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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

Box and whisker plots summarizing temporal trends in (A) D. geminata density, (B) ash-free dry mass (AFDM), (C) chlorophyll a (chl a), (D) total diatom density, and (E) percent D. geminata for all surveys conducted at seasonal sites, 2009–2010.Median value is indicated by the black center line, mean value is indicated by the black triangle, and the bottom and top of the box indicate the lower and upper quartiles, respectively. Whiskers represent the minimum and maximum values and hollow circles represent outliers.
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pone.0130558.g003: Box and whisker plots summarizing temporal trends in (A) D. geminata density, (B) ash-free dry mass (AFDM), (C) chlorophyll a (chl a), (D) total diatom density, and (E) percent D. geminata for all surveys conducted at seasonal sites, 2009–2010.Median value is indicated by the black center line, mean value is indicated by the black triangle, and the bottom and top of the box indicate the lower and upper quartiles, respectively. Whiskers represent the minimum and maximum values and hollow circles represent outliers.

Mentions: The density of D. geminata was high and variable at many sites during the November 2009 and June 2010 surveys while density was consistently low during the August 2009 and August 2010 surveys (Fig 2). No D. geminata cells were collected at any of the six sites during the April 2010 survey. The mixed model confirmed that period had a significant effect (P = 0.000) on the density of D. geminata (Table 4) and pairwise comparisons indicated the following grouping: June 2010: A, November 2009: AB, August 2010: BC, August 2009: C, April 2010: C (periods that do not share a letter are significantly different).Temporal changes in density of D. geminata were generally consistent with total diatom density and standing crop for most surveys. D. geminata cell density (Fig 3A), AFDM (Fig 3B), chl a (Fig 3C), and total diatom density (Fig 3D) were concurrently high during November 2009 and low during August 2009 and 2010. This relationship was not maintained in the April 2010 survey as no D. geminata cells were detected and total diatom density was low, yet standing crop measures were relatively high. Density of D. geminata and total diatoms was high in June 2010, but AFDM and chl a concentrations were relatively low during this survey.


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

George SD, Baldigo BP - PLoS ONE (2015)

Box and whisker plots summarizing temporal trends in (A) D. geminata density, (B) ash-free dry mass (AFDM), (C) chlorophyll a (chl a), (D) total diatom density, and (E) percent D. geminata for all surveys conducted at seasonal sites, 2009–2010.Median value is indicated by the black center line, mean value is indicated by the black triangle, and the bottom and top of the box indicate the lower and upper quartiles, respectively. Whiskers represent the minimum and maximum values and hollow circles represent outliers.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0130558.g003: Box and whisker plots summarizing temporal trends in (A) D. geminata density, (B) ash-free dry mass (AFDM), (C) chlorophyll a (chl a), (D) total diatom density, and (E) percent D. geminata for all surveys conducted at seasonal sites, 2009–2010.Median value is indicated by the black center line, mean value is indicated by the black triangle, and the bottom and top of the box indicate the lower and upper quartiles, respectively. Whiskers represent the minimum and maximum values and hollow circles represent outliers.
Mentions: The density of D. geminata was high and variable at many sites during the November 2009 and June 2010 surveys while density was consistently low during the August 2009 and August 2010 surveys (Fig 2). No D. geminata cells were collected at any of the six sites during the April 2010 survey. The mixed model confirmed that period had a significant effect (P = 0.000) on the density of D. geminata (Table 4) and pairwise comparisons indicated the following grouping: June 2010: A, November 2009: AB, August 2010: BC, August 2009: C, April 2010: C (periods that do not share a letter are significantly different).Temporal changes in density of D. geminata were generally consistent with total diatom density and standing crop for most surveys. D. geminata cell density (Fig 3A), AFDM (Fig 3B), chl a (Fig 3C), and total diatom density (Fig 3D) were concurrently high during November 2009 and low during August 2009 and 2010. This relationship was not maintained in the April 2010 survey as no D. geminata cells were detected and total diatom density was low, yet standing crop measures were relatively high. Density of D. geminata and total diatoms was high in June 2010, but AFDM and chl a concentrations were relatively low during this 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