1. A decade in the doldrums: depressed size-structure in the Celtic Sea fish community

2. Effects of fishing on community size-structure
Fishing is selective and directly removes large individuals/species
Removal of large piscivores leads to predation release which indirectly enhances small fish biomass

3. Shift from large to small fish dominated community

4. Size-based indicators
Direct and indirect effects of fishing can be integrated by metrics like the Large Fish Indicator (LFI):
Proportion by weight of ‘large’ fish =
Where ‘large’ is derived from the data

5. LFI responds to F (lag). Sustained F in the Celtic Sea until 2002
Peak LFI in low levels throughout the 2000s

6. Fishing (+ discarding) of ‘recruits’ prevents recovery (Monkfish, Hake, Cod, Haddock)
M + G R
M + G
G + F
G + F
G + F

7. Models suggest a multi-decadal recovery period, asymptote depends on F history

8. Perturbed system with LFI well below 1990
No recovery during 2000s due to sustained F
Some good recruitments but low survival
Recovery depends on F history
Decadal process - full recovery not guaranteed