The Mesoamerican Barrier Reef: Environmental Threats

Grace Adams

The Mesoamerican Barrier Reef:

• 2nd largest barrier reef in the world

• Extends from the Yucatan Peninsula, along the coasts of Belize, to the Bay Islands of Honduras

• Home to over 500 species of fish

• Threatened by many environmental factors

Threats: Global Warming

Rising Temperatures• Recent years have had record

setting temperatures • (2005 was hottest year since

accurate records)

• During these summer months, ocean temperatures rise 1°-2°C

• Average Northern Hemisphere temperatures have risen 0.6°-0.8°C in the last 10 years

• Warm waters cause stress to corals:

• Rising ocean levels (melting ice sheets)

• Increased hurricanes • Increased coral bleaching• Increased acidity

Hurricanes• Largest most destructive

hurricanes have occurred in the last 10 years

• Becoming more frequent and severe

• Stronger hurricanes result in more wave damage and flooding, stressing coral

• coral cover is reduced by approximately 17%, in the Caribbean in the year following a hurricane impact

Coral Bleaching• Warm waters cause large-scale bleaching

• Average of 25% of coral bleached in each temperature hot spot in 2005

• Occurs when symbiotic zooxanthellae (algae) that provides much of the energy for coral growth, and coral reef growth is expelled from host animal.

• Bleached corals starve and are more susceptible to disease

• Many bleached corals eventually die out

Ocean Acidification

• Parallel to climate change• Increased concentrations of CO2 dissolve in sea water,

reducing pH levels• Reduces coral’s ability to grow carbonate skeletons

• Results in slower growth and is more vulnerable to erosion

• By the end of this century, acidification may continue at a rate of 100 times faster

Threats: Fishing

Fishing

• Main industry in Central America and Caribbean

• Overfishing, illegal fishing, and fishing with inappropriate gear threatens natural resources, fish species, and coral

Overfishing• Commercial fishing industry

is expanding due to better technology and increased demand

• Over-exploitation of many targeted species such as shrimp, sharks, and lobster

• Causes ecological extinctions and loss of ecosystem function

• Of Belize’s 554 marine and 237 reef-associated fish species,21 of these species are threatened and 14 are protected under existing treaties and conventions

Illegal Fishing

• Illegal fishing issues include: • Fishing with scuba gear• Use of nets along reefs• Use of traps outside reefs• Taking conch or lobster below the

legal size limit• Fishing outside of closed seasons

• Although many Central American countries have laws to prevent illegal fishing, they are not adequately enforced

Cyanide Fishing• Used to stun reef fish in order

to collect them• Inexpensive and effective • Illegal in many countries

• Causes damage to surrounding coral reefs

• Destroys thousands of hectares each year

• Causes coral bleaching

• Kills both targeted and non-targeted fish as well as corals, invertebrates, eggs, larvae, and microorganisms

Protective Measures

Global Warming• Energy reduction to limit climate change and greenhouse

effects

Fishing• Enforce laws and create and infrastructure to monitor

large reef areas• When at a reef, do not touch the coral or take pieces

home• World Heritage Sites and marine reserves protect

important areas

BibliographyPlaya del Carmen. (2007). Mesoamerican barrier reef. Retrieved from

http://www.aboutplayadelcarmen.com/playadelcarmen/mesoamerican-barrier-reef.asp

Coral Reef Aliance, Initials. (2010). Caribbean/latin american crsd sites. Retrieved from http://www.coral.org/where_we_work/caribbean

Gardner, T.A., Cote, I.M., Gill, J.A., Grant, A., & Watkinson, A.R. (2005). Hurricanes and caribbean coral reefs: impacts, recovery. Unpublished manuscript, School of Biological Sciences and Environmental Sciences, University of East Anglia, Norwich, Retrieved from http://www.com.univ-mrs.fr/~boudouresque/Publications_FLUC_2006_2007/Gardner_et_al_2005_Ecology.pdf

Wilkinson, C., Souter, D. (2008). Status of Caribbean coral reefs after bleaching and hurricanes in 2005.Global Coral Reef Monitoring Network, and Reef and Rainforest Research Centre, Townsville, 152 p. Retrieved from http://cmsdata.iucn.org/downloads/status_carib_corals.pdf

BibliographyWorld Resources Institute, . (2005). Belize coastal threat atlas [p. 9].

Retrieved from http://pdf.wri.org/belize_threat_atlas.pdf

Belize Institute of Environmental Law and Policy, . (2004, November 15). Petition to the world heritage committee requesting inclusion of belize barrier reef reserve system. Retrieved from http://www.law.ufl.edu/conservation/international/pdf/belize.pdf

McClellan, K. (2008). Coral degradation through destructive fishing practices. The encyclopedia of earth. Retrieved July 9, 2011, from http://www.eoearth.org/article/Coral_degradation_through_destructive_fishing_practices?topic=4951

Novi Meadows, . (2002). Coral reef. Retrieved from http://library.thinkquest.org/CR0215471/coral_reef.htm