undisturbed marine habitats have a well-developed three-dimensional
structure and heterogeneity, providing niches for a diverse array of
organisms. Activities such as trawling and dredging, in particular,
grossly simplify habitat structures either by uprooting, crushing and
flattening epifaunal species or by disrupting sediment stratification,
burrows and other structures for infaunal species (see Section 6.10.2).