Turbidity, nutrients and macroalgae-consumer interaction: responses to climate change.

• Grant number: 25/03847-1
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: August 01, 2025
• End date: January 31, 2026
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Tânia Marcia Costa
• Grantee: Caio Augusto Paula
• Supervisor: Cintia Organo Quintana
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil
• Institution abroad: University of Southern Denmark (SDU), Denmark
• Associated to the scholarship: 23/16901-9 - The basis of the food web influenced by climate changes: combined effects of extreme environmental stressors on the amphipod Cymadusa filosa and the macroalgae Sargassum filipendula., BP.MS

Abstract

Climate change driven by human activities has numerous consequences for coastal and marine environments. One consequence of climate effects is increased runoff in coastal areas. Here, we will assess how turbidity (i.e., total suspended particles) and increased browning (i.e., dissolved organic matter) in seawater influence the relationship between marine macroalgae (Fucus vesiculosus, Ectocarpus sp., and Pylaiella littoralis) and consumers (Corophium volutator and Microdeutopus gryllotalpa) by measuring changes in primary and secondary productivity biomass, consumers survival, algal consumption, and dissolved compounds released into the water, such as dissolved organic carbon (DOC), carbon dioxide (CO¿), ammonium (NH¿¿), and nitrate (NO¿¿), produced through animal feeding. We hypothesize that increased turbidity and browning levels will induce effects that may impact the homeostasis of the studied organisms. To test this, we will conduct experiments with two fixed factors arranged orthogonally: turbidity (2 levels) and browning (2 levels). The turbidity treatments will include 2 NTU (control) and 200 NTU, while the browning treatments will consist of natural terrestrial soil solution, evaluated by a spectrophotometer. The organic carbon and nitrogen content, as well as the stable isotopic signatures (¿¹³C and ¿¹¿N) of macroalgae, consumers, sediments, and filters, will be determined.