An image of a trumpet tube worm growing on a discarded boat line

A trumpet tube worm (Ficopomatus enigmaticus) in high abundance growing on a discarded boat line

The management of marine INNS can be particularly challenging because of the environment they are found in, but early detection at the point of introduction can provide the evidence for rapid response to the new introduction, preventing the risk of further spread and potentially eradication.

Rather than just using a species-based approach to marine INNS, APEM recommends pathway management and rapid assessment as the key foundation points for effective actions.

Our best practice approach

APEM - invasion process

A simple invasion process

Prevention and biosecurity

Preventing introductions is considered the most cost-effective method of limiting the spread of INNS and the only opportunity to limit the introduction of new species. INNS are difficult to manage post-introduction, especially in the marine environment, so prevention, in this case, is preferable to attempting eradication of an established INNS. Preventing introductions from occurring is normally achieved through the application of biosecurity measures, to limit the risk of INNS from moving along a pathway, for example, the application of Check, Clean, Dry, hull cleaning or ballast water management. However, biosecurity can also be applied to contain INNS, preventing their further spread and establishment elsewhere.

For marine licence applications, an overall site biosecurity plan should be in place, with an operations biosecurity plan for time-limited projects such as construction works. Biosecurity plans include risk assessments and recommended management measures to control risk, and are vital for the application of best practice, effects on performance and operations, policy and legislation compliance and demonstration of appropriate mitigation for Environmental Impact Assessments (EIAs).

APEM has extensive experience in the development of biosecurity measures plans for a wide range of sectors, including marine industries. We combine a process of appraising suitable options in relation to efficacy, capital and operational costs in addition to environmental impacts in order to present the most suitable measures to our clients in a final plan. Plans can cover actions in relation to identified pathways or specific INNS depending on client needs.

Monitoring and early detection

Identifying what INNS may be present at a location is an essential part of the process of understanding risk and developing relevant management actions. These may be species that have already become established or ones that have only recently arrived. While the detection of either can assist with the identification of relevant pathways, actions in response to established or new introductions may differ, for example, long term containment or rapid response.

The team at APEM is at the forefront of the identification of marine INNS. For example, we are currently engaged by a large port authority to analyse marine ballast water samples for INNS in relation to the implementation of local ballast water management policies, as well as conducting environmental surveys to evidence effectiveness. This neatly illustrates the applied approach to the development and delivery of our marine INNS monitoring programmes.

Members of the INNS team have been involved in developing and conducting extensive marine INNS monitoring and surveillance programmes in the UK and Europe, including the use of Rapid Assessment Survey (RAS) methods. RAS involves surveying large areas by employing a semi-quantitative approach where target species are recorded on an abundance scale during timed searches of specific habitats. This requires the surveyors to make observations of growth on the sides of hard structures, such as floating pontoons. This approach is the essential first step in understanding the scale of an issue in port and marina environments, before further actions are taken.

The RAS method has been used in marinas around the world to record and map non-natives and document new arrivals. However, to ensure as robust results as possible, APEM’s specialists utilise a wide range of methods for INNS detection including:

  • Settlement plates
  • Trawl sampling
  • Scrape sampling
  • Intertidal core sampling
  • Grab sampling
  • Zooplankton and Phytoplankton sampling
  • Qualitative – citizen science
  • Crab/lobster traps
  • ROV and underwater camera systems

We can also develop bespoke methods based on individual client needs, environmental conditions, etc. Contact the team for more information.

To complete the picture, APEM offers physical and environmental surveys and ongoing environmental monitoring programmes, with a review of already-present INNS recorded from desk-based studies and surveys. APEM provides marine monitoring programmes for all site sizes, budgets and locations, from hydrographic surveys, water sampling strategy and taxonomic analysis covering seasonal changes, physical sampling with settlement panels and cores, molecular methods including analysis of eDNA and DNA, to assessment via remote aerial surveys.

Identifying risk


Non-native sea squirts attached to hull of boat, meaning they can be transferred into other water bodies

Identifying and understanding the key risks, both in relation to particularly damaging INNS and pathways by which they can be introduced and spread is essential in the development of targeted management plans.

We have extensive experience in the use of mapping in the context of INNS management, linking the outputs from our monitoring programmes to the visual representation of the spatial and temporal (where relevant) distribution of species. This helps us to identify hot spots where specific actions may be required to control established species or take rapid action to remove recently introduced ones.

We also undertake detailed assessments of pathways that may lead to the introduction and spread of INNS. This coupled with the monitoring data and spatial mapping of INNS can further assist in the development of biosecurity plans focused on those pathways that present the greatest immediate risks. Pathways can be tracked from bridgehead regions (where organisms are already established) to detect and prevent the release of INNS into new waters.

In addition to identifying current risks, we also examine potential future risks with the aim of preventing further introductions from occurring. We do this in two primary ways, examining how pathways of introduction and spread may change over time, and by examining horizon INNS. Horizon INNS are those not currently present at a particular site but which could be introduced in the future. We examine horizon INNS at a regional and national level to provide a comprehensive overview of future risks.

Working together

APEM’s specialist teams work seamlessly to provide the most cost-effective, suitable solution with reliable results. By having all the expertise under one roof we can quickly provide solutions. For example, our marine taxonomic experts in our BioLabs work closely with the marine INNS specialist to positively identify INNS present and assess potential pathways. This blend of integrated services is unique to APEM in the UK and Ireland and is often cited as a reason why clients work with us again and again.

An image showing the Stop the spread process

It’s not all about the scientists, however. Citizen science plays a part in both monitoring and preventing the spread of INNS. You can help by recording and reporting INNS in marinas and docks, or by taking part in the non-native species secretariat’s Check Clean Dry initiative to limit the spread of INNS by cleaning contaminated clothing, fishing equipment and paddleboards. APEM offer on site and virtual training and workshops on non-native species identification – find out more.

We have extensive experience with marine INNS, having conducted risk assessments as part of the UK horizon scanning process as well as conducting in-depth species-specific risk assessments. We have been involved in developing standardised risk assessment tools for pathways and horizon species.

APEM support our clients from planning and surveying through to implementing biosecurity plans and ongoing monitoring. To find out more about our projects, laboratories and results, click here.


Related posts

More about us

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