Sensitivity of aquatic insect eggs to elevated fine sediment and phosphate concentrations in rivers

Insect populations are declining at an alarming rate, globally. Aquatic insects have a crucial functional role in the environment and are used to monitor stream impairment. Despite the significance of aquatic insects, the majority of research is focused on the larval stage of these animals, with very little consideration of eggs. This is despite pollutants having potentially greater effects on early life stages that are typically the least mobile and most vulnerable to stressors. It is, therefore, essential that greater focus is given to the impacts of pollutants on insect eggs, rather than solely focusing on larvae. Orthophosphate and fine sediment are the leading cause of degradation to freshwater systems; however, legal thresholds in the UK are based on annual averages, assessed with monthly spot sampling which may not account for detrimental impacts of short-term spikes.

Therefore, this project aims to quantify the impacts of fine sediment and phosphorus on insect eggs and larval community composition in laboratory experiments, field manipulations and monitoring. Experiments will quantify the development of insect eggs under chronic low-level and spiked concentrations of key stressors. In addition, traits of insect species found at sites representing a gradient of environmental pressures, will be used to statistically explore the impacts of phosphorus and fine sediment on community composition. The successful candidate will work closely with project partners including Salmon and Trout Conservation, Hampshire and Isle of Wight Wildlife Trust, Environment Agency and Aquascience Consultancy, offering perspectives from government, charitable and consultancy organisations. The candidate will also undertake work placements in each partner organisation. Training will be provided by the inter-disciplinary supervisory team and project partners. Findings will influence the delivery of the lottery-funded restoration of the rivers Test & Itchen, and used to promote the reframing of legal thresholds of fine sediment and phosphorus concentrations in rivers.

Applicants should hold a minimum of a UK Honours Degree at 2:1 level or equivalent in subjects such as Ecotoxicology, Geography, Biology or Natural Sciences.

For further information, contact Dr Matthew Johnson (University of Nottingham, School of Geography) m.johnson@nottingham.ac.uk or Dr Helen West (University of Nottingham, School of Biosciences) helen.west@nottingham.ac.uk.