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Coral Reef Ecosystems

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Coral Reef Ecosystems

Is Earth’s climate and associated ecosystem about

to act erratically

Are humans to blame

What can we do


! --What is natural

! --What are natural variations and

what variations are controlled / caused by

human actions

! --What can we do to best serve

ourselves

! --Is the Earth ecosystem about

to die


The gross structure of climate change

and sea-level fluctuations - we know.


Climate changes. So what

Sea level fluctuates. So what


Can past fluctuations

of sea level help us

understand present

and future fluctuations

of sea level

What will happen

next


What are coral reefs

What is the concern

What is the evidence for concern

What can be done

What am I doing


WHAT IS A CORAL REEF


WHAT ARE WHAT CORALS IS CORAL


WHAT ARE CORALS

Animal

Mineral

Vegetable


Corals are animals

coral

polyp

jellyfish

sea anemone


Coral

Spawning


Corals are plants

Zooxanthellae: plant cells

within the coral tissue

Up to 50% of “coral” biomass

is plant material.


Corals are Minerals

Corals make skeletons of CaCO 3 (aragonite)


Global distribution of coral reefs


WHY DO CORALS DIE

DISEASE

OLD AGE

STRESS

! natural

! human-induced


STRESS

TEMPERATURE: ! too hot or too cold (climate)

SALINITY: !! too salty, too fresh! (climate)

TURBIDITY: ! algae (nutrients ocean circulation

! ! ! ! ! ! climate)

! ! ! sediment (land use, climate)

SEA LEVEL:!! too low, too high (climate)

WATER CHEMISTRY:! pH; CO 2 for skeletons (climate)

UV RADIATION:!

“POLLUTION”!

HUMAN CONTACTS

ozone!


Bleached coral could be environment warning

Monday, January 25, 1999

Scientists studying coral reefs in the

Florida Keys have found that 100-

year-old corals are suddenly

succumbing to diseases they were

previously able to resist. The

Cornell University researchers warn

this may be a sign of future

environmental stress on the planet.

http://www.enn.com


What is CORAL BLEACHING

Corals evolved in warmer environments than

today; so they should be able to survive. It may

be that if temperature change were slowly

increasing, corals could evolve, …

As water temperature “rapidly” rises above

normal (few degrees), corals are stressed and

their symbiotic zooxanthellae leave.

Temperature variability.


Mean Annual Temperature (1400 - present)


Mean Annual Temperature (1400 - present)

This is the concern.


El Niño

La Niña


Multivariate ENSO Index

Fluctuations: 3 to 7 years

The intensity of El Niño events is increasing.


Multivariate ENSO Index

Fluctuations: 3 to 7 years

The intensity of El Niño events is increasing.

(Really Perhaps this is part of a natural

variation in intensity.)


Aspergillosis (fungal)


Common plants and animals suffer from

diseases. Why not corals They do!

Black Band Disease (bacterial)


Black Band Disease


Unknown Disease


Coralline Lethal

Orange Disease

(CLOD)

Dark Spot

Disease


Red Band Disease

Rapid Wasting

Disease


HUMAN IMPACTS


HUMAN IMPACTS


ANCHOR DAMAGE


Miner’s

Canary


Surface temperatures have

warmed over the past century


WORLD

RESOURCES

INSTITUTE

The polar ice cap is melting


WORLD

RESOURCES

INSTITUTE

The polar ice cap is melting

How “natural” is this climate change


Humanity has grown in numbers over time

7,000

Millions of people

6,000

5,000

4,000

3,000

2,000

1,000

0

0 500 1000 1500 2000 2500

Year


Excess nutrients may spur algal blooms

Post 1972


For perhaps the first time in the history of our planet, a single

species may be close to exerting an effect that rivals the importance

of …. natural controls.

- Dennis Hubbard, coral scientist


Are global changes (in coral reefs) resulting from human

actions What is NATURAL


Earth’s Canary


How do Earth systems really work


Data

Fish Belt Transect Survey

2.5 m Colored Wire or Rod

100m Transect Line

Coral Reef


125,000 years old


coral rubble

in place corals


Catastrophic die-off of

corals YES.

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