Grantee Research Project Results
2002 Progress Report: Dynamics, Variability and Patterns of Harmful and Red Tide Bloom-Species in Narragansett Bay: Ecological Analysis of a 38-Year Time Series
EPA Grant Number: R829368Title: Dynamics, Variability and Patterns of Harmful and Red Tide Bloom-Species in Narragansett Bay: Ecological Analysis of a 38-Year Time Series
Investigators: Smayda, Theodore J. , Borkman, David G.
Institution: University of Rhode Island
EPA Project Officer: Packard, Benjamin H
Project Period: September 28, 2001 through January 27, 2006 (Extended to September 30, 2006)
Project Period Covered by this Report: September 28, 2001 through January 27, 2002
Project Amount: $348,912
RFA: Ecology and Oceanography of Harmful Algal Blooms (2001) RFA Text | Recipients Lists
Research Category: Aquatic Ecosystems , Water Quality , Water
Objective:
This project is directed towards filling fundamental knowledge gaps in the ecology of harmful algal blooms (HABs) and red tides. A 38-year time series of quantitative measurements of Narragansett Bay phytoplankton and their habitat is being used to meeting the following objectives: (1) identify the mechanisms underlying the selection and bloom cycles of 18 indigenous, cosmopolitan, and representative HAB and benign red tide species in Narragansett Bay; (2) describe the long-term patterns, trends, and variability in their blooms; (3) quantify the effects of meteorology, climate, physical, chemical, and biological factors on blooms; (4) evaluate the open niche hypothesis as a general HAB bloom paradigm; and (5) develop a Web page making the time-series analyses electronically available to scientists, local and regional environmental managers, and the general public.
Progress Summary:
In Year 1 of the project, we focused on Objectives 2 and 3 to identify mechanisms responsible for HAB species selection and bloom pattern variability. We have completed the computer-intensive time-series analyses of the targeted 18 HAB species, important competing non-HAB species, and habitat parameters (i.e., temperature, nutrients, light, river flow, etc.). Initial results for the benign, red tide diatom species Skeletonema costatum indicate that its abundance and its annual bloom pattern are influenced by long-term changes in winter temperature. In years with cold winters (the 1960s), winter zooplankton abundance was reduced and Skeletonema exhibited winter-spring blooms that dominated the annual cycle. In warm winters (the 1990s), winter zooplankton abundance was elevated and the annual bloom maximum of Skeletonema shifted to the summer. This shift, which is correlated with the North Atlantic Oscillation (a climate index), appears to impact HAB events and their variability, an effect that is being examined. The long-term seasonal shift in the annual phytoplankton bloom maximum is being analyzed for its impact on HAB dynamics because this bloom shift is expected to have altered nutrient availability and grazer abundance and their population cycles. These are factors that impact HABs.
Initial analyses of HAB species time-series behavior indicate that the variability in the occurrence, duration, and magnitude of their blooms has both random and stochastic features. There was a great increase in the abundance of harmful species beginning in the 1980s, which persisted for a decade. Prior and subsequent to this period, the diatom population dominated the phytoplankton community, and blooms of harmful species were less pronounced but remained regular features of the annual bloom cycle. Cross-correlation analyses were initiated to identify which, and the combinations of, biological (zooplankton, ctenophore), chemical (nutrient), and physical (temperature, salinity, river flow) features that may have led to the observed increase in HABs during the 1980s. There also is great interannual variability, in which harmful and red tide species will bloom. Cross-correlation analyses were begun to identify the linkages between habitat conditions and blooms of the individual species. The analyses suggest that species-specific critical factors are significant to bloom initiation, continuance, and duration. Thus, grazing pressure and allelopathy appear to be important factors in bloom generation of ichthyotoxic Heterosigma akashiwo, ground water delivery of nutrients to Prorocentum minimum and Aureococcus anophagefferens, and nutrient levels to Scrippsiella trochoidea and Heterocapsa triquetra.
The analytical results obtained were used to refine and propose new hypotheses in a series of three publications (see Publications/Presentations). A major finding is that the open niche hypothesis previously formulated by the principal investigator has been confirmed by the Narragansett Bay analyses. The "open niche" period is that period when HABs and red tides occur, but it is highly unpredictable which species then will bloom. We have found unexpectedly great interannual variation in the physical, chemical, and biological properties at the transition into the "open niche" period. We believe that the variability in temperature, irradiance, nutrient (nitrogen, phosphorus, silica) concentrations and ratios, and grazer (zooplankton) abundance influences the selection of phylogeny, genus, and species bloom during the "open niche" period.
Dr. Theodore Smayda received the Award of Excellence from the Phycological Society of America in August 2002. He also received the Yasumoto Life Time Achievement Award from the International Society for the Study of Harmful Algae (ISSHA) in October 2002.
Future Activities:
In the second year of the project, we will complete the qualitative descriptions of the long-term bloom patterns of the 18 bloom species. Cross analyses of the time-series data bank will be undertaken to identify the mechanisms underlying the selection and bloom cycles of the 18 indigenous species of interest, and to evaluate the causes of harmful bloom intensification observed during the 1980s. Work will continue on all objectives. Publications on the "open niche" period will be prepared.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
| Other project views: | All 35 publications | 8 publications in selected types | All 5 journal articles |
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Smayda TJ. Adaptive ecology, growth strategies and the global bloom expansion of dinoflagellates. Journal of Oceanography 2002;58(2):281-294. |
R829368 (2002) |
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Smayda TJ. Turbulence, watermass stratification and harmful algal blooms:an alternative view and frontal zones as "pelagic seed banks." Harmful Algae 2002;1(1):95-112. |
R829368 (2002) R829368 (Final) |
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Smayda TJ, Reynolds CS. Strategies of marine dinoflagellate survival and some rules of assembly. Journal of Sea Research 2003;49(2):95-106. |
R829368 (2002) R829368 (Final) |
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Supplemental Keywords:
coastal ecosystems, harmful algal bloom, HAB, ecology, phytoplankton, ecosystem protection, multidecadal time series, estuarine research, Narragansett Bay, Rhode Island, RI, Ecology and Oceanography of Harmful Algal Blooms, ECOHAB, red tides., RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Air, Geographic Area, Water, algal blooms, Aquatic Ecosystem, Aquatic Ecosystems & Estuarine Research, Ecosystem Protection, East Coast, estuarine research, Ecology, Atmosphere, Biology, Ecosystem/Assessment/Indicators, Oceanography, computing technology, Air Pollution Effects, Ecological Effects - Environmental Exposure & Risk, climate change, ECOHAB, marine biology, Narragansett Bay, mitigation, red tides, Narragansett Bay Time Series (NBTS), HAB ecology, environmental monitoring, data management, ecological exposure, coastal environments, red tide bloom, World Wide WebRelevant Websites:
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.