Limits...
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

Cell density of D. geminata plotted by site and month showing a possible upstream range expansion.Black dots indicate cell density >0 and red “x”s indicate a non-detection.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4493098&req=5

pone.0130558.g005: Cell density of D. geminata plotted by site and month showing a possible upstream range expansion.Black dots indicate cell density >0 and red “x”s indicate a non-detection.

Mentions: Results of this investigation indicate that D. geminata may have expanded its range across parts of the watershed during the 12-month study. This seems likely because D. geminata was only identified in this highly monitored river system three months prior to our first (August 2009) survey. During this survey, D. geminata was only detected at main stem sites downstream of the Shandaken Portal (USOP-03B, USOP-04, USOP-04A, USOP-04B, USOP-05 and USOP-06) and at three tributary sites (STOC-00, STOC-01, and WODC-01) which all enter the Upper Esopus downstream of the Portal (Table 3). During the subsequent November 2009 survey, D. geminata was collected at the same three seasonal main stem sites, and at USOP-03A (Fig 5). This survey was the first to collect D. geminata upstream of the Shandaken Portal. D. geminata was not detected at any site during the April 2010 survey, but was found at all six of the seasonal main stem sites during June 2010, marking its first detection at USOP-02 and USOP-03. During the August 2010 survey, D. geminata was collected again at all six seasonal main stem sites (although the only detection at USOP-02 was a qualitative fourth replicate not included in this analysis), at additional downstream sites (USOP-04, USOP-04B, and USOP-05), and at three tributary sites (STOC-00, STOC-01, and BSNL-01). These findings suggest the diatom expanded its range on the main stem from a 17 km reach exclusively downstream of the Portal in August 2009 to an additional 2 km upstream of the Portal in November 2009, and to at least another 6 km upstream of the Portal by June 2010. D. geminata was not detected at the uppermost main stem site (USOP-00) or at six of the tributary sites during either of the comprehensive August surveys.


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

George SD, Baldigo BP - PLoS ONE (2015)

Cell density of D. geminata plotted by site and month showing a possible upstream range expansion.Black dots indicate cell density >0 and red “x”s indicate a non-detection.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0130558.g005: Cell density of D. geminata plotted by site and month showing a possible upstream range expansion.Black dots indicate cell density >0 and red “x”s indicate a non-detection.
Mentions: Results of this investigation indicate that D. geminata may have expanded its range across parts of the watershed during the 12-month study. This seems likely because D. geminata was only identified in this highly monitored river system three months prior to our first (August 2009) survey. During this survey, D. geminata was only detected at main stem sites downstream of the Shandaken Portal (USOP-03B, USOP-04, USOP-04A, USOP-04B, USOP-05 and USOP-06) and at three tributary sites (STOC-00, STOC-01, and WODC-01) which all enter the Upper Esopus downstream of the Portal (Table 3). During the subsequent November 2009 survey, D. geminata was collected at the same three seasonal main stem sites, and at USOP-03A (Fig 5). This survey was the first to collect D. geminata upstream of the Shandaken Portal. D. geminata was not detected at any site during the April 2010 survey, but was found at all six of the seasonal main stem sites during June 2010, marking its first detection at USOP-02 and USOP-03. During the August 2010 survey, D. geminata was collected again at all six seasonal main stem sites (although the only detection at USOP-02 was a qualitative fourth replicate not included in this analysis), at additional downstream sites (USOP-04, USOP-04B, and USOP-05), and at three tributary sites (STOC-00, STOC-01, and BSNL-01). These findings suggest the diatom expanded its range on the main stem from a 17 km reach exclusively downstream of the Portal in August 2009 to an additional 2 km upstream of the Portal in November 2009, and to at least another 6 km upstream of the Portal by June 2010. D. geminata was not detected at the uppermost main stem site (USOP-00) or at six of the tributary sites during either of the comprehensive August surveys.

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