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Award Detail

Doing Business As Name:Florida State University
  • William M Landing
  • (850) 644-6037
Award Date:03/11/2014
Estimated Total Award Amount: $ 200,584
Funds Obligated to Date: $ 200,584
  • FY 2014=$200,584
Start Date:04/01/2014
End Date:03/31/2018
Transaction Type:Grant
Awarding Agency Code:4900
Funding Agency Code:4900
CFDA Number:47.050
Primary Program Source:040100 NSF RESEARCH & RELATED ACTIVIT
Award Title or Description:Collaborative Research: Vibrio as a model microbe for opportunistic heterotrophic response to Saharan dust deposition events in marine waters
Federal Award ID Number:1357140
DUNS ID:790877419
Parent DUNS ID:159621697

Awardee Location

Street:874 Traditions Way, 3rd Floor
Awardee Cong. District:02

Primary Place of Performance

Organization Name:Florida State University
Cong. District:02

Abstract at Time of Award

Overview: Dust and mineral aerosols are a significant source of micro and macronutrients to oligotrophic ocean surface waters. Evidence is growing that heterotrophic microbes may play key roles in processing deposited minerals and nutrients. Yet it is not known which components of dust stimulate the heterotrophic bacteria, which cellular mechanisms are responsible for the utilization of those components and how the activity of these bacteria affect the availability and utilization of dust-derived minerals and nutrients by marine autotrophs. Knowledge of these factors is key to understanding how dust deposition impacts carbon cycles and for predicting the response of tropical oceans to future changes in the frequency and intensity of dust deposition events. The objective of this project is to examine the specific effects of aeolian dust on heterotrophic microbes in a tropical marine system under controlled conditions. The central hypothesis is that in oligotrophic tropical systems numerically minor opportunistic bacteria are the first responders to influx of dust constituents and respond primarily by rapidly accessing soluble trace metals and limiting nutrients that are deposited with Saharan dust. The project will focus on two specific aims: 1) Quantify changes in community structure, composition and transcriptional activity among marine microbial populations upon exposure to dust, and 2) Identify key components in Saharan dust aerosols that stimulate or repress growth and/or activity in Vibrio, a model opportunistic marine heterotrophic group. The study will use a series of controlled experiments designed to identify and quantify heterotrophic microbial response to dust deposition events using both natural communities and model bacteria (Vibrio) through metagenomics, transcriptomics and atmospheric and marine biogeochemical techniques. This innovative approach will identify the most critical (reactive) components leached from dust aerosols on the microbial community as well as elucidate potential mechanisms of response. Intellectual Merit: There is great interest in the biological response to dust aerosols given its potentially large influence on biogeochemical cycling, but there has been relatively little work that has addressed the mechanisms of response (especially among the heterotrophic microbial fraction) or identified the relative importance of specific constituents of dust aerosols. A detailed framework for microbial response (focusing on opportunistic heterotrophs) will facilitate efforts to link autotrophic and heterotrophic processing. This contribution is significant because it will provide one of the first end-to-end (chemistry to physiology to ecology) mechanistic pathways for marine biological response to desert dust aerosols. Broader Impacts: The outcomes of this research will provide information on an often overlooked component of climate change, the long range effects of desertification, which could impact biogeochemical cycling throughout the oceans. Furthermore, working with Vibrio as a model will have the co-benefit of addressing the possible role of dust deposition on the global rise of a marine infectious agent. Additionally, this project will provide graduate, undergraduate and high school students with both training and active participation in research. All students will have opportunities to present their work at local and regional meetings as well as national (international) conferences. Through on-going programs at each institution, students from STEM under-represented groups will be recruited for research opportunities (and for entry into graduate programs). Additionally, through participation in the Georgia Coastal Research Council results of this work, and related issues in marine science and climate change, will be broadly disseminated to policy-makers and local (coastal) stakeholders through meetings, links to the GRGC website and listserv and targeted publications.

Publications Produced as a Result of this Research

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Alina M. Ebling and William M. Landing "Trace elements in the sea surface microlayer: rapid responses to changes in aerosol deposition" Elementa-Science of the Anthropocene, v.5, 2017, p.. doi:10.1525/elementa.237 

Westrich, J.W., A.M. Ebling, W.M. Landing, J.L. Joyner, D.W. Griffin, and E.K. Lipp "Saharan dust nutrients promote Vibrio bloom formation in marine surface waters" Proceedings of the National Academy of Sciences, v.113, 2016, p.5964. doi:doi/10.1073/pnas.1518080113 

Westrich, J.W., A.M. Ebling, W.M. Landing, J.L. Joyner, D.W. Griffin, and E.K. Lipp "Saharan dust nutrients promote Vibrio bloom formation in marine surface waters" Proceedings of the National Academy of Sciences, v., 2016, p..

Project Outcomes Report


This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

There are about 3 billion tons of microscopic marine plankton that are photosynthetic, harvesting light energy to make food for all other marine creatures while producing about half of the oxygen we breath. These phytoplankton are just like the plants in a garden; they grow best when the environmental conditions are right, and when they have the essential nutrients they need. Those nutrients include major elements like nitrogen and phosphorus, but they also need a variety of trace element “micronutrients” that make their enzymes work (such as manganese, iron, cobalt, copper, nickel, and zinc). In many coastal regions, these essential micronutrients can be delivered from rivers and streams, but when you are far from land these trace elements are delivered with “dust”, including mineral dust that blows off our desert areas and urban dust from human activities. Sometimes, the arrival of dust can enhance the growth of harmful microbes, such as triggering harmful algal blooms. We had some circumstantial evidence that the arrival of “Saharan dust” to the Florida Keys (a common phenomenon in the late summer) was responsible for the growth of certain species of Vibrio bacteria, and this might cause harm to the coral reefs. In our project, we wanted to see if we could understand why this might be happening, and what damage it might cause.

The best time to find desert dust from the Sahara in southern Florida is in the mid-to-late summer when the trade winds blow dust all the way from northern Africa into the Caribbean. We set up our equipment in a marine laboratory on the Florida Keys in July and August from 2014 through 2016, and we started collecting samples. We collected air samples to measure the dust concentrations. We collected rain samples to measure how much dust the rainfall brought down. We collected seawater samples to measure the nutrient and trace element concentrations and to measure which bacteria and phytoplankton were present. We collected big tanks of sea water so we could add things like nitrate or phosphate or iron to see whether it would trigger a bloom of harmful bacteria. And we collected samples from the coral reef itself to see how healthy it was.

We saw a significant increase in Vibrio bacteria within a day of dust arrival. The Vibrio population doubled and persisted for about 24 hr. Vibrio could be detected throughout the water column and in the coral mucus. From culturing experiments, we found that Vibrio alginolyticus, a pathogen for humans and corals, was the dominant species during the dust event, making up about 40% of the community. The next steps for this research are to find ways to measure how much stress the coral reef is feeling from this exposure, and to come up with ways to protect the reef. This should become even more important into the future since we believe that climate change will cause the desert areas in northern Africa to expand, leading to even more desert dust coming into the Caribbean and the Florida Keys.


Last Modified: 09/11/2018
Modified by: William M Landing

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