1
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Burkholder JM, Kinder CA, Dickey DA, Reed RE, Arellano C, James JL, Mackenzie LM, Allen EH, Lindor NL, Mathis JG, Thomas ZT. Classic indicators and diel dissolved oxygen versus trend analysis in assessing eutrophication of potable-water reservoirs. Ecol Appl 2022; 32:e2541. [PMID: 35072953 DOI: 10.1002/eap.2541] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/19/2021] [Accepted: 09/15/2021] [Indexed: 06/14/2023]
Abstract
Potable source-water reservoirs are the main water supplies in many urbanizing regions, yet their long-term responses to cultural eutrophication are poorly documented in comparison with natural lakes, creating major management uncertainties. Here, long-term discrete data (June 2006-June 2018) for classical eutrophication water quality indicators, continuous depth-profile data for dissolved oxygen (DO), and an enhanced hybrid statistical trend analysis model were used to evaluate the eutrophication status of a potable source-water reservoir. Based on classical indicators (nitrogen, N and phosphorus, P concentrations and ratios; phytoplankton biomass as chlorophyll a, chl a; and trophic state indices), the reservoir was eutrophic to hypereutrophic and stoichiometrically imbalanced. Anoxia/hypoxia occurred for 7-8 months annually systemwide, even throughout the water column for days to weeks in some years; and elevated total ammonia (up to ~900 μg tNH3 L-1 ) in surface waters from late summer/fall through late winter/early spring suggested substantial internal legacy nutrient loading. These surprising DO and tNH3 phenomena may characterize many reservoirs in urbanizing areas, and the associated cascade of negative impacts may increasingly affect them under global warming. Total organic carbon (TOC), seasonally influenced by phytoplankton biomass, commonly exceeded 6 mg L-1 , which is problematic for potable-water treatment, and significantly trended up over time. Wet-year inflow dilution influenced an apparent decreasing trend in nutrients within the hypereutrophic upper reservoir, which receives most tributary inputs. Nevertheless, significant reservoirwide trends (increasing total phosphorus [TP], phytoplankton chl a, TOC) and mid- and/or lower region trends (increasing total nitrogen [TN], tNH3 , decreasing TN:TP ratios) suggest that water quality degradation from eutrophication has worsened over time. These findings support broadly applicable recommendations to strengthen protection of potable source-water reservoirs in urbanizing watersheds: (1) protective numeric water quality criteria are needed for TOC as well as TN, TP, and chl a; (2) continuous diel data capture more realistic DO conditions than traditional sampling, and can provide important insights for water treatment managers; and (3) assessment of reservoir eutrophication status to track management progress over time should emphasize classic indicators equally as statistical trends, which are highly sensitive to short-term meteorological forcing.
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Affiliation(s)
- JoAnn M Burkholder
- Center for Applied Aquatic Ecology, Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA
| | - Carol A Kinder
- Center for Applied Aquatic Ecology, Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA
| | - David A Dickey
- Department of Statistics, North Carolina State University, Raleigh, North Carolina, USA
| | - Robert E Reed
- Center for Applied Aquatic Ecology, Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA
| | - Consuelo Arellano
- Department of Statistics, North Carolina State University, Raleigh, North Carolina, USA
| | - Jennifer L James
- Center for Applied Aquatic Ecology, Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA
| | - Linda M Mackenzie
- Center for Applied Aquatic Ecology, Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA
| | - Elle H Allen
- Center for Applied Aquatic Ecology, Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA
| | - Nicole L Lindor
- Center for Applied Aquatic Ecology, Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA
| | - Joshua G Mathis
- Center for Applied Aquatic Ecology, Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA
| | - Zachary T Thomas
- Center for Applied Aquatic Ecology, Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA
- Division of Water Resources, North Carolina Department of Water Quality, Raleigh, North Carolina, USA
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2
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Huang IS, Pietrasiak N, Gobler CJ, Johansen JR, Burkholder JM, D'Antonio S, Zimba PV. Diversity of bioactive compound content across 71 genera of marine, freshwater, and terrestrial cyanobacteria. Harmful Algae 2021; 109:102116. [PMID: 34815023 DOI: 10.1016/j.hal.2021.102116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 09/16/2021] [Accepted: 09/21/2021] [Indexed: 06/13/2023]
Abstract
Cyanobacterial blooms have increased in frequency, distribution, and intensity due to climate change and anthropogenic nutrient input. The release of bioactive compounds accumulated in these blooms can affect the health of humans and the environment. The co-occurrence of bioactive metabolites is well-documented in bloom samples from marine and freshwater ecosystems, with fewer reports from unialgal isolates. Cyanobacteria also are important terrestrial ecosystem components, especially in drylands, but reports on bioactive molecules from terrestrial cyanobacteria are sparse. This study determined bioactive metabolite profiles for 71 genera of cyanobacteria from seven orders isolated from freshwater (12 genera), marine (15 genera), and terrestrial (44 genera) habitats originally. Cultures were harvested for bioactive metabolites when entering the late-exponential phase for all 157 strains, and 33 were sampled at both early and late exponential phases. Bioactive metabolites were analyzed using an ultra high performance/pressure liquid chromatography in-line with a time-of-flight mass spectrometer. Overall, 12 bioactive classes of the 28 identified were ubiquitous in all samples. On average, each freshwater genus produced ∼12 bioactive classes, whereas each marine genus contained > 4 bioactive classes, and each terrestrial genus contained ∼6 bioactive classes. While 10 of 12 freshwater genera produced at least 10 bioactive classes, only a single genus each from marine and terrestrial habitats had the same number of bioactive classed accumulated. Aeruginosin was found in 58 of 71 total genera, carmabin in 51 of 71 genera, and anabaenopeptin in 48 of 71 genera. Chemotaxonomic use of these secondary metabolites may help resolve higher-level genetic classification(s). An additional growth curve experiment showed that bioactive metabolites were produced at both early and late exponential growth phases. The bioactive metabolite accumulation pattern between early and late exponential phases differed by bioactive classes, genera, and habitats. This survey of 55 bioactive classes in cyanobacteria isolated from freshwater, marine, and terrestrial habitats (71 genera) provides as one of the first systematic bioactive metabolite profiles for cyanobacteria, which should be useful in environmental and drinking water management. Further, it offers novel insights about the toxin potential of selected terrestrial cyanobacteria.
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Affiliation(s)
- I-Shuo Huang
- Center for Coastal Studies, Texas A&M University-Corpus Christi, 6300 Ocean Dr., Corpus Christi, TX 78412,USA; United States Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5001 Campus Drive, College Park, MD 20740,USA.
| | - Nicole Pietrasiak
- Department of Plant and Environmental Sciences, New Mexico State University, 1780 E University Ave, Las Cruces, NM 88003,USA
| | - Christopher J Gobler
- School of Marine and Atmospheric Science, Stony Brook University, 100 Nicolls Rd, Stony Brook, NY 11794,USA
| | - Jeffrey R Johansen
- Department of Biology, John Carroll University, 1 John Carroll Blvd, University Heights, OH 44118,USA; Department of Botany, Faculty of Sciences, University of South Bohemia, Branišovská 31, České Budějovice 37005, Czechia,USA
| | - JoAnn M Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, NC 27695,USA
| | - Sue D'Antonio
- Agilent Technologies Inc., 1834 TX-71 W, Cedar Creek, TX 78612,USA
| | - Paul V Zimba
- Center for Coastal Studies, Texas A&M University-Corpus Christi, 6300 Ocean Dr., Corpus Christi, TX 78412,USA; PVZimba, Inc., 12241 Percival St, Chester, VA 23831, USA
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3
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Shalygin S, Huang IS, Allen EH, Burkholder JM, Zimba PV. Odorella benthonica gen. & sp. nov. (Pleurocapsales, Cyanobacteria): an odor and prolific toxin producer isolated from a California aqueduct. J Phycol 2019; 55:509-520. [PMID: 30637743 DOI: 10.1111/jpy.12834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 11/28/2018] [Indexed: 06/09/2023]
Abstract
Pleurocapsales are one of the least understood groups of cyanobacteria in terms of molecular systematics and biochemistry. Considering the high number of cryptic taxa within the Synechococcales and Oscillatoriales, it is likely that such taxa also occur in the Pleurocapsales. The new genus described in our research is the first known pleurocapsalean cryptic taxon. It produces off-flavor and a large number of bioactive metabolites (n = 38) some of which can be toxic including four known microcystins. Using a polyphasic approach, we propose the establishment of the genus Odorella with the new species O. benthonica from material originally isolated from the California Aqueduct near Los Angeles.
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Affiliation(s)
- Sergei Shalygin
- Center for Coastal Studies, Texas A&M University Corpus Christi, 6300 Ocean Drive, Corpus Christi, Texas, 78412, USA
| | - I-Shuo Huang
- Center for Coastal Studies, Texas A&M University Corpus Christi, 6300 Ocean Drive, Corpus Christi, Texas, 78412, USA
| | - Elle H Allen
- Center for Applied Aquatic Ecology, North Carolina State University, 620 Hutton Street Suite 104, Raleigh, North Carolina, 27606, USA
| | - JoAnn M Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, 620 Hutton Street Suite 104, Raleigh, North Carolina, 27606, USA
| | - Paul V Zimba
- Center for Coastal Studies, Texas A&M University Corpus Christi, 6300 Ocean Drive, Corpus Christi, Texas, 78412, USA
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Flood SL, Burkholder JM. Chattonella subsalsa (Raphidophyceae) growth and hemolytic activity in response to agriculturally-derived estuarine contaminants. Harmful Algae 2018; 76:66-79. [PMID: 29887206 DOI: 10.1016/j.hal.2018.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 05/18/2018] [Accepted: 05/20/2018] [Indexed: 06/08/2023]
Abstract
The potential for toxic contaminants and nutrient pollution to alter natural cycles of estuarine phytoplankton blooms is well known, yet few studies have examined how these combined stressors affect harmful algal species. Here, a robust testing protocol was developed to enable an ecotoxicological assessment of responses to commonly co-occurring estuarine contaminants by harmful algal bloom species. The population growth and toxicity (as cell density and hemolytic activity, respectively) of a cultured strain of the toxigenic raphidiophycean, Chattonella subsalsa, were assessed in two experiments (duration 10 days and 28 days) across a gradient of atrazine concentrations and N:P ratios simulating nutrient-rich versus nutrient-depleted regimes. The response of this large-celled, slowly growing alga to atrazine × nutrients depended on growth phase; atrazine was most inhibitory during early exponential population growth (day 10), whereas nutrient regime was a more important influence during later phases of growth (day 28). Without atrazine, toxicity toward fish was highest in low-P cultures. At atrazine levels >25 μg L-1, hemolytic activity was highest in low-N cultures, and increased with increasing atrazine concentration in all nutrient-limited cultures. Hemolytic activity varied inversely with atrazine concentration in N,P-replete conditions. Overall, atrazine inhibitory effects on population growth of this C. subsalsa strain depended on the growth phase and the nutrient regime; hemolytic activity was higher and further enhanced by atrazine in low N-P regimes; and atrazine inhibited hemolytic activity in nutrient-replete conditions. The data suggest that, depending on the growth phase and nutrient regime, atrazine can help promote toxic C. subsalsa blooms.
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Affiliation(s)
- Stacie L Flood
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, NC, 27606, USA.
| | - JoAnn M Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, NC, 27606, USA
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5
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Flood SL, Burkholder JM. Imbalanced nutrient regimes increase Prymnesium parvum resilience to herbicide exposure. Harmful Algae 2018; 75:57-74. [PMID: 29778226 DOI: 10.1016/j.hal.2018.04.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 04/10/2018] [Accepted: 04/10/2018] [Indexed: 06/08/2023]
Abstract
The toxigenic haptophyte Prymnesium parvum is a mixotrophic phytoplankter with an extensive historic record of forming nearly monospecific, high-biomass, ecosystem-disrupting blooms, and it has been responsible for major fish kills in brackish waters and aquaculture facilities in many regions of the world. Little is known about how this species responds to commonly occurring environmental contaminants, or how nutrient (nitrogen, phosphorus) pollution may interact with environmentally relevant pesticide exposures to affect this harmful algal species. Here, standard algal toxicity bioassays from pesticide hazard assessments were used along with modified erythrocyte lysis assays to evaluate how atrazine exposures, imbalanced nutrient supplies, and salinity interact to influence the growth and toxicity in P. parvum isolates from three different regions. In nutrient-replete media, P. parvum 96 h IC50s ranged from 73.0 to 88.3 μg atrazine L-1 at salinity 10 and from 118 to >200 μg atrazine μg L-1 at salinity 20, and the response depended on the strain and the test duration. Relative hemolytic activity, used as an indication of toxicity, was a function of herbicide exposure, nutrient availability, salinity, geographic origin, and interactions among these factors. Highest levels of hemolytic activity were measured from a South Carolina strain in low-nitrogen media with high atrazine concentrations. Herbicide concentration was related to relative hemolytic activity, although a consistent relationship between growth phase and toxicity was not observed. Overall, these findings suggest that increasing chemical contamination is helping to promote ecosystem-disruptive, strongly mixotrophic algal blooms.
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Affiliation(s)
- Stacie L Flood
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, NC 27606 USA.
| | - JoAnn M Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, NC 27606 USA
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6
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Gobler CJ, Burkholder JM, Davis TW, Harke MJ, Johengen T, Stow CA, Van de Waal DB. The dual role of nitrogen supply in controlling the growth and toxicity of cyanobacterial blooms. Harmful Algae 2016; 54:87-97. [PMID: 28073483 DOI: 10.1016/j.hal.2016.01.010] [Citation(s) in RCA: 173] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/30/2016] [Indexed: 05/03/2023]
Abstract
Historically, phosphorus (P) has been considered the primary limiting nutrient for phytoplankton assemblages in freshwater ecosystems. This review, supported by new findings from Lake Erie, highlights recent molecular, laboratory, and field evidence that the growth and toxicity of some non-diazotrophic blooms of cyanobacteria can be controlled by nitrogen (N). Cyanobacteria such as Microcystis possess physiological adaptations that allow them to dominate low-P surface waters, and in temperate lakes, cyanobacterial densities can be controlled by N availability. Beyond total cyanobacterial biomass, N loading has been shown to selectively promote the abundance of Microcystis and Planktothrix strains capable of synthesizing microcystins over strains that do not possess this ability. Among strains of cyanobacteria capable of synthesizing the N-rich microcystins, cellular toxin quotas have been found to depend upon exogenous N supplies. Herein, multi-year observations from western Lake Erie are presented demonstrating that microcystin concentrations peak in parallel with inorganic N, but not orthophosphate, concentrations and are significantly lower (p<0.01) during years of reduced inorganic nitrogen loading and concentrations. Collectively, this information underscores the importance of N as well as P in controlling toxic cyanobacteria blooms. Furthermore, it supports the premise that management actions to reduce P in the absence of concurrent restrictions on N loading may not effectively control the growth and/or toxicity of non-diazotrophic toxic cyanobacteria such as the cosmopolitan, toxin-producing genus, Microcystis.
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Affiliation(s)
- Christopher J Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Hwy, New York 11968, USA.
| | - JoAnn M Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, NC 27606, USA
| | - Timothy W Davis
- NOAA Great Lakes Environmental Research Laboratory, Ann Arbor, MI 48108, USA
| | - Matthew J Harke
- School of Marine and Atmospheric Sciences, Stony Brook University, 239 Montauk Hwy, New York 11968, USA
| | - Tom Johengen
- Cooperative Institute for Limnology and Ecosystems Research, University of Michigan, Ann Arbor, MI 48109, USA
| | - Craig A Stow
- NOAA Great Lakes Environmental Research Laboratory, Ann Arbor, MI 48108, USA
| | - Dedmer B Van de Waal
- Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Post Office Box 50, Wageningen 6700 AB, The Netherlands
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7
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Rothenberger MB, Burkholder JM, Brownie C. Long-term effects of changing land use practices on surface water quality in a coastal river and lagoonal estuary. Environ Manage 2009; 44:505-23. [PMID: 19597872 DOI: 10.1007/s00267-009-9330-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 03/08/2009] [Accepted: 06/13/2009] [Indexed: 05/20/2023]
Abstract
The watershed of the Neuse River, a major tributary of the largest lagoonal estuary on the U.S. mainland, has sustained rapid growth of human and swine populations. This study integrated a decade of available land cover and water quality data to examine relationships between land use changes and surface water quality. Geographic Information Systems (GIS) analysis was used to characterize 26 subbasins throughout the watershed for changes in land use during 1992-2001, considering urban, agricultural (cropland, animal as pasture, and densities of confined animal feed operations [CAFOs]), forested, grassland, and wetland categories and numbers of wastewater treatment plants (WWTPs). GIS was also used together with longitudinal regression analysis to identify specific land use characteristics that influenced surface water quality. Total phosphorus concentrations were significantly higher during summer in subbasins with high densities of WWTPs and CAFOs. Nitrate was significantly higher during winter in subbasins with high numbers of WWTPs, and organic nitrogen was higher in subbasins with higher agricultural coverage, especially with high coverage of pastures fertilized with animal manure. Ammonium concentrations were elevated after high precipitation. Overall, wastewater discharges in the upper, increasingly urbanized Neuse basin and intensive swine agriculture in the lower basin have been the highest contributors of nitrogen and phosphorus to receiving surface waters. Although nonpoint sources have been emphasized in the eutrophication of rivers and estuaries such as the Neuse, point sources continue to be major nutrient contributors in watersheds sustaining increasing human population growth. The described correlation and regression analyses represent a rapid, reliable method to relate land use patterns to water quality, and they can be adapted to watersheds in any region.
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Skelton HM, Burkholder JM, Parrow MW. AXENIC CULTIVATION OF THE HETEROTROPHIC DINOFLAGELLATE PFIESTERIA SHUMWAYAE AND OBSERVATIONS ON FEEDING BEHAVIOR(1). J Phycol 2008; 44:1614-1624. [PMID: 27039873 DOI: 10.1111/j.1529-8817.2008.00601.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Pfiesteria shumwayae Glasgow et J. M. Burkh. [=Pseudopfiesteria shumwayae (Glasgow et J. M. Burkh.) Litaker, Steid., P. L. Mason, Shields et P. A. Tester] is a heterotrophic dinoflagellate commonly found in temperate, estuarine waters. P. shumwayae can feed on other protists, fish, and invertebrates, but research on the biochemical requirements of this species has been restricted by the lack of axenic cultures. An undefined, biphasic culture medium was formulated that supported the axenic growth of two of three strains of P. shumwayae. The medium contained chicken egg yolk as a major component. Successful growth depended on the method used to sterilize the medium, and maximum cell yields (10(4) · mL(-1) ) were similar to those attained in previous research when P. shumwayae was cultured with living fish or microalgae. Additionally, P. shumwayae flagellate cells ingested particles present in the biphasic medium, allowing detailed observations of feeding behavior. This research is an initial step toward a chemically defined axenic culture medium and determination of P. shumwayae metabolic requirements.
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Affiliation(s)
- Hayley M Skelton
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, North Carolina 27606, USADepartment of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA
| | - JoAnn M Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, North Carolina 27606, USADepartment of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA
| | - Matthew W Parrow
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, North Carolina 27606, USADepartment of Biology, University of North Carolina at Charlotte, Charlotte, North Carolina 28223, USA
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Anderson DM, Burkholder JM, Cochlan WP, Glibert PM, Gobler CJ, Heil CA, Kudela R, Parsons ML, Rensel JEJ, Townsend DW, Trainer VL, Vargo GA. Harmful algal blooms and eutrophication: Examining linkages from selected coastal regions of the United States. Harmful Algae 2008; 8:39-53. [PMID: 19956363 PMCID: PMC2677713 DOI: 10.1016/j.hal.2008.08.017] [Citation(s) in RCA: 213] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Coastal waters of the United States (U.S.) are subject to many of the major harmful algal bloom (HAB) poisoning syndromes and impacts. These include paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), ciguatera fish poisoning (CFP) and various other HAB phenomena such as fish kills, loss of submerged vegetation, shellfish mortalities, and widespread marine mammal mortalities. Here, the occurrences of selected HABs in a selected set of regions are described in terms of their relationship to eutrophication, illustrating a range of responses. Evidence suggestive of changes in the frequency, extent or magnitude of HABs in these areas is explored in the context of the nutrient sources underlying those blooms, both natural and anthropogenic. In some regions of the U.S., the linkages between HABs and eutrophication are clear and well documented, whereas in others, information is limited, thereby highlighting important areas for further research.
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Affiliation(s)
- Donald M. Anderson
- Biology Department, MS #32, Woods Hole Oceanographic Institution, Woods Hole MA 02543 USA
- Corresponding Author: Tel: (508) 289-2321; FAX: (508) 457-2027; E-mail:
| | - JoAnn M. Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, NC 27606 USA
| | - William P. Cochlan
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, California 94920 USA
| | - Patricia M. Glibert
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge, MD 21613
| | - Christopher J. Gobler
- Stony Brook University, School of Marine and Atmospheric Sciences, Stony Brook, NY 11794-5000
| | - Cynthia A. Heil
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, 100 8th Ave. S., St. Petersburg, FL 33701
| | - Raphael Kudela
- Ocean Sciences & Institute for Marine Sciences, University of California Santa Cruz, Santa Cruz, CA 95064 USA
| | - Michael L. Parsons
- Department of Marine and Ecological Sciences, Florida Gulf Coast University, Fort Myers, Fl 33965 USA
| | | | - David W. Townsend
- School of Marine Sciences, University of Maine, Orono, Maine 04469 USA
| | - Vera L. Trainer
- NOAA, Northwest Fisheries Science Center, Marine Biotoxins Program, Seattle, Washington, 98112 USA
| | - Gabriel A. Vargo
- University of South Florida, College of Marine Science, 140 Seventh Avenue South, St. Petersburg, FL 33701
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Glibert PM, Azanza R, Burford M, Furuya K, Abal E, Al-Azri A, Al-Yamani F, Andersen P, Beardall J, Berg GM, Brand L, Bronk D, Brookes J, Burkholder JM, Cembella A, Cochlan WP, Collier J, Collos Y, Diaz R, Doblin M, Drennen T, Dyhrman S, Fukuyo Y, Furnas M, Galloway J, Granéli E, Ha DV, Hallegraeff G, Harrison J, Harrison PJ, Heil CA, Heimann K, Howarth R, Jauzein C, Kana AA, Kana TM, Kim H, Kudela R, Legrand C, Mallin M, Mulholland M, Murray S, O’Neil J, Pitcher G, Qi Y, Rabalais N, Raine R, Seitzinger S, Solomon C, Stoecker DK, Usup G, Wilson J, Yin K, Zhou M, Zhu M. Ocean urea fertilization for carbon credits poses high ecological risks. Mar Pollut Bull 2008; 56:1049-56. [PMID: 18439628 PMCID: PMC5373553 DOI: 10.1016/j.marpolbul.2008.03.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Accepted: 03/02/2008] [Indexed: 05/12/2023]
Abstract
The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed.
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Affiliation(s)
- Patricia M. Glibert
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge MD 21613, USA; ; ; ;
- Corresponding author:; 410-221-8422 (office); 410-221-8490 (fax)
| | - Rhodora Azanza
- The Marine Science Institute, Velasquez, University of the Philippines, Diliman, Quezon City, Philippines;
| | - Michele Burford
- Griffith University, Australian Rivers Institute, Kessel Rd., Nathan Queensland 4111, Australia; ;
| | - Ken Furuya
- Department of Aquatic Bioscience, the University of Tokyo, Yayoi, Bunkyo, Tokyo 113-8657, Japan;
| | - Eva Abal
- South East Queensland Healthy Waterways Partnership, 239 George Street, GPO Box 1434, Brisbane Queensland 4001, Australia;
| | - Adnan Al-Azri
- Dept. of Marine Sciences and Fisheries, Sultan Qaboos University, P.O.Box 34, Al-Khodh, PC123 Muscat, Oman;
| | - Faiza Al-Yamani
- Kuwait Institute for Scientific Research, P.O Box 24885 Safat 13109, Kuwait;
| | - Per Andersen
- Orbicon A/S, Jens Juuls Vej 18, 8260, Viby J., Denmark;
| | - John Beardall
- School of Biological Sciences, Monash University, Clayton Victoria 3800, Australia;
| | - G. Mine Berg
- Department of Geophysics, Stanford University, Stanford, CA 94305, USA;
| | - Larry Brand
- Division of Marine Biology and Fisheries, Rosentiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA;
| | - Deborah Bronk
- Virginia Institute of Marine Science, P.O. Box 1346, Gloucester Point, VA 23062 USA; ;
| | - Justin Brookes
- Water Research Cluster, The University of Adelaide, Adelaide South Australia 5005, Australia;
| | - JoAnn M. Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh, NC 27695 USA;
| | - Allan Cembella
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany;
| | - William P. Cochlan
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, San Francisco, CA 94920, USA;
| | - Jackie Collier
- Marine Sciences Research Center, SUNY Stony Brook, Stony Brook, NY 11794, USA;
| | - Yves Collos
- Université Montpellier 2, CNRS, Ifremer, Laboratoire Ecosystèmes Lagunaires (UMR 5119) CC093, 34095 Montpellier Cedex 5, France; ;
| | - Robert Diaz
- Virginia Institute of Marine Science, P.O. Box 1346, Gloucester Point, VA 23062 USA; ;
| | - Martina Doblin
- Department of Environmental Sciences, University of Technology Sydney, P.O. Box 123, Broadway NSW 2007, Australia;
| | - Thomas Drennen
- Departments of Economics and Environmental Studies, Hobart and William Smith Colleges, Geneva NY 14456, USA; ;
| | - Sonya Dyhrman
- Biology Department MS#33, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA;
| | - Yasuwo Fukuyo
- Asian Natural Environmental Science Center, the University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan;
| | - Miles Furnas
- Water Quality and Ecosystem Health Team, Australian Institute of Marine Science PMB No. 3, Townsville MC, Queensland 4810, Australia;
| | - James Galloway
- Environmental Sciences Department, Clark Hall, University of Virginia, Charlottesville, 22903 VA, USA;
| | - Edna Granéli
- Department of Marine Sciences, University of Kalmar, 39182 Kalmar, Sweden; ;
| | - Dao Viet Ha
- Institute of Oceanography, Cauda 01, Vinh Nguyen, Nhatrang City, Vietnam;
| | - Gustaaf Hallegraeff
- School of Plant Science,University of Tasmania, Private Bag 55, Hobart Tasmania 7001, Australia;
| | - John Harrison
- School of Earth and Environmental Sciences, Washington State University, Vancouver Campus, 14204 NE Salmon Creek Avenue, Vancouver, WA 98686, USA;
| | - Paul J. Harrison
- Atmospheric, Marine and Coastal Environment Program, Hong Kong University of Science and Technology, Kowloon, Hong Kong, China;
| | - Cynthia A. Heil
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, 100 Eighth Ave., S., St. Petersburg, FL 33701 USA;
| | - Kirsten Heimann
- School of Marine and Tropical Biology, James Cook University, Townsville Queensland 4811, Australia;
| | - Robert Howarth
- Department of Ecology and Evolutionary Biology, Cornell University, E311 Corson Hall, Ithaca NY 14853, USA;
| | - Cécile Jauzein
- Université Montpellier 2, CNRS, Ifremer, Laboratoire Ecosystèmes Lagunaires (UMR 5119) CC093, 34095 Montpellier Cedex 5, France; ;
| | - Austin A. Kana
- Departments of Economics and Environmental Studies, Hobart and William Smith Colleges, Geneva NY 14456, USA; ;
| | - Todd M. Kana
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge MD 21613, USA; ; ; ;
| | - Hakgyoon Kim
- Pukyong National University, Department of Ocean Science, 599-1 Daeyon-Dong, Nam-gu, Busan, Korea;
| | - Raphael Kudela
- Ocean Sciences and Institute for Marine Sciences, University of California Santa Cruz, 1156 High St., Santa Cruz, CA 95064, USA;
| | - Catherine Legrand
- Department of Marine Sciences, University of Kalmar, 39182 Kalmar, Sweden; ;
| | - Michael Mallin
- Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K. Moss Lane, Wilmington, N.C. 28409;
| | - Margaret Mulholland
- Department of Ocean, Earth and Atmospheric Sciences, Old Dominion University, 4600 Elkhorn Avenue, Norfolk, VA 23529, USA;
| | - Shauna Murray
- School of Biological Sciences A08, University of Sydney, Sydney NSW 2006, Australia;
| | - Judith O’Neil
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge MD 21613, USA; ; ; ;
| | - Grant Pitcher
- Marine and Coastal Management, Private Bag X2, Rogge Bay 8012, Cape Town, South Africa;
| | - Yuzao Qi
- Jinan University, Research Center for Harmful Algae and Aquatic Environment, 510632, Guanzhou, P.R. China;
| | - Nancy Rabalais
- Louisiana Universities Marine Consortium, Chauvin, LA 70344, USA;
| | - Robin Raine
- Martin Ryan Institute, National University of Ireland, Galway, Ireland;
| | - Sybil Seitzinger
- Institute of Marine and Coastal Sciences, Rutgers, The State University of New Jersey, Rutgers/NOAA CMER, 71 Dudley Road, New Brunswick, NJ 08901, USA;
| | - Caroline Solomon
- Department of Biology, Gallaudet University, 800 Florida Ave, NE, Washington D.C. 20002, USA;
| | - Diane K. Stoecker
- University of Maryland Center for Environmental Science, Horn Point Laboratory, PO Box 775, Cambridge MD 21613, USA; ; ; ;
| | - Gires Usup
- Faculty of Science and Technology, Universitii Kebagsaan Malaysia, Bangi, Selangor, Malaysia;
| | - Joanne Wilson
- Coral Triangle Centre, The Nature Conservancy, Jl Pengembak 2, Sanur, 80228, Bali, Indonesia;
| | - Kedong Yin
- Griffith University, Australian Rivers Institute, Kessel Rd., Nathan Queensland 4111, Australia; ;
| | - Mingjiang Zhou
- Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, P.R. China;
| | - Mingyuan Zhu
- First Institute of Oceanography, 6 Xianxialing Road, High-tech Industrial Park, 266061 Qingdao, P.R. China;
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11
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Coyne KJ, Burkholder JM, Feldman RA, Hutchins DA, Cary SC. Modified serial analysis of gene expression method for construction of gene expression profiles of microbial eukaryotic species. Appl Environ Microbiol 2004; 70:5298-304. [PMID: 15345413 PMCID: PMC520878 DOI: 10.1128/aem.70.9.5298-5304.2004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2004] [Accepted: 05/13/2004] [Indexed: 11/20/2022] Open
Abstract
Serial analysis of gene expression (SAGE) is a powerful approach for the identification of differentially expressed genes, providing comprehensive and quantitative gene expression profiles in the form of short tag sequences. Each tag represents a unique transcript, and the relative frequencies of tags in the SAGE library are equal to the relative proportions of the transcripts they represent. One of the major obstacles in the preparation of SAGE libraries from microorganisms is the requirement for large amounts of starting material (i.e., mRNA). Here, we present a novel approach for the construction of SAGE libraries from small quantities of total RNA by using Y linkers to selectively amplify 3' cDNA fragments. To validate this method, we constructed comprehensive gene expression profiles of the toxic dinoflagellate Pfiesteria shumwayae. SAGE libraries were constructed from an actively toxic fish-fed culture of P. shumwayae and from a recently toxic alga-fed culture. P. shumwayae-specific gene transcripts were identified by comparison of tag sequences in the two libraries. Representative tags with frequencies ranging from 0.026 to 3.3% of the total number of tags in the libraries were chosen for further analysis. Expression of each transcript was confirmed in separate control cultures of toxic P. shumwayae. The modified SAGE method described here produces gene expression profiles that appear to be both comprehensive and quantitative, and it is directly applicable to the study of gene expression in other environmentally relevant microbial species.
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Affiliation(s)
- Kathryn J Coyne
- Graduate College of Marine Studies, University of Delaware, 700 Pilottown Rd., Lewes, DE 19958, USA
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12
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Tengs T, Bowers HA, Glasgow HB, Burkholder JM, Oldach DW. Identical ribosomal DNA sequence data from Pfiesteria piscicida (Dinophyceae) isolates with different toxicity phenotypes. Environ Res 2003; 93:88-91. [PMID: 12865051 DOI: 10.1016/s0013-9351(02)00087-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Complete small subunit ribosomal RNA, internal transcribed spacer 1 and 2, 5.8S, and partial large subunit ribosomal RNA gene sequences were generated from multiple isolates of Pfiesteria piscicida. Sequences were derived from isolates that have been shown to be ichthyotoxic as well as isolates that have no history of toxic behavior. All of the sequences generated were identical for the different cultures, and we therefore conclude that differences in toxicity seen between isolates of P. piscicida are linked to factors other than genetic strain variation detectable by ribosomal gene sequence analyses.
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Affiliation(s)
- Torstein Tengs
- Institute of Human Virology, University of Maryland at Baltimore, 725 West Lombard Street, Baltimore, MD 21201, USA
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13
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Levin ED, Blackwelder WP, Glasgow HB, Burkholder JM, Moeller PDR, Ramsdell JS. Learning impairment caused by a toxin produced by Pfiesteria piscicida infused into the hippocampus of rats. Neurotoxicol Teratol 2003; 25:419-26. [PMID: 12798959 DOI: 10.1016/s0892-0362(03)00011-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Pfiesteria piscicida, an estuarine dinoflagellate, which has been shown to kill fish, has also been associated with neurocognitive deficits in humans. With a rat model, we have demonstrated the cause-and-effect relationship between Pfiesteria exposure and learning impairment. In several studies, we have replicated the finding in Sprague-Dawley rats that exposure to fixed acute doses of Pfiesteria cells or filtrates caused radial-arm maze learning impairment. Recently, this finding of Pfiesteria-induced learning impairment in rats has been independently replicated in another laboratory as well. We have demonstrated significant Pfiesteria-induced learning impairment in both the win-shift and repeated-acquisition tasks in the radial-arm maze and in reversal learning in a visual operant signal detection task. These learning impairments have been seen as long as 10 weeks after a single acute exposure to Pfiesteria. In the current study, we used a hydrophilic toxin isolated from clonal P. piscicida cultures (PfTx) and tested its effect when applied locally to the ventral hippocampus on repeated acquisition of rats in the radial-arm maze. Toxin exposure impaired choice accuracy in the radial-arm maze repeated acquisition procedure. The PfTx-induced impairment was seen at the beginning of the session and the early learning deficit was persistent across 6 weeks of testing after a single administration of the toxin. Eventually, with enough practice, in each session, the PfTx-exposed rats did learn that session's problem as did control rats. This model has demonstrated the cause-and-effect relationship between exposure to a hydrophilic toxin produced by P. piscicida and learning impairment, and specifically that the ventral hippocampus was critically involved.
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Affiliation(s)
- Edward D Levin
- Department of Psychiatry and Behavioral Science, Duke University Medical Center, Durham, NC 27710, USA.
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14
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Touchette BW, Burkholder JM, Glasgow HB. Variations in eelgrass (Zostera marina L.) morphology and internal nutrient composition as influenced by increased temperature and water column nitrate. ACTA ACUST UNITED AC 2003. [DOI: 10.1007/bf02691701] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Lewitus AJ, Hayes KC, Willis BM, Burkholder JM, Glasgow HB, Fred Holland A, Maier PP, Rublee PA, Magnien R. Low abundance of the dinoflagellates,Pfiesteria piscicida, P. shumwayae, andCryptoperidiniopsis spp., in South Carolina tidal creeks and open estuaries. ACTA ACUST UNITED AC 2002. [DOI: 10.1007/bf02804892] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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16
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Jakobsen KS, Tengs T, Vatne A, Bowers HA, Oldach DW, Burkholder JM, Glasgow HB, Rublee PA, Klaveness D. Discovery of the toxic dinoflagellate Pfiesteria in northern European waters. Proc Biol Sci 2002; 269:211-4. [PMID: 11798438 PMCID: PMC1690870 DOI: 10.1098/rspb.2001.1852] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Several dinoflagellate strains of the genus Pfiesteria were isolated by culturing techniques from sediment samples taken in the Oslofjord region of Norway. Pfiesteria piscicida, well known as a fish killer from the Atlantic coast of America, was identified by genetic methods and light microscopy. The related species Pfiesteria shumwayae was attracted from the sediment by the presence of fish, and has proved toxic. This present survey demonstrates the wide distribution of these potentially harmful species, but so far they have not been connected with fish kills in Europe.
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Affiliation(s)
- Kjetill S Jakobsen
- Department of Biology, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway
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Rezvani AH, Bushnell PJ, Burkholder JM, Glasgow HB, Levin ED. Specificity of cognitive impairment from Pfiesteria piscicida exposure in rats: attention and visual function versus behavioral plasticity. Neurotoxicol Teratol 2001; 23:609-16. [PMID: 11792529 DOI: 10.1016/s0892-0362(01)00169-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Pfiesteria piscicida is a toxic dinoflagellate that has caused massive fish kills in estuaries along the East Coast of the United States, and exposure of humans to toxic Pfiesteria has been associated with cognitive impairment. A visual signal detection task was used to determine the possible importance of attentional and visual processes in Pfiesteria effects on cognitive function. Adult female rats were trained to perform the signal detection task. After training, the rats were injected subcutaneously with fish culture water containing toxic Pfiesteria (35,600 or 106,800 cells of Pfiesteria/kg of rat body weight) or with (control) fish culture water containing no Pfiesteria. Effects of toxic Pfiesteria on maintenance of signal detection behavior were assessed for 2 weeks after treatment. Then, the signal-response contingencies were reversed. After the discrimination was reestablished on the reversed levers, the rats received a second dose of toxic Pfiesteria. The rats were again tested for 2 weeks, after which a second reversal was imposed. Pfiesteria did not affect behavior in the signal detection task during 2 weeks of prereversal testing after either exposure. However, a significant Pfiesteria-induced deficit emerged when the signal-response contingencies were reversed. These findings suggest that Pfiesteria-induced deficits emerge during periods of behavioral transition and not during performance of previously learned tasks.
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Affiliation(s)
- A H Rezvani
- Neurobehavioral Research Laboratory, Department of Psychiatry, Duke University Medical Center, 341 Bell Building, Box 3412 Durham, NC 27710, USA.
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18
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Melo AC, Moeller PD, Glasgow H, Burkholder JM, Ramsdell JS. Microfluorimetric analysis of a purinergic receptor (P2X7) in GH4C1 rat pituitary cells: effects of a bioactive substance produced by Pfiesteria piscicida. Environ Health Perspect 2001; 109 Suppl 5:731-737. [PMID: 11677182 PMCID: PMC1240604 DOI: 10.1289/ehp.01109s5731] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Pfiesteria piscicida Steidinger & Burkholder is a toxic dinoflagellate that leads to fish and human toxicity. It produces a bioactive substance that leads to cytotoxicity of GH4C1 rat pituitary cells. Extracellular adenosine 5'-triphosphate (ATP) acting on P2X7 purinergic receptors induces the formation of a nonselective cation channel, causing elevation of the cytosolic free calcium followed by a characteristic permeabilization of the cell to progressively larger ions and subsequent cell lysis. We investigated whether GH4C1 rat pituitary cells express functional P2X7 receptors, and if so, are they activated by a bioactive substance isolated from toxic P. piscicida cultures. We tested the selective agonist 2'-3'-O-(benzoyl-4-benzoyl)-ATP (BzATP) and antagonists piridoxalphosphate-6-azophenyl-2'-4'-disulfonic acid (PPADS) and oxidized-ATP (oxATP) using elevated cytosolic free calcium in Fura-2 loaded cells, and induced permeability of these cells to the fluorescent dye YO-PRO-1 as end points. We demonstrated that in GH4C1 cells, BzATP induces both the elevation of cytosolic free calcium and the permeabilization of the cell membrane. ATP-induced membrane permeabilization was inhibited by PPADS reversibly and by oxATP irreversibly. The putative Pfiesteria toxin (pPfTx) also elevated cytosolic free calcium in Fura-2 in GH4C1 cells and increased the permeability to YO-PRO-1 in a manner inhibited fully by oxATP. This study indicates that GH4C1 cells express a purinoceptor with characteristics consistent with the P2X7 subtype, and that pPfTx mimics the kinetics of cell permeabilization by ATP.
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Affiliation(s)
- A C Melo
- Marine Biotoxins Program, Center for Coastal Environmental Health and Biomolecular Research, National Oceanic & Atmospheric Administration-National Ocean Service, Charleston, South Carolina 29412, USA
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Moeller PD, Morton SL, Mitchell BA, Sivertsen SK, Fairey ER, Mikulski TM, Glasgow H, Deamer-Melia NJ, Burkholder JM, Ramsdell JS. Current progress in isolation and characterization of toxins isolated from Pfiesteria piscicida. Environ Health Perspect 2001; 109 Suppl 5:739-743. [PMID: 11677183 PMCID: PMC1240605 DOI: 10.1289/ehp.01109s5739] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The isolation and partial purification of toxic substances derived from Pfiesteria piscicida Steidinger & Burkholder extracts is described. Four distinct bioassay systems were used to monitor bioactivity of the P. piscicida extracts, including a high throughput cell cytotoxicity assay and a reporter gene assay as well as assays using brine shrimp and fish. Using these bioassays to guide fractionation, we have isolated two distinct, active fractions from Pfiesteria culture medium and cell mass extracts on the basis of their solubility characteristics. We have identified and characterized a bioactive lipophilic substance from Pfiesteria-derived extracts as di(2-ethylhexyl)phthalate, a commonly used plasticizer. The source of this typically man-made substance has been identified as originating from Instant Ocean (Aquarium Systems, Mentor, OH, USA), a commercially available seawater salt mixture used to prepare our mass culture growth medium. We have developed chromatographic methodology to isolate a bioactive polar compound isolated from extracts of Pfiesteria culture and presently report the characterization of the activity of this substance. The molecular structural analysis of the polar active component(s) using mass spectrometry and nuclear magnetic resonance spectroscopy is currently under way.
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Affiliation(s)
- P D Moeller
- Marine Biotoxins Program, Center for Coastal Environmental Health and Biomolecular Research, National Oceanic & Atmospheric Administration-National Ocean Service, Charleston, South Carolina 29412, USA.
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Burkholder JM, Marshall HG, Glasgow HB, Seaborn DW, Deamer-Melia NJ. The standardized fish bioassay procedure for detecting and culturing actively toxic Pfiesteria, used by two reference laboratories for atlantic and gulf coast states. Environ Health Perspect 2001; 109 Suppl 5:745-756. [PMID: 11677184 PMCID: PMC1240606 DOI: 10.1289/ehp.01109s5745] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In the absence of purified standards of toxins from Pfiesteria species, appropriately conducted fish bioassays are the "gold standard" that must be used to detect toxic strains of Pfiesteria spp. from natural estuarine water or sediment samples and to culture actively toxic Pfiesteria. In this article, we describe the standardized steps of our fish bioassay as an abbreviated term for a procedure that includes two sets of trials with fish, following the Henle-Koch postulates modified for toxic rather than infectious agents. This procedure was developed in 1991, and has been refined over more than 12 years of experience in research with toxic Pfiesteria. The steps involve isolating toxic strains of Pfiesteria (or other potentially, as-yet-undetected, toxic Pfiesteria or Pfiesteria-like species) from fish-killing bioassays with natural samples; growing the clones with axenic algal prey; and retesting the isolates in a second set of fish bioassays. The specific environmental conditions used (e.g., temperature, salinity, light, other factors) must remain flexible, given the wide range of conditions from which natural estuarine samples are derived. We present a comparison of information provided for fish culture conditions, reported in international science journals in which such research is routinely published, and we provide information from more than 2,000 fish bioassays with toxic Pfiesteria, along with recommendations for suitable ranges and frequency of monitoring of environmental variables. We present data demonstrating that algal assays, unlike these standardized fish bioassays, should not be used to detect toxic strains of Pfiesteria spp. Finally, we recommend how quality control/assurance can be most rapidly advanced among laboratories engaged in studies that require research-quality isolates of toxic Pfiesteria spp.
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Affiliation(s)
- J M Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh 27606, USA.
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Rublee PA, Kempton JW, Schaefer EF, Allen C, Harris J, Oldach DW, Bowers H, Tengs T, Burkholder JM, Glasgow HB. Use of molecular probes to assess geographic distribution of Pfiesteria species. Environ Health Perspect 2001; 109 Suppl 5:765-767. [PMID: 11677186 PMCID: PMC1240608 DOI: 10.1289/ehp.01109s5765] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We have developed multiple polymerase chain reaction (PCR)-based methods for the detection of Pfiesteria sp. in cultures and environmental samples. More than 2,100 water and sediment samples from estuarine sites of the U.S. Atlantic and gulf coasts were assayed for the presence of Pfiesteria piscicida Steidinger & Burkholder and Pfiesteria shumwayae Glasgow & Burkholder by PCR probing of extracted DNA. Positive results were found in about 3% of samples derived from routine monitoring of coastal waters and about 8% of sediments. The geographic range of both species was the same, ranging from New York to Texas. Pfiesteria spp. are likely common and generally benign inhabitants of coastal areas, but their presence maintains a potential for fish and human health problems.
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Affiliation(s)
- P A Rublee
- Biology Department, University of North Carolina at Greensboro, 27402, USA.
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Burkholder JM, Glasgow HB, Deamer-Melia NJ, Springer J, Parrow MW, Zhang C, Cancellieri PJ. Species of the toxic Pfiesteria complex, and the importance of functional type in data interpretation. Environ Health Perspect 2001; 109 Suppl 5:667-79. [PMID: 11677174 PMCID: PMC1240596 DOI: 10.1289/ehp.01109s5667] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We describe the two species of the toxic Pfiesteria complex to date (Pfiesteria piscicida and Pfiesteria shumwayae), their complex life cycles, and the characteristics required for inclusion within this complex. These species resemble P. piscicida Steidinger & Burkholder and also have a) strong attraction to fresh fish tissues and excreta, b) toxic activity stimulated by live fish, and c) production of toxin that can cause fish death and disease. Amoeboid stages were verified in 1992-1997 by our laboratory (various stages from toxic cultures) and that of K. Steidinger and co-workers (filose amoebae in nontoxic cultures), and in 2000 by H. Marshall and co-workers (various stages from toxic cultures), from clonal Pfiesteria spp. cultures, using species-specific polymerase chain reaction-based molecular probes with cross-confirmation by an independent specialist. Data were provided from tests of the hypothesis that Pfiesteriastrains differ in response to fresh fish mucus and excreta, algal prey, and inorganic nutrient (N, P) enrichment, depending on functional type or toxicity status. There are three functional types: TOX-A, in actively toxic, fish-killing mode; TOX-B, temporarily nontoxic, without access to live fish for days to weeks, but capable of toxic activity if fish are added; and NON-IND, noninducible with negligible toxicity in the presence of live fish. NON-IND Pfiesteria attained highest zoospore production on algal prey without or without inorganic nitrogen or inorganic phosphorus enrichment. TOX-B Pfiesteria was intermediate and TOX-A was lowest in zoospore production on algal prey with or without nutrients. TOX-A Pfiesteria spp. showed strong behavioral attraction to fresh fish mucus and excreta in short-term trials, with intermediate attraction of TOX-B zoospores and relatively low attraction of NON-IND cultures when normalized for cell density. The data for these clones indicated a potentially common predatory behavioral response, although differing in intensity distinct from a toxicity effect, in attack of fish prey. The data also demonstrated that functional types of Pfiesteria spp. show distinct differences in response to fish, algal prey, and inorganic nutrient enrichment. Collectively, the experiments indicate that NON-IND strains should not be used in research to gain insights about environmental controls on toxic strains of Pfiesteria spp.
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Affiliation(s)
- J M Burkholder
- Center for Applied Aquatic Ecology, North Carolina State University, Raleigh 27606, USA.
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Glasgow HB, Burkholder JM, Mallin MA, Deamer-Melia NJ, Reed RE. Field ecology of toxic Pfiesteria complex species and a conservative analysis of their role in estuarine fish kills. Environ Health Perspect 2001; 109 Suppl 5:715-30. [PMID: 11677181 PMCID: PMC1240603 DOI: 10.1289/ehp.01109s5715] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Within the past decade, toxic Pfiesteria outbreaks have been documented in poorly flushed, eutrophic areas of the largest and second largest estuaries on the U.S. mainland. Here we summarize a decadal field effort in fish kill assessment, encompassing kills related to Pfiesteria (49 major kills in North Carolina estuaries since 1991 and 4 in Maryland estuaries in 1997) and to other factors such as low oxygen stress (79 major fish kills in North Carolina estuaries). The laboratory and field data considered in developing our protocols are described, including toxic Pfiesteria behavior, environmental conditions conducive to toxic Pfiesteria activity, and impacts of toxic clonal Pfiesteria on fish health. We outline the steps of the standardized fish bioassay procedure that has been used since 1991 to diagnose whether actively toxic Pfiesteria was present during estuarine fish kills. Detailed data are given for a 1998 toxic Pfiesteria outbreak in the Neuse Estuary in North Carolina to illustrate of the full suite of diagnostic steps completed. We demonstrate that our conservative approach in implicating toxic Pfiesteria involvement in fish kills has biased in favor of causes other than Pfiesteria. Data are summarized from experiments that have shown stimulation of toxic Pfiesteria strains by nutrient (N, P) enrichment, supporting field observations of highest abundance of toxic strains in eutrophic estuaries. On the basis of a decade of research on toxic Pfiesteria, we present a conceptual model of the seasonal dynamics of toxic strains as affected by changing food resources and weather patterns. We also recommend protocols and research approaches that will strengthen the science of fish kill assessment related to Pfiesteria and/or other causative factors.
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Affiliation(s)
- H B Glasgow
- Center for Applied Aquatic Ecology (CAAE), North Carolina State University, Raleigh 27606, USA.
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Kimm-Brinson KL, Moeller PD, Barbier M, Glasgow H, Burkholder JM, Ramsdell JS. Identification of a P2X7 receptor in GH(4)C(1) rat pituitary cells: a potential target for a bioactive substance produced by Pfiesteria piscicida. Environ Health Perspect 2001; 109:457-462. [PMID: 11401756 PMCID: PMC1240304 DOI: 10.1289/ehp.01109457] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We examined the pharmacologic activity of a putative toxin (pPfTx) produced by Pfiesteria piscicida by characterizing the signaling pathways that induce the c-fos luciferase construct in GH(4)C(1) rat pituitary cells. Adenosine-5'-triphosphate (ATP) was determined to increase and, at higher concentrations, decrease luciferase activity in GH(4)C(1) rat pituitary cells that stably express c-fos luciferase. The inhibition of luciferase results from cytotoxicity, characteristic of the putative P. piscicida toxin (pPfTx). The actions of both pPfTx and ATP to induce c-fos luciferase were inhibited by the purinogenic receptor antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS). Further characterization of a P2X receptor on the GH(4)C(1) cell was determined by the analog selectivity of P2X agonists. The P2X1/P2X3 agonist alpha,beta-methylene ATP (alpha,beta-MeATP) failed to increase or decrease c-fos luciferase. However, the P2X7 agonist 2',3'-(4-benzoyl)benzoyl ATP (BzATP), which had a predominant cytotoxic effect, was more potent than ATP. Immunoblot analysis of GH(4)C(1) cell membranes confirmed the presence of a 70-kDa protein that was immunoreactive to an antibody directed against the carboxy-terminal domain unique to the P2X7 receptor. The P2X7 irreversible antagonist oxidized-ATP (oxATP) inhibited the action of ATP, BzATP, and pPfTx. These findings indicate that GH(4)C(1) cells express purinogenic receptors with selectivity consistent with the P2X7 subtype and that this receptor pathway mediates the induction of the c-fos luciferase reporter gene by ATP and the putative Pfiesteria toxin
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Affiliation(s)
- K L Kimm-Brinson
- Marine Biotoxins Program, Center for Coastal Environmental Health and Biomolecular Research, National Oceanic and Atmospheric Administration-National Ocean Service, Charleston, South Carolina, USA
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Bowers HA, Tengs T, Glasgow HB, Burkholder JM, Rublee PA, Oldach DW. Development of real-time PCR assays for rapid detection of Pfiesteria piscicida and related dinoflagellates. Appl Environ Microbiol 2000; 66:4641-8. [PMID: 11055905 PMCID: PMC92361 DOI: 10.1128/aem.66.11.4641-4648.2000] [Citation(s) in RCA: 185] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pfiesteria complex species are heterotrophic and mixotrophic dinoflagellates that have been recognized as harmful algal bloom species associated with adverse fish and human health effects along the East Coast of North America, particularly in its largest (Chesapeake Bay in Maryland) and second largest (Albermarle-Pamlico Sound in North Carolina) estuaries. In response to impacts on human health and the economy, monitoring programs to detect the organism have been implemented in affected areas. However, until recently, specific identification of the two toxic species known thus far, Pfiesteria piscicida and P. shumwayae (sp. nov.), required scanning electron microscopy (SEM). SEM is a labor-intensive process in which a small number of cells can be analyzed, posing limitations when the method is applied to environmental estuarine water samples. To overcome these problems, we developed a real-time PCR-based assay that permits rapid and specific identification of these organisms in culture and heterogeneous environmental water samples. Various factors likely to be encountered when assessing environmental samples were addressed, and assay specificity was validated through screening of a comprehensive panel of cultures, including the two recognized Pfiesteria species, morphologically similar species, and a wide range of other estuarine dinoflagellates. Assay sensitivity and sample stability were established for both unpreserved and fixative (acidic Lugol's solution)-preserved samples. The effects of background DNA on organism detection and enumeration were also explored, and based on these results, we conclude that the assay may be utilized to derive quantitative data. This real-time PCR-based method will be useful for many other applications, including adaptation for field-based technology.
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Affiliation(s)
- H A Bowers
- Institute of Human Virology and University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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Abstract
The small but diverse group of angiosperms known as seagrasses form submersed meadow communities that are among the most productive on earth. Seagrasses are frequently light-limited and, despite access to carbon-rich seawaters, they may also sustain periodic internal carbon limitation. They have been regarded as C3 plants, but many species appear to be C3-C4 intermediates and/or have various carbon-concentrating mechanisms to aid the Rubisco enzyme in carbon acquisition. Photorespiration can occur as a C loss process that may protect photosynthetic electron transport during periods of low CO(2) availability and high light intensity. Seagrasses can also become photoinhibited in high light (generally>1000 µE m(-2) s(-1)) as a protective mechanism that allows excessive light energy to be dissipated as heat. Many photosynthesis-irradiance curves have been developed to assess light levels needed for seagrass growth. However, most available data (e.g. compensation irradiance I(c)) do not account for belowground tissue respiration and, thus, are of limited use in assessing the whole-plant carbon balance across light gradients. Caution is recommended in use of I(k) (saturating irradiance for photosynthesis), since seagrass photosynthesis commonly increases under higher light intensities than I(k); and in estimating seagrass productivity from H(sat) (duration of daily light period when light equals or exceeds I(k)) which varies considerably among species and sites, and which fails to account for light-limited photosynthesis at light levels less than I(k). The dominant storage carbohydrate in seagrasses is sucrose (primarily stored in rhizomes), which generally forms more than 90% of the total soluble carbohydrate pool. Seagrasses with high I(c) levels (suggesting lower efficiency in C acquisition) have relatively low levels of leaf carbohydrates. Sucrose-P synthase (SPS, involved in sucrose synthesis) activity increases with leaf age, consistent with leaf maturation from carbon sink to source. Unlike terrestrial plants, SPS apparently is not light-activated, and is positively influenced by increasing temperature and salinity. This response may indicate an osmotic adjustment in marine angiosperms, analogous to increased SPS activity as a cryoprotectant response in terrestrial non-halophytic plants. Sucrose synthase (SS, involved in sucrose metabolism and degradation in sink tissues) of both above- and belowground tissues decreases with tissue age. In belowground tissues, SS activity increases under low oxygen availability and with increasing temperatures, likely indicating increased metabolic carbohydrate demand. Respiration in seagrasses is primarily influenced by temperature and, in belowground tissues, by oxygen availability. Aboveground tissues (involved in C assimilation and other energy-costly processes) generally have higher respiration rates than belowground (mostly storage) tissues. Respiration rates increase with increasing temperature (in excess of 40 degrees C) and increasing water-column nitrate enrichment (Z. marina), which may help to supply the energy and carbon needed to assimilate and reduce nitrate. Seagrasses translocate oxygen from photosynthesizing leaves to belowground tissues for aerobic respiration. During darkness or extended periods of low light, belowground tissues can sustain extended anerobiosis. Documented alternate fermentation pathways have yielded high alanine, a metabolic 'strategy' that would depress production of the more toxic product ethanol, while conserving carbon skeletons and assimilated nitrogen. In comparison to the wealth of information available for terrestrial plants, little is known about the physiological ecology of seagrasses in carbon acquisition and metabolism. Many aspects of their carbon metabolism - controls by interactive environmental factors; and the role of carbon metabolism in salt tolerance, growth under resource-limited conditions, and survival through periods of dormancy - remain to be resolved as directions in future research. Such research will strengthen the understanding needed to improve management and protection of these environmentally important marine angiosperms.
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Affiliation(s)
- BW Touchette
- Department of Botany Box 7510, North Carolina State University, 27695-7510, Raleigh, NC, USA
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Abstract
Within the past few decades, major losses of seagrass habitats in coastal waters impacted by cultural eutrophication have been documented worldwide. In confronting a pressing need to improve the management and protection of seagrass meadows, surprisingly little is known about the basic nutritional physiology of these critical habitat species, or the physiological mechanisms that control their responses to N and P gradients. The limited available evidence to date already has revealed, for some seagrass species such as the north temperate dominant Zostera marina, unusual responses to nutrient enrichment in comparison to other vascular plants. Seagrasses derive N and P from sediment pore water (especially ammonium) and the water column (most nitrate). The importance of leaves versus roots in nutrient acquisition depends, in part, on the enrichment conditions. For example, a shift from reliance on sediment pore water to increased reliance on the overlying water for N and P supplies has been observed under progressive water-column nutrient enrichment. Seagrasses may be N-limited in nutrient-poor waters with sandy or (less so) organic sediments, and P-limited in carbonate sediments. On the basis of data from few species, seagrasses appear to have active uptake systems for NO(3)(-) and PO(4)(-3), but NH(4)(+) uptake may involve both low- and high-affinity systems. P(i) uptake affinities reported thus far are much lower than values for active ammonium uptake, but comparable to values for nitrate uptake by leaf tissues. Beyond such basic information, seagrass species have shown considerable variation in nutritional response. Dominance of acropetal versus basipetal nutrient translocation appears to vary among species as an innate trait. While some species follow classic Michaelis-Menten kinetics for N(i) uptake, others have exhibited sustained linear uptake with limited or negligible product feedback inhibition, perhaps in adaptation to oligotrophic environments. Zostera marina also is able to maintain nitrate reductase (NR) activity during dark periods if adequate carbohydrate reserves and substrate are available. Thus, this species can respond to nitrate pulses throughout a diel cycle, rather than being limited as most plants to nitrate uptake during the light period. Further adaptations may have occurred for seagrasses in extremely nitrate-depauperate conditions. For example, Halophila decipiens and H. stipulacea lack inducible NR and apparently have lost the ability to reduce nitrate; and a biphasic rather than hyperbolic P(i) uptake curve, with 'surge' uptake, has been described for Zostera noltii. Many seagrasses respond favorably to low or moderate N and/or P enrichment. However, excessive N(i) loading to the water column can inhibit seagrass growth and survival, not only as an indirect effect by stimulating algal overgrowth and associated light reduction, but-for some species-as a direct physiological effect. The latter direct impact has been most pronounced for plants growing in sandy (nutrient-poor) sediments, and is exacerbated by elevated temperatures and/or light reduction. Ammonia toxicity, known for many vascular plants, has been reported in seagrasses Ruppia drepanensis and Z. marina (125 µM water-column NH(4)(+), 5 weeks). Z. marina has shown to be inhibited, as well, by pulsed water-column nitrate enrichment (as low as 3.5-7 µM NO(3)(-), 3-5 weeks), which is actively taken up without apparent product feedback inhibition. Inhibition by elevated nitrate has also been reported, with description of the underlying physiological mechanisms, in certain macroalgae and microalgae. In Z. marina, this effect has been related to the high, sustained energy demands of nitrate uptake, and to inducement of internal carbon limitation by the concomitant 'carbon drain' into amino acid assimilation. In contrast, nitrate enrichment can stimulate growth of Z. marina when the sediment, rather than the water column, is the source. Because seagrass species have shown considerable variation in nutritional response, inferences about one well-studied species, from one geographic location, should not be applied a priori to that species in other regions or to seagrasses in general. Most of the available information has been obtained from study of a few species, and the basic nutritional physiology of many seagrasses remains to be examined and compared across geographic regions. Nonetheless, the relatively recent gains in general understanding about the physiological responses of some seagrass species to nutrient gradients already have proven valuable in both basic and applied research. For example, physiological variables such as tissue C:N:P content have begun to be developed as integrative indicators of nutrient conditions and anthropogenic nutrient enrichment. To strengthen insights for management strategies to optimize seagrass survival in coastal waters adjacent to exponential human population growth and associated nutrient inputs, additional emphasis is critically needed to assess the role of variable interactions-among inorganic as well as organic N, P and C, environmental factors such as temperature, light, and other community components-in controlling the physiology, growth and survival of these ecologically important marine angiosperms.
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Affiliation(s)
- BW Touchette
- Department of Botany, Box 7510, North Carolina State University, 27695-7510, Raleigh, NC, USA
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Levin ED, Rezvani AH, Christopher NC, Glasgow HB, Deamer-Melia NJ, Burkholder JM, Moser VC, Jensen K. Rapid neurobehavioral analysis of Pfiesteria piscicida effects in juvenile and adult rats. Neurotoxicol Teratol 2000; 22:533-40. [PMID: 10974591 DOI: 10.1016/s0892-0362(00)00080-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The estuarine dinoflagellate Pfiesteria piscicida is known to kill fish and has been associated with neurocognitive deficits in humans. We have developed a rat model to demonstrate that exposure to Pfiesteria causes significant learning impairments. This has been repeatedly seen as a choice accuracy impairment during radial-arm maze learning. Pfiesteria-induced effects were also seen in a locomotor activity test in the figure-8 apparatus. The current studies used the short-term radial-arm maze acquisition, the figure-8 activity test, and the functional observational battery (FOB) to assess Pfiesteria-induced neurobehavioral effects in adult and juvenile rats. In study 1, the neurobehavioral potency of three different Pfiesteria cultures (Pf 113, Pf 728, and Pf Vandermere) was assessed. Ninety-six (12 per group) adult female Sprague-Dawley rats were injected subcutaneously with a single dose of Pfiesteria taken from aquarium-cultured Pfiesteria (35,600 or 106,800 Pfiesteria cells per kilogram of rat body weight). One control group (N = 12) was injected with saline and one (N = 12) with aquarium water not containing Pfiesteria. All three of the Pfiesteria samples (p < 0.05) impaired choice accuracy over the first six sessions of training. At the time of the radial-arm maze choice accuracy impairment, no overt Pfiesteria-related effects were seen using an FOB, indicating that the Pfiesteria-induced choice accuracy deficit was not due to generalized debilitation. In the figure-8 apparatus, Pfiesteria treatment caused a significant decrease in mean locomotor activity. In study 2, the neurobehavioral effects of the Pf 728 sample type were assessed in juvenile rats. Twenty-four day-old male and female rats were injected with 35,600 or 106,800 Pf-728 Pfiesteria cells per kilogram of rat body weight. As with adult females, the juvenile rats showed a significant impairment in radial-arm maze choice accuracy. No changes in locomotor activity or the FOB were detected in the juvenile rats. Furthermore, there were no differences between male and female rats in the Pfiesteria-induced choice accuracy impairment. Pfiesteria effects on choice accuracy in the radial-arm maze in rats constitute a critical component of the model of Pfiesteria toxicity, because the hallmark of Pfiesteria toxicity in humans is cognitive dysfunction. Our finding that analysis of the first six sessions of radial-arm maze testing is sufficient for determining the effect means that this test will be useful as a rapid screen for identifying the critical neurotoxin(s) of Pfiesteria in future studies.
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Affiliation(s)
- E D Levin
- Department of Psychiatry, Duke University Medical Center, Duke University, Durham, NC 27710, USA.
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Oldach DW, Delwiche CF, Jakobsen KS, Tengs T, Brown EG, Kempton JW, Schaefer EF, Bowers HA, Glasgow 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. Proc Natl Acad Sci U S A 2000; 97:4303-8. [PMID: 10760297 PMCID: PMC18236 DOI: 10.1073/pnas.97.8.4303] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The newly described heterotrophic estuarine dinoflagellate Pfiesteria piscicida has been linked with fish kills in field and laboratory settings, and with a novel clinical syndrome of impaired cognition and memory disturbance among humans after presumptive toxin exposure. As a result, there is a pressing need to better characterize the organism and these associations. Advances in Pfiesteria research have been hampered, however, by the absence of genomic sequence data. We employed a sequencing strategy directed by heteroduplex mobility assay to detect Pfiesteria piscicida 18S rDNA "signature" sequences in complex pools of DNA and used those data as the basis for determination of the complete P. piscicida 18S rDNA sequence. Specific PCR assays for P. piscicida and other estuarine heterotrophic dinoflagellates were developed, permitting their detection in algal cultures and in estuarine water samples collected during fish kill and fish lesion events. These tools should enhance efforts to characterize these organisms and their ecological relationships. Heteroduplex mobility assay-directed sequence discovery is broadly applicable, and may be adapted for the detection of genomic sequence data of other novel or nonculturable organisms in complex assemblages.
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Affiliation(s)
- D W Oldach
- Institute of Human Virology and University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Harvell CD, Kim K, Burkholder JM, Colwell RR, Epstein PR, Grimes DJ, Hofmann EE, Lipp EK, Osterhaus AD, Overstreet RM, Porter JW, Smith GW, Vasta GR. Emerging marine diseases--climate links and anthropogenic factors. Science 1999; 285:1505-10. [PMID: 10498537 DOI: 10.1126/science.285.5433.1505] [Citation(s) in RCA: 725] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mass mortalities due to disease outbreaks have recently affected major taxa in the oceans. For closely monitored groups like corals and marine mammals, reports of the frequency of epidemics and the number of new diseases have increased recently. A dramatic global increase in the severity of coral bleaching in 1997-98 is coincident with high El Niño temperatures. Such climate-mediated, physiological stresses may compromise host resistance and increase frequency of opportunistic diseases. Where documented, new diseases typically have emerged through host or range shifts of known pathogens. Both climate and human activities may have also accelerated global transport of species, bringing together pathogens and previously unexposed host populations.
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Affiliation(s)
- C D Harvell
- Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
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Fairey ER, Edmunds JS, Deamer-Melia NJ, Glasgow H, Johnson FM, Moeller PR, Burkholder JM, Ramsdell JS. Reporter gene assay for fish-killing activity produced by Pfiesteria piscicida. Environ Health Perspect 1999; 107:711-4. [PMID: 10464070 PMCID: PMC1566442 DOI: 10.1289/ehp.99107711] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Collaborative studies were performed to develop a functional assay for fish-killing activity produced by Pfiesteria piscicida. Eight cell lines were used to screen organic fractions and residual water fraction by using a 3-[4, 5-dimethylthiazol-(2-4)]-diphenyltetrazolium bromide cytotoxicity assay. Diethyl ether and a residual water fraction were cytotoxic to several cell lines including rat pituitary (GH(4)C(1)) cells. Residual water as well as preextracted culture water containing P. piscicida cells induced c-fos-luciferase expressed in GH(4)C(1) cells with a rapid time course of induction and sensitive detection. The reporter gene assay detected activity in toxic isolates of P. piscicida from several North Carolina estuaries in 1997 and 1998 and may also be suitable for detecting toxic activity in human and animal serum.
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Affiliation(s)
- E R Fairey
- Marine Biotoxins Program, Center for Coastal Environmental Health and Biomolecular Research, NOAA-National Ocean Service, Charleston, South Carolina 29412, USA
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Levin ED, Simon BB, Schmechel DE, Glasgow HB, Deamer-Melia NJ, Burkholder JM, Moser VC, Jensen K, Harry GJ. Pfiesteria toxin and learning performance. Neurotoxicol Teratol 1999; 21:215-21. [PMID: 10386824 DOI: 10.1016/s0892-0362(98)00041-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Pfiesteria piscicida is an estuarine dinoflagellate involved with fish kills along the east coast of the United States. We previously documented a radial-arm maze learning deficit in rats exposed to Pfiesteria that may be related to cognitive deficits seen in humans after accidental Pfiesteria exposure. The current study elucidated important behavioral parameters of this deficit. There were six dose groups. Forty (10/group) adult female Sprague-Dawley rats were injected (s.c.) with a single dose of Pfiesteria taken from aquarium-cultured Pfiesteria (35,600, 106,800, or 320,400 Pfiesteria cells/kg of rat body weight or a cell-free filtrate of the 106,800 cells/kg dose). One control group (N = 10) was injected with saline and one (N = 10) with aquarium water not containing Pfiesteria. Half of the rats in each group were tested on an 8-arm radial maze in a standard test room, and the other half were tested on the radial maze in a sound-attenuating chamber. In the standard maze room, there was a significant effect of Pfiesteria (p < 0.05) impairing choice accuracy improvement over the first six sessions of training among rats administered 106,800, 320,400, and the 106,800 cells/kg filtered sample. In contrast, there was no indication of an effect of Pfiesteria when the rats were tested on the same configuration radial maze in the sound-attenuating chamber. After 18 sessions of training in one room, the rats were switched for six sessions of testing in the other room and finally were switched back to their original room for three sessions. There was a significant Pfiesteria-induced deficit when the rats were tested in the standard test room but not when they were tested in the sound-attenuating chamber. When the Pfiesteria-exposed rats were initially switched from the sound-attenuating chamber to the standard test room they performed significantly worse than controls, whereas Pfiesteria-treated rats switched from the standard test room to the sound-attenuating chamber did not perform differently from controls. These results suggest that the Pfiesteria-induced learning impairment may result from the negative impact of distracting stimuli. At the time of the learning impairment, no overt Pfiesteria-related effects were seen using a functional observational battery and no overall response latency effects were seen, indicating that the Pfiesteria-induced choice accuracy deficit was not due to generalized debilitation. In the initial use of the figure-8 maze in this line of research, the rats in the same Pfiesteria treatment groups that showed significant deficits in the radial-arm maze showed greater declines in activity rates in a 1-h figure-8 locomotor activity test. Both the 106,800 and 320,400 Pfiesteria cells/kg groups showed significantly greater linear trends of activity decline relative to tank water-treated controls. This reflected an initial slight hyperactivity in the Pfiesteria-treated animals followed by a decrease to control levels. Pfiesteria effects in the figure-8 maze and in early radial-arm maze training may be useful in a rapid screen for identifying the critical toxin(s) of Pfiesteria in future studies.
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Affiliation(s)
- E D Levin
- Department of Psychiatry, Duke University Medical Center, Durham, NC 27710, USA.
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Abstract
The toxic dinoflagellate, Pfiesteria piscicida, was recently implicated as the causative agent for about 50% of the major fish kills occurring over a three-year period in the Albemarle-Pamlico Estuarine System of the southeastern USA. Transformations between life-history stages of this dinoflagellate are controlled by the availability of fresh fish secretions or fish tissues, and secondarily influenced by the availability of alternate prey including bacteria, algae, microtauna, and mammalian tissues. Toxic zoospores of P. piscicida subdue fish by excreting lethal neurotoxins that narcotize the prey, disrupt its osmoregulatory system, and attack its nervous system. While prey are dying, the zoospores feed upon bits of fish tissue and complete the sexual phase of the dinoflagellate life cycle. Other stages in the complex life cycle of P. piscicida include cryptic forms of filose, rhizopodial, and lobose amoebae that can form within minutes from toxic zoospores, gametes, or planozygotes. These cryptic amoebae feed upon fish carcasses and other prey and, thus far, have proven less vulnerable to microbial predators than flagellated life-history stages. Lobose amoebae that develop from toxic zoospores and planozygotes during colder periods have also shown ambush behavior toward live fish. In the presence of abundant flagellated algal prey, amoeboid stages produce nontoxic zoospores that can become toxic and form gametes when they detect what is presumed to be a threshold level of a stimulatory substance(s) derived from live fish. The diverse amoeboid stages of this fish "ambush-predator" and at least one other Pfiesteria-like species are ubiquitous and abundant in brackish waters along the western Atlantic and Gulf Coasts, indicating a need to re-evaluate the role of dinoflagellates in the microbial food webs of turbid nutrient-enriched estuaries.
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Affiliation(s)
- J M Burkholder
- Department of Botany, North Carolina State University, Raleigh 27695, USA
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Glasgow HB, Burkholder JM, Schmechel DE, Tester PA, Rublee PA. Insidious effects of a toxic estuarine dinoflagellate on fish survival and human health. J Toxicol Environ Health 1995; 46:501-22. [PMID: 8523474 DOI: 10.1080/15287399509532051] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The estuarine dinoflagellate Pfiesteria piscicida gen. et sp. nov. produces exotoxin(s) that can be absorbed from water or fine aerosols. Culture filtrate (0.22 microns porosity filters, > 250 toxic flagellated cells/ml) induces formation of open ulcerative sores, hemorrhaging, and death of finfish and shellfish. Human exposure to aerosols from ichthyotoxic cultures (> or = 2000 cells/ml) has been associated with narcosis, respiratory distress with asthma-like symptoms, severe stomach cramping, nausea, vomiting, and eye irritation with reddening and blurred vision (hours to days); autonomic nervous system dysfunction [localized sweating, erratic heart beat (weeks)]; central nervous system dysfunction [sudden rages and personality change (hours to days), and reversible cognitive impairment and short-term memory loss (weeks)]; and chronic effects including asthma-like symptoms, exercise fatigue, and sensory symptoms (tingling or numbness in lips, hands, and feet; months to years). Elevated hepatic enzyme levels and high phosphorus excretion in one human exposure suggested hepatic and renal dysfunction (weeks); easy infection and low counts of several T-cell types may indicate immune system suppression (months to years). Pfiesteria piscicida is euryhaline and eurythermal, and in bioassays a nontoxic flagellated stage has increased under P enrichment (> or = 100 micrograms SRP/L), suggesting a stimulatory role of nutrients. Pfiesteria-like dinoflagellates have been tracked to fish kill sites in eutrophic estuaries from Delaware Bay through the Gulf Coast. Our data point to a critical need to characterize their chronic effects on human health as well as fish recruitment, disease resistance, and survival.
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Affiliation(s)
- H B Glasgow
- Department of Botany, North Carolina State University, Raleigh 27695-7612, USA
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Lewitus AJ, Jesien RV, Kana TM, Burkholder JM, Glasgow HB, May E. Discovery of the "Phantom" Dinoflagellate in Chesapeake Bay. ACTA ACUST UNITED AC 1995. [DOI: 10.2307/1352319] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Affiliation(s)
- E J Noga
- College of Veterinary Medicine, North Carolina State University, Raleigh 27606
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Burkholder JM, Noga EJ, Hobbs CH, Glasgow HB. Correction: New ‘phantom’ dinoflagellate is the causative agent of major estuarine fish kills. Nature 1992. [DOI: 10.1038/360768e0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
A worldwide increase in toxic phytoplankton blooms over the past 20 years has coincided with increasing reports of fish diseases and deaths of unknown cause. Among estuaries that have been repeatedly associated with unexplained fish kills on the western Atlantic Coast are the Pamlico and Neuse Estuaries of the southeastern United States. Here we describe a new toxic dinoflagellate with 'phantom-like' behaviour that has been identified as the causative agent of a significant portion of the fish kills in these estuaries, and which may also be active in other geographic regions. The alga requires live finfish or their fresh excreta for excystment and release of a potent toxin. Low cell densities cause neurotoxic signs and fish death, followed by rapid algal encystment and dormancy unless live fish are added. This dinoflagellate was abundant in the water during major fish kills in local estuaries, but only while fish were dying; within several hours of death where carcasses were still present, the flagellated vegetative algal population had encysted and settled back to the sediments. Isolates from each event were highly lethal to finfish and shellfish in laboratory bioassays. Given its broad temperature and salinity tolerance, and its stimulation by phosphate enrichment, this toxic phytoplankter may be a widespread but undetected source of fish mortality in nutrient-enriched estuaries.
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Affiliation(s)
- J M Burkholder
- Department of Botany, North Carolina State University, Raleigh 27695-7612
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Burkholder JM, Wetzel RG, Klomparens KL. Direct Comparison of Phosphate Uptake by Adnate and Loosely Attached Microalgae within an Intact Biofilm Matrix. Appl Environ Microbiol 1990; 56:2882-90. [PMID: 16348296 PMCID: PMC184859 DOI: 10.1128/aem.56.9.2882-2890.1990] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We report a direct comparison of phosphate uptake by adnate and loosely attached microalgae in an intact biofilm matrix, with resolution at the level of individual cells. Track scanning electron microscope autoradiography enabled assay of [
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P]phosphate uptake from the overlying water by adnate algae left undisturbed on mature leaves of the macrophyte
Potamogeton illinoensis
or on artificial plant mimics. The epiphyte communities developed in either phosphate-poor or moderately phosphate-enriched water, and they were assayed on both natural and artificial plants. All adnate taxa examined from both natural and artificial plants in both habitats took up significantly less radiolabel when assayed beneath the overlying matrix than when they were exposed to the water upon removal of the overstory material. Track scanning electron microscope autoradiography and track light microscope autoradiography were intercalibrated to enable comparison of [
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P]phosphate uptake by adnate and loosely attached components of the epiphyte matrix. Loosely attached cells on substrata from both habitats took up significantly more radiolabel than did underlying adnate cells, indicating that access to phosphate supplies from the water depended on the position of microbial cells in the matrix. In this short-term assay, the adnate microalgae were relatively isolated from the water column nutrient source.
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Affiliation(s)
- J M Burkholder
- W. K. Kellogg Biological Station, Michigan State University, Hickory Corners, Michigan 49060, and Center for Electron Optics, Department of Botany and Plant Pathology, and Pesticide Research Center, Michigan State University, East Lansing, Michigan 48824
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Bachmann MD, Carlton RG, Burkholder JM, Wetzel RG. Symbiosis between salamander eggs and green algae: microelectrode measurements inside eggs demonstrate effect of photosynthesis on oxygen concentration. CAN J ZOOL 1986. [DOI: 10.1139/z86-239] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Eggs of the spotted salamander, Ambystoma maculatum, are usually green because of the presence of symbiotic, chlamydomonad algae which inhabit the envelope of each egg. An oxygen-sensitive electrode was used to measure the effect of algal photosynthesis on oxygen concentration inside eggs and within the gelatinous matrix surrounding them. During darkness, oxygen became severely depleted within the eggs, but upon exposure to light oxygen concentrations increased rapidly. Photosynthetic oxygen production by the chlamydomonads exceeded respiratory consumption by the embryo–algae complex and led to oxygen supersaturation inside eggs, even when water surrounding the egg mass was almost anoxic.
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