Mayoral Speaker Forum & Lakeswater Quality Society Scientific Symposium 2017

The 10^th Symposium will deal with “Catfish, Lakeweeds and Nutrients – Complex Lake Systems Restoration”, and will be held Thurs 31st August –  Fri 1st September 2017, at the Millennium Hotel, Rotorua. The symposium will also integrate with the Annual Mayor’s Speaker Forum (5.30pm-6.30pm Thurs 31st Aug) featuring Sir Rob Fenwick (NZ Business Hall of Fame inductee) and Mr Rod Oram (Investigative Journalist and Environmentalist). The two-day symposium registration (incl. day catering) is $250, or $100 for LWQS Members and students.

Presentations will focus on the following topics:

• Effects of invasive pests (plants, fish and animals) on water quality, freshwater habitat and catchments, in particular, the effect of recent catfish incursions;

• Control measures for invasive pests;
• Freshwater and lakeswater quality management strategies (including nutrient management, lakeweed control and lake restoration planning);
• Understanding the value of freshwater resources and how we might fund restoration programmes;
• The politics of freshwater management and how the community needs to be involved;
• The role of local community organisations in effecting change.

[ Catfish are a serious threat to local waterways and lakes; they stir up sediment and prey on small native fish and fish eggs, and are known to eat and compete with koura (native freshwater crayfish). The brown bullhead catfish is well-established in Te Weta Bay, Lake Rotoiti but only low numbers have been found elsewhere in the lake. A pest-fish containment cordon has recently been installed across the Te Weta Bay entrance, and population control measures have been implemented. Dr Lindsay Chadderton is an international expert on the use of environmental DNA for the detection of pest fish; the biochemical analysis of water samples can be used to detect the presence of specified species.

Land-based pest animals such as wallabies destroy the native bush understory and predispose to increased surface erosion and nutrient runoff to lakes and waterways. Control strategies will be discussed at the symposium, along with the recently announced “Predator Free 2050” programme which aims to rid New Zealand of opossums, rats and stoats by 2050 as a New Zealand-wide goal. It will require new techniques and a co-ordinated team effort across communities, iwi, and the public and private sectors. Predator Free 2050 will deliver huge benefits across New Zealand – for the social and cultural links with our environment, for our regional economies through primary industries and tourism, and for our threatened native species. Dave Hansford (Investigative Journalist and author of “Protecting Paradise”) will share his insights on methods of pest control.

Exotic lake weed incursions have been a problem in Rotorua Te Arawa Lakes for many years. The Lakeswater Quality Society was in fact originally established as the Lake Weed Control Society some 50 years ago. Lake weed is actually more of a problem in better quality water; enhanced light penetration in clean water allows the proliferation of weed. Diquat spray has been used for many decades as an occasional control measure, but newer chemicals such as Endothall are proposed for trial. Low oxygen levels in bottom waters can result in the release of nutrients from lake sediments. One of the issues which requires better understanding is the impact of decaying lakeweed upon oxygen levels in bottom waters.]

For more details please refer:

LakesWater Quality Society Website: www.lakeswaterquality.co.nz
Facebook: www.facebook.com/RotoruaLakesWaterQualitySociety
or contact Warren Webber, wwebber@outlook.co.nz, mobile 027 478 7758