Coastal sentinels: using chemical signatures of dolphins to understand the ecological effects of a mining disaster

• Grant number: 24/18266-1
• Support Opportunities: Scholarships in Brazil - Program to Stimulate Scientific Vocations
• Start date: March 01, 2025
• End date: April 20, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Boniek Gontijo Vaz
• Grantee: Gabriel Mendonça Grellet
• Host Institution: Instituto de Química. Universidade Federal de Goiás (UFG). Ministério da Educação (Brasil). Goiânia , SP, Brazil

Abstract

Cetaceans, such as whales and dolphins, are top predators in marine food webs and act as sentinel species, sensitive to ecological changes caused by human activities such as overfishing and pollution. These changes can trigger trophic cascades, impacting biodiversity and the structure of marine ecosystems. Therefore, understanding these cetaceans' feeding habits is essential for preserving these environments. This project aims to investigate the feeding patterns of cetaceans along the Brazilian coast, using **carbon (¿¹³C) and nitrogen (¿¹¿N) isotopic analyses**. The study will focus on cetaceans with anomalous feeding behaviors, comparing them to a control group with everyday feeding habits. The Instituto Baleia Jubarte will provide samples and include lipid and amino acid fractions** from the studied populations. The isotopic analyses will be conducted using **Orbitrap mass spectrometry**, which allows for the direct measurement of isotopes in complex molecules without the need for conversion into simple gases, preserving detailed information about the carbon sources and the trophic position of the cetaceans. This will help identify dietary shifts and the impact of anthropogenic pressures, such as the use of coastal versus marine habitats. Finally, the project will contribute to the conservation of cetaceans and the health of aquatic ecosystems, providing insights into trophic interactions and the role of cetaceans in the food web while highlighting the effectiveness of Orbitrap mass spectrometry for future ecological research. (AU)