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time between disturbance events. Secondary

The ecological consequences of global change for the

impacts -- such as storm-associated runoff of low-

MAR could include:

salinity waters laden with nutrients, sediments and

· Increased coral susceptibility to bleaching and

pollutants -- are an additional concern. Hurricanes

disease,

will continue to be a major driving force of coral reef

condition in the MAR. The concern is whether corals

· Lower coral growth and reef accretion rates,

will be able to maintain resilience in light of their

already degraded condition and the likelihood that

· Increased bioerosion,

global climate change will alter the pattern of this

and other natural disturbances.

· Loss of reef structure due primarily to stronger and

more frequent hurricanes, and

Global climate change may also affect human health

and well-being in different ways and to different

· Sea level rise causing flooding of coastal habitats.

degrees. Direct impacts to human well-being may

The main GCC-related impacts that have been

include greater exposure to weather extremes (e.g.,

observed in the MAR include:

more hurricanes or droughts), an increase in the

transmission of infectious diseases (especially through

· Coral Bleaching: Corals are highly sensitive to

water and food), and a loss of food productivity and

changes in water temperature, and increases of

drinking water availability. Climate change is likely

only 1 to 2°C can have potentially lethal effects47.

to cause changes in the frequency or distribution

The MAR region has experienced several large-

of human diseases (i.e., insect vector diseases like

scale bleaching events (e.g., in 1995 and 1998),

malaria, waterborne diseases like cholera). For

causing significant coral mortality in some areas.

example, malaria and dengue cases increased in

Human-induced global warming is widely believed

Honduras after Hurricane Mitch in 199852. Poor

to be responsible for increases in global sea surface

populations will be at the greatest health risk

temperature. Coral bleaching may be a good early-

because of the lack of public health services and lack

warning indicator of climatic changes.

of financial resources or infrastructure to minimize

health risks. Managers, scientists, and policy makers

· Diseases: Coral disease outbreaks are one of the

are encouraged to develop mechanisms to address

single most devastating disturbances to coral reefs

the link between the ecological and social implications

in the Caribbean and MAR in the recent past49.

of global climate change (see Indicators SW2 -- Safe

Disease has always been a natural process in

Water and Sanitation and SW3 -- Cholera and Other

regulating populations, but the recent increased

Diseases).

magnitude of disease and resultant mortality may be

unique in the last several thousand years. Disease

Managers in the MAR can do little to alleviate the

organisms tend to thrive in higher temperatures, and

root causes of GCC or even to prevent impacts

some may also benefit from increased ultraviolet

(e.g., bleaching, hurricanes) on a local scale. But

(UV) radiation. Both stressors (temperature and UV)

they do need tools to evaluate the extent of these

may render host organisms more prone to disease.

GCC impacts. More importantly, effective, proactive

In addition to these effects related to global climate

management is needed to protect the coral reefs from

change, diseases have also been linked to elevated

additional anthropogenic stress, which compounds

nutrients (especially from sewage), sedimentation

the synergistic effects of global climate change,

and runoff50. Little specific information is available,

prevents recovery from acute disturbances, and

however, as it is usually difficult to identify the exact

further increases the likelihood of significant loss of

disease pathogen. Similar to humans, corals seem

ecosystem structure and function. Reefs that may be

to be more prone to disease when affected by other

naturally less susceptible or more resilient to bleaching

stressors.

and other disturbances need to be identified and

incorporated into MPA conservation zones.

· Powerful Storms: Powerful storms and hurricanes

are naturally occurring events to which corals have

Indicators selected to track the ecological effects of

adapted over evolutionary timescales. Storms

global climate change are:

can be both beneficial and detrimental to reefs.

The MAR region has a long history of hurricanes

D13 - Photic (Amphi) Index

damaging the coral reefs. One projection of global

D14 - Coral Bleaching Index

climate change models involves the predicted

increase in the frequency, intensity and duration of

D15 - Reef Resiliency to Bleaching

large storms fueled by warmer seas51. This effect

could prevent corals from having sufficient recovery

D

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