Sponge Ecology on Sublittoral Hard Substrates in a High Current Velocity Area

The ecology of sponges on shallow sublittoral hard substrates in Little Letite Passage, off Deer Island, Bay of Fundy, New Brunswick, Canada was studied with respect to their areal coverage and orientation to current direction. Coverage was found to increase with increasing depth and current velocity and was greater on hard substrates than on gravel or cobble substrates. The orientation of an individual sponge to the direction of the current was found to be dependent on its morphology, with upright species orientated across the current and massive or encrusting species showing a slight orientation parallel to the current direction. Of the 16 species recorded from Little Letite Passage, the two most common were Isodictya deichmannae and Eumastia sitiens.