Impact of the Landing obligation on the and food-web? · 0.0 1.0 2.0 3.0 Plunge.seabirds...

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?


Survival rate = 0

Selectivity assumed to effectively reduce all unwanted catch (Reduction in fishing mortality)


(F reduction) (F reduction)(F constant) (F constant)

Selectivity assumed to effectively reduce all unwanted catch (Reduction in fishing mortality)


Aegean Sea

0: BAU

1: NoD

2: NoD+Sel

3: LO

4: LO+sel

Eastern Channel


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




Azores



Summary

The of reducing or eliminating discards are , except for the seabirds


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


% D

isca

rds

/ liv

ing

bio

mas

s


Why? The amount of compared to other food sources available to opportunistic marine scavengers


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


Why? The was for all functional groups



Why? The was for all functional groups


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


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







BirdsSeals

Cetaceans

-40 0 20 40 60 80


Corpses


Kelp debris

Porewater ammonia

Porewater nitrate



-40 0 20 40 60 80

-91







BirdsSeals

Cetaceans

-40 0 20 40 60 80


Corpses


Kelp debris

Porewater ammonia

Porewater nitrate



-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


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

Impact of the Landing obligation on the and food-web? · 0.0 1.0 2.0 3.0 Plunge.seabirds...

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