To the waters and the wild: reflections on eco-social healing in the WILD project (original) (raw)

Trapping Aliens: Understanding the Complexities of Controlling Introduced Freshwater Crayfish in the United Kingdom

Transylvanian Review of Systematical and Ecological Research, 2016

Invasive non-native species pose practical and ethical problems for the people tasked with their management. Invasive freshwater crayfish species in the UK threaten rare native crayfish and freshwater habitats, yet their control is beset with social, practical and environmental barriers to success. This paper draws on an interdisciplinary study of stakeholders involved in crayfish management in East Anglia to explore the management of non-native freshwater crayfish in the UK. It concludes that when standard methods of control fail, stakeholders are willing to consider unusual management suggestions such as commercial trapping, whilst recognising that these may bring their own problems.

Bubb, D.H., Thom, T.J. & Lucas, M.C. (2008) Spatial ecology of the white-clawed crayfish in an upland stream and implications for the conservation of this endangered species. Aquatic Conservation: Marine and Freshwater Ecosystems 18, 647-657.

1. Populations of white-clawed crayfish (Austropotamobius pallipes) have undergone substantial declines across Europe. Remaining populations tend to be fragmented and in many catchments they are restricted to upland streams. Information is needed concerning their spatial ecology to assist with conservation and rehabilitation of existing fragmented populations, as well as possible reintroductions. 2. A novel method for the long-term tagging of white-clawed crayfish was used to study the spatial ecology of a white-clawed crayfish population fragment in a small, moderate-gradient upland stream. Internal passive integrated transponder (PIT) tags enabled adult crayfish (carapace length > 27 mm) to be permanently tagged, each with a unique identification code and resulted in a high number of recaptures. Of 501 crayfish tagged 413 were subsequently relocated at least once. 3. Crayfish did not make extensive movements, the median annual distance moved was 84.8 m yr À1 , equivalent to annual net movement of 0.233 m day À1 , substantially less than reported in previous studies. The lower levels of movement may reflect the study encompassing all seasons, including winter, when crayfish are relatively inactive. 4. Significantly more crayfish moved downstream compared with upstream and distances moved downstream were significantly greater than those in an upstream direction. This may be linked to the relatively high gradient of the stream and a reduced passability of the abundant riffles to upstream movements of crayfish. 5. A small weir acted as a barrier within the stream, preventing upstream movements of crayfish. Even small barriers may limit the movements of white-clawed crayfish and have the potential to limit connectivity within populations and prevent expansion or recolonization. 6. The results presented suggest that fragmented populations of white-clawed crayfish in upland streams are unlikely to expand rapidly and reconnect to other population fragments, even where habitat is suitable. In establishing stream populations care should be taken to ensure that even small barriers to movement are removed unless these are intended to exclude non-native biota, especially crayfish.

Experimental restocking of native crayfish in White lake, Co. Westmeath, Ireland (2000)

, Crayfish Conference Leeds, Leeds, UK, 2000, eds D. Rogers, J. Brickland. Environmental Agency, 2000, 123, 130

It Is Not Only Data—Freshwater Invertebrates Misused in Biological Monitoring

Animals

The article presents and discusses the issues of the use of free-living invertebrates to assess the ecological status of freshwater environments with different methods of biological monitoring. Invertebrates are excluded from ethical consideration in the procedures of environmental protection, which results in the killing of many more individuals during sampling than necessary. Biomonitoring is used as a routine method for environmental protection that results in the cruel death of even millions of aquatic animals annually. In many cases, the mortality of animals used in such types of activities has been shown as excessive, e.g., because the vast majority die due to unnecessary subsampling procedures. Improperly planned and conducted procedures which result in excessive mortality have or may have a negative impact on the environment and biodiversity. Their existence as sensitive beings is reduced to an information function; they become only data useful for biomonitoring purposes. Th...