Group
Friends of the Hauraki Gulf
Mama Fish
Sanford Limited		 Forest & Bird
Revive Our Gulf
Auckland City Centre Residents Group
Auckland Conservation Board
Auckland Council
Auckland Sea Kayaks
Auckland Sea Shuttles
Coromandel Marine Farmers Association
Devonport Yacht Club
Environmental Defence Society
Foundation North
Friends of Taputeranga Marine Reserve Trust
Goat Island Dive and Snorkel
Good Fishing
Hahei Residents and Ratepayers Association
Leigh Penguin Project
Live Ocean Foundation
Meadowbank School Marine team
Motuora Restoration Society
Mountains to Sea Conservation Trust
New Zealand Conservation Authority
New Zealand Geographic
New Zealand Marine Sciences Society
Ngāti Hei
Ngāti Manuhiri Settlement Trust
Ocean Voyages Inc
Pakiri Community Landcare Group
Pest Free Kaipātiki
Ports of Auckland Limited
Shakespear Open Sanctuary Society Inc
Sir Peter Blake MERC
Stet
Supporters of Tiritiri Matangi
Te Whanau o Pākiri
The Friends of Te Whanganui‐A‐Hei Marine Reserve Trust
The Glass Bottom Boat Whitianga
The Hauraki Gulf Conservation Trust
The Hauturu Supporters Trust
Tāmaki Estuary Protection Society
Tāwharanui Open Sanctuary Society Inc
Waiheke Marine Project
Waikato Regional Council
Wakatere Boating Club
Yachting New Zealand
Most of these submitters were upset about continued bottom impact fishing in the Gulf. Most of the Charter fishers all sent in the same submission. These submitters indicated support for marine protection but did not express that much support for the proposed measures: Most of these submitters wanted more protection than what was proposed and also wanted bottom impact fishing banned.

I have not published the names of many organisations who used the LegaSea form as those submissions contained dramatically less information than those from the above organisations. They were mostly small owner operator companies who are also keen fishers. The big Purse Sein operator Pelco NZ Ltd and Te Ahu wai o Tangaroa sustainable ecological aquaculture did make significant submissions but they did not speak to the protection proposal.

In response to the submissions the Department of Conservation has reduced the amount of protection. Submissions are now open on the Hauraki Gulf / Tīkapa Moana Marine Protection Bill.

P.S. These bottom impact fishing effort maps were made public by Fisheries Inshore NZ and are useful in considering the proposed ‘trawl corridoors’.

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Submissions on the Hauraki Gulf Fisheries Management Plan

Over 10,000 submissions on the Hauraki Gulf Fisheries Management Plan are likely to be the largest data set of opinions on fisheries management in Aotearoa and definitely the largest in the Hauraki Gulf Marine Park.

This copy is displayed when asking for public submissions:

Submissions are public information
Note that all, part, or a summary of your submission may be published on this website. Most often this happens when we issue a document that reviews the submissions received.

People can also ask for copies of submissions under the Official Information Act 1982 (OIA). The OIA says we must make the content of submissions available unless we have good reason for withholding it. Those reasons are detailed in sections 6 and 9 of the OIA.

If you think there are grounds to withhold specific information from publication, make this clear in your submission or contact us. Reasons may include that it discloses commercially sensitive or personal information. However, any decision MPI makes to withhold details can be reviewed by the Ombudsman, who may direct us to release it.

I’m disappointed that Fisheries New Zealand has not released all the submissions citing section 18(f) of the OIA—that the information requested cannot be made available without substantial collation or research.

I’m going to read over the submissions provided (which are substantial) before asking for more detail.

My request

FNZ response

Submissions Part 1

Submissions Part 2