Dr. Ruth Carmichael


Associate Professor, University of South Alabama
Senior Marine Scientist II, Dauphin Island Sea Lab
Ph.D. 2004, Boston University

Emphasis: Marine Ecosystem Response

Research Interests

My research focuses on marine ecosystem responses; understanding relationships between organisms and their environment and specific biological and physiological responses to environmental change.  In particular, I am interested in the mechanisms by which anthropogenic-driven perturbations affect coastal habitats and species.  I give special focus to commercially important coastal bivalves, horseshoe crabs, manatees and dolphins.

I use a variety of approaches to make these assessments.  I measure how perturbations affect habitat and food quality for consumers, and then determine the extent to which these effects may be transferred up coastal food webs in terms of change in growth, survival, and physiology.  I also employ natural abundance stable isotopes to trace N and C sources from consumers to their food sources and ultimately to N and C sources from land.  I use this information to discern trophic interactions, define linkages between anthropogenic factors and organism responses, assess nutritional importance of food sources, discern physiological state of organisms, and historically trace responses to environmental change.

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Current Research Grants

National Fish and Wildlife Foundation (NFWF) - Alabama Marine Mammal Conservation and Recovery Program. 2015-2020

MS Water Resources Research Institute (MWRRI) - Water quality in Bangs Lake —Effects of recurrent phosphate spills to a coastal estuary: Year 2. 2015-2016 

MS-AL Sea Grant Consortium - A circulation and transport model for fishery management in Mobile Bay and eastern Mississippi Sound. 2014-2016

Alabama Division of Wildlife and Freshwater Fisheries Preliminary determination of manatee warmwater refugia in Alabama waters

WHOI Sea Grant Program - A history of mercury impacts to Waquoit Bay, MA clams

US Army Corps of Engineers (USACE) - Determining sources, history and status of eutrophication at Naval Station Guantanamo Bay, Cuba. 2014-2015

Alabama Emergency Management Agency - Deepwater Horizon Incident Grant, Alabama Marine Mammal Stranding Network: A Strategy for strengthening and sustaining an efficient stranding response and research unit. 2012-2015

Past Research Grants

MS Water Resources Research Institute (MWRRI) - Water quality in Bangs Lake: Effects of recurrent phosphate spills to a coastal estuary: Year 1. 2014-2015

Alabama Division of Wildlife and Freshwater Fisheries Population ecology, movements, habitat use and diet of West Indian Manatees in Alabama waters.  Various projects 2009-2015

National Fish and Wildlife Foundation (NFWF) - Support for the Alabama Marine Mammal Stranding Network. 2014

NOAA, National Coastal Data Development Center (NCDDC) - Data Management in Support of NOAA’s Integrated Ecosystem Assessment for the Gulf of Mexico: Dauphin Island Sea Lab’s Data Management Center. Various projects 2007-2013

NOAA, Prescott Fund, Fisheries Protected Resources Program - Establishing a regionally cooperative dolphin stranding network for Alabama. 2011-2012

National Fish and Wildlife Foundation (NFWF) - A cooperative marine mammal stranding network for Alabama. 2011-2012

BP-GoMRI - Gulf of Mexico Ecosystem Recovery: Sentinel macrofauna (MESC).  2011-2012

Effects of oil contaminants on sentinel benthic and pelagic species in Mobile Bay, AL (NGI). 2010-2011

NOAA, National Estuarine Research Reserve (NERR) System - National Science Collaborative, Legacy effects of land-use change and nitrogen source shifts on a benchmark system: Building capacity for collaborative research leadership at the Grand Bay Reserve. 2010-2013

NOAA, Natural Resource Damage Assessment (NRDA) Program - Proposed data collection plan to assess injury to West Indian manatees from the Deepwater Horizon Oil Spill outside of Florida. 2010

Alabama Oyster Reef Restoration Program - Quantification of direct and indirect nitrogen removal by oysters (Crassostrea virginica). 2009-2011

Effects of N enrichment on oyster growth and survival via changes in food supply and habitat in Mobile Bay, AL. 2007-2009

Richard C. Shelby Center for Ecosystem-based Fisheries Management - From Mobile Bay to nGOM fisheries: The trophic importance of land-derived organic matter. 2009-2011

MS-AL Sea Grant Consortium - Use of stable isotope ratios to link wastewater sources to effects on shellfish and human health: Defining relevant and effective spatial and temporal scales for management. 2008-2010 

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2015                Dalrymple, J. D. and R. H. Carmichael*. Effects of age class on N removal capacity of oysters and implications for bioremediation. MEPS 528: 205-220. (G)

2015                Venn-Watson, S., K. M. Colegrove, J. Litz, M. Kinsel, K. Terio, J. Saliki, S. Fire, R. H. Carmichael, C. Chevis, W. Hatchett, J. Pitchford, M. Tumlin, C. Field, S. Smith, R. Ewing, D. Fauquier, G. Lovewell, H. Whitehead, D. Rotstein, W. McFee, E. Fougeres, T. Rowles. Adrenal Gland and Lung Lesions in Gulf of Mexico Common Bottlenose Dolphins (Tursiops truncatus) Found Dead following the Deepwater Horizon Oil Spill. PLoS ONE. 10(5): e0126538. DOI:10.1371/journal.pone.0126538

2015                Venn-Watson, S., L. Garrison, J. Litz, E. Fougeres, B. Mase, G. Rappucci, E. Stratton, R. H. Carmichael, D. Odell, D. Shannon, S. Shippee, S. Smith L. Staggs, M. Tumlin, H. Whitehead, T. Rowles. Demographic clusters identified within the northern Gulf of Mexico common bottlenose dolphin (Tursiops truncatus) unusual mortality event: January 2010- June 2013. PLoS ONE. 10(2): e0117248. doi:10.1371/journal.pone.0117248

2015                D'Ambra, I., W. M. Graham, R. H. Carmichael, F. J. Hernandez, Jr. Fish rely on scyphozoan hosts as a primary food source: evidence from stable isotope analysis. Mar. Biol. 162:247-252. Feature Article, Highlighted in Harrod 2015 Mar. Biol. Editorial 162:245-246. (G)

2014                Aven, A., R. H. Carmichael, M. Ajemian, S. Powers. Passive acoustic monitoring mitigates GPS tag loss by tracked manatees. Mar. Freshwater Res. Published online 26 Nov 2014 (G)

2014                Kellogg L., A. Smyth, M. W. Luckenbach, R. H. Carmichael, B. L. Brown, J. C. Cornwell, Michael F. Piehler, M. S. Owens, D. J. Dalrymple, C. Higgins. Use of oysters to mitigate eutrophication in coastal waters. Est Coast Shelf Sci. 151:156-168.

2014                Litz, J., M. Baran, R. H. Carmichael, K. Colegrove, S. Fire, E. Fougeres, R. Hardy, S. Holmes, W. Jones, B. MaseGuthrie1, D. Odell, P. Rosel, D. Shannon, J. Saliki, S. Shippee, S. Smith, E. Stratton, S. BowenStevens, M. Tumlin, H. Whitehead, G. Worthy, T. Rowles. A review of historical unusual mortality events in the Gulf of Mexico (1990-2009): providing context for the complex and long-lasting Northern Gulf of Mexico Cetacean UME. Dis. Aquat. Org. 112:161-175.

2014                Patterson H. K., A. Boettcher, R. H. Carmichael. Biomarkers of dissolved oxygen stress in oysters: A tool for restoration and management efforts. PLoS ONE 9(8): e104440. DOI:10.1371/journal.pone.0104440.(G)

2014                Martin, J., H. Edwards, F. Bled, C. Fonnesbeck, J. Dupuis, B. Gardner, S. Koslovsky, A. Aven, L. Ward-Geiger, R. H. Carmichael, D. Fagan, M. Ross, and J. Royle. Maximum number of manatees in areas potentially affected by the Gulf oil spill. PLoS ONE 9(3): e91683. DOI:10.1371/journal.pone.0091683.

2014                D’Ambra, I., R. H. Carmichael, W. M. Graham. Determination of δ13C and δ15N and trophic fractionation in jellyfish: implications for food web ecology. Mar. Biol. 161:473-480. (G)

2013                D'Ambra, I., W. M. Graham, R. H. Carmichael, A. Malej, V. Onofri. Predation patterns and prey quality of medusae in a semi-enclosed marine lake: implications for food web energy transfer in coastal marine ecosystems. J. Plankton Res. 35:1305-1312. DOI: 10.1093/plankt/fbt065. (G)

2012                Carmichael, R. H.* A. Jones, H. Patterson, W. Walton, A. Pérez-Huerta, E. Overton, M. Dailey, K. Willett. Assimilation of oil-derived elements by oysters due to the Deepwater Horizon oil spill. Environ. Sci. Technol. 46:12787-12795.  DOI: 10.1021/es302369h Featured by Gulf of Mexico Research Initiative http://gulfresearchinitiative.org/studies-indicate-that-oyster-tissue-and-shell-were-similar-in-pre-and-post-oil-spill-conditions/

2012                Prado, P., R. H. Carmichael, S. Watts, J. Cebrian, and K. L. Heck, Jr. Diet-dependent δ13Cand δ15N fractionation among sea urchin (Lytechinus variegatus) tissues: Implications for food web models. Mar. Ecol. Prog. Ser. 462:175-190.

2012                Carmichael, R. H.*, W. Graham, A. Aven, G. Worthy, S. Howden. Were multiple stressors a ‘perfect storm’ for northern Gulf of Mexico bottlenose dolphins in 2011? PloS ONE 7(7): e41155. doi:10.1371/journal.pone.0041155.  Featured in Nature News http://www.nature.com/news/perfect-storm-hit-gulf-of-mexico-dolphins-1.11011

2012                Carmichael, R. H.*, W. Walton, H. Clark. Bivalve enhanced N removal from coastal estuaries. Can. J. Fish. Aquat. Sci. 69:1131-1149.

2012                Carmichael, R.H.*, A. Shriver, and I. Valiela. Bivalve response to estuarine eutrophication: The balance between enhanced food supply and habitat alternations. J. Shellfish Res. 31: 1-11.

2012                Carmichael, R. H.* and E. Brush. Three decades of horseshoe crab rearing: A review of conditions for captive growth and survival. Rev. Aquac. 4: 32-43.

2012                Biancani, P. J., R. H. Carmichael*, J. H. Daskin, K. R. Calci, W. Burkhardt III. Seasonal and spatial effects of wastewater effluent on growth, survival, and accumulation of microbial contaminants by oysters in Mobile Bay, Alabama. Est Coasts. 35:121-131. CESN highlight article. (G)

2012                Drymon, J. M., S. P. Powers, R. H. Carmichael. Trophic plasticity in the Atlantic sharpnose shark (Rhizoprionodon terraenovae) from the north central Gulf of Mexico. Environ. Biol. Fish. 95:21-35.

2010                Graham, W., R. H. Condon, R. H. Carmichael, I. D’Ambra, H. K. Patterson, F. J. Hernandez, Jr. Oil carbon entered the coastal planktonic food web during the Deepwater Horizon oil spill. Environ. Res. Lett. 5(045301):1-6. 2010 Highlight.

2010                Kovacs, C., J. Daskin, H. Patterson, R. H. Carmichael*. Crassostrea virginica shells record local variation in wastewater inputs to a coastal estuary. Aquatic Biol. 9:77-84.  (U)

2009                Pabody, C., R. H. Carmichael*, L. Rice, M. Ross.  West Indian manatees in Mobile Bay, Alabama:  A new sighting network adds to twenty years of historical data on extralimital populations. Gulf Mexico Sci. 27:52-61.  (T)

2009                Carmichael, R. H.*, E. Gaines, Z. Sheller, A. Tong, A. Clapp, I. Valiela. Diet composition of juvenile horseshoe crabs: Implications for growth and survival of natural and cultured stocks, p. 521-534. In J. Tanacredi, M. Botton, D. Smith [eds.], Biology and Conservation of Horseshoe Crabs. Springer, New York.

2009                Smith, D., M. Millard, R. H. Carmichael. Status and assessment of Limulus polyphemus along the western Atlantic. p. 361-386. In J. Tanacredi, M. Botton, D. Smith [eds.], Biology and Conservation of Horseshoe Crabs. Springer, New York.

2008                Carmichael, R. H.*, T. Hattenrath, I. Valiela, R. H. Michener. Nitrogen stable isotopes in the shell of Mercenaria mercenaria trace wastewater inputs from watersheds to estuarine ecosystems. Aquatic Biol. 4:99-111. Feature Article.

2008                Daskin, J. H., K. Calci, W. Burkhardt, III, R. H. Carmichael*. Use of N stable isotope and alternative microbial analysis to define wastewater influence in Mobile Bay, AL. Mar. Pollut. Bull. 56:860-868.  (U)

2007                Bowen, J., K. Kroeger, G. Tomasky, W. J. Pabich, , M. L. Cole, R. H. Carmichael, I. Valiela. A review of land-estuary coupling by groundwater discharge to New England estuaries:  Mechanisms and effects. Applied Geochemistry. 22:175-191.

2005                Carmichael, R. H.* and I. Valiela. Coupling of near-bottom seston and surface sediment composition: Changes with nutrient enrichment and implications for estuarine food supply and biogeochemical processing. Limnol. Oceanogr. 50:97-105.

2004                Carmichael, R. H.*, A. Shriver, I. Valiela. Changes in shell and soft tissue growth, tissue composition, and survival of quahogs, Mercenaria mercenaria, and softshell clams, Mya arenaria, in response to eutrophic-driven changes in food supply and habitat. J. Exp. Mar. Biol. Ecol. 313: 75-104.

2004                Rutecki, D., R. H. Carmichael, I. Valiela.  Magnitude of harvest of Atlantic horseshoe crabs, Limulus polyphemus, in Pleasant Bay, MA. Estuaries 27:179-187. (G)

2004                Carmichael, R. H.*, B. Annette, I. Valiela. N loading to Pleasant Bay, Cape Cod:  Application of models and stable isotopes to detect incipient nutrient enrichment of estuaries. Mar. Pollut. Bull. 48: 137-143.

2004                Carmichael, R. H.* Effects of eutrophication on Mya arenaria and Mercenaria mercenaria: Growth, survival, and physiological responses to changes in food supply and habitat in estuaries receiving different N loads. Ph.D. Thesis, Boston University.

2004                Carmichael, R. H.*, D. Rutecki, B. Annett, E. Gaines, I. Valiela.  Position of horseshoe crabs in estuarine food webs: N and C stable isotopic study of foraging ranges and diet composition. J. Exp. Mar. Biol. Ecol. 299: 231-253.

2003                Carmichael, R. H.*, D. Rutecki, I. Valiela.  Abundance and population structure of the Atlantic horseshoe crab, Limulus polyphemus, in Pleasant Bay, Cape Cod. Mar. Ecol. Prog. Ser. 246:225-239.

2003                O'Connell, C. W., S. P. Grady, A. S. Leschen, R. H. Carmichael, I. Valiela.  Stable isotopic assessment of site loyalty and relationships between size and trophic position of the Atlantic horseshoe crab, Limulus polyphemus, in Cape Cod estuaries. Biol. Bull. 205:254-255.

2002                Weiss, E., R. H. Carmichael, I. Valiela.  The effect of nitrogen loading on growth of quahogs and softshell clams through changes in food supply.  Aquaculture  211:275-289.

2002                Shriver, A. C., R. H. Carmichael, I. Valiela.  Growth, condition, reproductive potential, and mortality of bay scallops, Argopecten irradians, in response to eutrophic-driven changes in food resources. J. Exp. Mar. Biol. Ecol. 279:21-40.

2002                Gaines, E., R. H. Carmichael*, S. P. Grady, I. Valiela.  Stable isotopic evidence for changing nutritional sources of juvenile horseshoe crabs. Biol. Bull. 203:228-230. (U)

2002                Suggs, D., R. H. Carmichael, S. P. Grady, I. Valiela.  Effects of individual size on pairing in horseshoe crabs. Biol. Bull. 203: 225-227. (U)

2001                Grady, S., D. Rutecki, R. H. Carmichael, I. Valiela.  Age structure of the Pleasant Bay population of Crepidula fornicata: A possible tool for estimating horseshoe crab age. Biol. Bull. 201:296-297. (U)

2001                Fila, L., R. H. Carmichael, A. Shriver, I. Valiela.  Stable N isotopic signatures in Bay scallop tissue, feces, and pseudofeces in Cape Cod estuaries subject to different N loads. Biol. Bull. 201: 294-296. (U)

1996                Herrold R. E., A. Marchini, S. Fruehling, R. Longnecker. Glycoprotein 110 (gp110), the Epstein-Barr Virus homolog of Herpes Simplex Virus Glycoprotein B (gB), is essential for Epstein-Barr replication in vivo. J Virol. 70: 2049-2054.

1996                Fruehling S., S. K. Lee, R. E. Herrold, B. Frech, G. Laux, E. Kremmer, F. A. Grasser, R. Longnecker. Identification of Latent Membrane Protein 2A (LMP2A) domains essential for the LMP2A dominant-negative effect on B-lymphocyte surface immunoglobulin signal transduction. J Virol. 70: 6216-6226.

*Carmichael is corresponding author. T, G, U = Technician, graduate student, or undergraduate student as first author working under Carmichael.

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  • Marine Conservation Biology
  • Marine Invertebrate Zoology
  • Scientific Communication
  • Stable Isotope Ecology Seminar
  • Biology and Conservation of Horseshoe Crabs


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