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Darren Rumbold, Ph.D. - Florida Gulf Coast University. Fort Myers, FL, US

Darren Rumbold, Ph.D.

Expert in landscape-scale ecology | Florida Gulf Coast University


Darren Rumbold is an expert in environmental toxicology and mercury in estuarine and coastal systems.





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Shark Tagging & Mercury Testing FGCU Perspectives - The Health of Our Estuaries FGCU Perspectives - Oil Spill Impacts



Darren Rumbold is a professor of Marine Science and director of the Coastal Watershed Institute at Florida Gulf Coast University. Prior to this, he was a Lead Environmental Scientist coordinating all mercury monitoring and research conducted by the South Florida Water Management District. He is a former recipient of an Environmental Science and Engineering Fellowship from the American Association for the Advancement of Science, during which he worked at U.S. EPA’s National Center for Environmental Assessment in Washington, DC. His research interests include landscape ecotoxicology and risk assessment. His current research focus is on the sources and fate of methylmercury (MeHg) in estuarine and coastal systems.

Areas of Expertise (5)

Marine Ecology

Ecological Risk Assessment

Mercury Biogeochemistry and Biomagnification

Environmental Toxicology

Water Quality

Education (4)

University of Miami: Ph.D. 1996

Florida Atlantic University: M.S. 1990

Florida Atlantic University: B.A. 1982

Florida Atlantic University: B.S. 1982

Affiliations (3)

  • Society of Environment Toxicology and Chemistry (SETAC)
  • American Water Resources Association (AWRA)
  • Florida Academy of Sciences

Selected Media Appearances (8)

FGCU study gains insight on how blacktip sharks are exposed to mercury

Naples Daily News  print


Darren Rumbold discusses new research that aims to better understand how young blacktip sharks are exposed to mercury along Southwest Florida’s coast.

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Red tide continues from Captiva south to Marco

Florida Weekly  print


Darren Rumbold discusses red tide.

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Burmese python could be coming to a dinner table near you

NBC2  tv


Darren Rumbold talks about mercury levels found in pythons.

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Chicken of the Glades: Can we eat pythons? Mercury levels studied to see if snakes could be the new other white meat

Palm Beach Post  print


Darren Rumbold discusses the amount of the neurotoxin, mercury, found in pythons.

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FGCU student researchers head to sea to check the red tide-devastated zone they found last year

The News-Press  print


Darren Rumbold discusses his work on dead zones left in the wake of red tide.

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Under our toxic sea

Fort Myers Florida Weekly  


FGCU's biologists, including Darren Rumbold, study the consequences of Florida's red tide.

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Darren Rumbold describes the problem

Fort Myers Florida Weekly  


Darren Rumbold talks about the algae comprising Florida's red tide.

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FGCU professor, students study freshwater releases' effect on ecosystem

NBC 2  


Darren Rumbold talks about freshwater releases, and their effect on the offshore marine environment.

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Selected Event Appearances (6)

Drivers responsible for the high rates of mercury biomagnification and its extreme geographic and temporal variability in the Florida Everglades: A formal causal analysis

Greater Everglades Ecosystem Restoration (GEER) Conference. April, 2017  Coral Springs, Fl.

Status and trends of the landscape-scale mercury problem in South Florida and the Everglades

11th International Conference on Mercury as a Global Pollutant (ICMGP). July 28- Aug 2, 2013  Edinburgh, Scotland

Trophic transfer of mercury to sharks off Southwest Florida

10th International Conference on Mercury as a Global Pollutant (ICMGP). July 24-29, 2011  Halifax, Nova Scotia, Canada

Marine Pollution: Is it all gloom and doom?

Planet Ocean Seminar Series. April, 2017  University of North Carolina Wilmington

Impacts from MC252 Oil on ecologically and commercially important plankton of the Gulf of Mexico

Centre of Documentation, Research and Experimentation on Accidental Water Pollution (CEDRE). June 30, 2011  Brest, France

South Florida Mercury Science Program: Lessons Learned

Gulf of Mexico Alliance, 2nd Annual Monitoring Forum. April 7-8 2009  New Orleans

Selected Research Grants (3)

Long-term monitoring of oysters Crassostrea virginica in Southwest Florida

South Florida Water Management District $1,037K

2010 - 2017 Co-Principal Investigator with A. Volety, S.G. Tolley, & A.N. Loh

Trophic transfer of mercury along salinity gradients in estuaries

Gulf of Mexico Alliance $73K

2014 - 2015 Principal Investigator with T. Lange, & D. Richards

Impacts from MC252 Oil on ecologically and commercially important plankton of the Gulf of Mexico

Florida Institute of Oceanography (block grant from BP) $332K

2010 - 2012 Principal Investigator with C. Jagoe, J. Barreto, A.N. Loh, S.G. Tolley, & A. Volety

Selected Articles (3)

Mercury biomagnification through food webs along a salinity gradient down-estuary from a biological hotspot

Estuarine, Coastal and Shelf Science

Rumbold, D.G., Lange, T.R., Richard, D., DelPizzo, G. & Hass, N.

2018 To examine down-estuary effects and how differences in food webs along a salinity gradient might influence mercury (Hg) biomagnification, we conducted a study from 2010 to 2015 in an estuary with a known biological hotspot at its headwaters. Over 907 samples of biota, representing 92 different taxa of fish and invertebrates, seston and sediments were collected from the upper, middle and lower reach for Hg determination and for stable nitrogen and carbon isotope analyses. Trophic magnification slopes (TMS; log Hg versus δ15N), as a measure of biomagnification efficiency, ranged from 0.23 to 0.241 but did not differ statistically among reaches. Hg concentrations were consistently highest, ranging as high as 4.9 mg/kg in top predatory fish, in the upper-reach of the estuary where basal Hg entering the food web was also highest, as evidenced by methylmercury concentrations in suspension feeders. Top predatory fish at the mouth of the estuary contained relatively low [THg], likely due to lower basal Hg. This was nonetheless surprising given the potential for down-estuary biotransport.

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Mercury concentrations in feathers of adult and nestling Osprey (Pandion haliaetus) from coastal and freshwater environments of Florida

Archives of Environmental Contamination and Toxicology

Rumbold, D.G., Miller, K.E., Dellinger, T.A. & Haas, N.

2017 We determined mercury (Hg) concentrations in feathers of osprey (Pandion haliaetus), both nestlings (n = 95) and adults (n = 110), across peninsular Florida and the Florida Keys during February-August 2014. Feathers plucked from nestlings, aged 3-7 weeks, contained Hg concentrations that ranged from 0.338 to 45.79 mg/kg and averaged 6.92 ± 7.58 mg/kg (mean ± 1SD). Feathers shed from adults contained significantly higher concentrations ranging from 0.375 to 93.65 mg/kg, with an average of 17.8 ± 16.1 mg/kg. These levels were in the upper range of previously reported feather Hg concentrations of osprey and clearly show that Florida continues to have Hg hotspots that are elevated compared with many other regions. While these concentrations did not exceed levels previously reported in osprey from heavily Hg contaminated areas that showed no evidence of reproductive impairments, we cannot rule out potential individual-level effects to highly exposed nestlings after fledging. Mercury concentrations in nestlings were highest in coastal habitats of Collier and Monroe counties, where ongoing declines in osprey populations also have been documented.

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Assessing the ecological risk of a municipal solid waste landfill to surrounding wildlife: A case study in Florida

Environmental Bioindicators

Rumbold, D.G., Morrison, M.B., & Bruner, M.C.

2009 To assess the ecological risk of siting a new municipal solid waste landfill near a National Wildlife Refuge in Florida, we carried out a retrospective assessment at a large waterbird colony located near an existing active landfill. Monitoring data collected over twenty years, including flight-line counts both at dawn and midday, shows the mixed-species, communal roost was active continuously from 1987 through 2007. The largest number of birds counted in any single flight-line count was 14,750 birds recorded in July 2007. The numerically dominant species recorded during flight-line counts were, in approximate order of abundance: White Ibis, (Eudocimus albus), Cattle Egret (Bubulcus ibis), Little Blue Heron (Egretta caerules), Great Egret (Ardea alba), and Tricolor Heron (E. tricolor). Breeding bird censuses revealed this site served also as a nesting colony each year since 1987; annual total nest numbers peaked in 1987 at 5,127 nests. Taxa richness increased over the monitoring period with new species nesting or roosting in the colony; in particular, the endangered Wood Stork (Mycteria americana) began nesting at this site in 1995 and eventually became one of the numerically important species. Nest success at the landfill colony was similar to or higher than success probabilities reported at other colonies in south Florida. Fidelity to this colony site was likely related to the area's environmental predictability in terms of: 1) food supply and, 2) the low, temporally constant level of predation. In general, resident waterbird populations at the colony were sustainable over the monitoring period, i.e., maintained abundance, survived and reproduced at rates comparable to other colonies. Therefore, although there was evidence of organism-level impacts, there was no evidence that landfill-related stresses propagated up and had population- or community-level consequences.

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