Invasive non-native species (INNS) have negative impacts on ecosystem services and are a major contributor towards biodiversity loss. As such, their spread poses a threat to species and habitats within designated protected areas in England. One of the most cost-effective actions that can be taken in relation to INNS is to prevent their introduction and spread from occurring in the first instance.
To focus on prevention, the pathways via which they can spread must first be identified. With respect to dredging operations, these pathways include the vessels and equipment used which could introduce INNS to the dredging site if imported from elsewhere, and to the disposal site when dredged sediment is moved. The potential pathway of dredged material during dredging operations has received little research and regulatory attention. This review was therefore commissioned to help fill this evidence gap.
Natural England were keen to understand the survival rates of species from dredging activity and through disposal, particularly for coastal inshore beneficial use / beneficial placement disposal sites as well as understand the subsequent (if any) risk to the marine environment.
The review outlines all the conditions which influence whether INNS will be transferred and survive during dredging and disposal operations and discusses the level of risk that this may pose. A key set of recommendations are outlined. The review drew upon literature, interviews with industry representatives and authors’ expert knowledge.
The information where appropriate is aimed at helping to inform Natural England’s advice to regulatory bodies and conversations with industry.