Impact of the Landing obligation on the and food-web? · 0.0 1.0 2.0 3.0 Plunge.seabirds Surf.feed.seabirds Baleen whales Toothed whales Sharks L Sharks/rays Anglerfish Sea bass Cod
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Impact of the Landing obligation on the and food-web?
Marie Savina, Telmo Morato, Eider Andonegi
Raphael Girardin, Sigrid Lehuta, Morgane Travers, Toni Quetglas, Robin Cook, Michael Heath, George Triantaphyllidis, Athanassios Tsikliras, Harriet Cole, Ambre Soszynski, Didier Gascuel
And the « Impact on Stocks and Ecosystems » WP team!
Oro et al., 2013. Ecology Letters
Stop discards (food source) in the ecosystem
O’Neill et al., 2019. The European Landing Obligation
Decrease fishing mortality of unwanted catch
Tools to evaluate effects of discard ban on the whole ecosystem and food-web?
Azores
North Sea
Bay of Biscay
Eastern Channel
Aegean Sea
Balearic Islands
Celtic Sea
Effects of reducing discards into marine food webs?
Effects of reducing discards into marine food webs?
Survival rate = 0
Survival rate = 0
Effects of reducing discards into marine food webs?
Survival rate = 0
Effects of reducing discards into marine food webs?
Selectivity assumed to effectively reduce all unwanted catch (Reduction in fishing mortality)
Effects of reducing discards into marine food webs?
(F reduction) (F reduction)(F constant) (F constant)
Selectivity assumed to effectively reduce all unwanted catch (Reduction in fishing mortality)
Effects of reducing discards into marine food webs?
Aegean Sea
0: BAU
1: NoD
2: NoD+Sel
3: LO
4: LO+sel
Eastern Channel
Effects of reducing discards into marine food webs?
Without F reduction With F reduction
0.2 0.4 0.6 0.8 1.0 1.2
Plunge.seabirdsSurf.feed.seabirds
Baleen whalesToothed whales
Sharks LSharks/rays
AnglerfishSea bass
Cod adCod juvenile
Blue whittingHake adulte
Hake juvenileHaddockWhittingMegrim
SoleBoarfish
PlaiceDemersal L
Demersal MDemersal S
Horse MackerelMackerel
SpratHerringSardine
PoutsPelagic L
Pelagic MCephalopods
Norway lobsterLobsters/Crabs
ShrimpsCarn.&necro.invert.Ss.dep.feed.invert.
Surf.susp.&des.feedersBenthic meiofauna
Sc2 Landing obligation Sc3 All discards landed
0.0 1.0 2.0 3.0
Plunge.seabirdsSurf.feed.seabirds
Baleen whalesToothed whales
Sharks LSharks/rays
AnglerfishSea bass
Cod adCod juvenile
Blue whittingHake adulte
Hake juvenileHaddockWhittingMegrim
SoleBoarfish
PlaiceDemersal L
Demersal MDemersal S
Horse MackerelMackerel
SpratHerringSardine
PoutsPelagic L
Pelagic MCephalopods
Norway lobsterLobsters/Crabs
ShrimpsCarn.&necro.invert.Ss.dep.feed.invert.
Surf.susp.&des.feedersBenthic meiofauna
Suprabenthic invert.
Sc4 L.O. + Selectivity Sc5 All discards avoided
Celtic sea
Effects of reducing discards into marine food webs?
Without F reduction With F reduction
Effects of reducing discards into marine food webs?
Azores
Without F reduction With F reduction
Effects of reducing discards into marine food webs?
Summary
The of reducing or eliminating discards are , except for the seabirds
Effects of reducing discards into marine food webs?
Summary
The of reducing or eliminating discards are , except for the seabirds
The of reducing or eliminating unwanted catch (through increased selectivity and reduced fishing mortality) are , except for
some mix-trophic impacts
The negative effects of reducing or eliminating discards are , except for the seabirds
Why? The amount of compared to other food sources available to opportunistic marine scavengers
Effects of reducing discards into marine food webs?
% D
isca
rds
/ liv
ing
bio
mas
s
The negative effects of reducing or eliminating discards are , except for the seabirds
Why? The amount of compared to other food sources available to opportunistic marine scavengers
Effects of reducing discards into marine food webs?
Are we sure about our results? Uncertainty is due to the
Solution:1) Increase of discard monitoring programs;2) Discard monitoring programs should (designed to estimate discard
rates per fleet and stock rather than to estimate the discard flow to the ecosystem)
Bio
mas
sch
ange
Prey on discards
The negative effects of reducing or eliminating discards are , except for the seabirds
Why? The was for all functional groups
Effects of reducing discards into marine food webs?
The negative effects of reducing or eliminating discards are , except for the seabirds
Why? The was for all functional groups
Effects of reducing discards into marine food webs?
Are we sure about our results? It’s in the diet studies
Solution:1) Novel methods for evaluating predation on discards need to be developed2) Better estimates on predation on discards
The of reducing or eliminating unwanted catch are , except for mix-trophic impacts
Why? by reducing fishing mortality of unwanted catch outweigh the negative effects of decreasing food source for scavengers
Effects of reducing discards into marine food webs?
Land Improved Landingeverything selectivity obligation
Percentage change relative to 2003-2013 baseline
Suspended bacteria & detritusWater column ammonia
Water column nitrateKelp
PhytoplanktonBenthic filt/dep feeder larvae
Omnivorous zooplanktonBenthic carn/scav feeder larvae
Carnivorous zooplanktonPelagic fish adults+larvae
Migratory fishDemersal fish adults+larvae
BirdsSeals
Cetaceans
-40 0 20 40 60 80
Fishery discards & offal
Corpses
Sediment bacteria & detritus
Kelp debris
Porewater ammonia
Porewater nitrate
Benthic filt/dep feeders
Benthic carn/scav feeders
-40 0 20 40 60 80
-89
Suspended bacteria & detritusWater column ammonia
Water column nitrateKelp
PhytoplanktonBenthic filt/dep feeder larvae
Omnivorous zooplanktonBenthic carn/scav feeder larvae
Carnivorous zooplanktonPelagic fish adults+larvae
Migratory fishDemersal fish adults+larvae
BirdsSeals
Cetaceans
-40 0 20 40 60 80
Fishery discards & offal
Corpses
Sediment bacteria & detritus
Kelp debris
Porewater ammonia
Porewater nitrate
Benthic filt/dep feeders
Benthic carn/scav feeders
-40 0 20 40 60 80
-91
Suspended bacteria & detritusWater column ammonia
Water column nitrateKelp
PhytoplanktonBenthic filt/dep feeder larvae
Omnivorous zooplanktonBenthic carn/scav feeder larvae
Carnivorous zooplanktonPelagic fish adults+larvae
Migratory fishDemersal fish adults+larvae
BirdsSeals
Cetaceans
-40 0 20 40 60 80
Fishery discards & offal
Corpses
Sediment bacteria & detritus
Kelp debris
Porewater ammonia
Porewater nitrate
Benthic filt/dep feeders
Benthic carn/scav feeders
-40 0 20 40 60 80
-91
StrathE2E modelling of the Landing Obligation in the North Sea
The of reducing or eliminating unwanted catch are , except for mix-trophic impacts
Why? by reducing unwanted catch outweigh the negative effects of decreasing food source for scavengers
Effects of reducing discards into marine food webs?
Are we sure about our results? Model, implementation, and ecological uncertainties
Solution:1) Technical measures; development and implementation of technical solutions for reducing
unwanted catch2) Tactical measures: Adapting fishing patterns3) Increase survival of unwanted catch
by reducing unwanted catch outweigh
the negative effects of decreasing food for scavengers
Conclusions
: increase fisheries selectivity
to reduce fishing mortality of unwanted catch and increase survival
Thank you
This project has received funding from the European Union’s Horizon 2020 research and innovation programme, under grant agreement No 633680 (DiscardLess)
This output reflects only the author’s view and the European Union cannot be held responsible for any use that may be made of the information contained therein
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