Vale Fin-Fish Farming!
Wednesday, December 17, 2014 at 3:37PM
Bill Barclay

I will put up a post by Geoffrey Robinson later that will outline the course of events that has led to the the total collapse of the once great Wilson's Bay Fin-Fish Farming Project. Another plank in the grand economic development plan of Mayor Leach and his side-kick Ben Day that has collapsed.

In the meantime take a look at the attached confidential Waikato Regional Council internal memo that was circulated to a limited audience in August that outlines the incredible news about the dissolved oxygen level degradation in the area of the Gulf where the fin-fish farming was planned. (Unfortunately, the URL is protected, so I have to reproduce the entire document here - but it is worth reading to get the full picture of just how our servants seek to hide the truth from us.)

CONFIDENTIAL – for internal use only
File No: 22 03 76
Date: 14 August 2013
To: Bob Laing
cc: Vaughan Payne, Tony Petch, Karen Bennett, Shaun Plant
From: Graeme Silver, Peter Singleton
Subject: Low dissolved oxygen in the Firth of Thames and potential risks
for Waikato Regional Council

Information recently obtained from NIWA indicate that dissolved oxygen levels in the Firth of
Thames are unusually low and may reach levels that would impede fish growth and even be
harmful to farmed and wild fish. Persistently low or periodically very low levels of dissolved
oxygen would be an indication of major environmental degradation and ecosystem collapse.
The reason for the observed low oxygen levels is unknown but it is likely a result of complex
dynamics between nutrients, organic material, sedimentation and water currents in the Firth
of Thames and the wider Hauraki Gulf. Likely causes include nitrogen and organic matter
inputs from the Waihou and Piako rivers that stimulate oxygen consuming decomposition.
Another potential factor is sediment input from the land as this reduces the light available for
oxygen production via photosynthesis.

At this stage the extent and duration of low dissolved oxygen, and its cause, is not known.
Some of the extreme low levels recorded may be due to a faulty instrument, but there is data
from other instruments that show similar results. External advice (obtained on a confidential
basis) indicates that the reported levels of dissolved oxygen would be harmful to farmed fish
and to wild snapper.

The available data is limited in its coverage. Staff from RIG are developing an investigation
plan to identify the scale of the issue. This will require unplanned expenditure in excess of

We are aware of a significant data set (14 years long) from a monitoring buoy near the
Coromandel marine farming zone that is held by NIWA. They have previously charged
$20,000 to provide a summary of this data. MPI may be willing to fund further analysis, or
access to the raw data, as it directly affects the fish farming zone. We have some concerns
that NIWA did not provide a more detailed analysis of dissolved oxygen when MPI
commissioned them to investigate the suitability of the new fish farming zone.
Implications for the environment and fish farming

Dissolved oxygen levels are normally close to saturation (100%) due to mixing with the air
and photosynthesis by algae. Dissolved oxygen is used up by all respiring organisms and even moderately low levels are harmful, reducing growth rates and causing metabolic stress.
Effects of this type have been observed at levels of 60% to 80%. Critical levels will kill fish
within a few hours. The critical level varies by species and temperature and is typically in the
range of 20% to 35%.

Low dissolved oxygen levels can occur naturally and are expected in deeper waters during
summer and autumn, due to the warmer surface waters not mixing with the deeper water
and enhanced oxygen consumption in warmer conditions. Very low dissolved oxygen is
often linked to decomposition of dead algae following a bloom.
Wild fish can normally avoid low dissolved oxygen areas by leaving them, assuming the
extent of depletion is not too great, but farmed fish will be trapped and suffer reduced
growth, respiratory distress and in extreme cases, death. If the low dissolved oxygen levels
occur frequently and for sustained periods of time, fish farming will not be viable in the
Wilson Bay zone or the new Coromandel marine farming zone.

Figure 1 below shows the dissolved oxygen levels at Area B of the Wilson Bay zone at a
depth of 5 metres from late January to mid-April 2013. Typical fish farm cages have a depth
of 10 to 15 metres. Figure 1: Dissolved oxygen levels at 5 metres depth at the Wilson Bay zone
(sorry - I cna't reproduce the table)

Risks for WRC

1. Fish farming
The immediate short term risk is that the fish farming space in both the Coromandel Marine
Farming Zone and Wilson Bay Area C is not viable and WRC could be liable for damages if
we release the space by tender without fully disclosing what we know. Conversely if we
release the available information without a better understanding of the extent, duration and
cause it would discourage potential investors. The ability of fish farmers to manage low
oxygen levels by, for example, aerating the water is unknown.

2. Environmental collapse
Low dissolved oxygen levels may be an indicator of (and contribute to) a wider ecosystem
collapse. If low dissolved oxygen levels are widespread, persistent and in a downward trend,
then this will cause significant damage to wildlife and fisheries. This could lead to a “dead
zone” as seen in the Gulf of Mexico and Chesapeake Bay. If the cause is linked to elevated
nutrient levels entering the Firth from the Hauraki Plains, then WRC would be held

3. Damage to the snapper fishery
MPI has recently released their stock assessment for snapper in the Hauraki Gulf. It notes
that the population has grown but not as much as expected. The reason suggested is that
the recreational take is much higher than predicted and MPI is considering options to limit it.
Low dissolved oxygen may be reducing snapper growth and reproduction. Recreational
fishers opposing the new restrictions may suggest that land based pollution is the reason
with a risk of WRC being subject to a negative publicity campaign for not doing enough to
manage it.

4. Stakeholder relationships
Stakeholder relationships are at risk if WRC does not act expeditiously on the information we
now have. If the information is leaked by a third party WRC risks negative publicity and
damaging key relationships, such as with Hauraki iwi who are expected to receive some
level of co-governance over the rivers and marine area within their rohe.
The available information is cause for concern but does not provide a complete picture of the
situation. The data shown in figure 1 covers a period of only three months at one depth at
one location, but a sustained period of sub-80% dissolved oxygen at the relatively shallow
depth of 5 metres is alarming. Dissolved oxygen is known to vary seasonally and in
response to a range of environmental and climatic factors. It is possible that the drought
during this period could have affected dissolved oxygen levels.
The extent, duration and depth of low dissolved oxygen levels are still to be determined. It
will take up to 12 months of data collection to answer these questions with any certainty.
This will require additional unbudgeted resources.
Long term trends will be of particular interest. Analysis of the NIWA dataset provide a clear
picture of seasonal patterns and long term trends in the Hauraki Gulf north of the Firth of
Thames. MPI may be willing to fund that analysis.

Staff are seeking an urgent executive decision on when to notify Council, MPI and other
stakeholders, noting that the Fish Farming Working Group has a meeting planned for
Tuesday 27 August. Council’s next meeting is Thursday 29 August.
Staff will develop a
communications plan to enable WRC to respond to this issue using an agreed process, and
manage any media attention, publicity and stakeholder queries.
(My Bold!)

It was so confidential that the information has been deliberately with-held until Geoffrey recently secured the document under the OIA.

This explains why there has been nary a dicky-bird out of the WRC, or TCDC on the subject of fin-fish farming since the initial onslaught of propaganda that accompanied the original announcements. You may be sure that this information coming on top of all the other bad press about the various projects that appear to be treading water is surely something that our councils would rather we did not know.

I will shortly post Geoffrey's analysis that supports my earlier guesses about what was going on up there at Wilson's Bay. The critical thing is that there was absolutely none of the international interest that Day and others had predicted when they were earlier promoting the project in Council. It also effects the economics of the major overhaul at Sugar-Loaf where they are still endeavouring to work out the how they will secure the support of the many and varied mussel farming interests in covering the costs of the Resource Consent, etc.

They appear to be entirely ignorant of the failure of the Kingfish project at Lincoln in South Australia that was the template for Wilson's Bay - there is a surplus of Kingfish on the world market, and it is not a popular traded fish - it makes you wonder if the long term game involved Tuna.

The suppression of the oxygen depletion memo is nothing short of disgraceful, like so much else that goes on in the WRC.




Article originally appeared on BillBarcBlog (
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