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Coastal & Marine Geology Program > St. Petersburg Coastal and Marine Science Center > Educational Materials > Honduras Coral Reefs Documentary

Coral Reefs in Honduras: Status after Hurricane Mitch
Online Mini-Documentary Movie

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Documentary Transcript

  opening title screen
science for a changing world

Coral Reefs in Honduras: Status after Hurricane Mitch

Coral reefs around the world...  
[narrator] Coral reefs around the world were severely affected by bleaching by a large El NiĖo event in 1997 and 1998 and on October 25, 1998, coral reefs along the northern coast of Honduras faced additional problems. Category 5 Hurricane Mitch had formed into the fourth strongest Atlantic hurricane on record. It followed a slow, meandering path as waves formed by the 180 mile per hour winds battered coral reefs and six feet of rain overflowed rivers and inundated reefs with fresh water and sediment. By the time it had passed, over 11,000 people were dead and 2 million were homeless throughout Honduras, Nicaragua, El Salvador, and Guatemala.

  In response to this devastation...
In response to this devastation, the U.S. Agency for International Development received funding from Congress to provide assistance to countries devastated by Mitch. Part of this money was allocated to the U.S. Geological Survey to study the impact of Hurricane Mitch on two coral reefs directly hit: Cayos Cochinos Biological Reserve, which is located on the continental shelf approximately 12 miles off the northern coast of Honduras, and Roatán Marine Reserve, located 18 miles north of Cayos Cochinos.

Cayos Cochinos is undeveloped...  
Cayos Cochinos is undeveloped but the surrounding waters are frequently turbid due to sediment from river discharge off the Honduran coast. Roatán is more developed but is generally free from outside sediment sources. These differences enabled USGS scientists to study hurricane effects on two different types of reefs that are in proximity to each other.

[Part 2]

  It became clear as soon as we got there...
[Bob Halley, USGS] It became clear as soon as we got there on our first visit that the Cayos Cochinos area was much more affected by Mitch than Roatán, even though Roatán was closer to the hurricane when it was a very strong hurricane. It was not the winds and waves and physical damage that affected the reefs; primarily it was the turbid water that came from nearshore areas so that the inshore reefs in Cayos Cochinos were much more affected by the turbid waters that came off after the flooding.

In order to measure the effects of flooding...  
[narrator] In order to measure the effects of the flooding, instruments that measure light, temperature, and salinity were installed at both reefs at a depth of 17 feet. Generally, river runoff lowers salinity levels and carries soil and debris that reduces the amount of light that the coral reef receives. This inhibits photosynthesis, increases nutrient levels that can trigger algal growth, and stresses the coral. One river in particular, the Aguan River, generated a plume of water large enough to inundate Cayos Cochinos and Roatán and to influence other reefs far out in the Caribbean.

  The major effect that we saw...
[Bob Halley] The major effect that we saw was on our first trip, which was about a year after the hurricane, there were abundant coral diseases. In fact, we were sort of taken aback with the amount of a particular disease - black band disease - that seemed to just be everywhere.

Coral disease was not alone...  
[narrator] Coral disease was not alone in impacting the reefs. Prior to Hurricane Mitch, some of the highest water temperatures ever recorded in the Caribbean were impacting the reefs, causing coral bleaching. To monitor post-Mitch water temperatures, an additional instrument that measures only temperature was installed at 3 different areas in the Cayos Cochinos Biological Reserve: Lion’s Head at a depth of 17 feet, Pelican Point at a depth of 66 feet, and a reef near the project’s field station at a depth of 3 feet.

  Coral bleaching occurs usually in the late summer...
[Bob Halley] Coral bleaching occurs usually in the late summer when water temperatures reach their annual extremes and, if they are high enough, it so stresses the coral that they expel the algae that live symbiotically in their tissues (it’s what gives the coral their color) and when they do that the corals turn absolutely white. They can exist that way for maybe 6 or 8 weeks and recover but if the bleaching persists longer than 2 months there is an amazing amount of fatality associated with it.

[Part 3]

Hurricanes affect coral reefs in many ways...  
[narrator] Hurricanes affect coral reefs in many ways. Pounding waves inflict direct physical damage. And sediment runoff from flooded rivers causes acute stress in coral reef organisms. There are also beneficial effects, such as the breaking and distribution of coral fragments that start new colonies and the cooling of high water temperatures.

  As with any large hurricane...
[Bob Halley] As with any large hurricane, Hurricane Mitch had a tremendous amount of upwelling associated with it where cooler, deeper ocean waters are brought to the surface by the mixing that the hurricane induces.

Hurricane Mitch actually reduced the water temperature...  
Hurricane Mitch actually reduced the water temperature by more than a degree. That may not seem like much, but often a single increase of a degree or two when the water temperature is already warm is enough to induce bleaching. So, while Hurricane Mitch did some damage and caused a fair amount of disease for a few years, it prevented a bleaching episode that evidently killed as much as 50% of the live coral in some other areas of the Caribbean in September of 1998.

  Each visit we made subsequently...
Each visit we made subsequently to our first visit we saw less and less coral disease and we thought, perhaps, the difference in less disease was just seasonal, but by the Fall of 2000, when the water warmed back up again, there was not an associated increase in disease. The amount of disease continued to decline so we think it was a real shift in just improvement of the reef over the two years we were there.

[Part 4]

Very little reef data existed in this area...  
[narrator] Very little reef data existed in this area prior to Hurricane Mitch so continued monitoring is essential in order to understand the long-term impacts that major storms, high water temperatures, sediment runoff, and low salinity events have on coral reef health.

  We have made arrangements with our colleagues...
[Bob Halley] We have made arrangements with our colleagues on Cayos Cochinos at the research station to continue to maintain this instrumentation with two goals in mind: 1) we will get a longer record which will help us differentiate what is a local and what is a more regional signal and 2) in any given year late in the hurricane season they may experience another hurricane and so we would very much like to see what kinds of data these instruments collect if another significant hurricane impacted the region.

Produced and Edited by:
Tim Holmes

Narration by:
Terry Edgar

Video Provided by:
Ginger Garrison – USGS
Bob Halley – USGS
Don Hickey – USGS
Thomas Michot – USGS
Chris Reich – USGS

Still Imagery Provided by:
Aerofoto Centro Americana
Air Force Open Skies Program of the Defense Threat Reduction Agency
Defense Mapping Agency
Earth Scan Laboratory, Coastal Studies Institute, Louisiana State University
NASA – Earth Sciences & Image Analysis, Johnson Space Center
National Center for Atmospheric Research (NCAR)
NOAA Geophysical Fluid Dynamics Laboratory (GFDL)
NOAA Magazine
NOAA Office of Satellite Data Processing and Distribution (OSDPD)
NOAA Operational Significant Event Imagery
NOAA National Climatic Data Center
University of Wisconsin – Madison Cooperative Institute for Meteorological Satellite Studies (CIMSS)
University of Wisconsin – Madison Space Science and Engineering Center
USGS Center for Integration of Natural Disaster Information (CINDI)

Special Thanks To:

Steven Carson – NOAA GFDL
Neal Dorst – NOAA AOML
Ginger Garrison – USGS
Peter Grimm – NOAA
Bob Halley – USGS
Don Hickey – USGS
Bob Jubach - NOAA
Frank Lepore -NOAA
Mary Matta – NOAA
Thomas Michot – USGS
Jeff Phillips – USGS
Edward Proffitt – USGS
Chris Reich – USGS
John Sheldon – NOAA GFDL
Mark Smith - USGS
John Walkey – USGS

The Honduras Coral Reef Fund and Cayos Cochinos Reserve:
Adoni Cubas
Carlos Garcia-Saez
Elias Aquilar Gonzales

The Roatan Institute for Marine Sciences:
Julio Galindo
Jennifer Keck


Bob Halley

Don Hickey

Chris Reich

St. Petersburg Coastal and Marine Science Center
600 Fourth Street South
St. Petersburg, FL 33701

science for a changing world

Coastal & Marine Geology Program > St. Petersburg Coastal and Marine Science Center > Educational Materials > Honduras Coral Reefs Documentary U. S. Department of the Interior | U.S. Geological Survey
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Updated December 05, 2016 @ 11:24 AM (THF)