scispace - formally typeset
Search or ask a question
Author

Jason W. Kempton

Bio: Jason W. Kempton is an academic researcher from South Carolina Department of Natural Resources. The author has contributed to research in topics: Pfiesteria shumwayae & Pfiesteria piscicida. The author has an hindex of 13, co-authored 13 publications receiving 897 citations.

Papers
More filters
Journal ArticleDOI
TL;DR: Results implicate toxic K. micrum as a causative factor in fish death in a non-aquaculture brackish pond associated with a housing development, and extend recent findings linking this species to fish kills in aquaculture ponds.

131 citations

Journal ArticleDOI
TL;DR: A sequencing strategy directed by 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.
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.

127 citations

Journal ArticleDOI
TL;DR: Diversity analysis shows that 363 and 286 unique genes were identified from the hemocyte and embryo libraries, respectively, indicating that full-scale EST collection is a valuable approach for the discovery of new genes of potential significance in the molluscan stress response.
Abstract: A pilot program was initiated to identify genes from the American oyster, Crassostrea virginica, that are potentially involved in the stress response for use as bioindicators of exposure to environmental pollutants and to toxic and infectious agents. A PCR-based method was used to construct cDNA libraries from pooled embryos and the hemocytes of a single individual. A total of 998 randomly selected clones (expressed sequence tags, ESTs) were sequenced. Approximately 40% of the ESTs are novel sequences. Several potential biomarkers identified include an antimicrobial peptide, recognition molecules (lectin receptors), proteinases and proteinase inhibitors, and a novel metallothionein. Diversity analysis shows that 363 and 286 unique genes were identified from the hemocyte and embryo libraries, respectively, indicating that full-scale EST collection is a valuable approach for the discovery of new genes of potential significance in the molluscan stress response.

97 citations

Journal ArticleDOI
TL;DR: The development and validation of a suite of real‐time polymerase chain reaction (PCR) assays for species associated with fish kill events in Japanese, European, Canadian, and U.S. coastal waters and phylogenetic analyses to determine the relationship between these species were performed.
Abstract: Species within the class Raphidophyceae were associated with fish kill events in Japanese, European, Canadian, and U.S. coastal waters. Fish mortality was attributable to gill damage with exposure to reactive oxygen species (peroxide, superoxide, and hydroxide radicals), neurotoxins, physical clogging, and hemolytic substances. Morphological identification of these organisms in environmental water samples is difficult, particularly when fixatives are used. Because of this difficulty and the continued global emergence of these species in coastal estuarine waters, we initiated the development and validation of a suite of real-time polymerase chain reaction (PCR) assays. Sequencing was used to generate complete data sets for nuclear encoded small-subunit ribosomal RNA (SSU rRNA; 18S); internal transcribed spacers 1 and 2, 5.8S; and plastid encoded SSU rRNA (16S) for confirmed raphidophyte cultures from various geographic locations. Sequences for several Chattonella species (C. antiqua, C. marina, C. ovata, C. subsalsa, and C. verruculosa), Heterosigma akashiwo, and Fibrocapsa japonica were generated and used to design rapid and specific PCR assays for several species including C. verruculosa Hara et Chihara, C. subsalsa Biecheler, the complex comprised of C. marina Hara et Chihara, C. antiqua Ono and C. ovata, H. akashiwo Ono, and F. japonica Toriumi et Takano using appropriate loci. With this comprehensive data set, we were also able to perform phylogenetic analyses to determine the relationship between these species.

89 citations

Journal ArticleDOI
TL;DR: The South Carolina coastal zone is among the fastest growing areas in the U.S., and population epicenters are marked by dense brackish water pond (lagoon) coverage associated with housing complexes and golf courses as discussed by the authors.
Abstract: The South Carolina coastal zone is among the fastest growing areas in the U.S., and population epicenters are marked by dense brackish water pond (lagoon) coverage associated with housing complexes and golf courses. Surveillance efforts in 2001–2002 documented the widespread occurrence of several types of potentially or measurably toxic harmful algal blooms (HABs) in these ponds. These man-made retention ponds were constructed in order to serve as a buffer between developed areas and open estuaries or for aesthetic reasons. However, the combination of restricted tidal flow and nutrient and/or contaminant deposition creates a stimulatory environment for potential HAB formation. These discoveries introduce the need to consider mitigation measures to existing ponds and HAB preventive strategies for future pond construction.

80 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: In this article, a global assessment of the effects of inorganic nitrogen pollution in aquatic ecosystems is presented, with detailed multi-scale data, and three major environmental problems: (1) increasing the concentration of hydrogen ions in freshwater ecosystems without much acid-neutralizing capacity, resulting in acidification of those systems; (2) stimulating or enhancing the development, maintenance and proliferation of primary producers, leading to eutrophication of aquatic ecosystems; (3) reaching toxic levels that impair the ability of aquatic animals to survive, grow and reproduce.

1,753 citations

Journal ArticleDOI
TL;DR: The Effects of Harmful Algal Blooms on Aquatic Organisms: Vol. 10, No. 2, pp. 113-390 as mentioned in this paper was the first publication of this article.
Abstract: (2002). The Effects of Harmful Algal Blooms on Aquatic Organisms. Reviews in Fisheries Science: Vol. 10, No. 2, pp. 113-390.

1,242 citations

Journal ArticleDOI
TL;DR: Information on metallothioneins in three important groups of aquatic invertebrates-the molluscs, crustaceans and annelid worms, and attempted to seek explanations for some of the apparent inconsistencies present in the dataset are collated.

992 citations

Journal ArticleDOI
TL;DR: The use of ecological indicators has been widely accepted by scientists, environmental managers, and the general public as mentioned in this paper, and they have been used to assess the condition of the environment, as early warning signals of ecological problems, and as barometers for trends in ecological resources.
Abstract: ▪ Abstract Ecological indicators have widespread appeal to scientists, environmental managers, and the general public. Indicators have long been used to detect changes in nature, but the scientific maturation in indicator development primarily has occurred in the past 40 years. Currently, indicators are mainly used to assess the condition of the environment, as early-warning signals of ecological problems, and as barometers for trends in ecological resources. Use of ecological indicators requires clearly stated objectives; the recognition of spatial and tempor al scales; assessments of statistical variability, precision, and accuracy; linkages with specific stressors; and coupling with economic and social indicators. Legislatively mandated use of ecological indicators occurs in many countries worldwide and is included in international accords. As scientific advancements and innovation in the development and use of ecological indicators continue through applications of molecular biology, computer technolog...

772 citations