The effect of temperature on rates of dissolved organic carbon (DOC) release by the kelp Ecklonia radiata (phylum Ocrophyta): Implications for the future coastal ocean carbon cycle.

Dissolved organic carbon (DOC) released by macroalgae is an intrinsic component of the coastal ocean carbon cycle, yet knowledge of how future ocean warming may influence this is limited. Temperature is one of the primary abiotic regulators of macroalgal physiology, but there is minimal understanding of how it influences the magnitude and mechanisms of DOC release. To investigate this, we examined the effect of a range of temperatures on DOC release rates and physiological traits of Ecklonia radiata, the most abundant and widespread kelp in Australia that represents a potentially significant contribution to coastal ocean carbon cycling.

Short-term hyposalinity stress increases dissolved organic carbon (DOC) release by the macroalga Sargassum fallax (Ochrophyta).

Dissolved organic carbon (DOC) released by macroalgae supports coastal ocean carbon cycling and contributes to the total oceanic DOC pool. Salinity fluctuates substantially in coastal marine environments due to natural and anthropogenic factors, yet there is limited research on how salinity affects DOC release by ecologically important macroalgae. Here we determined the effect of short-term salinity changes on rates of DOC release by the habitat-forming fucalean seaweed Sargassum fallax (Ochrophyta).