Aquatic Weed Control

Scientific Name: Lagarosiphon major 

Description: Lagarosiphon is a rhizomatous, perennial, submerged aquatic herb with spiralled leaves on slender to almost woody stems. It has tiny pink flowers in summer. The leaves of Lagarosiphon curl right back on themselves.

Problem: Lagarosiphon is currently found in several South Island Lakes including Lakes Dunstan, Benmore and Wanaka. It forms dense beds that smother other aquatic vegetation and often becomes surface reaching. Lagarosiphon can inhibit recreation activities such as swimming, fishing and will often cause difficulties with boat launching. Large rafts of Lagarosiphon can break off from wind and wave action and wash up onshore. As it dries this can become smelly and unsightly.

HORNWORT 

Scientific Name: Ceratophyllum demersum 

Description: Hornwort is a submerged freshwater weed found in still and flowing waters, growing to depths of 16 m in clear deep lakes. Leaves are finely divided, with minute teeth which make the plant feel rough to the touch. It lacks roots but has modified leaves that anchor the plant in bottom sediments. 

Problem: Hornwort is currently found in many North Island areas but thus far has been prevented from establishing in the South Island. It forms dense beds that smother other aquatic vegetation and usually becomes surface reaching in summer/autumn before dying back again over winter. Hornwort can inhibit recreation activities such as rowing, waterskiing, kayaking, swimming, fishing and will often cause difficulties with boat launching. Hornwort will interfere with hydro electric turbines and causes major disruption to electricity generation. Large rafts of Hornwort can break off from wind and wave action and wash up onshore or float down to infest downstream aquatic areas. As it dries it can become smelly and unsightly. 

AERIAL SPRAY OPERATIONS

Amuri Helicopters is one of New Zealands most experienced helicopter companies and has been carrying out aerial operations to control Aquatic weeds for over 10 years. Operations are conducted under rigid criteria to ensure high levels of personel, public, aircraft and environmental safety. 

Techniques are employed to ensure maximum herbicide/weed contact times to optimise results. Modern equipment is used to identify treatment areas, apply herbicides, provide pilot guidance for accurate placement and record placement and lake conditions.