Complex sentence: The burrowing activities of benthic invertebrates have a pronounced effect on sediment properties and biochemical processes, by enhancing the porosity of water flow through the sediment, and assisting in flushing away toxic substances.
Split into simpler sentences: The burrowing activities of benthic invertebrates have a pronounced effect on sediment properties and biochemical processes. They enhance the porosity of water flow through the sediment and assist in flushing away toxic substances.