Invasive Species

An Invasive Non-Native Species (INNS) is any non-native animal or plant that has the ability to spread causing damage to the environment, the economy, our health or the way we live.

In particular these invasive non-native species are a big threat to the native wildlife of Scotland. Many of these invasive species are able to spread via our rivers and water courses and threaten the iconic wildlife and landscapes of our rivers and lochs. The River Ericht catchment suffers from Japanese Knotweed, Himalayan Balsam, Giant Hogweed, American Signal Crayfish and most recently, American Mink.

We are working with the Scottish Invasive Species Initiative to set up community involvement opportunities to help tackle the invasive plant and American Mink problem. Please see further information below for more detail on volunteer opportunities and how to sign up to help. 

Himalayan Balsam at the confluence of the Ericht and the Isla, photo Markus Stitz
In 2024, the primary target species in the River Ericht catchment are Giant Hogweed, Japanese Knotweed and Himalayan Balsam. SISI are also looking for one or two volunteers to help monitor American Mink.
You will have the opportunity to get involved in a landscape scale conservation project and play a vital part in helping to restore the condition and biodiversity of our river banks. 
Scheduling Volunteering Days
As a general rule, Mark, from SISI, tries to send out a list of work sessions the week before they are taking place to give people time to sign up. With the unpredictable nature of the Scottish weather this doesn’t always happen however, and he will need to post work sessions at relatively short notice at times. There will be a decent spread of days of the week over a control season, but what days that are arranged will be entirely down to the weather. With the kind of work being done, it is really important that it is done in the right conditions so that it can be maximally effective. 
Kit and PPE
SISI provide all necessary kit and PPE for your work except for wellies. They also ask that you wear clothes that you don’t mind being damaged as this is often rough work.
Giant Hogweed
Mid April through June: Giant Hogweed Control
From mid April onwards (depending on the weather) SISI will start sending out dates for hogweed control work days that volunteers can join in with. They typically do this by asking volunteers to check certain areas where there is cause for concern and then via backpack sprayer control in small teams of between 4 to 8 people.
Japanese Knotweed
August through October: Japanese Knotweed Control
In 2023 SISI began work removing the extensive infestation of Japanese knotweed growing along the Ericht from the Blairgowrie road bridge to river Isla confluence.
Japanese knotweed outcompetes native flora, leading to an overall drop in biodiversity, and exacerbates river bank erosion – a serious issue on the Ericht in particular. For the first round of control, contractors were deployed, however as the situation improves we are looking for local volunteers who are interested in getting involved with seeing the control work through to eradication by working with SISI staff on site.
This is relatively physical and demanding work using backpack sprayers and stem injectors, however it is also incredibly rewarding and vital to help improve the ecological condition of the Ericht as well as preventing further exacerbation of bank erosion. This work is likely to be done in small work parties between August and October.
Himalayan Balsam
July and August: Himalayan Balsam Pulling
Another plant becoming an increasing problem on the Ericht is Himalayan balsam.
Similar to knotweed, it outcompetes native flora and creates a monoculture which negatively impacts biodiversity.
The problem on the Ericht and in the Blairgowrie area is not yet out of control, so with organised intervention the problem could be significantly reduced and possibly removed entirely.
The method of control is simple, hand pulling in late June through July, so most people are able to get involved.
Control sessions can be done with larger groups with more of a social element to them, and it’s a great way to get out with people from your community and do something positive together.
SISI are planning to run a number of these conservation sessions in the summer, and the more people we can get together the more impact we will have. 
American Mink

Mink monitoring and trapping
Mink are an incredibly damaging invasive species which decimate native wildlife, particularly small mammals and ground nesting/aquatic birds. There have been a number of mink sightings in the Blairgowrie/Rattray area and SISI have already caught several this season. 

We would like to improve our trapping coverage in the area and are looking for local people who would be interested in getting involved. The best method of catching mink is to deploy a floating raft on a river, burn, loch or other waterbody, as mink thrive in riparian environments. 

If you live near a waterbody, or have one in/running through your garden and would like to make a real difference protecting your native wildlife, adopting and monitoring a mink raft is one of the best things you can do. Mink monitoring and trapping is done virtually all year round, so there is never a bad time to get involved.

Contact Information: Sign Up to Volunteer | Scottish Invasive Species Initiative.