an introduction to the ecological impacts of invasive freshwater … · 2017-05-04 · fish are the...
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Julien CUCHEROUSSET
CNRS – University Paul Sabatier Toulouse, France
Email: [email protected]
An introduction to the ecological impacts of invasive freshwater fishes
Gozlan 2008 Fish Fish
Impacts of non-native fish: Rationale
Fish are the most frequently introduced organisms in freshwater ecosystems
Reasons - Aquaculture - Angling/Sport - Fisheries - Ornamental
Fish are the most frequently introduced organisms in freshwater ecosystems
Reasons - Aquaculture - Angling/Sport - Fisheries - Ornamental Gozlan 2008 Fish Fish
Native species
Ln (Maximum Body Size) 0 1 2 3 4 5 6 7
Den
sity
0.0
0.1
0.2
0.3
0.4
Blanchet et al. 2010 Ecol Let
Impacts of non-native fish: Rationale
Global distribution of freshwater fish body size:
Fish are the most frequently introduced organisms in freshwater ecosystems
Reasons - Aquaculture - Angling/Sport - Fisheries - Ornamental Gozlan 2008 Fish Fish
=> Introduction of large-bodied species
Native species
Non-native species
Ln (Maximum Body Size) 0 1 2 3 4 5 6 7
Den
sity
0.0
0.1
0.2
0.3
0.4
P < 0.001
Blanchet et al. 2010 Ecol Let
Impacts of non-native fish: Rationale
Global distribution of freshwater fish body size:
Nile perch (Lates niloticus)
European catfish (Silurus glanis)
Largemouth bass (Micropterus salmoides)
Rainbow trout (Oncorhynchus mykiss)
Peacock bass (Cichla ocellaris)
Impacts of non-native fish: Introduced predators
Distribution of body-mass in communities influences their structure and functioning Riede et al. 2011
Eltonian pyramid
Abundance Biomass
Body
mas
s or
trop
hic
leve
l
Trebilco et al. 2013
Body
size
Elton 1927 Lindeman 1942
Ecological pyramid
Impacts of non-native fish: Rationale
Introduced species could modify (directly and indirectly) these patterns
Impacts of non-native fish: Rationale
Terborgh 2015
Distribution of body-mass in communities influences their structure and functioning Riede et al. 2011
Eltonian pyramid
Abundance Biomass
Body
mas
s or
trop
hic
leve
l
Trebilco et al. 2013
Body
size
Elton 1927 Lindeman 1942
Ecological pyramid
New predators New predators
Genetic
Individual
Population
Community
Ecosystem
Cucherousset & Olden 2011 Fisheries
Impacts of non-native fish: Ecological impacts
Genetic
Individual
Population
Community
Ecosystem
Cucherousset & Olden 2011 Fisheries
- Gene transcription - Hybridization
- Behavior - Morphology - Vital rates
- Transmission of pathogens - Invasive fish as parasites - Demographic effects - Distributional effects
- Species extinction - Composition changes - Alteration of food webs
- Biochemical cycles - Energy fluxes between ecosystems - Ecological engineering
Impacts of non-native fish: Ecological impacts
Genetic
Individual
Population
Community
Ecosystem
Cucherousset & Olden 2011 Fisheries
- Gene transcription - Hybridization
- Behavior - Morphology - Vital rates
- Transmission of pathogens - Invasive fish as parasites - Demographic effects - Distributional effects
- Species extinction - Composition changes - Alteration of food webs
- Biochemical cycles - Energy fluxes between ecosystems - Ecological engineering
Impacts of non-native fish: Ecological impacts
Impacts on food-web structure
Zaret & Paine 1973 Science
BEFORE INVASION
Impacts of non-native fish: Food web structure
Zaret & Paine 1973 Science
Introduced predators
BEFORE INVASION AFTER INVASION
=> Strong changes in community and food-web structure
Impacts of non-native fish: Food web structure
Vander Zanden et al. 1999 Nature
Micropterus dolomieu INVASION Ambloplites rupestris
Introduced predators
Trop
hic p
ositi
on
4
3
2
-30 -28 -26 -24 δ13C
40%
60%
Zooplankton
Prey fish
LITTORAL PELAGIC Native predator
LAKES WITHOUT INVASION
Impacts of non-native fish: Food web structure
Salvelinus namaycush
LAKES WITH INVASION
-30 -28 -26 -24 δ13C
20%
80%
Vander Zanden et al. 1999 Nature
Micropterus dolomieu INVASION Ambloplites rupestris
LITTORAL PELAGIC
Zooplankton
Prey fish
Introduced predator
Introduced predators
Native predator
Trop
hic p
ositi
on
4
3
2
-30 -28 -26 -24 δ13C
40%
60%
Zooplankton
Prey fish
LITTORAL PELAGIC Native predator
LAKES WITHOUT INVASION
Impacts of non-native fish: Food web structure
Salvelinus namaycush
Cucherousset et al. 2012 Frontiers in Ecology and the Environment
- Fish community composition
- Species status (native vs non-native)
- Trophic position TP (Fishbase)
13 rivers worldwide
Impacts of non-native fish: Food web structure
Historical
No change in mean trophic position Increased trophic variability
Curr
ent
Mean TP
Historical
CV TP
Curr
ent
p = 0.19 p < 0.01
Impacts of non-native fish: Food web structure
Cucherousset et al. 2012 Frontiers in Ecology and the Environment
Historical
No change in mean trophic position Increased trophic variability
Modified basal structure of food webs
Increased food chain length
Curr
ent
Mean TP
Historical
CV TP
Historical Cu
rren
t
p = 0.19 p < 0.01
Maximum TP
Curr
ent
Curr
ent
Historical
Impacts of non-native fish: Food web structure
Cucherousset et al. 2012 Frontiers in Ecology and the Environment
Minimum TP
Historical
No change in mean trophic position Increased trophic variability
Modified basal structure of food webs
Increased food chain length
=> Trophic dispersion of food webs
Curr
ent
Mean TP
Historical
CV TP
Historical Cu
rren
t
p = 0.19 p < 0.01
Maximum TP
Curr
ent
Curr
ent
Historical
Impacts of non-native fish: Food web structure
Cucherousset et al. 2012 Frontiers in Ecology and the Environment
Minimum TP
Impacts on energy fluxes and ecosystem functioning
0
Knight et al. 2005. Nature
Impacts of non-native fish: Fluxes and ecosystems
0
Knight et al. 2005. Nature
Impacts of non-native fish: Fluxes and ecosystems
Cucherousset et al. 2012 Plos ONE Source: Le silure, géant des rivières (ARTE)
Impacts of non-native fish: Fluxes and ecosystems
45 beaching behaviour observed ⇒ 28% of success rate ⇒ Trophic specialisation
Baxter et al. (2004) Ecology
Impacts of non-native fish: Fluxes and ecosystems
Baxter et al. (2004) Ecology
Impacts of non-native fish: Fluxes and ecosystems
(1) Control
Baxter et al. (2004) Ecology
(2) Habitat alteration
(1) Control
Impacts of non-native fish: Fluxes and ecosystems
Baxter et al. (2004) Ecology
(2) Habitat alteration
(3) Trout invasion
(1) Control
Impacts of non-native fish: Fluxes and ecosystems
Baxter et al. (2004) Ecology
(2) Habitat alteration
(3) Trout invasion
(1) Control
(4) Habitat + Invasion
Impacts of non-native fish: Fluxes and ecosystems
Baxter et al. (2004) Ecology
(2) Habitat alteration
(3) Trout invasion
(1) Control
(4) Habitat + Invasion
Impacts of non-native fish: Fluxes and ecosystems
Terrestrial invertebrates consumed by the native species
1 2 3 4
Baxter et al. (2004) Ecology
(2) Habitat alteration
(3) Trout invasion
(1) Control
(4) Habitat + Invasion
Impacts of non-native fish: Fluxes and ecosystems
Herbivorous invertebrates biomass
1 2 3 4
Baxter et al. (2004) Ecology
(2) Habitat alteration
(3) Trout invasion
(1) Control
(4) Habitat + Invasion
Impacts of non-native fish: Fluxes and ecosystems
Primary production
1 2 3 4
Baxter et al. (2004) Ecology
(2) Habitat alteration
(3) Trout invasion
(1) Control
(4) Habitat + Invasion
Impacts of non-native fish: Fluxes and ecosystems
Emergent invertebrates biomass
1 2 3 4
Baxter et al. (2004) Ecology
(2) Habitat alteration
(3) Trout invasion
(1) Control
(4) Habitat + Invasion
Impacts of non-native fish: Fluxes and ecosystems
Riparian spider density
1 2 3 4
Impacts of non-native fish: Conclusion
Salmonids are an important group of invasive fish and can help filling some of the knowledge gaps in the field of biological invasions:
Julien CUCHEROUSSET
CNRS – University Paul Sabatier Toulouse, France
Email: [email protected]
An introduction to the ecological impacts of invasive
freshwater fishes