Characterising the sources and fate of dissolved organic matter in Shark Bay, Australia: a preliminary study using optical properties and stable carbon isotopes

Shark Bay, a seagrass-dominated subtropical ecosystem with limited freshwater inputs, exhibits complex sources and transformations of dissolved organic matter (DOM). A study combining excitation/emission fluorescence spectroscopy (EEM-PARAFAC) and stable carbon isotope analysis revealed that DOM in Shark Bay originates from multiple sources, including terrestrial inputs, plankton, macroalgae, and seagrass. While isotopic data suggests substantial contributions from seagrass, fluorescence analysis indicates that much of this input is derived from decomposing detritus rather than active exudation during primary production. The study also highlights the role of evaporation in concentrating DOM and the potential significance of photo-degradation in transforming DOM within the system.

Cawley, K. M., Ding, Y., Fourqurean, J., & Jaffé, R. (2012). Characterising the sources and fate of dissolved organic matter in Shark Bay, Australia: a preliminary study using optical properties and stable carbon isotopes. Marine and Freshwater Research, 63(11), 1098–1107. https://doi.org/10.1071/mf12028