Spring 2012 Writing 20:Ocean Acidification

January 19, 2012

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 of ecosystems– Trophic cascades– Biodiversity & regime shifts

• Types of studies, experiments

Physiological Processes

• Calcification• Photosynthesis• Hypercapnia (too much CO2 in blood)

• Nutrient uptake and limitation• Reduced gene expression• Sensory perception

Physiological Processes

• Calcification• Photosynthesis• Hypercapnia (too much CO2 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 CO2 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 of ecosystems– Trophic cascades – 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 acclimationB

yrne et al. 2011, Mar. B

iol.

Outline

• Physiological processes– Different types– Acclimation and adaptation

• Ecosystem-level effects– Ecosystem concepts– Different types of ecosystems– Trophic cascades– 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

Outline

• Physiological processes– Different types– Acclimation and adaptation

• Ecosystem-level effects– Ecosystem concepts– Different types of ecosystems– Trophic cascades– Biodiversity & regime shifts

• Types of studies, experiments

Outline

• Physiological processes– Different types– Acclimation and adaptation

• Ecosystem-level effects– Ecosystem concepts– Different types of ecosystems– Trophic cascades– Biodiversity & regime shifts

• Types of studies, experiments

Regime shifts

Kroeker et al. 2011 PNAS

Outline

• Physiological processes– Different types– Acclimation and adaptation

• Ecosystem-level effects– Ecosystem concepts– Different types of ecosystems– Trophic cascades– Biodiversity & regime shifts

• Types of studies, experiments

http://www.pmel.noaa.gov/co2/story/Ocean+Acidification

http://www.whoi.edu/OCB-OA/FAQs/

http://oceanacidification.wordpress.com/

http://www.us-ocb.org/publications/OCB_OA_rept.pdf

http://www.whoi.edu/sites/OceanAcidificationMeeting

http://tos.org/oceanography/issues/issue_archive/22_4.html