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Serge Thomas, Ph.D. - Florida Gulf Coast University. Fort Myers, FL, US

Serge Thomas, Ph.D.

Expert in the ecology of aquatic environments | Florida Gulf Coast University


Serge Thomas specializes in the consequences of natural and human stresses in aquatic ecosystems.





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Ponds of Southwest Florida: Ticking Time Bombs | Dr. Serge Thomas | TEDxFGCU



Serge Thomas is an associate professor in The Water School at Florida Gulf Coast University. He studies what factors of natural/human origins, and especially nutrients, trigger (harmful) algae blooms in various inland/nearshore shallow ecosystems. Such systems vary from fresh to saltwater, man-made and natural, still and moving water bodies, as well as wetlands. Understanding what controls algae growth allows him to rehabilitate hydrosystems, use algae and associated plants to remove water nutrients in engineered man-made shallow impoundments (such as treatment wetlands and stormwater ponds), and to better predict (harmful) algae blooms.

Areas of Expertise (18)

Ecological Engineering


Technologies to Clean Water


Algal Blooms



Algal Physiology



Stormwater Treatment

Freshwater Algae



Drone Mapping

Environmental Education

Ecosystem Rehabilitation


Education (5)

Florida International University / Southeast Environmental Research Center: Postdoctoral Fellow

2001 - 07

Pierre and Marie Curie University: Ph.D., Oceanology 2000

Pierre and Marie Curie University: D.E.A., Oceanology 1995

Pierre and Marie Curie University: M.S., Organisms and Populations Biology 1994

Pierre and Marie Curie University: B.S., Organisms and Populations Biology 1993

Affiliations (2)

  • Member : Association Francaise de Limnologie
  • Vice President: Florida Lake Management Society

Languages (3)

  • French
  • German
  • English

Selected Media Appearances (10)

Ian's storm surge changed Sanibel's freshwater lake environments and now brings a new algae concern

Fox 4  tv


Serge Thomas talks about Sanibel Island's freshwater lake environments after Hurricane Ian.

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FGCU researchers testing if mangroves can filter out landfill toxins

Fox 4  tv


Serge Thomas and students are conducting research to see if mangroves can be used to keep landfills cleaner.

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As mountains of debris pile up, environmental concerns arise

Fox 4  tv


Serge Thomas talks about the amount of debris collected after Hurricane Ian and how it impacts the environment.

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Experts weigh in on effectiveness of storm detention ponds

NBC2  tv


Serge Thomas discusses the importance of building efficient storm water retentions ponds.

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Biden's E15 waiver might not impact your wallet but could accelerate climate change

WTSP  tv


Serge Thomas discusses ethanol's impact on the environment.

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Experts say brewing beer can help control red tide

ABC7  tv


Serge Thomas explain why spent grain can help control red tide.

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Local scientist says EAA reservoir needs more treatment areas

NBC 2  


Serge Thomas talks about his concerns about the lack of treatment areas to clean phosphorus from the Everglades Agricultural Area (EAA) reservoir.

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Florida waits to see if Hurricane Michael put an end to red tide outbreak



Serge Thomas discusses the effects of Hurricane Michael on Florida's red tide.

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Hurricane Michael could turn Florida’s “red tide.” But how?



Serge Thomas talks about the impact of cooler water from hurricane winds impacting Florida's red tide.

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Hurricane Michael may affect red tide and blue-green algae. Here's how.

Naples Daily News  


Serge Thomas is quoted discussing the impact of hurricane winds on blue-green algae in canals.

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Selected Event Appearances (3)

Settling and Entrainment Properties of STA Particulates.

GEER 2019  Coral Springs, Florida


Ponds of Southwest Florida: Ticking time bombs

Association of Limnology and Oceanography (ASLO)  Sante Fe, New Mexico


Wet Detention Stormwater Treatment Ponds: Thousands of Ticking Time Bombs for Water Quality in Southwest Florida

23rd Annual Southwest Florida Water Resources Conference, American Water Resource Association  Fort Myers, Florida


Research Focus (1)

Research Interests

Dr. Thomas mainly studies the physiology of microscopic floating (phytoplankton) and attached algae (periphyton). This allows him to better monitor eutrophication and understand what factors trigger eutrophication in hydrosystems of various hydroperiods and of very broad morphometries and salinities. A large aspect of his research is applied and focuses on the rehabilitation of eutrophied shallow hydrosystems with a strong emphasis on the use of algae, plants and bacteria to remove nutrients and other pollutants from surface waters in ecologically engineered treatment wetlands and stormwater ponds. He also looks at sediment internal loading in water bodies and how sediment accumulates and is advected. Finally, besides the use of Unmanned Aircraft Vehicles (drones) to better track eutrophication, his research includes Environmental Education to bring awareness to the general public and schools about eutrophicated water issues and subsequent Best Management Practices that should ensue to ensure sustainable good water quality for the future.

Selected Research Grants (3)

Settling and entrainment properties of STA particulates

South Florida Water Management District $121,154


Developing a water and nutrient budget for Lake Trafford, Florida, U.S.A.

Florida Department of Environmental Protection $117,587.64


Health assessment of the Pelican Landing ponds

The Bayside Improvement Community Development District, Coconut Creek. Florida $35,330.26


Selected Articles (3)

Differences in the photoacclimation and photoprotection exhibited by two species of the ciguatera causing dinoflagellate genus, Gambierdiscus

Harmful Algae

Leynse A.K., Parsons M.L., Thomas S.


In culture, Gambierdiscus spp. have been shown to prefer irradiances that are relatively low (≤250 μmol photons m−2 s−1) versus those to which they are frequently exposed to in their natural environment (>500 μmol photons m−2 s−1). Although several behavioral strategies for coping with such irradiances have been suggested, it is unclear as to how these dinoflagellates do so on a physiological level. More specifically, how do long term exposures (30 days) affect cell size and cellular chlorophyll content, and what is the photosynthetic response to short term, high irradiance exposures (up to 1464 μmol photons m−2 s−1)? The results of this study reveal that cell size and chlorophyll content exhibited by G. carolinianus increased with acclimation to increasing photon flux density. Additionally, both G. carolinianus and G. silvae exhibited reduced photosynthetic efficiency when acclimated to increased photon flux density. Photosynthetic yield exhibited by G. silvae was greater than that for G. carolinianus across all acclimation irradiances. Although such differences were evident, both G. carolinianus and G. silvae appear to have adequate biochemical mechanisms to withstand exposure to irradiances exceeding 250 μmol photons m−2 s−1 for at least short periods of time following acclimation to irradiances of up to 150 μmol photons m−2 s−1.

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Brevetoxin, the Dinoflagellate Neurotoxin, Localizes to Thylakoid Membranes and Interacts with the Light-Harvesting Complex II (LHCII) of Photosystem II


Cassell R.T., Chen W., Thomas S., Liu L., Rein K.S.


The brevetoxins are neurotoxins that are produced by the “Florida red tide” dinoflagellate Karenia brevis. They bind to and activate the voltage‐gated sodium channels in higher organisms, specifically the Nav1.4 and Nav1.5 channel subtypes. However, the native physiological function that the brevetoxins perform for K. brevis is unknown. By using fluorescent and photoactivatable derivatives, brevetoxin was shown to localize to the chloroplast of K. brevis where it binds to the light‐harvesting complex II (LHCII) and thioredoxin. The LHCII is essential to non‐photochemical quenching (NPQ), whereas thioredoxins are critical to the maintenance of redox homeostasis within the chloroplast and contribute to the scavenging of reactive oxygen. A culture of K. brevis producing low levels of toxin was shown to be deficient in NPQ and produced reactive oxygen species at twice the rate of the toxic culture, implicating a role in NPQ for the brevetoxins.

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The different primary producers in a small African tropical reservoir during a drought: temporal changes and interactions

Freshwater Biology

Thomas S., Cecchi P., Corbin D., Lemoalle J.


1. The biomass of the different primary producers, and their relative contributions to the total, were measured quarterly from July 1997 to September 1998 in a tropical reservoir (Brobo, Côte‐d'Ivoire). The study period was marked by an exceptional decrease in the water level as a result of a long drought with only one significant rainfall in June 1998. 2. In July 1997, at the beginning of the usual rainy season, the level of the lake was normal and the ecosystem was in a moderately clear water state dominated by littoral macrophytes, mostly Potamogeton octandrus (more than 55% of the 6.4 tons of carbon of the total primary biomass). The microphytobenthos (19%) and the phytoplankton (25%) were secondary contributors, whereas the periphyton on macrophytes (0.5%) and the epixylon (periphyton on dead flooded trees, 0.3%) were negligible. 3. As a result of the steady decline in water level due to a lack of rain, the macrophytes were progressively stranded on the shores and had disappeared by March 1998. From this time, microalgae (microphytobenthos and phytoplankton) became dominant. Their combined biomass increased slowly from 2.8 tons of carbon in July 1997 to 3.7 tons in September 1998. The microphytobenthic biomass contributed 78% to the total in March, 55% in June and 60% in September, while other contributions were mainly due to the phytoplankton. The epixylon remained negligible throughout the study (≤0.5% of the whole primary biomass). 4. The distribution and temporal changes in the biomass during each survey were mainly linked to hydrology and to interactions between primary producers. 5. The effect of water level changes on free (planktonic) and fixed primary producers (periphytic microalgae and rooted macrophytes) is discussed.

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