Grantee Research Project Results
Final Report: The Toxic Dinoflagellate, Pfiesteria piscicida, as a Potential Biosensor of Estuarine Stress
EPA Grant Number: R825551Title: The Toxic Dinoflagellate, Pfiesteria piscicida, as a Potential Biosensor of Estuarine Stress
Investigators: Burkholder, Joann M. , Shumway, Sandra E. , Rublee, Parke
Institution: North Carolina State University , Long Island University - Southampton College , University of North Carolina at Greensboro
EPA Project Officer: Packard, Benjamin H
Project Period: May 19, 1997 through May 18, 2000 (Extended to May 18, 2001)
Project Amount: $500,000
RFA: Harmful Algal Blooms (1997) RFA Text | Recipients Lists
Research Category: Water Quality , Water , Aquatic Ecosystems
Objective:
This project on the ecology of Pfiesteria was subdivided into three components: (1) improving detection of Pfiesteria (P.) piscicida through development of a molecular probe for this species; (2) examining controlling influences of both inorganic and organic N and P on growth of toxic strains of P. piscicida zoospores when given food resources as dissolved or particulate (algal) carbon; and (3) assessing the acute and sublethal/chronic impacts of Pfiesteria on life stages of commercially/ecologically valuable shellfish species.Summary/Accomplishments (Outputs/Outcomes):
The project yielded findings of major importance to the field of Pfiesteria research as follows:Species-Specific Molecular Probes. Our project team developed the first reliable, species-specific molecular (PCR) probe for P. piscicida. We also developed a fluorescent in situ hybridization probe for P. piscicida. Colleague Dr. D. Oldach, University of Maryland, worked with us to determine the first correct entry of the 18S rDNA sequence for P. piscicida. In additional research on this project that originally had not been foreseen, we described and formally named the second known toxic Pfiesteria species, P. shumwayae. We also worked with Dr. Oldach to develop a PCR probe for P. shumwayae as part of this project effort.
Nutrient Enrichment and Pfiesteria. We experimentally documented stimulation of toxic strains of Pfiesteria, both P. piscicida and P. shumwayae, to N and P enrichments (organic and inorganic forms) and algal prey. We also experimentally showed that toxic Pfiesteria strains (grown temporarily with algal prey rather than fish) were stimulated by sterile-filtered swine wastes, human sewage, and poultry wastes.
Laboratory experiments also indicated comparatively higher P stimulation of P. piscicida zoospores, and higher N stimulation of P. shumwayae. Toward strengthening insights about environmental controls on Pfiesteria, we considered the laboratory nutrient data together with a decade-long database that we have obtained on the mesohaline Neuse Estuary (where most toxic Pfiesteria outbreaks have occurred). The information enabled construction of a conceptual model of Pfiesteria seasonal dynamics in relation to nutrient pollution and other environmental factors, based on statistically significant interactions from trend analyses. The field data supported the laboratory data: based on archived sample analysis with our molecular probes (below), P decline with concomitant N increase in the Neuse Estuary over the past decade has coincided with a shift in Pfiesteria dominance from P. piscicida to P. shumwayae. The conceptual model is guiding collaborative research in progress to construct a quantitative, predictive model of Pfiesteria abundance and toxic activity.
Impacts on Shellfish from Toxic Pfiesteria. We documented lethal effects of P. piscicida on pediveliger larvae of two commercially important shellfish species, the eastern oyster (Crassostrea virginica) and the bay scallop (Argopecten irradians), through two mechanisms. Zoospores of toxic strains of Pfiesteria actively attacked and consumed the pediveliger larvae, usually within minutes. Some toxic strains also were capable of killing the shellfish larvae via exotoxin when they were held in porous membranes to prevent direct contact with the larvae. Juvenile and sub-adult oysters were capable of grazing toxic Pfiesteria without apparent adverse effects, indicating a potential for trophic control of toxic Pfiesteria via grazing. However, there was high survival of zoospores during passage through the sub-adult oyster gut tract. The zoospores formed temporary cysts, and 85 percent of the cysts produced actively swimming zoospores within 24 hours after gut tract passage.
Conclusions. The following conclusions were reached:
- We were successful in developing species-specific molecular probes for P. piscicida and also for the second known toxic species, P. shumwayae.
- Both experimental laboratory data and supporting field studies provided evidence that toxic strains of the two known Pfiesteria spp. can be strongly stimulated by both organic and inorganic N and P enrichments, as pure N or P compounds.
- P. piscicida was tested with complex nutrient sources (mixtures) as well. They were experimentally shown to be stimulated by all three complex nutrient sources tested, including sterile-filtered swine, poultry, and human wastes.
- Toxic P. piscicida can be lethal to larval shellfish (eastern oysters, bay scallops) via physical attack, and by toxin production. The data indicate that Pfiesteria could adversely affect shellfish recruitment.
- Juvenile and sub-adult oysters, which can consume toxic Pfiesteria without apparent adverse impacts, do not digest most of the cells and, therefore, Pfiesteria zoospores show excellent survival following gut tract passage. To the extent that oysters concentrate the toxic cells via filtration before disposing of them in pseudofeces, the data suggest potential concerns in issues of seafood safety. In addition, transported oysters (e.g., in the aquaculture industry) probably provide a mechanism for dispersal of toxic Pfiesteria strains to other geographic areas.
Journal Articles on this Report : 16 Displayed | Download in RIS Format
Other project views: | All 19 publications | 16 publications in selected types | All 16 journal articles |
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Burkholder JM, Mallin MA, Glasgow Jr HB, Larson LM, McIver MR, Shank GC, Deamer-Melia N, Briley DS, Springer J, Touchette BW, Hannon E. Impacts to a coastal river and estuary from rupture of a large swine waste holding lagoon. Journal of Environmental Quality 1997;26(6):1451-1466. |
R825551 (Final) |
not available |
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Burkholder JM, Glasgow HB. Pfiesteria piscicida and other Pfiesteria-like dinoflagellates: Behavior, impacts, and environmental controls. Limnology and Oceanography 1997;42(5):1052-1075 |
R825551 (Final) |
not available |
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Burkholder JM, Glasgow HB. Trophic controls on stage transformations of a toxic ambush- predator dinoflagellate. Journal of Eukaryotic Microbiology 1997;44(3):200-205. |
R825551 (Final) |
not available |
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Burkholder JM, Mallin MA, Glasgow HB. Fish kills, bottom-water hypoxia, and the toxic Pfiesteria complex in the Neuse River and Estuary. Marine Ecology - Progress Series 1999;179:301-310. |
R825551 (Final) |
not available |
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Burkholder JM, Glasgow HB, Deamer-Melia N. Overview and present status of the toxic Pfiesteria complex (Dinophyceae). Phycologia 2001, Volume: 40, Number: 3 (MAY), Page: 186-214. |
R825551 (Final) |
not available |
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Burkholder JM, Glasgow HB. History of toxic Pfiesteria in North Carolina estuaries from 1991 to the present. Bioscience 2001;51(10):827-841 |
R825551 (Final) |
not available |
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Cancellieri PJ, Burkholder JM, Deamer-Melia NJ, Glasgow HB. Chemosensory attraction of zoospores of the estuarine dinoflagellates, Pfiesteria piscicida and P. shumwayae, to finfish mucus and excreta. Journal of Experimental Marine Biology and Ecology, Volume 264, Issue 1, 15 September 2001, Pages 29-45. |
R825551 (Final) |
not available |
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Glasgow HB, Burkholder JM. Water quality trends and management implications from a five-year study of a eutrophic estuary. Ecological Applications 2000;10(4):1024-1046. |
R825551 (Final) |
not available |
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Glasgow HB, Burkholder JM, Morton SL, Springer J. A second species of ichthyotoxic Pfiesteria (Dinamoebales, Dinophyceae). Phycologia 2001;40(3):234-245. |
R825551 (Final) |
not available |
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Lewitus AJ, Willis BM, Hayes KC, Burkholder JM, Glasgow HB, Glibert PM, Burke MK. Mixotrophy and nitrogen uptake by Pfiesteria piscicida (Dinophyceae). Journal of Phycology 1999;35(6 suppl):1430-1437. |
R825551 (Final) |
not available |
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Mallin MA, Burkholder JM, Cahoon LB, Posey MH. North and South Carolina Coasts. Marine Pollution Bulletin 2000;41(1-6):56-75. |
R825551 (Final) |
not available |
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Oldach DW, Delwiche CF, Jakobsen KS, Tengs T, Brown EG, Kempton JW, Schaefer EF, Bowers HA, Glasgow Jr HB, Burkholder JM, Steidinger KA, Rublee PA. Heteroduplex mobility assay-guided sequence discovery: elucidation of the small subunit (18S) rDNA sequences of Pfiesteria piscicida and related dinoflagellates from complex algal culture and environmental sample DNA pools. Proceedings of the National Academy of Sciences of the United States of America 2000;97(8):4303-4308. |
R825551 (Final) R827084 (2000) R827084 (2001) R827084 (Final) |
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Rublee PA, Kempton J, Schaefer E, Burkholder JM, Glasgow Jr HB, Oldach D. PCR and FISH detection extends the range of Pfiesteria piscicida in estuarine waters. Virginia Journal of Science 1999;50(4):325-335. |
R825551 (Final) R827084 (2000) R827084 (2001) R827084 (Final) |
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Rublee PA, Kempton JW, Schaefer EF, Allen C, Harris J, Oldach DW, Bowers H, Tengs T, Burkholder JM, Glasgow Jr HB. Use of molecular probes to assess geographic distribution of Pfiesteria species. Environmental Health Perspectives 2001;109(Suppl 5):765-767. |
R825551 (Final) R827084 (2000) R827084 (2001) R827084 (Final) |
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Shumway SE, Cucci TL, Lesser MP, Bourne N, Bunting B. Particle clearance and selection in three species of juvenile scallops. Aquaculture International 1997;5(1):89-99. |
R825551 (Final) |
not available |
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Ward JE, Levinton JS, Shumway SE, Cucci T. Site of particle selection in a bivalve mollusc. Nature 1997;390(6656):131-132 |
R825551 (Final) |
not available |
Supplemental Keywords:
harmful algal blooms, dinoflagellate, estuaries, fish kill, fish disease, functional type, life cycle, PCR probe, toxic Pfiesteria complex, mollusk, scallops., RFA, Scientific Discipline, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, Hydrology, Nutrients, Contaminated Sediments, exploratory research environmental biology, Ecosystem/Assessment/Indicators, Chemical Mixtures - Environmental Exposure & Risk, Ecosystem Protection, Ecological Effects - Environmental Exposure & Risk, Environmental Microbiology, algal blooms, Ecological Effects - Human Health, Ecological Risk Assessment, Ecology and Ecosystems, Ecological Indicators, aquatic ecosystem, nutrient supply, nutrient transport, pfiesteria piscicida, ecological exposure, dinoflagellates, estuaries, food web, watershed management, fish lesions, harmful algal blooms, contaminated sediment, estuarine stress, nutrient kinetics, phytoplankton, heterotrophic microbial prey, algal growth, pfiesteria, phytoplankton dynamics, estuarine ecosystems, nutrient cycling, phytoplankton blooms, dinoflagellate, water quality, biosensor, estuarine food webRelevant Websites:
http://www.Pfiesteria.orgProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.