UCL Division of Biosciences


CBER Seminar - Alejandro Maeda-Obregon, UCL

20 February 2023, 1:00 pm–2:00 pm


Title: 'Biodiversity and ecological analyses with Environmental DNA for the freshwater fauna of the imperilled wetland ecosystem of Lake Xochimilco, Mexico'

Event Information

Open to

UCL staff | UCL students | UCL alumni




Amy Godfrey


Roberts Building

Abstract: Freshwater biodiversity is declining at an alarming rate, with freshwater ecosystems among the most degraded environments. Mexico's Lake Xochimilco (LX), a remnant wetland, is particularly under pressure from anthropological causes. As a result, the status and distribution of native and non-native species are uncertain. Of critical concern is the low occurrence of native freshwater fishes and amphibians (e.g., mexclapique fish and axolotl salamander). While these species have been detected by previous traditional surveys, these methods are losing their sensitivity because of the low population numbers of such rare species. Using environmental DNA (eDNA) metabarcoding and environmental data, we aim to address the biodiversity status and ecological relationships of the LX aquatic vertebrate community and their environment. We present our findings from two eDNA metabarcoding loci (12S and 16S), in which results suggest severe ecological impacts on the freshwater ecosystem of LX.


A chinampero (local farmer) in his canoe navigating through the canals and waterbodies of Lake Xochimilco, Mexico. Photo by Alejandro Maeda-Obregon

About the Speaker

Alejandro Maeda-Obregon

PhD Student at UCL-CBER

I am a biologist from northern Mexico, a region of the country with several types of ecosystems, from deserts to wetlands to pine forests. I enjoy being in the field, the lab and playing with bioinformatic codes. After graduating from my bachelor’s degree (from Universidad Autónoma de Nuevo León in Monterrey) and a year of working experience as a technician I decided to pursue my postgrad education at University College London. During my MRes degree I discovered that by specialising in the field of molecular ecology I can do science outdoors and indoors while learning to work with different types of organisms and their environments. Currently, my PhD has allowed me to continue my preparation as a molecular ecologist by working with Mexican ecosystems and building collaborations with British institutions. These experiences are shaping my mindset as a scientist: I want to continue contributing to the conservation of both Mexico and the planet’s biodiversity through future international collaborations!