Proactive management of aquatic weeds to protect the nationally important Northland dune lakes, New Zealand

摘要

Northland dune lakes are of national significance, with many having good water quality. Perhaps the most outstanding character of these lakes is the current limited impact of invasive species on their native biota. However, invasive aquatic weeds arestead-ily invading and having major impacts on their ecology. This paper presents a proactive lake management strategy that involves the identification and protection of lakes with highest ecological value. Key components of this strategy include targeted weed surveillance of high use areas, weed spread prevention and targeted weed eradication of the worst weed species in order to protect adjacent high value lakes. Progress to date includes 1) the detection of weeds during surveillance activities whilein the very early stages of invasion, thus allowing successful eradication and 2) three lake-wide eradication programmes resulting in the expected eradication of target weeds, with restoration of indigenous vegetation resulting from selective herbicide use.