Integrated submerged aquatic vegetation management in an urban New Zealand river

  • Published source details Schwarz A. & Snelder T. (1999) Integrated submerged aquatic vegetation management in an urban New Zealand river. Hydrobiologia, 415, 235-241.


Action: Use cutting/mowing to control problematic plants

A study in 1996–1997 in a lowland river invaded by curlyleaf pondweed Potamogeton crispus in Christchurch, New Zealand (Schwarz & Snelder 1996) reported that over 20 months after cutting and removing aquatic macrophytes from the centre of the channel, cover of native stonewort Nitella hookeri increased. Statistical significance was not assessed. A first cut was made in March (autumn) 1996. Over the following winter and spring, the dominant macrophyte was curlyleaf pondweed (66–98% cover). Stonewort cover was only 0–3%. Total aquatic macrophyte cover was 76–98%. A second cut was made in September (spring) 1997. In the following two months, the dominant macrophyte was stonewort (66–68% cover) with little curlyleaf pondweed (5–22% cover). Total aquatic macrophyte cover was 86–99%. Methods: The study took place in a stretch of the Avon River (maximum depth 1.5 m), in which aquatic macrophytes had historically been cut (twice annually, with weed-cutter boats) across the whole 20-m-wide channel. In March 1996 and September 1997, only the central 10-m-wide strip was cut. Aquatic macrophytes were surveyed at 1 m intervals across the river until November 1997.

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 18

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape Programme Red List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Bern wood Supporting Conservation Leaders National Biodiversity Network Sustainability Dashboard Frog Life The international journey of Conservation - Oryx British trust for ornithology Cool Farm Alliance UNEP AWFA Butterfly Conservation People trust for endangered species Vincet Wildlife Trust