This study explores spatio-temporal changes in epibenthic communities due to salmon aquaculture at deep (>30 m), hard-bottom dominated sites in Newfoundland (Canada). Using a drop-camera approach, we followed changes with production at two aquaculture sites, as well as potential recovery processes at two fallow sites, comparing their epibenthic composition with nearby non-production sites. Multivariate analysis revealed that aquaculture production led to rapid changes in epibenthic communities, as evidenced primarily by the presence of two visual indicators: bacterial mats and opportunistic polychaetes. Due to low taxon richness and abundances, as well as variability among sites, no clear intermediate successional stages were apparent. Beggiatoa-like mats and opportunistic polychaetes appeared rapidly once aquaculture production began; these indicators did not increase in spatial extent during the survey and were typically observed up to 100 m, and occasionally up to 160 m from cages. After 15 months of fallowing, Beggiatoa-like mats and opportunistic polychaetes remained present at sites and were occasionally accompanied by few other taxa, suggesting incomplete recovery.

Depth range
8- 144 m

Mesophotic “mentions”
0 x (total of 8480 words)

Classification
* Presents original data
* Focused on 'mesophotic' depth range
* Focused on 'temperate mesophotic ecosystem'

Fields
Community structure
Fisheries
Management and Conservation
Biodiversity

Focusgroups
Overall benthic (groups)

Locations
Canada - Atlantic Ocean

Platforms
Drop / Towed Video