Impacts of Climate Change on the marine environment –

a case study of the CaribbeanIFES Symposium on Climate Change

October 20-25, 2008

Marcia M. CrearyEnvironmental Data Manager

CARIBBEAN COASTAL DATA CENTRECARIBBEAN COASTAL DATA CENTRECENTRE FOR MARINE SCIENCESCENTRE FOR MARINE SCIENCESTHE UNIVERSITY OF THE WEST INDIES THE UNIVERSITY OF THE WEST INDIES AT MONA, JAMAICAAT MONA, JAMAICA

Climate change and the marine environment

• Over the last 200 years, human induced emissions of greenhouse gases have also contributed to global climate change

• Many marine ecosystems are responding both physically and biologically to changes in regional climate

• This is caused predominately by the – warming of air, – the increase in sea surface temperature (SST) – modification of currents, – precipitation regimes – wind patterns.

Impact on marine ecosystems and wildlife

• Marine Ecosystems– Mangroves– Seagrass beds– Coral Reefs– Open Ocean

• Marine Wildlife– Marine mammals, reptiles and amphibians– Fishes stocks– Marine birds– Plankton

Coral Reefs Under Threat • Over a third of the world's coral species are at

elevated risk of extinction.

• Reefs of the Western Atlantic have generally decreased in living corals since the 1970’s

• Reefs of the Great Barrier Reef were resilient until 1996, they are now beginning to struggle

• The degradation of many reefs are due to combination of the global stresses of climate change

• Also regional and local stressors including runoff from agriculture, other land-based sources of pollution, over-fishing, and habitat destruction associated with coastal development.

What are corals?• The corals that form reefs are “hard corals” with skeletons of

calcium carbonate.• These “reef-building” corals are usually composed of

• many polyps (colonial) • microscopic plants (zooxanthellae) in their tissues which

provide some additional food for the coral by photosynthesis • need light and so grow close to the surface of the sea.• reef-builders require water temperatures of 20-28°C and so

are located almost entirely between 30°N and 30°S.

What are coral reefs?• Coral reefs are large structures

composed mainly of dead coral skeletons built up over thousands of years.

• The reef maintains itself by the continued growth of living corals

Complex three dimensional framework provides habitat for numerous other species

Climate change factors that affect coral reefs

• Increased sea surface temperature• Sea level rise as a result of large melting of the

ice-caps • Increasing concentration of CO2 in seawater. • Altered circulation patterns• Increased frequency of severe weather events

Why do coral bleach?

• Corals go pale or white as a result of stress– Prolonged elevated sea surface

temperatures.– High levels of UV light– Low light conditions– High turbidity, sedimentation– Disease– Variable salinity– Pollution

What is coral bleaching?

Mass Bleaching – a recent phenomenon

• 1997-1998– Mass mortality of corals – 16% of worlds reef seriously damaged and

on 40% of these recovered• 2002

– Great Barrier Reef and SW Pacific• 2005/2006

– Caribbean and Western Atlantic

Status of Caribbean Coral Reefs after Bleaching and Hurricanes in 2005 and 2006. Special Report by GCRMN

Global trends in the extent and severity of mass bleaching. (IUCN)

The Wider Caribbean

Thermal Stress(Degree heating weeks map – NOAA)

Number of weeks of exposure to higher than normal temperatures.

Assessment of Bleaching in Jamaica

• August - October 2005 Jamaica and other Caribbean nations experienced prolonged high sea surface temperatures

• Jamaica experienced 5-6 weeks of exposure to higher than normal temperatures which resulted in widespread bleaching

• Funding was received from Reef Check International though NOAA to document the event.

• November 2005 to May 2006 , Reef Check surveys with an additional bleaching component were conducted.

• Sites located in Negril, Discovery Bay, Portland, Port Royal and the Portland Bight Protected Area were assessed twice. First to determine the extent of bleaching and second to assess level of recovery.

Observed bleaching• Bleaching was first noted on the north coast of

the island late August to early September and later manifested on the south coast in late September to early October.

• The effects of the bleaching episode were more pronounced on the south coast than on the north.

Bleached coral populations at various sites around Jamaica

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Bleaching was observed at most sites.

On the resurvey, up to 50% of the bleached corals had recovered.

Sites exhibited varying degrees of bleaching from10 % to 95%.

Bleaching and subsequent mortality of corals in some

Caribbean Countries

Bleached coralsCoral species bleached• Montastrea annularis• Montastrea faveolata• Montastrea cavernosa• Siderastrea siderea • Diploria strigosa• Agaricia spp. • Millepora complanata• Porites porites

Coral Diseases• September 2006 - black band and

white plague disease noted in the Port Royal Cays

• Affected mainly the massive corals Siderastrea, Montastraea and Diploria species

Hurricanes

• Major hurricanes that have impacted Jamaica’s reefs include Hurricane Allen in 1980, Hurricane Gilbert in 1988 and Hurricane Ivan in 2004.

• Hurricane Ivan caused visible damage to coastal areas. Variable levels of damage were noted on the north and south coasts.

• In 2004 and 2005 (Dennis, Emily and Wilma) hurricanes passed south of Jamaica, as such reefs on the south coast have been hardest hit.

Hurricane tracks 2000-2006

Other threats to Caribbean Reefs

• Coastal development• Inland activities• Over-fishing• Destructive fishing

practices• Waste disposal• Ship-based activities• Physical damage

Implication for coral reef health in the future

• More frequent bleaching events• Increased susceptibility to coral

diseases• Shift in community structure• Reduced ability to withstand

anthropogenic impacts• Further damage as a result of storm

events

Can coral adapt to climate change?

• Adaptation– Genetic variability, resistant genotypes

• Acclimatization– Biochemical or physiological

• Range shift– Expand to the sub-tropics

What can be done?• Coral reef restoration

– Artificial reefs– Coral gardening

• Research– Species resistant to temperature increases

and diseases– Stress history of specific species

• Reduced localized stressors– Less stressed reefs recover better– Marine protected areas

• Changes is resource use– Fisheries and tourism

International Year of the Reef:

IYOR 2008• Resolution was approved by the ICRI

members at the ICRI General Meeting held in Cozumel, Mexico (22-23 October 2006)

• Goals– Strengthening awareness about the

ecological, economic, social and cultural value of, and critical threats to, coral reefs and associated ecosystems; and

– Generating urgent action at all levels to develop and implement effective management strategies for conservation and sustainable use of these ecosystems.

Call to Action

• Cut CO2 emissions by lowering our carbon footprint and ask our policymakers to commit to low carbon economic growth.

• Eliminate open access fisheries in coral reef ecosystems. • Protect coral reef herbivores, including parrotfish. • Establish and strictly enforce networks of Marine Protected

Areas that include No-Take Areas. • Effectively manage the waters in between Marine Protected

Areas. • Maintain connectivity between coral reefs and associated

habitats.• Report regularly and publicly on the health of local coral

reefs. • Recognize the links between what we do on land and how it

affects the ocean. • Bring local actors together to develop a shared vision of

healthy reefs and a road map for getting there. • Work for change with management to produce desired

outcomes.

Thank you.