Weed & Algae Control

Potamogeton natans

Potamogeton natans

Weed and algae control

AES Europe Ltd has a wealth of experience in a range of methodologies to control nuisance aquatic weeds and algae.

A lily strewn lake

A lily strewn lake

Herbicides

We have consultants that are certified in the care and use of pesticides and particularly in application to water.  Although recent European legislation has necessitated the banning of the majority of synthetic herbicides, some remain. We are well placed to handle all official consents required and find a way forward.  We stress, however, that the use of synthetic herbicides should remain a last resort.

Cutting

We are equipped with modern, robust, boat-mounted weed cutting apparatus which will make quite short work of any rooted water weeds.  Although only a temporary fix, sometimes this is all that is required so please do contact us with details of your situation if you would like a quotation for weed cutting.

Our weed cutter with 1.3 meter blade

Our weed cutter with 1.3 meter blade

Biomanipulation

We have been conducting trials with native fish species to compliment the existing published literature on which fish species may offer the best benefits in controlling rooted weeds.  In fact, the results of our trials are not quite what we expected but it all helps to enable us to refine our recommendations.  There are no directly herbivorous native fish species and even the non-native grass carp has only a 26% vegetation diet, so results hinge on selecting the best species and balance to disturb the lake bed without causing excessive turbidity (as will certainly be the case if common carp are stocked).

Similarly, biomanipulation can have important benefits in the control of unicellular green algae.  Zooplanktivorous fish species, in excess, will feed heavily on the important “primary consumer” level of the lake’s food chain, allowing single-celled algae to flourish.  So the carefully planned stocking or encouragement of predatory fish, or the sensitive reduction in stock of zooplanktivores, can both bring about huge benefits (please see our page on Fisheries work).  It is startling how often excessive algal growth can be related directly back to overstocking with one fish species or another.

 

Other methods of algal control

Staff of AES Europe Ltd have supplied and installed ultrasonic algal control apparatus with varying results: in some instances, the benefits have been immense and customers delighted.  In other cases, results have been disappointing and we are unable to determine the factors which lead to either result.  Regardless of this, if you have faith in ultrasonic algal control and wish us to advise on the most appropriate units and positioning, then please contact us.  As part of a consultancy package, we can bring our experience to bear and offer you the best advice available, plus we can put you in touch with the manufacturers of the most reliable apparatus.

A better approach, in our opinion, is the control of the factors which cause algal blooms in the first place and this is where our consultancy packages offer the most comprehensive answers.  In most cases, an excess of nutrients will be implicated but these can have many and varied sources.  Cutting off the supply of nutrients to algae is key to reducing populations but do please remember that algae are a critical part of the food chain in most waters and so a lake with NO algae will probably be barren and devoid of life.  Limitation, not elimination, is what is usually required.

To show our capabilities here are some previous projects completed by our consultants:

  • Large scale removal of  feral goldfish from a Sussex pond to reduce the presence of blue-green algae
  • Weed removal by hand on a Cambridgeshire stillwater
  • Eradication of non-native Lagarosiphon from a Cornish lake using an approved herbicide
A Cornish Lake with excessive weed growth

A Cornish Lake with excessive weed growth

  • Algae prevention on an inner city London lake using a combination of Siltex, aeration and ultrasonic control
  • Weed eradication on a small lake in the North Yorkshire Moors using an approved herbicide

    Lagarosiphon infestation

    Lagarosiphon infestation