Invasive species survey & control: Quagga Mussels

The client: Affinity Water

The site: The site consists of a reservoir surrounded by areas of grassland, scrub, woodland and reedbeds which are managed by the Herts and Middlesex Wildlife Trust. The reservoir is approximately 0.45km2, there is a water tower structure and dam wall on the west side.

The brief: To determine whether Quagga Mussels where extant in the reservoir before a statutory scour test was undertaken.

Our solution: Maydencroft was commissioned to survey the reservoir, the survey utilised an underwater drone that was remotely controlled. The drone had a built-in camera streaming live footage to a laptop viewed onsite. It was positioned to film the surface of underwater structures in great detail.

The result: A total of 65 minutes of footage was recorded and analysed for any evidence of Quagga Mussels. The survey identified no evidence to suggest that Quagga Mussels were present within the reservoir. Visibility of the water tower and scour valve were good however, visibility of the dam was not optimal. This outcome will allow Affinity Water to undertake the scour test without risking the introduction of Quagga Mussels to the wider environment. Maydencroft recommended periodic monitoring of the reservoir to ensure infestations are dealt with at the earliest opportunity.

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