The enchanted gardens of North Eastern New Zealand

Photo Auckland Libraries Heritage Collections NZG-19071116-0009-03

I was horrified by this photo I found in the Auckland Libraries Heritage Collection. It was taken 116 years ago in 1907. The caption reads ‘beautiful but profitless’ and describes a haul of corals and sponges undertaken by a research trawler. One large Black coral is remarkably intact, a tragic loss. The caption describes the scene “A haul as this—which in trawling parlance is “muck”—though useless is a glorious sight. This one in particular was gorgeous. The fish were a brilliant rose-pink, and all the hues of the rainbow were to be found in the strange dwarf trees, and other growths which came up in the net.”

The photo was from an article published in New Zealand Graphic which can be found in Papers Past, a second part to the article was published the following week.

The story is written about a single trip which started in Auckland on the 17th of October, the end is not mentioned in the article but based on the fisheries scientist’s report (from 1907 on PapersPast, there is also a 1901 report in the same National Library archive ) they went to the North Cape and back, making 23 trawls in 11 to 55 fathoms (20-100 meters). There are notes on all 23 trawls, the photo is likely from one of these:

Station 177: The net was shot again at 9.55 a.m., 6 miles N.W. £ W. of Channel Island, depth 25 fathoms, bottom mud and sand. As soundings indicated rough bottom, the net was only towed an hour and hauled up in 27 fathoms, bottom coral and shell. The result of this haul, poor both as regards the quantity and variety of fish.

Station 178: From last station steamed 5 miles S. x E., and shot the net at 12noon, 4miles S.S.E. from Little Barrier, depth 28 fathoms, bottom mud and sand. Hauled up 4J miles W. \S. of the Little Barrier in 28 fathoms, bottom coral and shell. This was also a short haul, and the results were as poor as the previous one.

Station 183: Left Russell at 6 a.m. for Great Exhibition Bay, near the North Cape. Arrived there and shot the net at 3 p.m. in 32 fathoms, the soundings made showing sand and shell; but the net had only been towed ten minutes when it fouled, and. when hauled up it was found that the foot-rope was cut through, showing plainly that it had come in contact with rocky bottom.

Station 191: After hauling up from station 190 several soundings were taken, and showed a risky bottom, so we steamed south 17 miles, and shot the net at 4.30 p.m. off Takau Bay in 35 fathoms, bottom fine sand. Towed S.E. 2 miles, and hauled up from the same depth and character of bottom as we shot in. This was a very poor haul as regards fish-taking : the net came up with large quantities of marine vegetation. After hauling up we steamed into Russell, and anchored for the night.

They lost a £lOO net on “foul ground” and they were constantly mending nets. The author describes the seafloor based on the bycatch “places must be like a fairy grove, or one of those enchanted gardens in the Arabian Nights”. He goes on to describe a particular haul from the Bay of Islands in detail:

“There were several dwarf trees about three or four feet high, which realised one’s idea of the sort of thing that grew in the garden of the Princess Bulbul. They had evidently been torn from the solid rock. The branches were covered with feathery leaves of a most delicate form, coloured cream-brown, and attached to them were all manner of things just like a Christmas-tree. From a short distance off, it was difficult to say that it was not hung with all manner of vivid-hued fruits—bananas, grapes, tomatoes, and what not—anu round the branches at intervals were twined starfish in knots resembling what sailors call “Turk’s Heads.” They were not spiked like ordinary star-fish, but smooth and bright as a Japanese lacquered box. Some were cream with maroon stripes, others a rich golden yellow, others crimson, and on no two was the marking the same. From one branch depended a cluster of things half prawn, half sea-horse, and from different points swung shark’s eggs—a semi-transparent lyre-shaped bag of the same colour and quality as celluloid (from which it was difficult to distinguish it), some four inches in attached to the shrub by cartilaginous tendrils, whose spirals seemed intended by wonderful Mother Nature to catch in such growths and find a safe hatching place. One branch minus leaves, if one could so term the feathery growth, looked exactly like a frond of coral, the colour a rich crimson-lake, with the tips of the countless excrescences lighter in tint. On a closer examination the branch was found to be sheathed with a gelatinous substance, quite soft to the touch, which soon dried and lost its exquisite colour.

Some of the shells were very strange and interesting, particularly one that seemed to be very plentiful. It was an ordinary-looking spiral shell as big as a man’s hand, but round the base was ranged a number of smaller shells, forming a sort of base which would apparently keep the shell off the ground, like a house on piles. They were stuck on with some kind of cement, and in other specimens small stones or pebbles were used in a similar way.

Sponges, and fungoid growths of many colours and fantastic shapes—umbrellas, hats, bowls, etc.—were common, and some of them weighed half a hundredweight and more. Star fish, squids, molluscae, medusae, seaweed and yards of gelatinous transparent stuff as thick as leather and marked with red spots were brought up at nearly every haul. They would no doubt be greatly prised by the naturalist, but are shovelled over without the slightest compunction by the business-like fisherman.”

By 1907 there were many trawlers operating around the country, many purchased with government subsidies. There had been much public outcry about the method and one area in the Gulf protected (temporarily) but only after it had been trawled. In 2023 commercial bottom trawlers and Danish seiners will repeatedly deploy their gear thousands of times within the Hauraki Gulf Marine Park alone.

The image is a stark reminder of what’s been directly lost to mobile bottom impact fishing. The industry like to say they only trawl on ‘sand or mud’ but we know that our mud and sand once supported more complex habitats. Examples of biogenic habitats that associate with soft sediments include horse mussel beds, scallop beds, dog cockle beds, green-lipped mussel beds, seagrass, sponge gardens, tubeworm mounds and rhodolith beds. Our poorly protected corals and other epibenthic fauna like sea squirts attach to hard structures created by these habitats, enriching and expanding these ‘enchanted gardens’. All of these habitats are easily destroyed by mobile bottom impact fishing.

To this day NIWA carry on this tradition of ‘scientific’ bottom trawling for the government, even in areas protected from bottom trawling. Some tows are stoped due to ‘foul ground’. When will we stop all mobile bottom impact fishing and begin to restore our ‘enchanted gardens’?

My experience in designing ‘trawl corridors’

Unlike the Sea Change 2017 marine spatial plan that sought to phase out bottom impact fishing from the Hauraki Gulf Marine Park the governments response (Revitalising the Gulf 2021) was to create ‘trawl corridors’. Bottom trawlers do not have a public license to keep smashing the seafloor, a 2021 Horizon Research poll had 84% support for a banning the practice. I love the seafloor and volunteer for an organisation that restores damage done to it by bottom impact fishing. I’m completely opposed to trawling as a fishing method but I put my hand up to help limit its impact in the Gulf using a science based process by joining the Hauraki Gulf – Benthic Spatial Planning Advisory Group (HG-BSPAG).

This was my first experience in a collaborative decision making process run by the Government with industry representatives. I represented an environmental Non-Government Organisation (eNGO), there were three eNGO participants, everyone else was either from NIWA, central & local govt or the fishing industry. The process was chaired and controlled by Fisheries NZ. The other two eNGO participants were awesome and I learnt a lot from them.

I particularly liked the data first approach to marine spatial planning, Zonation is a great tool and I liked the way it starts by removing the human impacts then making an economic case for re-introducing them. Unfortunately some data that would have been useful was not quite complete.

Fisheries NZ controlled the outputs by defining what is in scope. Here is a list of requests that were disregarded:

  1. Ground truthing the modelling work (out of scope).
  2. Modelling the distribution of Unwanted Organisms (UOs) . We know from NIWA surveys that trawl nets catch UOs in the HGMP, transporting UOs is an offence under Section 52 of the Biosecurity Act 1993. By excluding UO’s from the study FNZ failed to protect native benthic habitats from UO’s which can be spread by bottom impact fishing (see appendix for more details).
  3. Infauna (animals that live in the sediments) that are sensitive to bottom impact fishing were excluded from the modelling due to technicalities.
  4. Mobile species that contribute biogenic habitat like tipa / scallops (see appendix) and burrowing animals like ghost shrimp and crabs were excluded because they were mobile which did not suit their definition of biogenic habitat. This is ridiculous as the smallest grid size is 250m and previously mentioned adult animals are unlikely to move more than 10m.
  5. Important habitats for fish (like spawning and nursery areas) were not considered (out of scope).
  6. The indirect effects of bottom impact fishing. Sediment plumes from bottom impact fishing choke and kill filter feeding animals and smother photosynthesising plants. These effects were not included but have been discussed at the end of the report.
  7. Climate change impacts (e.g. CO2 released from resuspending sediments and heart urchins moving deeper as water warms) also not included but have been discussed at the end of the report.
  8. Modelling the economic benefits of excluding bottom impact fishing to other fisheries that don’t impact the seafloor, this could have dramatically altered the findings (out of scope).
  9. Monitoring changes in the money made in an area over time during the transition from one fishing method to another, I think it’s critical this is done with any changes to bottom impact fishing.
  10. Using the regulations, not existing fishing effort, as the starting point for limiting Danish seining (see appendix on Danish seining regulations). Despite multiple requests FNZ would not even put the existing regulations on the maps.
  11. Protecting the deeper areas of the HGMP (see appendix).

We did not discuss substrate. Is it better to trawl on sand which emits a smaller plume but may transition to mud with intensified disturbance, or mud which has a larger sediment plume? We know repeated bottom impact fishing alters the chemistry of the seafloor.

The narrow scope of the project was frustrating because there is an aspiration for Ecosystem Based Management of the Hauraki Gulf Marine Park. Once all the environmental effects of bottom trawling and Danish seining are considered, the fishing methods should be banned everywhere.

I have some sympathy for fisheries managers, they have specific deliverables and get pushed around by industry. I did think their approach was often callous, in the face of uncertainty they often chose the status quo rather than taking a more precautionary approach. One member of the Hauraki Gulf Fisheries Management Plan Working Group HG-FMPWG that will finish the corridor design work has publicly criticised the process.

There were no opportunities for feedback on the corridors the scenarios produced. Final trawl corridor design will be Fisheries NZ’s responsibility and will get input from the HG-FMPWG. Other than the above I have no criticisms of the process, it just needs bigger budgets and managers who care more about te taio. I learnt a lot and am happy to volunteer my time again to use scientific modelling in a spatial planning process to protect the environment.

One difficulty I had was proposing trawl corridors. I decided not to volunteer a low impact scenario because the process had already generated a near zero impact scenario which I thought was reasonable (Similar to Figure 14C in the published report – 90% of recovery potential habitat and current trawl footprint & current/proposed protected areas and 100% of current distribution of biogenic habitat (minimising impacts on trawl fishery.) This meant I was left very unhappy with the scale of the proposed scenarios. It was obvious that the scenarios would need work before Fisheries NZ could designate corridors, however I may end up regretting that decision.

I hope Fisheries NZ will monitor recovery (which may take centuries) the data gained could help ground truth this model and develop more robust models in future.

You can read the published report on the design process here: Exploring the use of spatial decision support tools to identify trawl corridors in the Hauraki Gulf Marine Park

Advice for the Hauraki Gulf Fisheries Management Plan Working Group

The outputs of the process will be used by the Hauraki Gulf Fisheries Management Plan Working Group to design bottom trawling corridors in the marine park. Here are some key points they should be aware of:

  • Because the process is not ground truthed and does not account for secondary impacts, important habitats for fish or climate change impacts a precautionary approach should be taken. (I suggested massive buffers but they were deemed out of scope).
  • Danish seining impacts have not been included in the model. This skews the impacts, recovery in areas where this fishing method is practiced has been understated.
  • The corridors should be much deeper (further from the coast) to avoid the illegal transport of Unwanted Organisms.
  • Consider the existing Danish regulations as the starting point, not the area where the fishing method is currently practiced.
  • Protect the deeper areas of the Gulf because they are included in the Hauraki Gulf Marine Park (see appendix).
  • Include monitoring (fisheries method transition) in any recommendations.
  • Take special note of the sediment resuspension impacts detailed on page 68 of the report which were excluded from the study.

Appendix

Avoiding tipa / scallop beds

Running heavy trawl gear over tipa / scallop beds is incredibly damaging and foolish behaviour. It not only damages the tipa including juveniles, but also the settlement substrates the tipa use as part of their lifecycle. The Review of Sustainability Measures for New Zealand scallops (SCA 1 & SCA CS) for 2022/23. 3.1.18 states that:

“Within the Hauraki Gulf Marine Park, overlap between trawl activity and scallop beds will be considered as part of the proposal to establish defined ‘trawl corridors’ that will limit the areas where bottom trawling can continue to operate. With the introduction of electronic reporting and Global Position Reporting (GPR) on commercial fishing vessels, Fisheries New Zealand has the ability, through fine scale data, to monitor any notable overlap between fisheries and methods.”

It was frustrating that even though tipa are the most surveyed biogenic habitat in the Gulf the fisheries scientists decided that instead of identifying them they would just model their associated habitats. In the paper they literally say they ‘hope’ that this would mean the beds would be avoided rather than just mapping them out. Only the small beds that remained open at the time of the study (the fishery has since collapsed with bottom impact fishing implicated as a key stressor) were removed from the study area.

The rationale for the exclusion of tipa was that they are very mobile. This is ridiculous given the grid size of the study is 250m. Adult tipa and burrowing animals are unlikely to move more than 10m in their lifetime. For adult tipa mobility see Morrison, M. A. (1999). Population dynamics of the scallop Pecten novaezelandiae in the Hauraki Gulf (Doctoral dissertation, ResearchSpace@ Auckland).

Danish seining regulations

The restrictions prescribed in fisheries regulations for Danish seining define a different area than what is currently applied by Fisheries NZ. The State of our Gulf 2020 quotes Fisheries  NZ as ‘committed to reviewing this discrepancy as part of management actions put forward in a fisheries plan for the Hauraki Gulf’. The discrepancy is not recorded in the final report.

Protecting the deeper areas of the HGMP

The deeper areas of the HGMP were excluded from the final scenarios. I asked that they be protected because:

  1. The edges of continental shelves are biodiversity hots spots. Predicted diversity along the depth incline is one of the reasons for excluding the area from the model.
  2. This process was designed to protect biodiversity.
  3. This is the only deep water area in a marine park in New Zealand.

Unwanted organisms discussion document

Here is the discussion document on an unwanted organism (Mediteranean fanworm) I prepared for the working group, similar logic could have been applied to other species including the two recently introduced Caulerpa species.

Omissions

The report details protection measures proposed by Sea Change 2017 but omits the most important benthic protection measure, “the phase out of all bottom trawling, Danish seining and scallop dredging from the Hauraki Gulf, with all such methods excluded by 2025” It’s a strange omission that reads like an attempt to exclude the measure from the history books.

Northern New Zealand dotterel productivity rates

Northern New Zealand dotterel are classified as a Conservation Dependent species, this means that without human help they will go extinct (usually because of predation from introduced predators like rats & cats). So how do you know if your local dotterel are going extinct or not?

Well first you need to work out their productivity rate. Productivity is measured by the average number of chicks fledged per breeding pair (per season). Chicks divided by adults. So if you had two pairs and they fledged one chick you can say the site averaged half a chick (0.5) per pair.

Management is considered effective if productivity values are greater than 0.5 for three consecutive years or longer (Dowding & Davis, 2007).

I help manage dotterel at three sites, I can not claim effective management and any of them. This means that over time these sites are a population sink. It’s important to track and share this metric to help conserve the species.

Tarāpunga / red-billed gulls nest extension

The tarāpunga that nest under the Panmure Bridge are heavily impacted by humans, the national population is in decline. While deploying a nesting structure for tara / white-fronted tern yesterday we also added a small extension to the Panmure tarāpunga nesting structure. We upcycled old wood which fitted the rustic nature of the old bridge. The six nesting areas were c35cm x 25cm. The gulls were already a few weeks into nesting with some three eggs nests. As the colony is currently space limited I think the structure will help, but we may have been a bit late deploying. The gulls also nest on boats in the estuary so if some get disturbed they may move to the main colony. It was promising to see two gulls having a tussle over the new nesting area while we exited the estuary.

Photo taken 5:30pm 18 September. Gulls regularly seen on the platform, but not sitting.
Photo taken 2 November. Success!
Photo taken on pole camera shows six nests.

I checked many old boats moored in the Estuary and did not find any with nests which is great. One pair of gulls nested on a post, another on a jetty where it’s likely to be disturbed. There is a clear case for extending the nesting platform in 2023.

This photo of a parent attending a chick in the current upstream from the colony indicates there may be some benefits to creating a ramp of sorts for the juveniles.
New addition added. Noted 8 infertile eggs on site, one dead chick, two chicks remaining, no dead birds with fishing line attached but any bodies may have been blown into the estuary by the cyclone. Some fishing line removed from site. One fledgling was in the water and calling, it would be good to have a ramp or additional floating area(s), this may reduce chick mortality and would definitely reduce colony stress.

Added some extensions after taking this video (30 September 2004)

This one has quite tight spacing (c25cm) but I know from the tara next box experiment it will not be a problem.
We ran out of wood and this large platform only has one divider, it will be interesting to see how many gulls still want to use it.
Both new platforms utilised. Photos October 10 2024 by Matt Rayner.

Missing reef balls

24 Reef balls were deployed in two reefs at Long Bay-Okura Marine Reserve in 2001.

Launching the reef balls, photo care of Jonathan Jaffrey

They were quickly colonised and dramatically increased the biodiversity in the area.

A lonely reef ball, photo care of Jonathan Jaffrey.

I have wanted to find these artificial reefs for years and made three attempts. The first dive from the shore was unsuccessful (its too far out and I dont have underwater GPS). The second and third efforts below used line and sonar but still came up empty. I think they have been buried (sunk into the substrate) but I would love to be wrong. The photo above shows a lot more shell on the seafloor than I found 20 years later. I’m not planning any future searches.


12 January 2022
4:15pm High Tide
5-10 knots
.5m-1m swell
Shaun Lee & Jordi Tablada

Boat to from Winstons Cove to Long Bay
12:00pm Look for Reef Balls:

Zig Zag Reef
36° 40’ 52” S, 174° 45’ 14.8” E
36.681111, 174.754111
5.5m at Low tide

Octagon Reef
36° 40’ 51.1” S, 174° 45’ 19.6” E
36.680861, 174.755444
6.2 M at low tide

Dropped anchor 5m from Zig Zag using Garmin GPS
Dived down anchor with line on reel
Vis 5m surface, <1m bottom 5.5m deep, tied line around anchor, spiral search pattern Let line out >30m possibly didn’t turn enough and made more of a sweeping arc
Hoped line would have snagged of epibenthic fauna attached to reef balls but following line back found nothing
Quick check near boat found nothing c30mins total bottom time
Noted layer of mud under sand
A few cushion stars, some heart urchins, Jordi saw a Spengler’s Trumpet
Some dead tutua shells under sand
Large snapper under us when we surfaced

Dropped anchor 5m from Octagon using Garmin GPS
7 minute look in the direction of the reef
Nothing in particular

2:30pm head back as wind pickup up (15knots developing in afternoon).

Resolved to search with a boat that has sonar / fish finder next time.


Thursday 9 September 2022
High Tide 5:30pm
With skipper Ed Chignell

Zig Zag Reef 6.7m
2:45pm
c7 spirals out from waypoint. No clear benthic structure seen on downscan or sidescan.

Octagon Reef 8m
3:10pm
c3 spirals out from waypoint. Drifted south over fishy looking shape 5m south of the waypoint on the downscan. It was still there 5 minutes later so we dropped anchor on it.

I descended the anchor line. Vis 3m, bottom 8.8m. I spiralled out from the anchor for 5 minutes then headed north for an additional 5 minutes. The seafloor was sand/mud with some shell. Nine cushion stars and about six large hermit crabs were seen in 10 minutes. After ascending and heading a bit further south I dropped down for another 5 minutes to check out another fishy shape but didn’t see any reef balls or fish. Many fish were seen in the fish finder.

Note visibility much better than last dive even tho it rained heavily just a few days ago. Hardly any swell or wind over the last two days.

UPDATE: WE FOUND THEM!

https://inaturalist.nz/journal/shaun-lee/74488-dive-report-reef-balls-long-bay

Article about the find here https://gulfjournal.org.nz/2023/02/reef-balls-rediscovered/

Thanks to Andreas Proesl who has been in touch and supplied his internship report which shows how the ReefBalls were constructed and deployed

Photo kickstarts stream restoration

I recently had a great experience with Waikato Regional Council (WRC) which showed the value of just letting council know whats happening.

I was driving past  270 Kuaotunu, Wharekaho in the Coromandel and saw cattle defecating in the stream. I was in a hurry but decided to take a quick photo and reported it a few days later. I got a great response from WRC. The land is owned by the crown, managed by Thames-Coromandel District Council (TCDC) and leased to a farmer. The stream is a priority one waterway given it’s proximity to the coastal marine area which cannot have stock access without a resource consent.

Staff discussed the issue and the farmer running cattle on the property will now remove cattle from the land. TCDC envisage releasing the tenure to the Department of Conservation who may review activities at the site and consider restoring it. What a great outcome! I am very impressed with all agencies involved.

August 2024