The Solent Forum

Working in partnership for the future

Biosecurity Pathway: Recreation


The Solent is a hotspot for recreational boating and watersports, people participate in a wide range of activities and there are numerous competitions and events. Recreation can be either more formal, for example from a sailing club, or can be people just coming to the coast with their own craft like paddleboards and windsurfers.

Boats and watercraft can spread invasive species via hull fouling and/or by the transport of plant fragments, seeds, eggs, larvae, juveniles and adults in small gaps or water-retaining niches on kit, craft or in equipment (e.g. boat propellers, trailers, wetsuits) and within bilge water.  The carpet sea squirt (Didemnum vexillum) which is found in the Solent, can attach to boat engines, propellers and vessel hulls affecting performance and damaging parts. Spread risk is increased by watercraft that move outside of their 'home' area such as yachts cruising to other harbours or windsurfers being used for events that take place at multiple locations. Please refer to our marine invasive species information page for specific species of concern in the Solent.

The risk of a boat hull becoming a host for marine invasive hull colonisation depends on the length of time it is kept in the water, please see our page on the fouling cycle for more information. 

An effective and least damaging approach to removing marine fouling organisms is to dry smaller craft by removing them from the water (see RAPID LIFE project). Complete mortality can be achieved within a few days in dry, hot (or very cold) conditions, although species normally adapted to survive in the intertidal or in sediment can survive in dark crevices, or mud adhering to the hull, for longer if the weather is damp and cool. For this reason drying moorings, used by many recreational boats, offer some protection against marine invasives but are not totally effective. If boats can be removed from the water seasonally, over winter or when not in use for example, this is sufficient to kill off all attached marine growth. Boat stacks provide this service.

Boating Events

Events and competitions that require biosecurity measures are those that have participants arriving from outside the locality bringing in vessels or watercraft and external equipment. Solent based competitors should also take biosecurity measures such as Check Clean Dry when going to other locations to compete to stop the spead of invasives found in the Solent to other locations.

Guidance has been designed to help event organisers develop a simple biosecurity plan which works for a variety of marine events such as rallies, races and maritime festivals and at scales ranging from a small dinghy racing event up to international regattas such as a tall ships event. It explains what you may need to consider and simple actions that can be taken. The NNSS has guidance and resources for waterside events in a variety of different languages for paddling, angling and boating.

The Green Blue has produced a sustainable boating event checklist which provides an excellent resource for event managers including information on biosecurity measures.

The Green Blue Sustainable Boating Event Checklist Guidance

• Advertise your event as welcoming clean hulls and ask all participants to clean their boats and trailers before arriving on site.
• Ask all participants to ensure their antifoul is fresh and effective.
• Circulate information to all participants about issues relating to invasive non-native species and the threat they pose to boating.  Include biosecurity in contracts to any external contractors. For example all equipment arriving on site must be clean including pontoons and other in-water structures.
• Create a biosecurity plan for your event that includes procedures in the event of a fouled vessel arriving on-site.
• Set up a wash – down area, and promote its location to attendees, to use to clean their boats and equipment before leaving the site.
• Provide INNS information to an eco-champion and encourage them to monitor biosecurity throughout the event.

Hull Pressure Washing

By the stage pressure washing is required, a hull is likely to be extensively fouled so containment and good biosecurity practice is needed to stop the fouling debris going back into the water and potentially causing invasive spread.  This risk is increased if the vessel comes from a location outside of the Solent. Wash water collection mats can be used at smaller sites where limited pressure washing takes place and for busy, bigger sites wash water recycling systems are available. These process the water through a sand filter to a reuse tank or discharge back to the marina or sewer. Although not primarily designed for marine invasive spread management, these systems will prevent spread in addition to their primary use for pollution prevention.

Case studies: Boat wash-down water recycling

Beaulieu River Management has installed a filtration system from Bywater Services, this is a closed bay with a drain at the end and a large sump under the concrete pad that stores used water. The system is a closed loop, filtering any used water for re-use, no water from washing the boats goes back into the river. An added benefit is reduced water consumption for the pressure washer.

Premier Marinas installed a closed loop system on the River Dart which collects all debris and water run-off, this is filtered through a three stage filtration system and recycled. The FiltaBund system is able to deal with copper, zinc, marine debris, silt and various proprietary additives. The process starts by removing large marine debris and paint flakes through bag filtration, followed by coagulation and settlement of free-floating particles. PH is then adjusted to precipitate soluble copper and zinc and the resulting cleansed water is passed through an activated carbon bed to remove trace elements. Water is also dosed with hydrogen peroxide and treated with UV light to kill residual bacteria. Premier Marinas has commissioned FiltaBund to retrofit a wash down system at Chichester Marina.

Kit and Equipment

Fouled rope and buoy

Kit and equipment that is used between multiple sites by watercraft users, contractors or site visitors has the potential to spread marine invasives. Species can survive for up to two weeks in wet kit and clothing and longer in equipment with water filled niches. The Check Clean Dry Campaign has lots of practical advice on how to ensure that kit and equipment does not become a pathway for invasives spread. 

The key messages are:

  1. Check your equipment and clothing for living organisms after you enter the water
  2. Clean all equipment, clothing and shoes before after leaving the water and rinse in freshwater
  3. Dry all equipment and clothing carefully

Clean your wellies and waders

The Non Native Species Secretariat recommend cleaning footwear like waders, wellies and sailing boots by scraping any debris on the bottom into the bin, cleaning with freshwater (ideally hot water for 15 minutes) and then drying to make sure no invasive species can survive. There is Check Clean Dry information available for field workers including free online training.

Washdown Stations

To prevent the spread of invasive species, washdown stations can be installed near bodies of water. These stations allow water users to clean their watercraft, kit and equipment before launching them into a new body of water, reducing the risk of spreading invasive species. They typically consist of a pressure hose (ideally hot), disinfectant dip tank, boot brushes and a means to contain the water used so it doesn't drain back into the water environment. If a cleaning station is not available then kit and clothing should be bagged up and cleaned back at home.


Live Bait

Live bait can contain marine invasive species, so please use carefully and do not dispose of unwanted bait in the water. If you find something unexpected in your bait please do not use it. The Check Clean Dry campaign has lots of great resources for anglers.


Marine litter can pose a significant risk in spreading invasive species. It can travel vast distances through ocean currents, transporting invasive species to new locations. Invasive species often attach themselves to floating debris as a means of dispersal. They can use litter items like plastic bottles, buoys, and even abandoned boats as rafts, which help them survive longer journeys across oceans. It is important for recreational participants to take litter home or dispose of in appropriate receptacles to minimise this risk.

Biosecurity Actions

Please refer to our biosecurity action plans on how you can help to control and prevent marine invasive species spread for this pathway.

The Green Blue have produced a great video that gives an overview of developing a biosecurity plan for marinas and boatyards.

Recreation Pathway Biosecurity Resources