vulnerability of open ocean food webs in the tropical pacific to climate change
DESCRIPTION
Vulnerability of open ocean food webs in the tropical Pacific to climate change. Presented by Valerie Allain. Authors. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/1.jpg)
Vulnerability of open ocean food webs in the tropical Pacific to
climate change Presented by
Valerie Allain
![Page 2: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/2.jpg)
This presentation is based on Chapter 4 ‘Vulnerability of open ocean food webs in the tropical Pacific to climate change’ in the book Vulnerability of Tropical Pacific Fisheries and Aquaculture to Climate Change, edited by JD Bell, JE Johnson and AJ Hobday and published by SPC in 2011.
The authors of Chapter 4 are: Robert Le Borgne, Valerie Allain, Shane P Griffiths, Richard J Matear, A David McKinnon, Anthony J Richardson and Jock Young
Authors
![Page 3: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/3.jpg)
Photo: Marc Taquet, FADIO, IRD/IFREMER
Photo: Photoshot/Superstock
![Page 4: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/4.jpg)
The tuna food web
Food webs are complex
![Page 5: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/5.jpg)
The tuna food web
Nutrients
Phytoplankton at the base of the food web require light and nutrients to develop
Light
![Page 6: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/6.jpg)
PhytoplanktonPhoto: Gustaaf Hallegraeff
![Page 7: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/7.jpg)
The five oceanic provinces
![Page 8: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/8.jpg)
The five oceanic provinces• Warm Pool
Normal El Niño
![Page 9: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/9.jpg)
The five oceanic provinces• North and South Gyres (Case 3) and equatorial
divergence (Case 4)
![Page 10: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/10.jpg)
Impact of climate change
• Surface area of the provinces
Present day
![Page 11: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/11.jpg)
The impact of climate change
• Surface area of the provinces
2035
↘ rich equatorial divergence↗ poorer gyres and warm pool
![Page 12: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/12.jpg)
Impact of climate change
• Surface area of the provinces
2050
↘ rich equatorial divergence↗ poorer gyres and warm pool
![Page 13: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/13.jpg)
Impact of climate change
• Surface area of the provinces
2100
↘ rich equatorial divergence↗ poorer gyres and warm pool
![Page 14: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/14.jpg)
Impact of climate change
• GYRESExchanges
between deep rich water and surface poorer waters
↘ of nutrients reaching the surface where photosynthesis can occur
present future
![Page 15: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/15.jpg)
Impact of climate change
↘ nutrients reaching the surface where photosynthesis can occur
present future
• Equatorial upwelling
Exchanges between deep rich water and surface poorer waters
![Page 16: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/16.jpg)
presentpresent
Impact of climate change• Effect on phytoplankton and zooplankton
20352050Today
![Page 17: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/17.jpg)
presentpresent
Impact of climate change• Effect on phytoplankton and zooplankton
↘ of phytoplankton and zooplankton
203520502035
![Page 18: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/18.jpg)
presentpresent
Impact of climate change• Effect on phytoplankton and zooplankton
↘ of phytoplankton and zooplankton
203520502050
![Page 19: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/19.jpg)
presentpresent
Impact of climate change• Effect on phytoplankton and zooplankton
↘ of phytoplankton and zooplankton
203520502100
![Page 20: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/20.jpg)
Impact of climate change• Effect on micronekton
↘ micronektonIm
age:
Val
erie
Alla
in,
SP
C
![Page 21: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/21.jpg)
Uncertainties and adaptation• Need to establish long-term observations for
biological processes
Image: Valerie Allain, SPCPhytoplankton
![Page 22: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/22.jpg)
Uncertainties and adaptation• Need to establish long-term observations for
biological processes
Zooplankton
![Page 23: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/23.jpg)
Uncertainties and adaptation• Need to establish long-term observations for
biological processes
Longitude d.dm
Depth
m
06-13-2008 NZ-Aust start lat-40.4641 end lat -40.6744
150 152 154 156 158 160 162 164 166 168 170
0
200
400
600
800
1000
1200 -80
-75
-70
-65
-60
Micronekton
Image: Rudy Kloser, CSIRO
Imag
e: V
aler
ie A
llain
, S
PC
Image: Valerie Allain, SPC
![Page 24: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/24.jpg)
Uncertainties and adaptation• Need to establish long-term observations for
biological processes
PredatorsPhoto: Peter Sharples
![Page 25: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/25.jpg)
Uncertainties and adaptation
• Global reduction of greenhouse gas emissions
• Appropriate tuna fisheries management measures can help maintain healthy food webs and fisheries giving better chances to food webs and tuna to adapt to climate change
![Page 26: Vulnerability of open ocean food webs in the tropical Pacific to climate change](https://reader036.vdocument.in/reader036/viewer/2022062408/568144ba550346895db1835a/html5/thumbnails/26.jpg)
Conclusions
• Food webs are complex, based on phytoplankton• 5 provinces and food webs in the Pacific• Reduction of the production• Long-term monitoring is needed• Reducing greenhouse gas emissions and
managing tuna fisheries