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A survey of the subtidal physical and biological features of the VEHEAP Harbours area (Victoria and Esquimalt Harbour, Gorge and Portage Inlet and Esquimalt Lagoon) with the intent of mapping the general distribution and position of physical and biological features for both inventory and harbour management purposes. The distribution of seabed sediments based on visual classification of the video imagery for the survey area. Visual estimates are made of sediment size and percentage occurrence within each second of video imagery. Sediment size classes are defined as follows: boulder: >25.6cm (general category - gravel); cobble: 6.4 to 25.6cm (gravel); pebble: 4mm to 6.4cm (gravel); granules: 2-4mm (gravel); sand: 0.062 to 2mm (sand); mud: <0.62mm (mud). Six sediment types based on a systematic application of percentage of gravel and the sand/mud ratio estimates are mapped for the survey area. It was often difficult to distinguish mud from mud/sand mixtures in the video imagery, and mud/sand was used as a default category in these cases. Gravel Content >30% = gravel; Gravel Content 5-30% and Mud/Sand Mixture = gravelly mud/sand; Gravel Content 5-30% and >90% Sand = gravelly sand; Gravel Content 0-5% and >90% Mud = mud; Gravel Content 0-5% and Mud/Sand Mixture = mud/sand; Gravel Content 0-5% and >90% Sand = sand; Other categories: Wood Debris = wood debris - substrate obscured; vegetation = Dense Vegetation - substrate obscured; Rock; no survey |