Sediment pore water nutrient profiles in Portuguese marine canyons

Shelf morphology and local hydrodynamical conditions may significantly influence the partitioning of material (terrestrial or in situ production) between shelf sediments (0-200 m) and the deeper ocean margin sediments (200-2000 m). Submarine canyons are typical morphological features of the rather narrow Iberian shelf. They have been shown to trap and transport material from the shelf to the abyss. During the OMEX cruise in 1999 the relative contribution of canyons in off-shelf transport was studied by comparing sediment carbon budgets for the Nazar?? Canyon and for ???normal??? shelf-slope-abyssal transects. In this study, three different canyon-shelf systems were compared, Setubal and Nazar?? Canyons on the Iberian Margin and Cap de Cr??us Canyon in the Gulf of Lyon.