ECOHAB is a peer-reviewed, national, competitive program that funds regional-scale and targeted studies. Regional ecosystem investigations of the causes and impacts of HABs leading to development of model-based operational ecological forecasting capabilities in areas with severe, recurrent blooms are a high priority.

Measurements of Harmful Algal Blooms (HABs) in the Gulf of Mexico, Chesapeake Bay, and Great Lake regions during 2006.

Multiple Harmful Algae Bloom (HAB) (K. brevis) data sets were obtained for this data layer, including Harmful Algal BloomS Observing System data (HABSOS) from NCEI (1953-2018) and the NOAA HAB Operational Forecast System Dataset (2007-2018). Data includes samples from Texas Parks and Wildlife Department (TPWD) the Louisiana Department of Health and Hospitals, Florida Fish and Wildlife Conservation Commission, Florida Fish and Wildlife Research Institute (FWRI), and the HAB Monitoring Database. Data were combined and reviewed for erroneous entries. Duplicate data from the resulting database were deleted, leaving a total of 155,307 observations. For the purpose of this K. brevis layer, only data from 2000-2018 were used due to sampling biases. An 8 square kilometer hexagonal grid was created covering the Gulf of Mexico and eastern Florida. Each year between 2000-2018 was evaluated separately. If a grid cell contained an observation that registered a value of over 100,000 cells/L (the lethal toxicity level for finfish), the grid cell received a value of '1‘. All other grid cells received a value of '0’ to represent observations below the lethal level of concern to fish. After all years were evaluated, the values for each year were totaled to obtain a resulting frequency value for that grid cell, representing the number of years that grid cell had values greater than or equal to 100,000 cells/L for the years 2000-2018.

Measurements of Harmful Algal Blooms (HABs) in the Gulf of Mexico, Chesapeake Bay, and Great Lake regions during 2006.

Interactions between bacteria and species of harmful and/or toxic algae are potentially important factors affecting both the population dynamics and toxicity of these algae. Recent reports of bacteria lethal to certain harmful algal bloom (HAB) species, coupled with a rapidly evolving interest in attempting to minimize the adverse effects of HABs through various prevention, control, and mitigation strategies, has focused attention on defining the role of algicidal bacteria in bloom termination. The aim of the present study was to determine if algicidal bacteria active against Karenia brevis, a dinoflagellate responsible for frequent and protracted red tides in the Gulf of Mexico, are present in the waters of the west Florida shelf. To date we have detected one algicidal bacterium from samples obtained during ECOHAB-Florida cruises and we are continuing this effort. A taxon-specific 16S rRNA probe was developed for a previously isolated algicidal strain, 41-DBG2, and we have begun to screen water samples for its presence using fluorescent in-situ hybridization. In addition, we have employed denaturing gradient gel electrophoresis (DGGE) to characterize the diversity of the ambient microbial assemblages and to visualize the band characteristic of strain 41-DBG2. This band can then be analyzed further by excising and sequencing. Our screening results to date have yielded negative results on all but one of the field samples tested, which was positive with the rRNA probe. These largely negative findings may not be unexpected due to the marked temporal and spatial separation of the original algicidal bacterial isolation and the water samples being screened. Future efforts will focus on isolating algicidal bacteria from the same bloom event as the samples for screening are obtained, thereby increasing the likelihood of detecting algicidal strains and permitting a more effective analysis of their population dynamics.

An Ecopath with Ecosim (EwE) model of the WFS explicitly simulating HABs was recently developed for illuminating the potential ecosystem impacts of red tides within the WFS region. These results were produced by research funded by the National Oceanic and Atmospheric Administration (NOAA’s) RESTORE Act Science Program under award NA15NOS4510233 a the University of Miami and award NA15NOS4510232 to the University of South Florida.

Harmful algal blooms (HABs) are overgrowths of algae or cyanobacteria in water and can be harmful to humans and animals directly via toxin exposure or indirectly via changes in water quality and related impacts to ecosystems services, drinking water characteristics, and recreation. While HABs occur frequently throughout the United States, the driving conditions behind them are not well understood, especially in flowing waters. In order to facilitate future national model development and characterization of HABs, this data release publishes a synthesized and cleaned collection of HABs-related water quality and quantity data for river and stream sites across the United States. It includes nutrients, major ions, sediment, physical properties, streamflow, chlorophyll and other types of water data. This data release contains files of harmonized data from the USGS National Water Information System (NWIS). Continuous sensor data for 132 parameters (35 of which returned data) between January 1, 2005 and December 31, 2022 were downloaded from NWIS programmatically. All data were harmonized into a shared format and grouped by generic parameters; data are in files named "daily_{parameter_grp}.csv", and the "pcode_group_xwalk.csv" maps parameter codes to parameter groups. Lastly, we include a "site_metadata.csv" containing site identification and location information for all sites with water quality and quantity data, and mappings to the National Hydrography Dataset flowlines where available. This work was completed as part of the USGS Proxies Project, an effort supported by the Water Mission Area (WMA) Water Quality Processes program to develop estimation methods for PFAS, harmful algal blooms, and metals, at multiple spatial and temporal scales.

Harmful algal blooms (HABs) are overgrowths of algae or cyanobacteria in water and can be harmful to humans and animals directly via toxin exposure or indirectly via changes in water quality and related impacts to ecosystems services, drinking water characteristics, and recreation. While HABs occur frequently throughout the United States, the driving conditions behind them are not well understood, especially in flowing waters. In order to facilitate future national model development and characterization of HABs, this data release publishes a synthesized and cleaned collection of HABs-related water quality and quantity data for river and stream sites across the United States. It includes nutrients, major ions, sediment, physical properties, streamflow, chlorophyll and other types of water data. This data release contains files of harmonized data from the USGS National Water Information System (NWIS). Continuous sensor data for 132 parameters (35 of which returned data) between January 1, 2005 and December 31, 2022 were downloaded from NWIS programmatically. All data were harmonized into a shared format and grouped by generic parameters; data are in files named "daily_{parameter_grp}.csv", and the "pcode_group_xwalk.csv" maps parameter codes to parameter groups. Lastly, we include a "site_metadata.csv" containing site identification and location information for all sites with water quality and quantity data, and mappings to the National Hydrography Dataset flowlines where available. This work was completed as part of the USGS Proxies Project, an effort supported by the Water Mission Area (WMA) Water Quality Processes program to develop estimation methods for PFAS, harmful algal blooms, and metals, at multiple spatial and temporal scales.

Harmful algal blooms of the toxic dinoflagellate, Karenia brevis, have caused massive fish kills in the Gulf of Mexico since the 1500's, with most occurrences on the west coast of Florida. In 1996, the list of states that have experiences natural resource, public health and economic impacts related to this organism expanded, with the addition of Alabama, Mississippi, and Louisiana, to include all the Gulf-coast states and North Carolina. Estimates of economic impacts to Florida and North Carolina from two moderate intensity blooms ranged from 15 to 25 million dollars respectively. The harmful impacts caused by K. brevis occur only when cell concentrations increase significantly above low background concentrations that are present year-round in the Eastern Gulf of Mexico. Once a bloom has developed offshore in typically oligotrophic waters, cell concentrations at the 105 level can be maintained for months. During 21 of the past 22 years, red tide blooms have been observed within the region between Tampa Bay and Charlotte Harbor. The key to understanding any HAB lies in knowing how one algal species has adapted and come to dominate in its particular realm of physical, biological and chemical conditions. Our ability to predict initiation, maintenance, and dispersal of blooms on the Florida shelf has been severely limited by the lack of a quantitative description, or model, of their population dynamics and the physical, biological and chemical regime in which they are embedded. The modeling components of this project will incorporate the quantitative description of blooms and their surrounding environment provided by the field and laboratory portions of this project. The field component will employ a set of monthly hydrographic transects.