Great Walks takes a look at some of the biosecurity concerns out there in the bush and what bushwalkers can do to help.
There are many wonderful bushwalking trails to explore around Australia, encouraging us to head out and take a look, and bring some great photos back with us. However, we can also unintentionally carry some tiny hitchhikers into the area that we’re visiting, or even pick them up on our boots and other gear as we walk through and then accidentally transport them somewhere else.
These tiny hitchhikers can include micro-organisms like Phytophthora cinnamomi, fungal spores such as myrtle rust, and a large variety of weed seeds – all of which have the potential to completely change a landscape and its ecology by killing off or outcompeting the native species.
Prevention is better than a cure and there are many ways for bushwalkers to help prevent the spread of these pests and diseases, from cleaning our equipment to reporting any sightings, and lots of information to help us do so. First, let’s take a closer look at some of these hitchhikers…
Phytophthora
Phytophthora dieback is a deadly plant disease that’s caused by a micro-organism (Phytophthora cinnamomi) that attacks the roots of a susceptible plant. This causes the roots to rot, preventing the plants from taking the water and nutrients they need from the soil and causing ‘dieback’ symptoms (it looks like the plant is dying of drought, so it’s tough to detect the disease), which can eventually lead to the plant’s death. Thousands of native Australian plants, including banksias, boronias, grevilleas, eucalyptus and xanthorrhoea, are susceptible to this disease – it thrives in moist, warm conditions and is capable of destroying entire vegetation communities.
Myrtle rust
Myrtle rust (Puccinia psidii, also known as eucalypt rust or guava rust) is a serious fungal disease that can affect and even kill many of the plants in the family Myrtaceae, which includes eucalypts, bottlebrushes, tea trees, lillypillies and paperbarks. This disease was first detected in New South Wales in 2010 and can now also be found in Victoria, Queensland, Tasmania and on the Tiwi Islands in the Northern Territory – it isn’t known to be in South Australia or Western Australia yet and it’s critical to keep it from spreading any further, so take extra care when travelling between states.
Myrtle rust can be recognised from the bright orange to yellow clumps of powdery spores or pustules (however, the appearance can vary slightly, depending on its host plant). It spreads via spores naturally via wind, water, insects and other animals; however, it can also travel even further if the spores are carried on contaminated clothing, other equipment or infected plant material.
Weeds
Another risk while walking is having weed seeds latch on to your socks or stick to the mud on your boots so they can use your equipment as a way of hitchhiking from one area to another. Weeds often have a lot of methods that can help them colonise an area quickly, including producing plenty of seeds (and therefore potential offspring) with barbs, hooks or sticky surfaces that can latch on to animal fur (or our clothing and packs). They can outcompete native plants, destroy native habitats and choke creeks and other waterways, so they need to be kept under control… or out of areas altogether.
Twelve ways to help
There are plenty of ways that bushwalkers can help prevent the further spread of pests… and even help get rid of some of the ones that are already there:
- Make sure your walking gear – your boots, hat, other clothing, gaiters pack, tent and pegs, trowel, walking poles, anything that would have come into contact with soil, water and plants – are clean, both before and after a walk, so you don’t carry anything in or out with you. This doesn’t just apply at the start and end of a trip – if you’re moving from one walk to another, clean your gear in between walks.
- To clean your gear, wash with tap water and dry it – aim to let it dry completely, and disinfect it if it won’t dry before you set out on your next walk.
- Check everything for weed seeds as well (particularly any gear with Velcro), even if it seems unlikely that it can harbour these little hitch-hikers, and carry them out in a re-sealable bag so you don’t spread them further.
- If you’re cleaning your gear at home after your walk, avoid washing any weed seeds down the drain.
- Make sure you stay on the track as you walk and only camp in the designated areas.
- Park your car in the designated parking areas if you’re driving to the start/finish of the walk.
- If the walk has a designated direction (e.g. starting at the easternmost point and finishing at the west), make sure you follow this.
- Did you refill your water supplies from a creek or river on the way? Make sure you empty out any leftover water well away from any water bodies.
- When sorting out food for your walk, make sure that you’re not taking any fruit or vegetables into restricted areas… or possibly bringing them back into restricted areas once you finish your walk.
- If you see anything unusual while you’re out walking (such as a large colony of weeds or a potential Myrtle rust sighting), take some photos (don’t take samples) and a precise location with your GPS (or mark it on your map), and report it as soon as you get back – see below for the Exotic Plant Pest Hotline details.
- There are also websites where you can help track feral animals and plants that you’ve seen out on a bushwalk, or in your local area in general.
- If you’d like to do something to help out in your local area, you can take part in a weed removal or bush revegetation day to help get rid of the weeds that have arrived there once you get back.
Words_Laura Boness