There are some factors that affects outwelling, first is the amount ofprimary production of an estuary wherein highly productive salt marshes results in increase outwelling. Second thetidal amplitude and geomorphology since estuary is not a stable environment which is typically affected by rainfall, the greater the rainfall the larger the outwelling.
Outwelling is the course by which coastal marshes and mangroves production generates an overload quantity of organic carbon and drive out these organic nutrients and detritus into the surrounding and coastal areas, which in turn increase the productivity oflocal fisheries and marine plants. It also nourishes plankton communities.
Outwelling takes place as rhythm that link toinundation events, productivity andtidal fluctuations, but in some cases, macrofauna and algae are force out from the salt marshes into the water rather than nutrients, but this has aparallel effect of drawing small fish and nourishing the marine environment. On the other hand, outwelling does not every time occur in an estuary, in some study done in England salt marsh reveals no evidence of outwelling, it rather show that salt marshesimport organic carbons.