Complex sentence: These large quantities in addition to typically small sediment grain size and dense populations make bioturbators important in estuarine respiration, as they enhance the transport of oxygen into sediments through irrigation and increase the surface area of oxygenated sediments through burrow construction.
Split into simpler sentences: These large quantities, in addition to typically small sediment grain size and dense populations, make bioturbators important in estuarine respiration. Bioturbators enhance the transport of oxygen into sediments through irrigation and increase the surface area of oxygenated sediments through burrow construction.