SPECIALIST WATER FERN [azolla] CONTROL SERVICES

OUR SPECIALIST CONTROL SERVICES WILL TREAT OR ERADICATE THIS SPECIES. TO FIND OUT IF YOU HAVE WATER FERN USE OUR FREE ID TOOL OR BOOK A SURVEY

treatment & removal

Water fern (or more commonly called azolla) can be treated with a suitable aquatic herbicide or by manual or mechanical control. Dredging or hand pulling has limited success. As the plant waste is deemed as special ‘controlled waste’ it will need to be taken to a suitably licensed landfill.

More on Water fern control in this blog.

To find out the best way to control or remove Water fern and the best time of year to have treatment or eradication carried out get in touch.

WHY IS WATER FERN A PROBLEM?

Water fern will often require repeat treatments due to its rapid growth rate – it can quickly double it’s population size.

It can also be present in ‘seepages’ such as overflow water from mains drains or rain water run off overfilling waterbodies causing them to seep into other rivers or waterways or backwaters of rivers and streams.

Drinking water quality can be reduced, and farmers have been known to lose animals due to contaminated water-bodies, and drowning due to dense infestations appearing as solid ground.

ABOUT WATER FERN

SCIENTIFIC NAME: Azolla filiculoides
ORIGIN: North & South America

Water fern is a genus of seven species of aquatic ferns in the family Salviniaceae. A floating variety, first introduced as a decorative water plant for garden ponds and aquaria. It has since naturalised, entering lakes and ponds and has become well established in some areas in Northern Ireland. Considered to be of tropical origin; however, it is thought to have evolved a cold-tolerant strain since introduction to the UK.

• Forms small plants around 2.5cm long which can cluster to form a dense mat up to 30cm deep.
• Small leaves consisting of rosettes up to a few cm in diameter, which turn a deep shade of red in autumn and winter.
• Dark brown hair like roots.

HABITAT

Water fern is frequently found in ponds, lakes, canals, ditches and slow flowing rivers.  It thrives in semi-aquatic and aquatic habitats such as swamps, wet woods and shrubs, along streams and riverbanks, lake sides, ponds, boggy and other wet areas. As long as the site is wet, it has no specific soil requirements, can grow in shade or full light.

IMPACT: HIGH

Azolla forms dense mats on the water surface up to 30cm deep with 100% coverage of the water surface, for this reason it is often called Mosquito fern as it is said that mosquitoes are unable to hatch, but can also called Fairy moss. It has economic impact by causing a detrimental effect on the fish farming industry. Mats of water fern on reservoirs and slow-moving water-bodies can also cause economic loss to water facility companies. Azolla alters the pH of water which poses a risk to other native species. It out-competes native vegetation caused by the lack of light penetration, which creates an anaerobic environment and prevents photosynthesis of aquatic plants. It also prevents amphibians and invertebrates from reaching the surface and may disrupt movement of water borne species on the water surface itself.

TOXICITY: LOW

Water fern itself presents no physical danger to either humans or animals, however the effect on drinking water for livestock can be harmful.