Didymosphenia geminata in the Upper Esopus Creek: current status, variability, and controlling factors

New York State Dept of Environmental Conservation; USGS
By:  and 



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 Dgeminata invasion, determine the impact of supplemental flows from the Portal on Dgeminata, and identify potential factors that may limitDgeminata 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 Dgeminata and all diatoms. Density of Dgeminata 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 Dgeminata cell density. In general, Dgeminata was most abundant during the November 2009 and June 2010 surveys and at sites immediately downstream of the Portal. We found that Dgeminata 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 Dgeminatain this watershed.

Publication type Article
Publication Subtype Journal Article
Title Didymosphenia geminata in the Upper Esopus Creek: current status, variability, and controlling factors
Series title PLoS ONE
DOI 10.1371/journal.pone.0130558
Volume 10
Issue 8
Year Published 2015
Language English
Publisher Public Library of Science
Publisher location San Francisco, CA
Contributing office(s) New York Water Science Center
Description 20 p.
First page 1
Last page 20
Online Only (Y/N) N
Additional Online Files (Y/N) N
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