pathways to spread

An ounce of prevention is worth a pound of cure

There is an increasing emphasis on preventing introductions and spread of INNS as the most efficient and cost-effective management approach. Understanding the risk which specific pathways present in the dispersal of INNS is an essential step in this process. A pathway in this context refers to a method by which organisms may be dispersed, such as transport by human activity, passive dispersal, or active movement. Human activities can aid in the dispersal of INNS, for example by organisms hitchhiking on angling equipment to being caught in propellers of boats.

Order, order!

Pathways that present the highest risk of transferring INNS have been identified by the GB Non-Native Species Secretariat (NNSS). Key pathways include, hull fouling, escapes from horticulture, ballast water, fishing equipment and hitchhiking on aquaculture animals. Additionally, the movement of raw water has been identified as a pathway of concern. Raw water transfers, where untreated water is moved between locations to ensure water demand is met, occur between many locations in the UK, such as between reservoirs and rivers, while taking a wide variety of forms, for example pipelines and canals. While raw water transfers have been identified as a high-risk pathway in general terms, which of the many transfers are in the most need of management to reduce the risk of moving INNS?

Who’s first?

APEM’s INNS team has developed risk assessment tool kits and processes to risk rank pathways under a variety of different circumstances. For example, we have a tool kit specifically designed to rank raw water transfers according to risk by quantifying different parameters of the pathway, such as if the transfer occurs between or within catchments, the types of transfer (e.g. pipeline or canal), how long it is and how often it is used. The tool kit takes this information and through a series of calculations provides a single score as an indication of risk. This score can then be compared with those calculated from the assessment of other transfers and then ranked, thereby ordering the assessed transfer from highest to lowest risk. Similarly, we have tools where we can quantify a broad range of pathways relating to a specific location, such as a reservoir or port, and the risk they present collectively. This allows us to provide information to clients on how ‘at risk’ from INNS a location may be, how this compares to other locations, and which activities may be contributing to the risk. We can even apply this process pre-emptively to sites which have yet to be constructed, so that activities which may present a risk of INNS introduction can identified. Our risk assessment tool kits and processes are designed to be transparent, easy to interpret and accessible to the non-expert.

Actions speak louder than words

Once those pathways that presented the greatest risk have been identified and ranked, this information is used to inform on the development of biosecurity plans. Having been involved in the development of current biosecurity practices, along with our extensive experience of providing advice and implementing biosecurity for a range of clients, our INNS team is ideally placed to provide specific and evidence-based advice on the most appropriate measures to implement. This advice is usually provided in the form of a bespoke options appraisals where a range of potential actions for the management of the pathway or pathways are identified and their applicability to the specific circumstance examined. From the options appraisal we then develop a biosecurity plan aimed at reducing the risk the pathway(s) present. This process allows us to work closely with the client to build a plan which is effective but also realistic in its application.

If you would like to know more about APEM’s approach to INNS and how we can support you where you need it please visit our INNS page. Alternatively, please contact or contact Dr Paul Stebbing, Aquatic Non-Native Species Specialist to directly discuss your requirements.

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APEM are a global environmental consultancy providing independent advice and guidance to support government and environmental regulatory guidelines.