A recent prosecution has illustrated the consequences of releasing non-native species into UK habitats, notwithstanding that the motivation of the two defendants was entirely benevolent.

Section 14 of the Wildlife and Countryside Act 1981 makes it an offence to release or allow to escape into the wild any animal of a kind which is not ordinarily resident in and is not a regular visitor to Great Britain in a wild state, or which is listed in Schedule 9 of the act. The maximum penalty is an unlimited fine and/or two years’ imprisonment. Zhixiong Li and Ni Li organised a boat trip from Brighton Marina in 2015. Their intention was to release thousands of live crustaceans into the sea as part of a Buddhist “life release” ritual designed to save animals destined for slaughter. However, amongst the crustaceans were 361 American lobsters and 350 Dungeness (US) crabs, which Miss Li had purchased from a wholesale fish supplier. The case came to light when two local fishermen subsequently captured some of the foreign shellfish in June 2015. Only 323 crustaceans had been recovered and the most recent American lobsters found had been carrying “viable eggs”, which showed that they had been breeding. Mr Li and Miss Li were subsequently prosecuted by the Maritime Management Organisation, who had spent thousands of pounds trying to recover the shellfish, even offering local fishermen a bounty of £20 to capture them. The defendants pleaded guilty at Brighton Crown Court and were fined a total of £5,800 and ordered to pay plus £9,000 in compensation. The judge commented that the full impact of the defendants’ actions was not known, but that it could have a significant impact upon native fish stocks.

The introduction of non-native species can have a devastating effect on an ecosystem, for example, by introducing disease, preying on native species or simply outcompeting native species in the search for food. Well known examples include the introduction from the USA of grey squirrels and signal crayfish ravaging the UK’s native red squirrel and white clawed crayfish populations respectively. In the plant kingdom, the introduction of Japanese Knotweed to the UK has led to a menace which can damage buildings, overwhelm other plants and blight property. In each of these cases, the motivation behind the introduction was not malicious: grey squirrels and Japanese knotweed were introduced by Victorians for essentially ornamental purposes; signal crayfish to bolster stocks affected by crayfish plague (paradoxically, signal crayfish are not only carriers of, but also immune to, crayfish plague).

Mr Li and Miss Li, whilst naïve, had certainly never intended to cause harm to wildlife. So unpredictable are the consequences of introducing invasive species that it is a cruel irony that they may have unwittingly sealed the fates of far more animals than they had hoped to save.