Skip to main content

Story: Water quality

Lagarosiphon

Image
Lagarosiphon

A serious concern in South Island lakes, and widespread in the North Island, Lagarosiphon major is an aggressive water weed. The stems grow up to 5 metres long. Stem fragments are the main means by which the weed spreads. The small fish is about 5 centimetres long.

Using this item

NIWA – National Institute of Water and Atmospheric Research

by John Clayton

This item has been provided for private study purposes (such as school projects, family and local history research) and any published reproduction (print or electronic) may infringe copyright law. It is the responsibility of the user of any material to obtain clearance from the copyright holder.

All images & media in this story

How to cite this page

Mike Scarsbrook and Kit Rutherford, Water quality – Problem plants and microbes, Te Ara – the Encyclopedia of New Zealand, https://teara.govt.nz/en/photograph/15528/lagarosiphon (accessed 4 June 2026).

Story by Mike Scarsbrook and Kit Rutherford, published 1 March 2009, updated 18 July 2016.