In 2013 the red swamp crayfish (Procambarus clarkii) was introduced in Lake Yahuarcocha, a tropical, high altitude lake located in the Andes of northern Ecuador. Abundance of this alien invasive species has increased to such extent that it is disturbing the autochthonous aquatic ecosystem. Little is known about its distribution throughout Ecuador. Monitoring is therefore important to assess the current distribution and to control future spread. A molecular method based on environmental DNA (eDNA) was developed and used to assess the distribution of P. clarkii at 21 sites in Lake Yahuarcocha, and three sites each at Lake Mojanda and Lake San Pablo in the Ecuadorian highlands. The molecular detection of crayfish from water samples were compared to catch-based distribution patterns obtained from traditional trapping. Results showed an eDNA detection accuracy of 86% in water samples, without any false positives. The results indicate that this budget-friendly method is easy to use and can provide important information on the occurrence of alien species in the tropics.

Ecuador is well-known as one of the most biodiverse countries, but this species richness is being threatened by invasive alien species. The early detection of these invasive species is crucial for their fast and successful eradication and for limiting their effects on aquatic communities. Therefore, a Belgian VLIR-UOS project was started that aims at the development of a fast detection method to monitor the Ecuadorian Amazon river basin for the presence of invasive fishes, macroinvertebrates and amphibians. An (e)DNA field lab, equipped with miniaturized and portable DNA-processing equipment, such as centrifuges, thermal cyclers, and electrophoresis equipment (MiniPCR), was developed. In the next phase, the Nanopore Next-Generation sequencing (NGS) technique (MinION) will be optimized to enable the eDNA-based biomonitoring of tropical aquatic environments in the field. The fast detection of invasive species may help to prevent their further spread and perhaps even facilitate their eradication, and will promote more effective actions for the conservation of aquatic ecosystems. Furthermore, new DNA-sequences of amphibians, macroinvertebrates, and fishes are being incorporated into the newly developed Ecuadorian DNA database. We also focus on building and strengthening the capacities of staff and students (Ecuadorian as well as Belgian) through theses, practical courses, field work, trainings and internships.