Native European crayfish conservation was triggered by invasion of crayfish plague disease agent, Aphanomyces astaci, starting 1860s in Northern Italy. Resulting crayfish plague epidemics quickly spread over Continental Europe, then to Finland, Sweden and finally, after running amok around Europe, A. astaci was discovered also in Iberian Peninsula, Norway, Ireland and UK in 1970s and 1980s. By that time significant proportion of native crayfish stocks had been lost, and while crayfish plague epidemics were still recorded, also industrialization and waterways construction were causing damage to remaining native crayfish stocks. While alien crayfish introductions, at least Faxonius limosus, already gave rise to first wave of crayfish plague epidemics in late 19th century, later in 1960s it was decided that introductions of alien Pacifastacus leniusculus should be initiated to replace native European crayfish populations. Decisions were based on presumed advantages for fishery, suitable habitat requirements and supposed immunity against A. astaci. Furthermore, conservation of native European crayfish species was sidelined and focus shifted towards alien crayfish stocking routine and consumption. Alien crayfish species introductions resulted in repeated waves of crayfish plague epidemics among remaining native crayfish stocks. It was soon discovered that alien crayfish of North American origin were, as suspected, permanent reservoirs for A. astaci, that some of those alien species were losing their resistance against selected strains of A. astaci and struggled in European aquatic ecosystems. In this article, we introduce numerous motives behind grand mistake of introducing alien crayfish species to Europe and then promoting their stocks instead of focusing on conservation of native crayfish species. We outline how false economical, biological and ecologic assumptions were used to justify a hasty introduction of alien crayfish, which has further devastated native crayfish and also permanently changed European aquatic ecosystems, both with disastrous consequences. Lesson to be learnt is that science-based warnings about alien species damage to native ecosystems and native crayfish must be taken with utmost caution. Protection of native European crayfish should be core issue, not commercial activities. Finally, we summarize main threats and actions needed to protect remaining native freshwater crayfish fauna in Europe.

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金钱扼杀了原生生态系统：以欧洲小龙虾为例

欧洲本土小龙虾保护是由小龙虾瘟疫病原体 Aphanomyces astaci 的入侵引发的，始于 1860 年代的意大利北部。由此产生的小龙虾瘟疫流行迅速蔓延到欧洲大陆，然后蔓延到芬兰、瑞典，最后，在欧洲肆虐之后，1970 年代和 1980 年代在伊比利亚半岛、挪威、爱尔兰和英国也发现了小龙虾。到那时，很大一部分本地小龙虾种群已经消失，虽然小龙虾瘟疫流行仍在记录，但工业化和水道建设也对剩余的本地小龙虾种群造成了破坏。虽然外星小龙虾的引入，至少是 Faxonius limosus，已经在 19 世纪后期引发了第一波小龙虾瘟疫流行，1960 年代后期，决定引进外来的 Pacifastacus leniusculus 以取代欧洲本土小龙虾种群。决定是基于假定的渔业优势、合适的栖息地要求和对 A. astaci 的假定免疫力。此外，欧洲本土小龙虾物种的保护被搁置一边，重点转向外来小龙虾放养和消费。外来小龙虾物种的引入导致在剩余的本地小龙虾种群中反复爆发小龙虾瘟疫流行。人们很快发现，北美起源的外来小龙虾被怀疑是 A. astaci 的永久储存库，其中一些外来物种正在失去对 A. astaci 选定品系的抵抗力，并在欧洲水生生态系统中挣扎。在本文中，我们介绍了将外来小龙虾物种引入欧洲然后促进其种群而不是专注于保护本地小龙虾物种的重大错误背后的众多动机。我们概述了错误的经济、生物和生态假设是如何被用来证明仓促引入外来小龙虾的合理性的，这进一步破坏了本地小龙虾，也永久地改变了欧洲的水生生态系统，两者都带来了灾难性的后果。需要吸取的教训是，必须极其谨慎地对待有关外来物种对本地生态系统和本地小龙虾造成损害的基于科学的警告。保护欧洲本土小龙虾应该是核心问题，而不是商业活动。最后，我们总结了保护欧洲剩余的本地淡水小龙虾动物群所需的主要威胁和行动。