PhD Research Project: Resurrecting ghost ponds to fight loss of aquatic biodiversity
Ponds provide clean freshwater environments in farmland and are vital habitats for aquatic biodiversity covering plants, invertebrates, amphibians, fishes, and mammals 1. Recent studies conducted by University College London (UCL) show that ponds are also important for farmland birds through the provision of insect food. In short, good ponds contribute to sustain aquatic biodiversity. In addition, by facilitating the migration of species across the landscape they play a central role in maintaining genetic diversity of species. Genetic diversity has long been accepted to be the foundation of biodiversity (e.g. 2). Regrettably, many ponds have been reclaimed for farming. In the Norfolk area (UK) farming intensification has been particularly severe post World War II (http://www.landscapes.org/researchers-offer-uk-ghost-ponds-new-lease-life/). In this area, many ponds have been claimed by farmers and filled with soil thus reducing landscape connectivity and creating a shortage of water supply. Pond density in this area has decreased from 46,000 farmland ponds before 1950s to just 23,000 today (E. Alderton, unpublished data). However these ponds are not lost and often damp depressions of ‘ghost’ ponds remain in place or former water reservoirs (https://ghostponds.wordpress.com/). Ghost ponds contain the buried sediments, seeds and eggs of the former pond community. By re-excavating these sites we may be able to fight loss of aquatic biodiversity and loss of genetic diversity at regional scale. The restoration of ghost ponds as a resource of biodiversity and genetic diversity is an itriguing one and may radically tranform conservation strategies to maintain or replenish regional bioversity.
This project will be the first to show whether the excavation of ghost ponds may contribute to fight loss of aquatic diversity, with a focus on genetic diversity of a keystone species, responsible for sustaining the food web of aquatic habitats.
Objective 1: Sample and characterize the genetic diversity of the keystone grazer Daphnia magna from ghost and established ponds in the Norfolk landscape.
Objective 2: Identify migration dynamics between ghost and established ponds via population genetic approaches and assess whether ghost ponds contribute to genetic diversity of established ponds.
Objective 3: Experimentally quantify the extent to which ghost ponds contribute to increase genetic diversity in the landscape.
Objective 1: Field work. Sample the surface sediment of five ghost (already excavated) and several established surrounding ponds.
Objective 2: Laboratory work. Perform DNA extraction and genotyping on isolates from objective 1 with at least 30 microsatellite markers arranged in multiplexes Identify the migration dynamics between excavated and established ponds.
Objective 3: Laboratory work. Perform competition experiments with isolates from the ghost and the established ponds in different ratios and quantify shifts in genotypic composition.
Training and skills
CENTA students are required to complete 45 days training throughout their PhD including a 10 day placement.
The supervisors have a long track record of graduate and postgraduate supervision and have been collaborating on paleogenetic projects. The DR will receive training as field biologist and conservationist from Dr Sayer. He/she will receive training in experimental evolution and population genetics from Dr Orsini. Dr Orsini’ interest is deeply rooted in discovering the molecular targets of natural selection and their contributions to the process of adaptation. Her group at the UoB is part of the Joint Centre for Environmental Omics, which offers training in the most up to date ‘omics’ technologies. The DR will be offered training in these cutting-edge technologies as well as in population genetics.
Year 1: resurrect Daphnia magna specimens from already excavated ghost ponds and established ponds; establish isoclonal lines of D. magna and collect tissue for DNA extraction and genotyping. Present project plan in a poster at the student conference in Birmingham
Year 2: perform DNA extraction and genotyping and complete data analysis using a suite of population genetic software. Identify migration dynamics between ghost and established ponds. Present preliminary data in a workshop or national conference. Prepare draft of first thesis chapter to be submitted for publication.
Year 3: perform competition experiments and quantify shifts in genotypic composition after the experiment to quantify the contribution of ghost ponds to the regional genetic diversity. Present thesis work in an international conference. Prepare draft of second thesis chapter for publications.
please refere to the CENTA webpage http://www.centa.org.uk/themes/anthropogenic/b6/
1. Perkins DM, Bailey RA, Dossena M, Gamfeldt L, Reiss J, Trimmer M, et al. Higher biodiversity is required to sustain multiple ecosystem processes across temperature regimes. Global Change Biol 2015, 21(1): 396-406.
2. Taberlet P, al E. Genetic diversity in widespread species is not congruent with species richness in alpine plant communities. Ecology Letter 2016, 15: 1439-1448
3. Orsini L, Spanier KI, De Meester L. Genomic signature of natural and anthropogenic stress in wild populations of the waterflea Daphnia magna: validation in space, time and experimental evolution. Molecular Ecology 2012, 21: 2160–2175.