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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

MDS ordination based on fourth-root transformed diatom abundance data for each of the five surveys as indicated by colored symbols.
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pone.0130558.g004: MDS ordination based on fourth-root transformed diatom abundance data for each of the five surveys as indicated by colored symbols.

Mentions: Diatom community structure was strongly influenced by survey period but not by the cell density of D. geminata. Assemblages from each period clustered tightly in the MDS and April 2010 samples were most strongly isolated (Fig 4). A two-way ANOSIM test confirmed that differences between survey period were highly significant (Global R: 0.764, P = 0.001) and all pairwise comparisons between periods were significant (P<0.05). The density class of D. geminata (no detection, 0–100 cells cm-2, >100 cells cm-2) did not significantly affect the composition of the diatom community (Global R: 0.106, P = 0.053). PERMDISP indicated that multivariate dispersion (community homogeneity) differed significantly between periods (P = 0.002) and density class of D. geminata (P = 0.014). Pairwise comparisons indicated that diatom assemblages from the >100 cells cm-2 class were significantly more homogenous than the no detection class (P = 0.023) but did not differ from the 0–100 cells cm-2 class (P = 0.311). Sites where D. geminata was present in high densities, however, did not consistently separate in the ordination from nearby sites where it was not detected. For example, during the November survey, diatom assemblages at USOP-02 and USOP-04A had a high degree of similarity and were located close to one another in the ordination yet D. geminata was not detected at USOP-02 and was present at a density of 1,410 cells cm-2 at USOP-04A.


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

George SD, Baldigo BP - PLoS ONE (2015)

MDS ordination based on fourth-root transformed diatom abundance data for each of the five surveys as indicated by colored symbols.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0130558.g004: MDS ordination based on fourth-root transformed diatom abundance data for each of the five surveys as indicated by colored symbols.
Mentions: Diatom community structure was strongly influenced by survey period but not by the cell density of D. geminata. Assemblages from each period clustered tightly in the MDS and April 2010 samples were most strongly isolated (Fig 4). A two-way ANOSIM test confirmed that differences between survey period were highly significant (Global R: 0.764, P = 0.001) and all pairwise comparisons between periods were significant (P<0.05). The density class of D. geminata (no detection, 0–100 cells cm-2, >100 cells cm-2) did not significantly affect the composition of the diatom community (Global R: 0.106, P = 0.053). PERMDISP indicated that multivariate dispersion (community homogeneity) differed significantly between periods (P = 0.002) and density class of D. geminata (P = 0.014). Pairwise comparisons indicated that diatom assemblages from the >100 cells cm-2 class were significantly more homogenous than the no detection class (P = 0.023) but did not differ from the 0–100 cells cm-2 class (P = 0.311). Sites where D. geminata was present in high densities, however, did not consistently separate in the ordination from nearby sites where it was not detected. For example, during the November survey, diatom assemblages at USOP-02 and USOP-04A had a high degree of similarity and were located close to one another in the ordination yet D. geminata was not detected at USOP-02 and was present at a density of 1,410 cells cm-2 at USOP-04A.

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