The most important biogeochemical transformations and boundary exchanges in the Indian Ocean seem to occur in the northern region, where the processes originating at the land-ocean boundary extend far beyond the continental margins. Exchanges across the eastern and western boundaries are generally less significant. However, several important biogeochemical fluxes (e.g. exchanges across the air-sea, sedimentwater, land-sea and continental shelf-open ocean) remain to be quantified for most biogenic elements in the latter two areas. Some of these fluxes are expected to be substantial in the case of Indonesian continental margins and probably also across the eastern coasts of Africa not covered in this chapter. However, a dearth of information makes these margins some of the least known in the world calling for concerted research efforts, involving regional/international initiatives with emphasis on local capacity building, in future.