Supplementary file 1_Temperature effects on productivity, respiration, and dissolved organic matter degradation in subtropical Florida waters following hurricane-driven riverine runoff and brownification.docx

This study investigated how elevated temperature and humic acid enrichment, under both pre- and post-hurricane (Idalia, Debby, Helene and Milton) in situ and manipulated conditions, affect the metabolic rates of phytoplankton communities on the West Florida Shelf (WFS). We hypothesized that warming, combined with hurricane-driven humic inputs, would decrease primary production rates while enhancing respiration and dissolved organic matter (DOM) degradation, shifting system toward net heterotrophy.

Using ¹⁸O techniques combined with oxygen concentration measurements, the differences between light-dependent respiration (hereafter Gross Respiration, GR, representing only that associated with algal respiration) and dark respiration (hereafter Community Respiration, CR, representing the sum of microbial respiration) were measured in addition to rates of Gross Primary Production (GPP), and Net Primary Production (NPP).