DNA-based resolution of freshwater arthropod communities and interactions

Davidson, Elizabeth 2022. DNA-based resolution of freshwater arthropod communities and interactions. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Freshwater biodiversity is widely considered to be in crisis. The need for new methods to quickly assess and monitor biodiversity is urgent. DNA-based identification of biodiversity offers promising new methods. Compared to monitoring species presence and richness, DNA-based identification of ecological interactions through predator diets has gained much less attention. The study of these interactions has the potential to provide new insights into species ecology and new methods of identifying and monitoring changes in biodiversity. This thesis aimed to explore how DNA-based resolution of predator diets can contribute to improving the assessment and monitoring of freshwater biodiversity and to identify the method development necessary to achieve this improvement. The studies in this thesis aimed to improve understanding of how DNA-based identification methods can be used to characterise freshwater arthropod communities and to resolve trophic interactions within those communities. Gaps in the coverage of publicly stored reference sequences for UK freshwater arthropods coupled with low data quality will lead to poor taxonomic resolution and potential misidentifications. A systematic framework for prioritising current and future sequencing and curation needs was produced to address these issues. Thorough optimisation and validation of methods for metabarcoding of bulk zooplankton samples was found to be essential in order to produce meaningful community data. Optimisation of primers, bioinformatic processing and data analysis improved the detection of target taxa, reduced false positives and negatives, and improved relative abundance data. The combination of community metabarcoding of prey taxa and dietary screening of individual predators provided detailed and informative information on how predator-prey interactions change over time. Overall, DNA-based resolution of predator diets has great potential for resolving freshwater food web interactions and providing new insights for improving assessment and monitoring. Curation of reference databases and method development for freshwater arthropods are urgent to realise this potential.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Biosciences
Subjects:	Q Science > Q Science (General)
Date of First Compliant Deposit:	12 May 2023
Last Modified:	06 Jan 2024 04:19
URI:	https://orca.cardiff.ac.uk/id/eprint/159438

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