Scotian shelf (Eastern)

Exploitation of groundfish on the eastern Scotian Shelf was intense from the 1950s to the early 1990s. The long term trends (1980-2010) demonstrate significant fishing impacts with decreases in fish size, trophic level, biomass, landings, and proportion of predatory fish indicating fishing down the foodweb. In the early 90s, the cod stock collapsed, other groundfish species experienced serious declines and the ecosystem switched from one dominated by demersal fish to one dominated by forage species. Since 1993 there has been a groundfish fisheries moratorium and Fisheries and Oceans Canada has adopted an ecosystem approach leading to improved management and governance. The recent trends in the ecological indicators’ (2001–2010) show that the long term declines have stopped but the absence of significant increases, other than for life span, implies no ecosystem recovery. Compared to other systems, the recent ecological status, as depicted in the pie diagram suggests that the ecosystem is relatively healthy compared to others: this reflects its temperate location, not its fishing history.


Table of Frequencies (percent)
Direction Fish size Trophic Level % Predators Life Span Biomass Stability % Sustainable Stocks
Fish size 0.293063 0.00 0.00 0.00 0.00 0.00
Trophic Level 0.00 0.563074 0.00 0.00 0.00 0.00
% Predators 0.00 0.00 0.523261 0.00 0.00 0.00
Life Span 0.00 0.00 0.00 0.579787 0.00 0.00
Biomass Stability 0.00 0.00 0.00 0.00 0.154303 0.00
% Sustainable Stocks 0.00 0.00 0.00 0.00 0.00 0.280332

Chla = Chlorophyll A (mg/m3)
SST = Sea Surface Temperature (°C)
Table of Frequencies (percent)
Direction Management Governance Contribution Wellbeing
Management 0.57 0.00 0.00 0.00
Governance 0.00 0.63 0.00 0.00
Contribution 0.00 0.00 0.09 0.00
Wellbeing 0.00 0.00 0.00 0.31