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Didymosphenia geminata in the Upper Esopus Creek: Current Status, Variability, and Controlling Factors.

George SD, Baldigo BP - PLoS ONE (2015)

Bottom Line: Survey period and Portal (upstream or downstream) each significantly affected D. geminata cell density.We found that D. geminata did not reach nuisance levels or strongly affect the periphyton community.A number of abiotic factors including variable flows and moderate levels of phosphorous and suspended sediment may limit blooms of D. geminata in this watershed.

View Article: PubMed Central - PubMed

Affiliation: New York Water Science Center, U.S. Geological Survey, Troy, New York, United States of America.

ABSTRACT
In May of 2009, the bloom-forming diatom Didymosphenia geminata was first identified in the Upper Esopus Creek, a key tributary to the New York City water-supply and a popular recreational stream. The Upper Esopus receives supplemental flows from the Shandaken Portal, an underground aqueduct delivering waters from a nearby basin. The presence of D. geminata is a concern for the local economy, water supply, and aquatic ecosystem because nuisance blooms have been linked to degraded stream condition in other regions. Here we ascertain the extent and severity of the D. geminata invasion, determine the impact of supplemental flows from the Portal on D. geminata, and identify potential factors that may limit D. geminata in the watershed. Stream temperature, discharge, and water quality were characterized at select sites and periphyton samples were collected five times at 6 to 20 study sites between 2009 and 2010 to assess standing crop, diatom community structure, and density of D. geminata and all diatoms. Density of D. geminata ranged from 0-12 cells cm(-2) at tributary sites, 0-781 cells cm(-2) at sites upstream of the Portal, and 0-2,574 cells cm(-2) at sites downstream of the Portal. Survey period and Portal (upstream or downstream) each significantly affected D. geminata cell density. In general, D. geminata was most abundant during the November 2009 and June 2010 surveys and at sites immediately downstream of the Portal. We found that D. geminata did not reach nuisance levels or strongly affect the periphyton community. Similarly, companion studies showed that local macroinvertebrate and fish communities were generally unaffected. A number of abiotic factors including variable flows and moderate levels of phosphorous and suspended sediment may limit blooms of D. geminata in this watershed.

No MeSH data available.


Related in: MedlinePlus

Continuous (15-minute) water temperature (A) and daily discharge (B) at USOP-03A (red), USOP-03B (green), and the Shandaken Portal (black) for the period 7/1/2009–9/1/2010.
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pone.0130558.g006: Continuous (15-minute) water temperature (A) and daily discharge (B) at USOP-03A (red), USOP-03B (green), and the Shandaken Portal (black) for the period 7/1/2009–9/1/2010.

Mentions: High water temperatures may limit the growth and blooms of D. geminata and promote die back during mid to late summer in parts of the Upper Esopus Creek. Although the upper thermal tolerance of D. geminata appears variable [2], peak biomass of D. geminata has been linked to water temperatures that do not exceed 18°C [50] and D. geminata is more frequently found in locations where average summer air temperatures remain below 20°C [47]. Several laboratory studies using static tests confirmed that temperature was an important variable affecting the survival of D. geminata cells [51, 52]. Lagerstedt [51] found that cells were unable to survive more than 60 hours at 28°C and densities of viable cells gradually declined at 20°C. In the Upper Esopus, peak summer temperatures in the main stem consistently exceed 20°C. During 2010, water temperature at USOP-03A (and many other sites) exceeded 20°C for long periods of time and peaked at 28.1°C (Fig 6A). These temperatures far exceeded the preferred range of D. geminata and may be responsible for the low cell densities observed during the August 2010 survey.


Didymosphenia geminata in the Upper Esopus Creek: Current Status, Variability, and Controlling Factors.

George SD, Baldigo BP - PLoS ONE (2015)

Continuous (15-minute) water temperature (A) and daily discharge (B) at USOP-03A (red), USOP-03B (green), and the Shandaken Portal (black) for the period 7/1/2009–9/1/2010.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493098&req=5

pone.0130558.g006: Continuous (15-minute) water temperature (A) and daily discharge (B) at USOP-03A (red), USOP-03B (green), and the Shandaken Portal (black) for the period 7/1/2009–9/1/2010.
Mentions: High water temperatures may limit the growth and blooms of D. geminata and promote die back during mid to late summer in parts of the Upper Esopus Creek. Although the upper thermal tolerance of D. geminata appears variable [2], peak biomass of D. geminata has been linked to water temperatures that do not exceed 18°C [50] and D. geminata is more frequently found in locations where average summer air temperatures remain below 20°C [47]. Several laboratory studies using static tests confirmed that temperature was an important variable affecting the survival of D. geminata cells [51, 52]. Lagerstedt [51] found that cells were unable to survive more than 60 hours at 28°C and densities of viable cells gradually declined at 20°C. In the Upper Esopus, peak summer temperatures in the main stem consistently exceed 20°C. During 2010, water temperature at USOP-03A (and many other sites) exceeded 20°C for long periods of time and peaked at 28.1°C (Fig 6A). These temperatures far exceeded the preferred range of D. geminata and may be responsible for the low cell densities observed during the August 2010 survey.

Bottom Line: Survey period and Portal (upstream or downstream) each significantly affected D. geminata cell density.We found that D. geminata did not reach nuisance levels or strongly affect the periphyton community.A number of abiotic factors including variable flows and moderate levels of phosphorous and suspended sediment may limit blooms of D. geminata in this watershed.

View Article: PubMed Central - PubMed

Affiliation: New York Water Science Center, U.S. Geological Survey, Troy, New York, United States of America.

ABSTRACT
In May of 2009, the bloom-forming diatom Didymosphenia geminata was first identified in the Upper Esopus Creek, a key tributary to the New York City water-supply and a popular recreational stream. The Upper Esopus receives supplemental flows from the Shandaken Portal, an underground aqueduct delivering waters from a nearby basin. The presence of D. geminata is a concern for the local economy, water supply, and aquatic ecosystem because nuisance blooms have been linked to degraded stream condition in other regions. Here we ascertain the extent and severity of the D. geminata invasion, determine the impact of supplemental flows from the Portal on D. geminata, and identify potential factors that may limit D. geminata in the watershed. Stream temperature, discharge, and water quality were characterized at select sites and periphyton samples were collected five times at 6 to 20 study sites between 2009 and 2010 to assess standing crop, diatom community structure, and density of D. geminata and all diatoms. Density of D. geminata ranged from 0-12 cells cm(-2) at tributary sites, 0-781 cells cm(-2) at sites upstream of the Portal, and 0-2,574 cells cm(-2) at sites downstream of the Portal. Survey period and Portal (upstream or downstream) each significantly affected D. geminata cell density. In general, D. geminata was most abundant during the November 2009 and June 2010 surveys and at sites immediately downstream of the Portal. We found that D. geminata did not reach nuisance levels or strongly affect the periphyton community. Similarly, companion studies showed that local macroinvertebrate and fish communities were generally unaffected. A number of abiotic factors including variable flows and moderate levels of phosphorous and suspended sediment may limit blooms of D. geminata in this watershed.

No MeSH data available.


Related in: MedlinePlus