Thursday Update 12/13

Lagarosiphon major. Oxygen weed.


In 1966 Lagarosiphon was first found in the Northern part of Lake Taupo. Within 2 years it had spread around the Lake to the detriment of native aquatic plants.

Lake Kuratau was important as a lake with only native aquatic plants.

Lagarosiphon has now been found in Lake Kuratau.

The probability is that it was transported from Lake Taupo into Lake Kuratau by boat by someone who did not Check Clean Dry.

What is Lagarosiphon?

Lagarosiphon major

Propagation: Vegetative reproduction from fragments. It is a Class B noxious plant and is illegal to cultivate in NZ

L. major is an aquatic, submerged plant that can grow in dense mats up to 2-3 m thick and cause many negative environmental and economic impacts. Some of these impacts include displacing native plant species, decreasing water quality, reducing biodiversity, blocking hydroelectric intakes, impeding recreational activities, and diminishing aesthetic value. L. major is very difficult to control, and its ability to form new plants vegetatively facilitates its spread to new locations. The trade and potential escape of L. major through the aquarium and water garden industry plays a large role in its spread to new locations (Australia Natural Heritage Trust, 2003), as does the transportation of this plant on recreational equipment moving between water bodies (Cronk and Fuller, 1995). L. major is declared a noxious weed in New Zealand (Winterton and Scher, 2007), the United States (USDA-NRCS, 2006), and is on the Alert List for Environmental Weeds in Australia (Australia Natural Heritage Trust, 2003). L. major is already well established in New Zealand and parts of Europe. Other species of the family Hydrocharitaceae also have the potential to become invasive, and Elodea canadensis, Egeria densa, and Hydrilla verticillata, have been recorded as problematic outside of their native range.

How easy was it for this illegal weed to move from Lake Taupo to Lake Kuratau.

Didymo is this easy to move to Didymo free water.

Every Freshwater angler must have a license, A Taupo Fishery Licence for the Taupo Fishery or a Fish and Game License for the rest of New Zealand. In both cases there is a clear message stating the risk. There is no excuse for failing to observe CHECK CLEAN DRY

Eric Wilson