The Lability of Riverine Particulate Organic Carbon Delivered to the Ocean

University Of Maine, Orono ME

Investigators

Abstract

The large annual flux of organic carbon from land to the ocean largely disappears in the sea. Reasons for this loss are not clear. Under this award, the PI will examine abiotic and biotic aspects of the lability to loss of riverine particulate organic matter. Work will focus on the Mississippi, as it demonstrates the clearest loss of particulate organic material of any North American river upon deposition in the ocean. Photochemical experiments will follow up on initial work showing significant dissolution of particulate organic matter subjected to solar levels of radiation. Interactions with metal cycling will be studied, as will a variety of other physicochemical variables. Biochemical lability will be explored via enzyme hydrolyses and bacterial incubations. Seasonal patterns will be examined, as will be the influence of deposition in freshwater environments.