Invasive species

Bottom lining is the installation of a flexible covering over the top of beds of aquatic weeds, similar to using weed matting in home gardens. This control method is also called ‘benthic barriers’.

A combination of artificial intelligence and scientific ingenuity looks set to be the next step forward in protecting Aotearoa New Zealand’s lakes and rivers from invasive aquatic weeds.

Diquat is a herbicide (chemical) that has been used in New Zealand for many decades for submerged (underwater) weed control and also on agricultural crops. It is registered for freshwater use in New Zealand.

Submerged plants have a number of advantages that favour their use as indicators of lake ecological condition.

Estuaries are at the bottom of the freshwater drainage network and, effectively, are a part of it. This means that every time we act to protect and enhance streams and rivers we are also benefiting the estuary at the downstream end.

The condition of many NZ lakes is under threat from land-use changes and the invasion of alien aquatic plants.

A summary of the LakeSPI method.

LakeSPI delivers information that is directly applicable to lake-ecosystem conservation and management.

LakeSPI can be used in many ways depending on what the interests or management needs are for a lake.

LakeSPI (Lake Submerged Plant Indicators) is based on the principle that New Zealand lakes can be characterised by the composition of native and invasive plants growing in them, and the depths to which these plants grow.

This is a user guide on non-native fish, reptile, invertebrate, algal and plant species that are recorded in New Zealand freshwaters.