Our Northland - Tõ Ttou Taitokerau Our Stories and updates on the great work happening around the region to help our environment, economy and people thrive. Brought to you by Northland Regional Council. Freshwater Improvement Fund helps eradicate aggressive aquatic weed A New Zealand-first operation saw an entire Northland dune lake treated with a herbicide in September of this year. Northland Regional Council staff are optimistic that the operation has been successful in helping to eradicate an unwanted oxygen weed. Lagarosiphon major was causing issues at 56-hectare Lake Ngatu, northwest of Awanui. This invasive plant smothers native plants, affects food and shelter for fish and other wildlife and can make recreational activities like boating and swimming difficult. Biodiversity Advisor Dylan Smith says after thorough research, consultation and monitoring. it was decided that a full-lake treatment (using roughly 7000 itres of the herbicide called Aquathol K, a derivative of Endothall) would be the most effective way of eradicating Lagarosiphon major from Ngatu. Lake Ngatu is home to a number of important native species including the longfin tuna (een Photo credit: Irene Middleton, Seacologynz.com lake as they rot. (In this case, the risk was much The operation is part of the council's commitment less likely because there wasn't so much weed It would have caused big changes to the lake's water chemistry once it started dying) Mr Smith says Endothall is a 'highly selective herbicide that only targets select species, to proactively protect freshwater against aquatic pest plants and future threats, says Deputy Chair Justin Blaikie, who also heads the council's Water including Lagarosiphon major. The herbicide spares native plants, is non-toxic to fish and aquatic invertebrates and the water can be safely a Rotorua-based contractor in September, with used again within a relatively short timeframe; typically several days. The operation was undertaken by airboat through and Land Working Party. involvement from Northland Regional Council, the Department of Conservation and NgaiTakoto Kaitiaki Rangers. "The success at Lake Ngatu builds on our knowledge of the issue, and it means we have a solution to the problem of Lagarosiphon major at Lake Ngatu and Targeting the lake's oxygen weed problem this way was a national first as the Environmental Protection Agency (EPA) only allows quarter lake treatments to avoid the potential for large volumes the native plant community was thriving but the of dead pest plants lowering oxygen levels in the pest plant had died off significantly. A dive survey 15 days after the operation showed anywhere else it's found," he says. The Ngatu operation was carried out as part of a shared fund with the Ministry for the Environment from their Freshwater Improvement Fund (FIF). PLANTING AT LONG BEACH Over winter, Russell Landcare Trust has continued dune restoration work at Long Beach. Since 2010, CoastCare and Russell Landcare Trust have been working with residents and school pupils, reshaping and planting the dunes, providing access and controling weeds. This year's focus was on maintenance with weed control and infil planting in the dune restoration area. Russell School joined in and got stuck in to the very important task of weeding! Thank you everyone who got their hands dirty! Our Northland - Tõ Ttou Taitokerau Our Stories and updates on the great work happening around the region to help our environment, economy and people thrive. Brought to you by Northland Regional Council. Freshwater Improvement Fund helps eradicate aggressive aquatic weed A New Zealand-first operation saw an entire Northland dune lake treated with a herbicide in September of this year. Northland Regional Council staff are optimistic that the operation has been successful in helping to eradicate an unwanted oxygen weed. Lagarosiphon major was causing issues at 56-hectare Lake Ngatu, northwest of Awanui. This invasive plant smothers native plants, affects food and shelter for fish and other wildlife and can make recreational activities like boating and swimming difficult. Biodiversity Advisor Dylan Smith says after thorough research, consultation and monitoring. it was decided that a full-lake treatment (using roughly 7000 itres of the herbicide called Aquathol K, a derivative of Endothall) would be the most effective way of eradicating Lagarosiphon major from Ngatu. Lake Ngatu is home to a number of important native species including the longfin tuna (een Photo credit: Irene Middleton, Seacologynz.com lake as they rot. (In this case, the risk was much The operation is part of the council's commitment less likely because there wasn't so much weed It would have caused big changes to the lake's water chemistry once it started dying) Mr Smith says Endothall is a 'highly selective herbicide that only targets select species, to proactively protect freshwater against aquatic pest plants and future threats, says Deputy Chair Justin Blaikie, who also heads the council's Water including Lagarosiphon major. The herbicide spares native plants, is non-toxic to fish and aquatic invertebrates and the water can be safely a Rotorua-based contractor in September, with used again within a relatively short timeframe; typically several days. The operation was undertaken by airboat through and Land Working Party. involvement from Northland Regional Council, the Department of Conservation and NgaiTakoto Kaitiaki Rangers. "The success at Lake Ngatu builds on our knowledge of the issue, and it means we have a solution to the problem of Lagarosiphon major at Lake Ngatu and Targeting the lake's oxygen weed problem this way was a national first as the Environmental Protection Agency (EPA) only allows quarter lake treatments to avoid the potential for large volumes the native plant community was thriving but the of dead pest plants lowering oxygen levels in the pest plant had died off significantly. A dive survey 15 days after the operation showed anywhere else it's found," he says. The Ngatu operation was carried out as part of a shared fund with the Ministry for the Environment from their Freshwater Improvement Fund (FIF). PLANTING AT LONG BEACH Over winter, Russell Landcare Trust has continued dune restoration work at Long Beach. Since 2010, CoastCare and Russell Landcare Trust have been working with residents and school pupils, reshaping and planting the dunes, providing access and controling weeds. This year's focus was on maintenance with weed control and infil planting in the dune restoration area. Russell School joined in and got stuck in to the very important task of weeding! Thank you everyone who got their hands dirty!