This documentary presents how recent changes in the composition and quantities of African dust transported to the Caribbean and the Americas might provide clues to why Caribbean coral reef ecosystems are deteriorating and human health may be impacted.
Nutrients in Dust from the Sahara Desert cause Microbial Blooms on the East Coast of the United States Completed
Satellite Image of a Dust Cloud from the Sahara Desert
Saharan dust nutrients, particularly iron, deposited episodically in tropical marine waters stimulate marine microbial bloom growth and change microbial community structure.
Saharan desert dust transported by easterly trade winds across the Atlantic Ocean provides pulses of nutrients, including iron, to ocean surface waters, yet the biological response to these events is not fully known, especially in the microbial community. Vibrio is a ubiquitous genus of marine bacteria that constitute a small fraction of the microbial community and are important in biogeochemical cycling of nutrients and trace metals. This genus also includes many well-known pathogens of marine organisms and humans, including the causative agent of the severe diarrheal disease cholera, shellfish-associated gastroenteritis, and seawater-associated wound infections; however, the research reported here did not assess the health effects or exposures to pathogens.
Scientists used a unique combination of simulated dust events in a laboratory setting and field sampling during a Sahara dust event in the Florida Keys to understand the effects of the dust on Vibrio bloom growth and changes in microbial community structure. The scientists determined that Saharan dust nutrients can promote rapid growth of the relatively rare Vibrio's and indicate that Vibrio species are "first responders" to dust-associated iron. This work indicates that marine bacteria play an important role in biogeochemical cycles related to periodic input of iron from Saharan dust-deposition and emphasizes that the periodic iron pulses rapidly increase the growth of marine bacteria, some of which are known to cause disease in humans and marine organisms.
This research was funded by the USGS Ecosystems Mission Area’s Environmental Health Program (Contaminant Biology and Toxic Substances Hydrology). The study was also supported by the National Oceanic and Atmospheric Administration Oceans and Human Health Initiative S0867882; National Science Foundation Grants EF-1015342 and OCE- 1357423 and OCE-1357140, and the Association of Marine Laboratories of the Caribbean.
Below are other science projects associated with this project.
Toxins and Harmful Algal Blooms Science Team
Nitrate Addition Enhances Arsenic Immobilization in Groundwater
USGS Scientists Measure New Bacterial Nitrogen Removal Process in Groundwater
New Study on Cyanotoxins in Lakes and Reservoirs Provides Insights into Assessing Health Risks
Importance of Lake Sediments in Removal of Cyanobacteria, Viruses, and Dissolved Organic Carbon
U.S. Geological Survey Scientists Complete First Systematic Regional Survey of Algal Toxins in Streams of the Southeastern United States
Remote Sensing Provides a National View of Cyanobacteria Blooms
Contaminants Affect Fish and Wildlife in the Chesapeake Bay
Algal Blooms Consistently Produce Complex Mixtures of Cyanotoxins and Co-Occur with Taste-and-Odor Causing Compounds in 23 Midwestern Lakes
Below are multimedia items associated with this project.
This documentary presents how recent changes in the composition and quantities of African dust transported to the Caribbean and the Americas might provide clues to why Caribbean coral reef ecosystems are deteriorating and human health may be impacted.
Below are publications associated with this project.
Saharan dust nutrients promote Vibrio bloom formation in marine surface waters
- Overview
Saharan dust nutrients, particularly iron, deposited episodically in tropical marine waters stimulate marine microbial bloom growth and change microbial community structure.
Saharan desert dust transported by easterly trade winds across the Atlantic Ocean provides pulses of nutrients, including iron, to ocean surface waters, yet the biological response to these events is not fully known, especially in the microbial community. Vibrio is a ubiquitous genus of marine bacteria that constitute a small fraction of the microbial community and are important in biogeochemical cycling of nutrients and trace metals. This genus also includes many well-known pathogens of marine organisms and humans, including the causative agent of the severe diarrheal disease cholera, shellfish-associated gastroenteritis, and seawater-associated wound infections; however, the research reported here did not assess the health effects or exposures to pathogens.
Scientists used a unique combination of simulated dust events in a laboratory setting and field sampling during a Sahara dust event in the Florida Keys to understand the effects of the dust on Vibrio bloom growth and changes in microbial community structure. The scientists determined that Saharan dust nutrients can promote rapid growth of the relatively rare Vibrio's and indicate that Vibrio species are "first responders" to dust-associated iron. This work indicates that marine bacteria play an important role in biogeochemical cycles related to periodic input of iron from Saharan dust-deposition and emphasizes that the periodic iron pulses rapidly increase the growth of marine bacteria, some of which are known to cause disease in humans and marine organisms.
This research was funded by the USGS Ecosystems Mission Area’s Environmental Health Program (Contaminant Biology and Toxic Substances Hydrology). The study was also supported by the National Oceanic and Atmospheric Administration Oceans and Human Health Initiative S0867882; National Science Foundation Grants EF-1015342 and OCE- 1357423 and OCE-1357140, and the Association of Marine Laboratories of the Caribbean.
- Science
Below are other science projects associated with this project.
Toxins and Harmful Algal Blooms Science Team
The team develops advanced methods to study factors driving algal toxin production, how and where wildlife or humans are exposed to toxins, and ecotoxicology. That information is used to develop decision tools to understand if toxin exposure leads to adverse health effects in order to protect human and wildlife health.Nitrate Addition Enhances Arsenic Immobilization in Groundwater
The addition of nitrate in a low oxygen groundwater resulted in the immobilization of naturally occurring dissolved arsenic and the conversion of nitrate to innocuous nitrogen gas.USGS Scientists Measure New Bacterial Nitrogen Removal Process in Groundwater
For the first time, U.S. Geological Survey (USGS), Virginia Institute of Marine Science, and the University of Connecticut scientists have detected active anammox bacteria in groundwater.New Study on Cyanotoxins in Lakes and Reservoirs Provides Insights into Assessing Health Risks
Newly published study provides new evidence of the widespread occurrence of cyanotoxins in lakes and reservoirs of the United States and offers new insights into measures used for assessing potential recreational health risks.Importance of Lake Sediments in Removal of Cyanobacteria, Viruses, and Dissolved Organic Carbon
U.S. Geological Survey (USGS) scientists determined that the colmation layer (top 25 centimeters of lake sediments) was highly effective in removing cyanobacteria, viruses, and dissolved organic carbon during water passage through the lake bottom to aquifer sediments.U.S. Geological Survey Scientists Complete First Systematic Regional Survey of Algal Toxins in Streams of the Southeastern United States
U.S. Geological Survey (USGS) scientists detected microcystin—an algal toxin—in 39 percent of 75 streams assessed in the southeastern United States. These results will inform and become part of a larger, systematic national survey of algal toxins in small streams of the United States.Remote Sensing Provides a National View of Cyanobacteria Blooms
Four Federal agencies, including the U.S. Geological Survey (USGS), are collaborating to transform satellite data into information managers can use to protect ecological and human health from freshwater contaminated by harmful algal blooms.Contaminants Affect Fish and Wildlife in the Chesapeake Bay
“Legacy contaminants” and “contaminants of emerging concern” that persist in the environment are affecting the health of fish and wildlife in the Chesapeake Bay and its watershed. State continue to report impaired water resources due to the persistence and toxicity of some previously banned pollutants. In addition, other contaminants of emerging concern are released to the environment at levels...Algal Blooms Consistently Produce Complex Mixtures of Cyanotoxins and Co-Occur with Taste-and-Odor Causing Compounds in 23 Midwestern Lakes
U.S. Geological Survey (USGS) scientists studying the effects of harmful algal blooms on lake water quality found that blooms of blue-green algae (cyanobacteria) in Midwestern lakes produced mixtures of cyanotoxins and taste-and-odor causing compounds, which co-occurred in lake water samples. Cyanotoxins can cause allergic and/or respiratory issues, attack the liver and kidneys, or affect the... - Multimedia
Below are multimedia items associated with this project.
African Dust, Coral Reefs and Human HealthThis documentary presents how recent changes in the composition and quantities of African dust transported to the Caribbean and the Americas might provide clues to why Caribbean coral reef ecosystems are deteriorating and human health may be impacted.
This documentary presents how recent changes in the composition and quantities of African dust transported to the Caribbean and the Americas might provide clues to why Caribbean coral reef ecosystems are deteriorating and human health may be impacted.
- Publications
Below are publications associated with this project.
Saharan dust nutrients promote Vibrio bloom formation in marine surface waters
Vibrio is a ubiquitous genus of marine bacteria, typically comprising a small fraction of the total microbial community in surface waters, but capable of becoming a dominant taxon in response to poorly characterized factors. Iron (Fe), often restricted by limited bioavailability and low external supply, is an essential micronutrient that can limit Vibrio growth. Vibrio species have robust metaboliAuthorsJason R. Westrich, Alina M. Ebling, William M. Landing, Jessica L. Joyner, Keri M. Kemp, Dale W. Griffin, Erin K. Lipp