These processes play a prominent role in both freshwater and marine ecosystems and are influenced by a number of chemical, biological, and physical forces that are crucial to functions from nutrient cycling to energy transfer in food webs.
[3] The depth of an aquatic ecosystem is a key factor for benthic-pelagic exchanges because it determines the proximity and degree of interactions between the two environments.
[3] Diel vertical migrations (DVM) of fishes, zooplankton, and larger invertebrates, such as cephalopods and jellyfish, from the surface to the bottom can transfer nutrients and detritus from the pelagic zone to the benthos.
'[7] These daily migrations are along a vertical gradient were movements are typically downward by day and an upward at night in response to several factors, such as predator avoidance,[8] food availability,[9] and light intensity.
[10] Organisms who occupy both benthic and pelagic habitats as part of their life history help maintain adult populations and community structure, and serve as inputs essential for ecological interactions such as predation, competition, and parasitism.
Bioturbation by macrofauna affects sediment permeability and water content, destabilizes chemical gradients, subducts organic matter, and influences rates of remineralization and inorganic nutrient flux.
In response, sediments transform the deposited material (such as through degradation and dissolution) back into nutrients available for uptake in the water column.
[15] Anthropogenic pressures regulate benthic–pelagic coupling directly and indirectly through their effects on the physical (e.g., salinity, oxygen, temperature) and biological (e.g., species, communities, functional traits) components of ecosystems.