Lake weed can be blown to the lake edge, where it rots and causes a stink like in February. Photo / Andrew Warner
More than 30 of New Zealand's leading scientists, government department officials and Rotorua decision-makers will meet next month in a bid to eradicate lake weed after years of the pest species damaging lake health and attractiveness.
Lakes Water Quality Society has advocated for lake health restoration and protection for nearly 50 years and chairman John Gifford said it was hosting the two-day symposium next month.
Topics covered will include lake water quality, threats from climate change, catchment management options and new policy tools.
Speakers included leading scientists, government department officials and Rotorua decision-makers.
In Gifford's eyes, one of the most important topics to be covered was lake weed, which he said the society wanted to see more action on in terms of eradication.
He said there was a "major" issue with pest lake weeds in many of the lakes which caused issues for recreation, weed rafts blew ashore and created nuisances, lowered the lake shore amenity and also limited habitat for native plants.
Each of Rotorua's lakes had an aquatic plant management plan and Gifford said, through council and iwi work, there had been examples of success.
Herbicides were one of the present strategies, as well as uwhi, harakeke flax mats. Other Te Arawa-led mahi (work) included its Te Arawa Catfish Killers and Te Ngaki Otaota, its aquatic weed management programme.
Solutions would be sought at the symposium for "accelerating" that success and finding control and intervention strategies that would make invasive weed eradication more achievable.
There were a lot of benefits to eradication, he said. While the council did a "pretty good job" at keeping the lakefront clear, it was a "never-ending job" until eradication became more achievable.
While Land Information New Zealand is responsible for weed management in the beds of the Te Arawa Lakes, Bay of Plenty Regional Council Rotorua catchments manager Helen Creagh said it worked with Te Arawa Lakes Trust and Rotorua Lakes Council to remove weed wash-ups in public access areas such as the Rotorua Lakefront.
The regional council had a budget of $55,000 available annually for this, although this was infrequently totally spent, she said.
Creagh said the symposiums were a fantastic opportunity for the community to learn about the challenges and opportunities for the management of the ecology and water quality of the lakes, be informed and contribute to that.
Te Arawa Lakes Trust chairman Geoff Rolleston said the lake's system was reflective of the Te Arawa identity, "because we share whakapapa or genealogy and fundamentally is our intrinsic connection to these mega water systems".
As the trust neared its centenary, he said it had collected evidence to prove this, through mātauranga Māori, pūrākau, waiata, whaikōrero, stories, observations and learnings which he said will always serve as a base for innovative solutions to the lakes' complex conditions.
Te Tūāpapa o Ngā Wai is one of its strategic solutions, its Te Arawa cultural values framework, and was an enabler of the work it was doing in the restoration and preservation of our lakes, he said.
The work could not be done alone, however, and he said for the lakes' system to thrive. it needed, as an entity, to bridge the gap between policy and community to ensure whānau and hapū voices were heard and the health and wellbeing of its rotomoana (rivers, lakes, streams) was reflected in the engineering of the lakes' mega system.
The community is invited to attend the symposium. It is on November 10 and 11 at the Millennium Hotel from 8.30am.