Collectomics in Mauritania - An integrated biodiversity assessment in underexplored lagoons and the implementation of a scientific reference collection

Abstract

The waters of the West African country Mauritania are characterised by a particularly high biodiversity. Due to its geographical location, the distribution of tropical, subtropical, and boreal species overlap off its coast. This resulting species richness is further enhanced by surplus of nutrients, which arises from seasonal upwelling events off Northwest Africa. Consequently, the Mauritanian coastline is home to not only a remarkably high marine biodiversity but also houses some of the most productive fish stocks in the Atlantic Ocean. Despite the significant biodiversity, the coastal areas of Mauritania have been insufficiently studied, as previous research has primarily focused on fisheries, seagrass beds, and the behaviour of migratory birds and their overwintering in Mauritania. To address this gap and to establish an essential foundation for future marine conservation in Mauritania, this dissertation investigates the marine biodiversity of the country and compiles a scientific reference collection of the studied marine fauna, expanded integratively through modern methodologies such as DNA barcoding and digitalisation following the principles of Collectomics. To achieve this, multiple ecosystems along the coast were examined, and artisanal fish markets were surveyed. During the field campaigns conducted for this purpose, new, previously undocumented fish species from Mauritania were discovered and scientifically described. The collected tissue samples of the documented fauna were utilised for species identification and were deposited in a genetic database for future research. Additionally, the marine biodiversity of two different bays was assessed using environmental DNA to examine seasonal dynamics and the impact of anthropogenic stressors on the marine biodiversity. The gathered data aims to establish a much-needed and solid foundation for biodiversity research in Mauritania, enabling future biodiversity assessments to be referenced and potentially vulnerable marine areas to be identified and designated for protection