“Zooremediation” - a novel strategy to remediate contaminated aquatic environments

We are seeking a highly motivated individual to carry out PhD research in the field of environmental pollution, water quality, ecological engineering and bioremediation. This prestigious IAPETUS studentship, funded by the Natural Environment Research Council (NERC), will provide a platform to build an interdisciplinary research career in the field of integrated environmental and ecological sciences.

The successful candidate will be based at the University of Stirling, supervised by Dr Richard Quilliam and Prof Laurence Carvalho (at the Centre for Ecology and Hydrology, Edinburgh), and co-supervised by Prof Nigel Willby & Dr David Oliver at Stirling.

Background
Many invertebrates in aquatic ecosystems are able to hyperaccumulate, stabilize or degrade pollutants. Such invertebrate species have simple life histories, are resistant to toxicity and have the ability to generate an economic return following remediation activities. Therefore, there is a growing interest in using invertebrates for the bioremediation of contaminated waterways. Using invertebrates for bioremediation initiatives has been termed ‘zooremediation’, with evidence in the literature suggesting that bivalves (oysters, mussels and clams), polychaetes and sponges are suitable candidates; however, the concept of zooremediation is still poorly developed and not widely recognised. Zooremediation can be achieved in several ways: through the culture, introduction, and harvest of invertebrates, i.e. a form of aquaculture; or supplementation or maintenance of wild invertebrate populations, leading to the stabilisation or degradation of pollutants. The ability of invertebrates to take up or assimilate organic and inorganic pollutants has been demonstrated in controlled laboratory experiments, whilst several small scale field studies (particularly in Scandinavia) have indicated the potential for efficient invertebrate pollutant uptake and removal.

Using invertebrates for zooremediation is a non-invasive process for sustainably treating impacted waterbodies. One strategy is to harvest and remove the invertebrates from the water and, depending on the type of pollutant the animal has sequestered, use their biomass (including the shell of bivalves) as a soil conditioner, animal feed or as feedstock for bioenergy production. Alternatively, the pollutant can be recovered during a depuration process and the animals returned to the water. However, this strategy for sustainably protecting & increasing environmental water quality needs to be optimised for context-specific situations to provide innovative solutions that are relevant in UK catchments. In this project the student will explore the opportunities for exploiting zooremediation in nutrient enriched and multi-pollutant impacted waters (e.g. point source discharge areas, areas of intensive livestock, transitional waters, estuaries and coastal zones).

The overarching aim of this project is to optimise a series of strategies that can improve water quality by exploiting the ability of filter-feeding aquatic invertebrates to assimilate waterborne pollutants. This studentship aims to provide transformative and sustainable solutions to address the increasing demand for water security, and provide the necessary data for introducing environmental management options throughout the UK. The student will contribute towards a strategic blueprint that can be translated to other areas of the world where there is growing pressure on water resources because of increasing population demands, and provide the scientific basis for national scaling-up in countries with pressing water security challenges. Crucially, the student will integrate biological, environmental and engineering dimensions that cut across traditional academic disciplines.

Key Research Aims:
Specifically, this project aims to:
1. Identify native invertebrates that provide maximum sequestration potential for nutrient and microbial pollutants
2. Develop a novel ecological-engineering system capable of deploying ‘zooremediation units’ into highly impacted waters, and carry out field-scale experiments to determine optimal deployment and extraction efficiencies
3. Quantify the potential for resource recovery from zooremediation as part of a circular economy approach
4. Assess the feasibility of scaling-up zooremediation strategies, and calculate the economic practicality of implementing these systems at the field- and catchment scale