Literature values for macroalgal impacts suggest that during the dry season, the accumulation 
of benthic green macroalgae could have a negative effect on the abundance of some infaunal 
invertebrates (while possibly enhancing epifauna), and on certain other fauna (e.g., juvenile flatfish, 
shorebirds). However, the preponderance of green macroalgae occurs in the marine dominated Zone 1 
of Yaquina Estuary during the dry season. Results from stable isotope studies (Section 3.3 and Lee et 
al., 2006) provide strong support for the conclusion that benthic green macroalgae in Zone 1 of the 
Yaquina Estuary derive most of their nutrients from tidal influx of near shore marine waters. Summer 
green macroalgal blooms thus appear to be a natural response of the estuarine system. Thus, at 
present, the occurrence of benthic green macroalgae does not appear to be a useful indicator of 
eutrophication in Yaquina Estuary. 
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