THE ACOUSTIC DETECTION AND CHARACTERISTICS OF SUBLITTORAL BIVALVE REEFS IN THE BAY OF FUNDY

Bivalve reefs are universal topographic features of the continental sh elf benthic environment at depths which may exceed 100 m. The use of m odern acoustic survey methods (sidescan sonar and high-resolution seis mic reflection systems) within the Bay of Fundy located novel, flow-pa rallel bioherms tentatively identified as horse mussel, Modiolus modio llus, reefs. We show, using a remote operated vehicle (ROV) on which a color video camera was mounted, that the acoustically identified feat ures are indeed horse mussel reefs. Their linear shape, distribution a nd orientation suggest a dominant control by strong tidal currents. (C ) 1998 Elsevier Science Ltd. All rights reserved.