Issue: The Health of the Taupo Fishery - i.e. concern over the deteriorating condition of trout from the discussion paper prepared by Richard Kemp.

 

 

 

John introduced his team and advised they had read the discussion paper by Richard and were aware of anglers ongoing concerns.

 

Richard commented on the fact that trout were starving and had DoC considered the introduction of farmed smelt. DoC Answer Yes.

 

Heather asked if excessive lake levels were affecting smelt spawning.  DoC Answer - No.

 

Bob commented on whether climate change was affecting the timing of trout spawning runs.  DoC Answer - No.

 

Glenn elaborated - from his paper prepared for publication in Target Taupo in August - on timings of runs being later - 58% of 2007 season runs went through the Waipa trap in October & November.  They are no longer running in the traditional April-May-June-July periods.  Because of the later spawning the trout in the lake are three months less mature - hence too small compared to 45 cm minimum.  Average only 1.8 pounds.  Historical average sizes show very little changes until just recently.  Trout are not leaving the lake until late spring.  Confirmed last winter the trout were not in good condition - 12% of trout through Waipa trap were under 45 cm.  

 

The Waipa trap results were considered to be entirely representative of the Tongariro River.  

 

To answer the poor growth issue - Glenn explained one of the reasons is the lake stratifies - all growth being in the nutrient rich top layer which mixes throughout the year to bring all nutrients to the top for zoo plankton.  The crux of the problem was that in 2005 this did not turn over.  Smelt had no food and the population got hit.  Elsewhere healthy smelt normally spawn three times a year but due to the lack of nutrients in Taupo they spawn only once.  The productivity - or nutrients - of Lake Taupo is at the lowest limit for healthy smelt spawning.  

 

 

Glenn compared it to a farm lacking fertiliser.  Overall teh lake is now more nutrient rich than it was but the nutrient level is still poor compared to other lakes.

 

Richard commented that previous years he returned any trout under 5 pound but now they are 2 pound.

 

Glenn summarised that they - DoC - are cautiously optimistic on the future.  Better fish have become apparent in the last three weeks.

 

The five main factors affecting size and condition were as: (I hope I have interpreted this correctly?)

 

1 Smaller fish last year was because they were younger.

2 Lake anglers were catching & releasing more in late Autumn - most of which die anyway.

3 The few achieving legal size are early runners - selective pressure of keeping only one out of six to eight caught increases selection pressure.

4 Trout protected in lake over winter results in late spawning runs.

5 Late runners force more into the lake at the wrong time for recovery by feeding on smelt.

 

Glenn emphasised the lower the number of fish, the higher the vulnerability of individual fish being caught.  So the proposed reduction to 40 cm is to reduce the effects of five reasons above.  Other options are available such as closing the river lower down, more flexibility in size limit.

 

John emphasised DoC are funded by licence revenues which need to be spent on fishing - not the lake issues BUT they are acutely aware that what goes on in the lake is the key to the fishery.  They are now working with Prof. Hamilton x University of Waikato and other agencies in research on the lake but everything in the lake re algae etc. was described as "patchy" - i.e. not consistent..  

 

 

They concur the need for comprehensive research into the lake re biofish to benefit everyone.

 

Heather asked is there anywhere on the DoC website to show what research is being done?  Answer - No.  They (DoC) lack the resources to even put Target Taupo on their web site.  DoC would welcome more funding for research but their statutory imperative is to maximise the angling opportunities using funding from sales of fishing licences.  John estimated that trout fishing adds $80 million annually to the Taupo economy.  Fishing is the single most important item to the local economy but funded by sales of licences without any council support.

 

Heather asked what research has been done on the food chain?  Michel answered that is his special area - looking at other lakes in the world but there are very few precedents because it is so complex.  He is collating all the info on zoo plankton interactions to create simulations to see the results.  Michel advised last summer the lake was the clearest for the last 25 years - no algae or zoo plankton (hence nothing for smelt to feed on).

 

Richard asked that if the fish are not growing as they should is there anything they can do?  Answer - No - it is a one off situation.

 

 

Richard asked if it is an on going problem is there anything DoC can do to improve size or condition?  Answer by John - they suspect not.

 

Richard asked if there are any other types of smelt which may be suitable.  John repled there are no other species which would meet the conditions in Lake Taupo.

 

Glenn commented there are now more nutrients in the lake than in the past so if the smelt are doing badly there s something subtle going on.

 

Michel advised smelt used to be predictable but are now more patchy following the patchy distribution of their food.

 

John commented any variation to the lake levels would not have any effects on smelt breeding or on numbers.  The vast majority are in water less than half a metre depth where they hatch in 9 days - usually along beaches and around stream mouths.

 

Michel commented that given the shape of the shoreline the smelt spawning could not be affected - the key ingredient of smelt numbers is not their spawning but their food source (zoo plankton).

 

Richard asked if the injection of more smelt would help?  John replied they will respond without help.

 

Richard asked if there was any evidence of reduction in koura numbers and are catfish a problem?  Glenn explained they used three traps in Motuoapa, Tokaanu and at Whakaipo Bay where they set traps next to raupo.  The trap numbers have not changed.

 

The catfish at the southern end of the lake are smaller.  They do not do as well in the lake as they do in the Waikato RIver.  The numbers have been very stable over the last 5-6 years.  The catfish numbers peaked at the same time as top trout were caught in late 1990's.  They keep to the shallows and do not compete.  Michel commented that most trout still do not eat koura.  Over 90% prefer smelt.  The orange flesh colour does not come from koura but from smelt - depending on the type of plankton they have been eating.  

 

Richard asked if there is not much we can do about size in another year what can DoC do.  Glenn replied the 1995 eruption reduced trout numbers but size increased.  DoC can manipulate the harvest.  

 

Richard asked whether there are too many trout?  Glenn suggested that it does not cause any concern - reducing the minimum size will increase the harvest.

 

The Waipa trap results in 2007 indicated the trout numbers were the third lowest in the last ten years - since 1998.

 

John advised licence sales had reduced from the peak of over 80,000 in 1990's to 50,000, but the lower number of anglers were spending more time fishing so the impact had not changed.  He reminded that 75% of the harvest is from the lake - where smaller trout are caught than in the rivers, and 75% of the angling effort is on the lake. 

 

 In discussion Michel confirmed DoC do not support catch and release.  He gave example of pike in USA where slot limits failed when anglers stopped fishing when they could not target the larger fish.  

 

Bob asked what had happened to the smelt which used to cover the tail race - where had they gone?  They explained that the zoo plankton from Lake Rotoaira had changed and was no longer suitable for smelt.  Therefore the concentration of smelt had gone from the tail race.  

 

Lake Rotoaira ecology has changed - now has blue green algae which are toxic and an indication of poor enrichment.  They compared Lake Rotoiti where the algae is inconsistent and they do not know what will happen from year to ear.

 

 

Glenn advised most juvenile trout leaving the river do not make the transition to feed on smelt that they need to to thrive.

 

He commented that jigging is harder and potentially catches more trout but the majority of boat anglers still prefer deep trolling - which is the least successful method.  He suggested it was a myth that jiggers caught better fish.  Deep trolling done properly is just as successful.  From a management perspective, fly fishing is not a very effective way to catch trout. 

 

Heather asked about the study of river flushes - variable flow trials - on trout.  Glenn replied the study is ongoing.  Invertabrates distribution is shifting.

 

Bob asked what has happened to the rafts of green beetles.  Michel advised their habitat - manuka - has been destroyed.

 

Michel commented on cicadas - not considered important on diet on Lake Taupo but are t Lake Otamangakau.

 

John commented that at Taupo the new land uses are not affecting the lake.  Farming is not any more intensive.  Nutriment levels are worse but not from run offs.  

 

Heather explained the use of the management filter that Advocates use to monitor progress to identify what research info is available and whether DoC research info is public information.  John replied that the nature of research information would still takes the same time to analyse and publish in Target Taupo three times each year.  Glenn's article will appear next month.  There is no room on the DoC website for an electronic version of TT.  John wanted to dispell any impression that DoC are hiding any research information.  All info is available on their website and is published in TT in a popular readable format.  It takes time to check the technical information is accurate as it is often reproduced in overseas publications.

 

John advised that DoC Head Office funding restrictions will not affect the Taupo Fishery which is totally funded from licence revenues.  They can and do bring in outside expertise and scientists - often on an informal or personal basis - but are restricted by funds.  They confirmed there is a lack of good research available beyond Taupo and therefore have had to build up their own internal research capability.  Glenn reiterated NZ is small but DoC have regular dialogue with outside agencies which have research gaps on Trout.

 

Michel advised they were not keen on scientific modelling scenarios which cannot provide for unexpected events.

 

Heather asked if there was any thought to forming an international scientific committee.  John confirmed that discussion is happening all the time and thee was a strong level of exchanging information.

 

Michel commented that at overseas conferences he was amazed to realise that the Taupo Fishery management was so good.  Comparatively USA examples are poor due to political interference.  DoC's management at Taupo is at the level that makes it attractive for overseas biologists and scientists to come here to study it.

 

Richard asked if there was any way to get back to traditional spawning timings without intervention.  Glenn suggested they can by manipulating the angling pressure - as they are doing.  John suggested it was difficult to achieve changes as most anglers are visitors from beyond Taupo and the rules are deliberately kept simple to improve their understanding.  TT will cover these issues.

 

Richard suggested that DoC need to publicly advise of any programme to address these issues.  If they do not then they need to advise what remedies are needed.

 

The headlines from Taupo Times re local politician's headline comments were briefly mentioned and dismissed as politics and not helping DoC's public relations at all.

 

Richard asked how the Advocates can help DoC?  John asked for more cooperation and funding from Taupo District Council would help.  Environment Waikato survey of ratepayers confirmed the importance of Lake Taupo in the local economy but not funded at all by local or regional councils.

 

Glenn argued that DoC had all the information they needed on smelt and would not necessarily change their direction but TDC and EW or central Government should still assist.  It is getting beyond DoC's trout management role to have to do research on smelt and the food chain.  NIWA had captured most of the funding form Government in the past.  

 

Advocates could have a useful role to play in helping DoC to attract other funding from Councils.

 

Glenn advised DoC are reviewing smelt monitoring to see what is working and what is not and exploring other options.  The intent over the next few months is to identify the steps - what to persue and what to not.  Then they hope to sit down with Waikato University and other agencies but the size of their plan will be based on available funding.

John advised DoC's website monitoring report on the lake and their analysis is all available.

 

Richard's last question was did DoC know of any instances where trout fisheries were similarly run down and had recovered again.  Michel answered No.  Ross asked what about the improvement using "R" type jacks at Lake Tarawera?  John advised the "R" type came from Tongariro Trout Centre.

 

 

 

Meeting ended about 1.30 pm

 

It was my intention to edit these minutes but feel that they are best left in the format as recorded.

I thank Ross for taking the minutes.

It is important to state that on Thursday 17.7.08 the Taupo Times front page story reported the deteriorating size and quality of Taupo trout with Turangi Tongariro Community Board Chairman and Taupo Mayor Rick Cooper speaking out on the decline in the fishery. That article will be available on our website shortly.

 

Eric Wilson

Secretary/Treasurer