giant hogweed by Olivier Bacquet

Invasive Non Native Species (INNS) are defined as any non-native animal or plant that has the ability to spread causing damage to the environment, the economy, our health and the way we live. There is increasing awareness regarding the damage caused by the proliferation of INNS. The Spey catchment is not immune to the spread of invasive species with several species already established and others known to be present in close proximity.

Rivers can be a good conduit for the spread of INNS and it is quite often the case that they will be found in greater abundance in the lower reaches. The Spey is typical in that respect with Japanese knotweed, Giant Hogweed and Himalayan balsam present from Craigellachie downstream, although with greater abundance towards the river mouth.

None of these species are strictly riparian plants, rather their occurrence on the banks of the rivers are the result of the downstream spread of seeds, roots or shoots by the river. Once established they will eventually spread away from the river banks making control more difficult and costly.

There is one truly aquatic invasive plant species present in the Spey. Although native in other parts of Scotland water crowfoot (Ranunculus fluitans) was first identified in the River Spey in the late 1970’s after “escaping” from an ornamental pond upstream of Grantown.

Another highly damaging INNS, the american signal crayfish is present in a nearby river. The introduction of this species in the Spey would be extremely detrimental to the ecology of the river.

Eradication of INNS once present is always difficult, costly or even impossible. The key message has to be prevention is better than cure.