1. Coral Reefs and Climate Change
Management Solutions and Challenges for a Changing System
By: William Adams
ATOC 4800
17 April, 2017

2. Table of Contents I-Coral Reefs II-Environmental Threats
A. Climate Change
B. Ocean Acidification
III-Coral Bleaching
IV-Managing Impacts
V-Reef Resilience: Management Opportunities/Limitations
A. Local Solutions
B. Limits
VI-Adaptation
VII-Discussion

3. I. Coral Reefs
Make up 1% of ocean floor, but are home to over 25% of species in the ocean
Result of symbiotic relationship between coral and unicellular algae known as zooxanthellae
Relationship possible only under small range of environmental conditions
Not only essential for biodiversity, but monetary value to humans

4. II. Reefs Under Threat
3 Most important factors to reef growth and health:
1. Seawater Temperature
2. Carbon Chemical Conditions
3. Light
The biggest threats to coral reefs:
A. Climate Change
B. Ocean Acidification

5. A. Climate Change Physical consequence of carbon in the atmosphere
Drives ocean warming which disrupts biological and ecological reef processes, that drives coral bleaching
NOAA: 2014/2015 ocean temperatures are approximately .74 degrees C warmer than the global average for the 20th century
Since the start of the industrial era, the ocean has absorbed 1/3 of CO2 emitted from human activity
Source: Ken Anthony—Australian IMS

6. B. Ocean Acidification
Chemical consequence of increased CO2 in the atmosphere
Process
1. CO2 in the ocean produces carbonic acid
2. Lowers the pH and reduces concentrations of carbonate ions
3. Chemical building blocks of marine carbonic structures are destroyed and reef growth and function is impaired
Unlike climate variability, ocean acidification is a creeping stressor that results in marine calcification

7. III. Bleaching The result of warming, as well as, acidification
Breakdown in relationship between coral and algae
Host expel dysfunctional algae, causing coral to turn white
Algae loss starves coral of energy from photosynthesis, causing extensive reef systems to die out
2016: Great Barrier Reef undergoes the worst bleaching event in history enhanced by an El Nino event, bleaching 90% of the corals in the reef system
Great Barrier Reef 2016
Source: GBRMPA

8. IV. Managing Impacts Managing impacts requires 3 things:
Drivers/activities that result in stress on reef systems
The scales they operate on
What way these influences interact
These indicators help identify stress pathways and management possibilities through these “effective management levers”
Maps pathways from sources to impacts on the ecosystem goods and services and a possible analysis for mitigation by closing the loop back to stressors through management policies

9. Source: Ken Anthony—Australian IMS

10. V. Reef Resilience: Management Opportunities and Limitations
Ecological Resilience
capacity of a system to absorb stress, reorganize and recover from disturbances and over time, retain same function, structure and identity
Managing for Resilience: builds on the premise that smart actions on the ground can provide some level of protection against decline caused by climate change
Example: protected marine parks and no-take fishing reserves

11. A. Local Solutions Examples Challenges Example Spatial planning
Improved land-use practices to enhance water quality in costal zones
Protection of herbivorous fish to promote top- down control of macroalgae
Intensified control of coral eating organisms
Challenges
Limits to resilience (maximum resilience potential)
Local-scale actions have limited geographical reach
Example
Crown-of-Thorns Starfish Outbreaks and the Great Barrier Reef
Source: GBRMPA

12. B. Limitations
Resilience lost to one pressure might not be replaceable by mitigation of another pressure and impairment of resilience caused by acidification and warming cannot directly be restored by protecting more fish or reef systems
Reduced coral calcification will be a resilience handicap that can only be addressed by the reversal of changes in ocean carbon chemistry
Management--Understanding the spatial and temporal scope of actions is critical to set realistic expectations for what can be achieved through management actions in the face of global climate change
1. Zone of impact of different stressors
2. Zone of influence from management and policy

13. VI. Adaptation Human-Assisted Evolution being considered
Artificial selection
In theory, this approach could help reef managers break through the resilience ceiling imposed by climate change and ocean acidification
Genetically engineered or modified organisms are not feasible, but assisted evolution (artificial selection) are an area of research with a mgmt. application in the future

14. VII. Discussion 3-5 minutes
Discuss in a group what the benefits/risks are of the adaptation management strategy are
Discuss the question: is spread and dominance of selected keystone species better then total decline?