Spatial and connectivity analysis for aquatic ecosystems using environmental DNA

• Grant number: 23/17041-3
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2024
• End date: April 30, 2026
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Alexandre Camargo Martensen
• Grantee: Alexandre Peressin
• Host Institution: Centro de Ciências da Natureza (CCN). Universidade Federal de São Carlos (UFSCAR). Campus de Lagoa do Sino. Buri , SP, Brazil
• Associated scholarship(s): 25/05100-0 - Effects of Connectivity on Ichthyofauna Sampled Through Environmental DNA, BE.EP.PD

Abstract

Connectivity patterns regulates the dispersion of organisms, one of the most relevant processes in community structuring. Due to the increasing demand for food and climate change-induced expansion of irrigated agriculture, riverine ecosystems have undergone anthropogenic interventions, exposing them to constant fragmentation pressure. Recent studies have shown that stream fish has high sensitivity to landscape alterations and difficulties in overcoming even small barriers. In this way, fragmentation tends to reduce the available area, potentially causing species substitution due to environmental changes and biological invasion. Additionally, it limits gene flow, because decreasing connectivity hindering recolonization after extinction events. In this context, this project aims to evaluate possible effects of reduced connectivity on the diversity and composition of fish assemblages. This will be done using environmental DNA samples collected from 40 streams of 1st to 3rd order, representing a gradient of connectivity. Different river connectivity indices will be tested to determine the one that best explains the observed variability in the assemblage. By understanding the effects of connectivity, this Project aims to provide support for the planning of irrigation permits and the restoration of river connectivity. This project will also result in a non-invasive and innovative sampling techniques that can detect species not identified through conventional means.