Impact studies examining scallop dredging have been limited to loose-sediment habitats typical of most
scallop grounds. However, it is likely that rocky-reef habitats also suffer damage from dredging activity
since commercially viable grounds are often found in close proximity. This study presents a photographic
survey of four experimental tows performed in two rocky-reef biotopes. Survey images show characteristic
dredge damage in both study areas, with the greatest damage apparent on the site that is likely to
have been unfished previously. Moreover, whilst vulnerable species such as the elephant sponge, Pachymatisma
johnstonia, exhibited visible damage in the majority of recorded cases, damage to other epifauna,
although in evidence, was restricted. This unexpected result is likely to be caused by the manner in which
the scallop dredge fishes hard, uneven substrates. Hence, in instances were the morphology of the rockyreef
is particularly uneven, damage to some epifaunal species may be incremental. This is in contrast to
loose sediment habitats where the majority of damage occurs on the first tow of fishing gear through a
pristine site. The importance of these findings to the planning of protected areas and the incorporation
of fishing effects into ecosystem approaches of fisheries management is discussed.