Distribution of White-clawed crayfish in the Upper Thames - Lead Organisation: Environment Agency and Thames Valley Environmental Record Centre (TVERC)
To establish the current distribution of White-clawed crayfish in the West Area of Thames Region of the Environment Agency, through survey of sites with historical records and also of sites with no previous survey information. To identify the proximity of signal crayfish to remaining White-clawed crayfish sites, and recommend conservation action.
Crayfish of the western Thames Area - Lead Organisation: Thames Valley Environmental Record Centre (TVERC)
The project aims to investigate water courses with historic records of White-clawed crayfish and other water courses with suitable habitat. Emphasis is on establishing the current extent of populations of native crayfish and determining their relation, if any to Signal crayfish populations. Habitat details for the water courses surveyed are routinely captured and also biometric data all crayfish caught during the project.
To investigate the potential impacts of the non-native invasive Virile Crayfish (Orconectes virilis) in Britain by studying life history and dispersal rates of the species in the River Lee, Hertfordshire - Lead Organisation: Environment Agency
To study the wild population if non-indigenous Virile crayfish in the River Lee, Hertfordshire in order to better understand their impacts and potential risk to native fauna. How will they differ to the more widespread Signal Crayfish. Using mesocosm experiments, surveys and telemetry.
Crayfish management in the Upper Thames - Lead Organisation: WildCRU, Oxford University
This project aims to provide the necessary knowledge and tools to manage more effectively the ecological impacts of the invasive signal crayfish (Pacifastacus leniusculus) in the Upper Thames. The emphasis is the quantitative assessment of crayfish distribution, seeking out especially places where the native white-clawed crayfish (Austropotamobius pallipes) survive in the absence of invaders and devising means to protect them. A further emphasis is on the impacts on the invasive species in local conservation planning, in terms of damage caused, impacts on the relationship between otters and mink, and aspects of both water quality and local economics, all with a view to developing practical conservation management strategies.
Interactions among invasive crayfish in the UK
- Lead Organisations: Queen Mary University of London
A solitary invasive species can have numerous effects from the individual level through to the whole ecosystem level. However, many ecosystems sustain several invasive species and little attention has been paid to the impact multiple invaders can have. Using controlled mesocosm experiments and field surveys, we are examining interactions among synergistic invasive crayfish species. Population metrics derived from stable isotope data are used to provide quantitative measures of trophic diversity within a population. We then use them to explore variation in the trophic ecology of each species. Additionally, we aim to determine if interactions among invasive crayfish leads to amplification or moderation of their impact on ecosystem structure and function compared to their allopatric counterparts.
Subtle effects of crayfish ecosystem engineering
Lead Organisation: Queen Mary University of London
While the effects of crayfish engineering (bioturbation) such as resuspension of fine sediments and destabilising of banks by burrowing activities are relatively obvious, the more insidious effects such as oxygen stress by increasing oxygen demand overnight are more subtle and harder to determine.
Using a suite of pond mesocosms, set-up to represent sahllow lirroral zones of stillwaters, we will measure a range of biological, physical and chemical parameters under controlled and well replicated experimental conditions. Treatments will include controls (no crayfish) versus varying densities of particular species starting with red swamp crayfish.
Contribution of Signal crayfish and angler baits to Barbel diet
Lead Organisation: Queen Mary University of London
We will determine the extent to which Barbel diet is influenced by both an invasive species (Signal crayfish) and the bait introduced by anglers (mainly fishmeal pellets). In doing so, we can characterise the dietary ecology of the Barbel compared to 'natural' food resources such as macro-invertebrates, and other potential competitor fish species such as Chub. Whilst we can show that crayfish and pellets may contribute to Barbel diet, we will not be able to say whether these are causing the large weights that individual Barbel have attained in recent years.
Aim: To deter mine the influence of Signal crayfish and introduced angler baits on the diet and feeding ecology of Barbel in rivers in England using stable isotope analysis (SIA).
Crayfish in the River Lea
Lead Organisations: Groundbreaking Projects and Crayfish Study Group
The crayfish study group are specialists who study signal crayfish, and other less known species from the waterways. By tackling the problems caused by crayfish and researching them we are able to be more efficient in eradicating the invasive species. Only with the permission from the Environmental agency and other government bodies can we remove them.
The group has been setup to enable specialists to come together and create a better awareness of the problem, current studies have not provided a solution although it is an on going problem.
Visit the Crayfish Study Group site