3 June 2017

Biosecurity - doing your bit!

As keen naturalists, how many of us think that by roaming the countryside we might be doing more harm than good? With high profile diseases such as Chalara dieback of ash, and if you are old enough to remember, the foot-and- mouth crisis of 2001 many people are more aware of the concept of biosecurity.

In Scotland we have great outdoor access laws and you can pretty much roam as you wish as long as you do so responsibly. This is where an awareness of biosecurity comes in.

It is everyone’s responsibility to take proportionate measures to minimise the risk of transmitting pests/diseases onto or off any sites that they visit!

Professional ecologists will be well aware of biosecurity and carry specialist equipment. But for citizen scientists and amateur naturalists there doesn't seem to be a lot of information floating around on this increasingly important area. For many volunteer surveys you will be issued with a specific set of instructions for health and safety; ALWAYS read these!

I will not dwell on the intricacies of biosecurity here, that's what the links in the sections are for. I will instead want to ensure you are aware of the concept of biosecurity, how what you do relates to it and give you some simple instructions on how you can avoid spreading things around!

Among what can be spread are;

  • seeds and regenerating vegetative parts, especially from Invasive Non-Native Species (INNS) such as Himalayan Balsam and Japanese Knotweed
  • spores responsible for disease in plants such as Phytophthora
  • microbes responsible for animal disease (viruses, bacteria, fungi)
Most citizen science and volunteer surveying will require only to be aware of Level 1 and 2 Biosecurity Control. This basically means wearing footwear that can be easily cleaned with a brush and soapy water. Wellingtons are excellent to clean, but can be awkward to walk in longer distances. I always recommend a pair of synthetic waterproof walking boots; these will not suffer from washing if done right.

Level 1 and 2 biosecurity measures
  • Respect any notices or instructions!
  • Ensure footwear is clean prior to the visit (visually free from loose soil and plant debris)
  • Ensure that vehicles are cleaned regularly to remove any accumulated mud, especially from wheels and wheel arches
  • Keep vehicular access to a minimum and keep to established hard tracks
  • Don't forget to wipe down / wash dogs! 
Cleaning footwear
If you are visiting several sites in one day it might be easier to pack several pairs of footwear so that you can just clean them all when you come back home instead of carrying equipment in your car. Or you can make up a Virkon S solution in a garden sprayer. You can find Virkon S tablets in farm shops or on Amazon but please make sure you read the instructions! Virkon S is not effective against Phytophthora, Forestry Commission Scotland recommends Cleankill Sanitising Spray, which may be available from a farm shop. Neither of these are suitable for aquatic use! Please use Virkon Aquatic for this.

What you need:
  • Water
  • Plastic cat litter tray (to catch dirt for disposal and to soak boots)
  • Hoof pick and stiff dish washing brush
Tools of the trade!
1) Remove visible dirt: If your boots are wet, allow them to dry a bit. Brush any visible debris into the cat litter tray and put it into the household bin (not your bin for garden/food waste!). I use a hoof pick (for horse grooming) and an old dish washing brush - the hoof pick makes light work of getting soil out of deep ridged soles! A dish washing brush is usually very stiff and gets into all the nooks and crannies of your boots.

2) Washing: For this step I use a litter tray for cats as they are big enough for the majority of shoe sizes! Rinse out the tub if you used it to catch dirt. Make up a solution of 1 part household bleach to 9 parts water and let the soles of your footwear rest in this for 15 minutes. Don't let the solution onto the fabric of the boots, you only need it on the rubber soles. Carefully rinse to remove the bleach solution or the materials of your footwear could suffer! Always pour washing solution down the sink, NEVER into street drains or onto the ground. You can use a solution of Virkon S or Cleankill instead of bleach in this step, please follow the instructions if you do!

Vehicle disinfection
Consider where you drive and park your vehicle; park on hard standing away from plant materials and ideally park off-site if you can. This is especially important if you are driving through farmland or forestry woodland. You should clean the wheel arches and tyres of your car by using a hose or high pressure washer but don't do this at home! The drains in your street are only meant to carry surface water runoff (ie rain) and should not be contaminated with foreign soil or chemicals. The best place to clean your car is at a petrol station car wash or other commercial car wash as their drains by law have to be connected to so-called 'foul water drains/sewers' which means the water will be decontaminated.


Amphibian surveys/pond dipping
There is detailed guidance from ARG-UK, Froglife and SNH how to prevent the spread of amphibian disease, mainly chytrid fungus and Ranavirus. For our NARRS survey, even though we only visit the same pond, we disinfect the equipment carefully. This is best done in a bathtub due to the size of the equipment cleaned.

  • Buckets and net: wash carefully to remove all visible debris.
  • Measure out 1 part household bleach to 9 parts water and soak for 15 minutes. Rinse very carefully to remove the bleach solution as it may otherwise enter the watercourse/affect the creatures you are trying to survey.
  • Wash your clothes in 40C machine wash!
  • Wash footwear as previously
Tree biosecurity
Always, always heed signs and instructions where there are restrictions to access due to infected trees! Phytophthora are a large group of pathogens that cause diseases in plants including many species of tree. The name is derived from Greek and literally means 'plant destroyer' from phyto (plant) and phthora (destroyer). There is only one disinfectant that has been proven to be effective against Phytophthora ramorum spores and it's called Cleankill Sanitising Spray. It is classed as a substance harmful to health and should ideally not be used unless you are trained in Control of Substances Harmful to Health (COSHH). Therefore if the area you are going into is likely to have Phytophora ramorum present you may wish to reconsider going there. You will not be able to kill Phytophthora with a bleach solution. There is more detailed information here.


Why do I need to scrub all visible dirt off if I can just soak my boots?
Seeds, spores and microbes are easily picked up in dirt on your shoes and clothing. For example, seeds of Himalayan Balsam are small and will easily transport themselves on your shoes to a more sensitive habitat where they will then spread like wildfire! Fungal spores may attach to your clothing, and so spread between sites as you brush against vegetation. Microbes are invisible to the human eye and are everywhere - hence why dirt must come off AND bleach solution must be applied.

Why do I need to chemically treat my shoes and equipment as well?
Just because your shoes have no dirt on them doesn't mean they won't carry microbes or spores. The only way to kill these effectively is by high temperature washing or chemical treatment.


Forestry Commission Scotland Keep it Clean Campaign