Invasive non-native species and wildlife disease
Invasive non-native species (INNS) and wildlife disease can
have significant impacts on biodiversity and on human society and
its economic interests. INNS are recognised as one of the major
causes of global biodiversity loss in the Millennium
Invasive Non-Native Species and wildlife disease are growing
problems because of:
- Increasing movement of people and materials around the world
including international trade in livestock and wildlife, animal
products, food crops, timber, and biologically contaminated wastes
such as agricultural commodities, waste/by-products, landfill and
- Increasing trade in exotic pets and horticulture products.
- Indirect effects of climate change, such as the pressure to use
biofuels and the use of non-native species for rapid growing
- Global biodiversity loss, which increases the opportunity for
establishment and spread of non-native species.
Invasive non-native species have a major impact on
biodiversity and are costly to eradicate. Japanese knotweed
Fallopia japonica and Himalayan balsam Impatiens
glandulifera can reduce plant diversity through competition
and the formation of dense monospecific stands.
Aquatic plants such as the water fern Azolla
filiculoides form dense floating mats which cover on the water
surface and obstruct sunlight from entering the water. Many
invasive aquatic plants reproduce very quickly and out compete
native plants as a result.
The carpet sea squirt Didemnum vexillum reproduces
rapidly and overgrows shellfish (e.g. mussels, scallops) and other
sessile invertebrates and inhibits settlement of native
invertebrates. It is a pest to mussel farmers and must be removed
either manually or by innovative engineering.
The Quagga Mussel Dreissena rostriformis bugensis and
Zebra Mussel Dreissena polymorpha are highly invasive
non-native freshwater mussels from the Ponto-Caspian region. They
can significantly alter whole ecosystems by filtering out large
quantities of nutrients and are serious biofouling risks blocking
pipes, smothering boat hulls and other structures. Also from the
same area are Dikerogammarus
villosus and Dikerogammarus haemobaphes,
sometimes known as 'killer shrimps'. These predators kill a range
of native species, including young fish, and can alter
The impact of disease on wildlife populations can be dramatic,
particularly when those populations are small or fragmented. For
example, in the UK red squirrel populations succumb to the deadly
squirrel pox virus (as well as suffering from competition with the
non-native grey squirrel). Our native freshwater crayfish are
impacted by crayfish plague, harbour and grey seals are impacted by
seal distemper virus, bats with Lyssavirus and birds can succumb to
The impact of disease on domesticated animals and humans can
also be immense. For example the Foot and Mouth outbreak in 2001 in
Britain lead to the death of millions of cattle and sheep and cost
vast amounts of money.
Both wild animal disease and invasive species require similar
responses: prevention through policy, surveillance and control.
JNCC provides advice and comment on non-native species as a long
standing member of the programme board of the Non-native Species
The EU has recently passed the Invasive Alien Species
Regulation which came into force on 1 January 2015 and requires
member states to undertake various actions. JNCC is working with
the UK governments to advise on non-native species surveillance,
identification of priority pathways of entry of invasive species,
management measures for invasives and listing species of European
Union and member state concern.