Class 11 - Conservation II

Happy New Year!
今年も宜しくお願いします。

Outline
• 1. Centers of endemism.
• 2. How to stop bleaching (?).
• 3. The importance of fish and mangroves to coral reefs.
• 4. Not just coral reefs: how other ecosystems are connected.
• 5. Conclusions.
• 6. Video: Coral reef organisms.
Part 1 - Centers of endemism
Roberts et al. 2002
• Examined 3235 species of fish, corals, snails, lobsters.
• Ranges in 1 X 1 degree squares (cells).
• 7.2 to 53.6% have restricted ranges; vulnerable to extinction.
• Looked for centers of endemism.

• 10 richest centers cover 15.8% of reefs; 0.012% of oceans.
• Contain 44.8 to 54.2% of restricted range species.
• Major biodiversity hotspots.

Hotspots threatened by human activity.
Conservation should focus on these areas.

• Many threats linked to land.
• Many hotspots next to land hotspots.
• Integrating conservation may be effective.
Part 2 -
How to stop bleaching (?)
West & Salm 2003
• What factors help corals against bleaching?
• Reviewed all research up until 2003.

• Many examples of resistance to or recovery from bleaching.

• Many factors contribute to resistance.
• Can be included in management plans.
• Cumulative stresses worse than one stressor.
Many factors contribute to resilience.
Can be included in management plans.
Healthy diverse reefs more stable than reefs under threat.


Mumby et al. 2004
• Reef fish often use mangroves as nurseries.
• But can use other environments, not confined.
• Also, despite deforestation, other pressures (fishing, larval supply) likely larger.
Examined biomass and numbers of grazing fish at reefs with and without connecting mangrove forests.
Consistently shown despite higher fishing pressure reefs with mangroves have more fish!
Reefs that have lost mangrove have extinctions.


• Management should include connected habitats, not islands of each type.
• Future destruction of mangroves will have negative influence on reef.
Mumby et al. 2007
• Caribbean reefs have damage from loss of Diadema antillarum and two species of coral.
• “Sick” reefs characterized by macroalgae.
• Can macroalgae be reversed? Or is it a stable state?

• Used computer modeling and simulation.
• Showed reefs can easily change to other states once D. antillarum died off.
• With only parrotfish as grazers, small negative change in parrotfish numbers results in macroalgae blooms.
• Coral becomes unstable state with low grazing.

• Regular impact of hurricanes worsens with lack of grazers (fish and urchins).
• Modeling useful for conservation targets.
Part 4 - Not just coral reefs: how other ecosystems are connected
Baum et al. 2003
• Examined shark populations in NW Atlantic.
• Sharks caught in large numbers by longline fishing nets.
• No data until this study.


• All species examined showed rapid declines over last 15 years.
• Most species declined over 50%.
• Three species declined over 75%.

• Recommends marine conservation areas AND reduction in fishing.
• This is because sharks have large ranges and slow rates of population growth.
• Sharks worldwide in danger.
James et al. 2005
• Examined leatherback turtle migration and ranges using satellite telemetry (n=38).
• Tagged off E. Canada.
• Leatherback turtle now critically endangered (IUCN) despite worldwide distribution.

• Turtles migrated south to Caribbean and back within 1 year.
• Most turtles avoided areas of protection; and most spent time in areas of longline fishing.

• Turtles vulnerable to 1) northern coastal and 2) shelf water fisheries.
• Action must be taken to prevent; current conservation is not enough.
Part 5 - Conclusions
1. Coral reefs are linked to other ecosystems, both marine and on land.
2. Conservation plans must protect linked areas and ecosystems, and not “islands”.
3. Protected areas should be decided based on endemism, geographic features, neighboring ecosystems, etc.
4. We must do MORE!

Thanks! References cited:
1. Roberts et al. 2002. Marine biodiversity hotspots and conservation priorities for tropical reefs. Science 295: 1280-1284.
2. West & Salm. 2003. Resistance and resilience to coral bleaching. Conservation Biol 17: 956-967.
3. Mumby et al. 2004. Mangroves enhance the biomass of coral reef fish communities in the Caribbean. Nature 427: 533-536.
4. Mumby et al. 2007. Thresholds and the resilience of Caribbean coral reefs. Nature 450: 98-101.
5. Baum et al. 2003. Collapse and conservation of shark populations in the northwest Atlantic. Science 299: 389-392.
6. James et al. 2005. Identification of high-use habitat and threats to leatherback sea turtles in northern waters: new directions for conservation. Ecol Letters 8: 195-201.