Showing papers by "Patricia A. Tester published in 2003"
TL;DR: The Gulf of Mexico Harmful algal blooms (HABs) of Karenia brevis are a recurrent problem in the Gulf of the USA as discussed by the authors, with nearly annual occurrences on the Florida southwest coast and fewer occurrences on northwest Florida and Texas coasts.
313 citations
TL;DR: These PCR assays had a minimum sensitivity of 100 cells in a 100‐mL sample and were successfully used to detect PLOs in the St. Johns River system in Florida, USA.
Abstract: The putative harmful algal bloom dinoflagellate, Pfiesteria piscicida (Steidinger et Burkholder), frequently co-occurs with other morphologically similar species collectively known as Pfiesteria -like organisms (PLOs). This study specifically evaluated whether unique sequences in the internal transcribed spacer (ITS) regions, ITS1 and ITS2, could be used to develop PCR assays capable of detecting PLOs in natural assemblages. ITS regions were selected because they are more variable than the flanking small subunit or large subunit rRNA genes and more likely to contain species-specific sequences. Sequencing of the ITS regions revealed unique oligonucleotide primer binding sites for Pfiesteria piscicida , Pfiesteria shumwayae (Glasgow et Burkholder), Florida “Lucy” species, two cryptoperidiniopsoid species, “H/V14” and “PLO21,” and the estuarine mixotroph, Karlodinium micrum (Leadbetter et Dodge). These PCR assays had a minimum sensitivity of 100 cells in a 100-mL sample (1 cell·mL � 1 ) and were successfully used to detect PLOs in the St. Johns River system in Florida, USA. DNA purification and aspects of PCR assay development, PCR optimization, PCR assay controls, and collection of field samples are discussed.
125 citations
TL;DR: Measurements of gyroxanthin‐diester and other diagnostic pigments of Karenia brevis were incorporated into the initial pigment ratio matrix of the chemical taxonomy program (CHEMTAX) to resolve the relative contribution of K. brevis biomass in mixed estuarine phytoplankton assemblages from Florida and Galveston Bay, Texas.
Abstract: Diagnostic photopigment analysis is a useful tool for determining the presence and relative abundance of algal groups in natural phytoplankton assemblages. This approach is especially useful when a genus has a unique photopigment composition. The toxic dinoflagellate Karenia brevis (Davis) G. Hansen & Moestrup comb. nov. shares the diagnostic pigment gyroxanthin-diester with only a few other dinoflagellates and lacks peridinin, one of the major diagnostic pigments of most dinoflagellate species. In this study, measurements of gyroxanthin-diester and other diagnostic pigments of K. brevis were incorporated into the initial pigment ratio matrix of the chemical taxonomy program (CHEMTAX) to resolve the relative contribution of K. brevis biomass in mixed estuarine phytoplankton assemblages from Florida and Galveston Bay, Texas. The phytoplankton community composition of the bloom in Galveston Bay was calculated based on cell enumerations and biovolumetric measurements in addition to chl a-specific photopigment estimates of biomass (HPLC and CHEMTAX). The CHEMTAX and biovolume estimates of the phytoplankton community structure were not significantly different and suggest that the HPLC–CHEMTAX approach provides reasonable estimates of K. brevis biomass in natural assemblages. The gyroxanthin-diester content per cell of K. brevis from Galveston Bay was significantly higher than in K. brevis collected from the west coast of Florida. This pigment-based approach provides a useful tool for resolving spatiotemporal distributions of phytoplankton in the presence of K. brevis blooms, when an appropriate initial ratio matrix is applied.
63 citations
TL;DR: In this article, airborne laser-induced fluorescence measurements were used to detect and monitor ecosystem wide changes in the distribution and concentration of chlorophyll biomass and colored dissolved organic matter in the Pamlico-Albemarle Sound system, North Carolina, U.S., following massive flooding caused by a series of three hurricanes in the late summer of 1999.
Abstract: Airborne laser-induced fluorescence measurements were used to detect and monitor ecosystem wide changes in the distribution and concentration of chlorophyll biomass and colored dissolved organic matter in the Pamlico-Albemarle Sound system, North Carolina, U.S., following massive flooding caused by a series of three hurricanes in the late summer of 1999. These high-resolution data provided a significantly more detailed representation of the overall changes occurring in the system than could have been achieved by synoptic sampling from any other platform. The response time for the distribution of chlorophyll biomass to resume pre-flood conditions was used as a measure of ecosystem stability. Chlorophyll biomass patterns were reestablished within four mo of the flooding, whereas higher chlorophylla biomass concentrations persisted for approximately 6 mo. The primary trophic level in the Pamlico-Albemarle Sound system returned to equilibrium in less than a year of a major perturbation.
33 citations
TL;DR: These PCR assays had a minimum sensitivity of 100 cells in a 100 mL sample (1 cell mL-1) and were successfully used to detect PLOs in the St. Johns River system in Florida, USA.
Abstract: The putative harmful algal bloom dinoflagellate, Pfiesteria piscicida, frequently co-occurs with other morphologically similar species collectively known as Pfiesteria-like organisms (PLOs). This study specifically evaluated whether unique sequences in the ribosomal internal transcribed spacer regions (ITS1 and ITS2) could be used to develop PCR assays capable of detecting PLOs in natural assemblages. ITS regions were selected because they are more variable than the flanking small subunit (SSU) or large subunit (LSU) ribosomal RNA genes and more likely to contain species-specific sequences. Sequencing of the ITS regions revealed unique oligonucleotide primer binding sites for Pfiesteria piscicida, Pfiesteria shumwayae, Florida “Lucy” species, two cryptoperidiniopsoid species, “H/V14” and “PLO21,” and the estuarine mixotroph, Karlodinium micrum. These PCR assays had a minimum sensitivity of 100 cells in a 100 mL sample (1 cell mL-1) and were successfully used to detect PLOs in the St. Johns River system in Florida, USA.
11 citations
01 Nov 2003
01 Nov 2003
TL;DR: In this article, the authors have made advances in three areas: algorithm development (Table 16.1), field data collection, and data applications for SeaWiFS in the coastal zone.
Abstract: SeaWiFS has the ability to enhance our understanding of many oceanographic processes. However, its utility in the coastal zone has been limited by valid bio-optical algorithms and by the determination of accurate water reflectances, particularly in the blue bands (412-490 nm), which have a significant impact on the effectiveness of all bio-optical algorithms. We have made advances in three areas: algorithm development (Table 16.1), field data collection, and data applications.