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Anna McGrath
Research interests
CV
MSc research
PhD research
Contact
Research Interests
My research interests to date have evolved around the general theme of how humans manage aquatic and semi-aquatic species, focusing on both the consequences of mistakes that have been made and ways in which these can be rectified. The species that are the subject of my current and past research (grass snake Natrix natrix, slow worm Angius fragilis, natterjack toad Bufo calamita, Atlantic cod Gadus morhua, brown trout Salmo trutta) have been valued both for their intrinsic conservation and/or commercial value and the research associated with them has had the underlying unifying goal of achieving population viability through the enhancement and refinement of management methods.
CV
2004-present: PhD Imperial College London
2003-2004: Weekend Receptionist and Site Monitoring of Slow Worm Population, London Wetland Centre, Wildfowl and Wetland Trust.
2003-2004: MSc Environmental Technology, Imperial College London.
2003: Environmental Business Volunteer, Groundwork West London.
1999-2002: BA (Hons) Geography, Oxford University.
MSc research
Introduction of Grass Snakes to the London Wetland Centre: A Feasibility Study
Opened in 2000, the London Wetland Centre is an area of recreated wetland in Barnes, Southwest London, which was designated a Site of Special Scientific Interest in 2002. It is managed by the Wildfowl and Wetland Trust – the largest international wetland conservation charity in the UK - concerned with the conservation of wetlands and wetland species. Grass snakes (Natrix natrix) are known to be an important element of the biodiversity found on natural areas of wetland. They are highly aquatic animals, usually associated with ponds, lakes, marshes, streams or ditches. Consequently, as part of their management plan, the London Wetland Centre proposed to introduce grass snakes to the site. If agreed, grass snakes would be the second reptile to be introduced after the introduction of slow worms in 2002.
Aim and Context:
The purpose of this research was to determine the feasibility of introducing grass snakes to the London Wetland Centre by establishing the suitability of the site as a receptor for grass snakes in relation to providing for their ecological requirements in the long term. The study was set in the context of the aims of the Framework for the Conservation of Amphibians and Reptiles in the UK (JNCC, 1994) to: a) prevent further declines in the range, distribution and viability of amphibians and reptiles and b) where feasible, enhance the distribution and abundance of amphibians and reptiles, and the IUCN/SSC Guidelines for Re-Introductions (IUCN, 1995) which were prompted by the increasing occurrence of projects involving species introductions, re-introductions and translocations in the UK and worldwide.
Research Objectives:
- To assess the status of grass snakes at the London Wetland Centre and ascertain whether it is likely that they are present or absent.
- To identify key habitat requirements for grass snakes throughout their life cycle and to assess provision for these within the London Wetland Centre, potential habitat corridors and surrounding sites.
- To assess the status of prey and predator species across the site and understand the likely impact of introducing grass snakes on the existing ecosystem.
- To determine whether the London Wetland Centre could support a viable population of grass snakes in the long term in relation to demographic, genetic and environmental factors through population viability analysis using a stochastic simulation model.
- To recommend or discourage grass snake introduction to the London Wetland Centre based on the findings of this feasibility study.
For more information on the outcome of this research see:
McGrath, A. (2004) Introduction of Grass Snakes to the London Wetland Centre: A Feasibility Study. MSc thesis, Imperial College London, University of London, UK. PDF
This research was carried out in collaboration with the London Wetland Centre, Wildfowl and Wetland Trust and supervised by Dr. Kai Lorenzen, Imperial College London.
PhD research
Captive Breeding and Translocation in the Conservation of Rare Fauna in Britain
Species are targeted for translocation for several different reasons including conservation, commerce, amenity and research. Many translocations of captive-bred native British fauna take place primarily for conservation reasons - rare and endangered species are introduced, reintroduced or supplemented into the wild in order to conserve them for their own sake and to make amends for past destructive human action. However, the occurrence of translocations of captive-bred individuals for primarily commercial reasons is also sizeable, particularly in relation to stock enhancement for fisheries which have a large economic incentive. Although the two approaches have different motivations for translocation, they have similar fundamental objectives: to help maintain and enhance existing wild populations or re-establish extinct or declining populations to a desired state. There exists between these two contrasting purposes, the unifying need for conservation managers to make decisions concerning the most effective way to aid the recovery of a rare species. Despite this, these two approaches are not commonly investigated together in conservation research. Such an investigation could prove to be enlightening as although biologically and technically similar, conservation and commercial translocations of captive-bred individuals differ valuationally and organisationally – a fact that may have an important impact on the programme’s effectiveness. As more and more species decline or become extinct, a pressing concern for conservationists is if and under what circumstances captive breeding and translocation can be seen as an effective tool to help recover existing rare populations, whatever the underlying rationale.
Aim and Context:
This aim of this research is to provide a rigorous and practical framework for the initial appraisal, planning and evaluation of captive breeding and translocation programmes using the contrasting case studies of a species conserved for its conservation value and a species conserved for its commercial value. The two species chosen to represent these contrasting approaches are: the natterjack toad (Bufo calamita) and brown trout (Salmo trutta). The natterjack toad is considered endangered in Britain due to loss of suitable habitat and although some natural sites exist in Scotland and England, translocations of captive-bred toads have taken place in order to conserve this unusual amphibian and there are now several sites of artificially introduced populations. It is hoped that this species will be saved from extinction and restored to its historic range.
Natterjack pond in the Ainsdale Sand Dunes
Conversely, brown trout is generally widespread in Britain and not considered threatened, but it is an economically important fish species. However, in some areas, local populations are under threat and becoming isolated and as a result stock size and distribution are in decline. Consequently, efforts have been made to restock wild brown trout populations with captive-bred brown trout. It is hoped that the introduced trout will supplement the existing wild populations and help to maintain the commercial viability of the freshwater fishery.
Research Objectives:
- To use population modelling as an experimental tool to assess the impact of alternative captive breeding and translocation management strategies on population viability for each species (natterjack toad and brown trout), using a scenario-based approach.
- To carry out a risk assessment of the alternative strategies identified by the modeling in order to ascertain the likelihood of management success or failure and find optimal management methods.
- To use cost-benefit analysis to assess the costs and benefits of these captive breeding and translocation strategies and also of wild-wild translocations and habitat restoration to assess the appropriateness of these as alternatives or additions to captive-wild translocations.
- To establish the effect of the different organizational structures and existing supporting guidelines relating to the conservation of the two species on management success.
- To formulate recommendations as a result of the above, concerning changes or improvements that may need to be made to the management approaches used for each species both in captivity and in the wild, with the intention that this comparative research is mutually beneficial.
- To use decision analysis as an analytical tool to build an explicit framework for the management of the two species to help decision-makers determine the best course of action to take in relation to captive breeding and translocation programmes, whilst taking into account uncertainties and multiple management objectives.
It is hoped that the results of this research will help inform decision-makers to make appropriate decisions about how captive breeding and translocations for conservation and commercial reasons should take place and will help to improve the efficiency of these efforts for the two chosen species as well as providing a more widely applicable framework to encourage conservation efforts and resources to be applied in a more efficient and ecologically sound way.
This research is supervised by Dr. Kai Lorenzen, Imperial College London.
Contact
Anna McGrath
Division of Biology
Imperial College London
Silwood Park Campus
Buckhurst Road
Ascot, Berkshire
SL5 7PY
E-mail: anna.mcgrath@imperial.ac.uk
Tel: +44 (0) 20 7594 2527
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