Lecture 2 - Sites@Duke
Fall 2011
Writing 20:Ocean Acidification
September 5, 2011
Lecture 2
“Physiological and Ecosystem
Effects of Ocean Acidification:
Potential Direct and Indirect Effects
Some of this lecture obtained from http://aslo.org/lectures/11_005/11_005_rfeely_sdoney.html
Outline
• Physiological processes
– Different types
– Acclimation and adaptation
• Ecosystem-level effects
– Ecosystem concepts
– Different types
– Biodiversity & regime shifts
• Types of studies, experiments
Physiological Processes
• Calcification
• Photosynthesis
• Hypercapnia (too much CO
2 in blood)
• Nutrient uptake and limitation
• Reduced gene expression
• Sensory perception
Physiological Processes
• Calcification
• Photosynthesis
• Hypercapnia (too much CO
2 in blood)
• Nutrient uptake and limitation
• Reduced gene expression
• Sensory perception
Photosynthesis
• Two different species of algae
• OA could lead to shifts in algal species composition
Physiological Processes
• Calcification
• Photosynthesis
• Hypercapnia (too much CO
2 in blood)
• Nutrient uptake and limitation
• Reduced gene expression
• Sensory perception
Sensory perception
Outline
• Physiological processes
– Different types
– Acclimation and adaptation
• Ecosystem-level effects
– Ecosystem concepts
– Different types
– Biodiversity & regime shifts
• Types of studies, experiments
Acclimation means the ability of an organism to change its phenotype , or expressed trait so that it can survive in an environment as it changes.
Adaptation means the ability of a population of organisms to change its genotype , or its genes in the DNA, over successive generations (evolution).
- generation times are important
- genetic diversity is important
Example of possible acclimation
Outline
• Physiological processes
– Different types
– Acclimation and adaptation
• Ecosystem-level effects
– Ecosystem concepts
– Different types
– Biodiversity & regime shifts
• Types of studies, experiments
Ecosystem
• Definition: A spatial explicit unit of Earth where living things and the environment interact
• Perturbations (like ocean acidification) can have various direct and indirect effects:
– Shifts in species composition and trophic cascade (food web) effects
– Temporal and spatial shifts in ecosystem functions
– All of these can change the structure, energy flow, and other functions of the ecosystem => regime shift
Different Types of Ecosystems
Likely to be Affected by OA
• Tropical coral reefs
• Pelagic ecosystems (pelagic = open water)
• Coastal/ benthic (benthic = bottom substrate)
• Deep sea
• High latitude
Regime shifts
Kroeker et al. 2011 PNAS
Outline
• Physiological processes
– Different types
– Acclimation and adaptation
• Ecosystem-level effects
– Ecosystem concepts
– Different types
– Biodiversity & regime shifts
• Types of studies, experiments
http://www.whoi.edu/OCB-OA/FAQs/ http://www.pmel.noaa.gov/co2/story/Ocean+Acidification http://oceanacidification.wordpress.com/ http://tos.org/oceanography/issues/issue_archive/22_4.html
http://www.us-ocb.org/publications/OCB_OA_rept.pdf
http://www.whoi.edu/sites/OceanAcidificationMeeting
