Bj. Brown et Jh. Olive, DIATOM COMMUNITIES IN THE CUYAHOGA RIVER (USA) - CHANGES IN SPECIES COMPOSITION BETWEEN 1974 AND 1992 FOLLOWING RENOVATIONS IN WASTE-WATER MANAGEMENT, The Ohio journal of science, 95(3), 1995, pp. 254-260
Periphytic diatom communities along the Cuyahoga River were analyzed f
or possible changes in. species composition resulting from improvement
s in wastewater management within the river basin during the past 18 y
ears. The results, compared to a similar study conducted in 1974, and
controlled for seasonality and microhabitat effects, show an increase
in total diatom species (75 to 105), especially pollution-sensitive sp
ecies, and a reduction in pollution-tolerant species-all indications o
f improved water quality, Reductions were evident in the number and. p
roportion of pollution-tolerant species such as Gomphonema parvulum, M
elosira varians, Navicula cryptocephala, N. pelliculosa, Nitzschia com
munis, N. palea, and Synedra ulua. The number and proportion of pollut
ion-sensitive species such as Achnanthes linearis, Amphora pediculus,
Cocconeis pediculus, Diatoma vulgare, Navicula tripunctata, and Nitzsc
hia dissipata increased. Despite changes in species composition, headw
aters of the river, managed as a domestic water supply and Ohio Scenic
River, continue to support 2-3 X more taxa than the lower river below
the City of Akron. Substantial degradation of water quality in the lo
wer river persists despite recent restoration efforts, A major source
of pollution occurs upstream from the Akron Water Pollution Control fa
cility because sample sites above and below this facility were very si
milar in diatom species composition, each dominated by Nitzschia amphi
bia (similar to 40%), a well known saprophilic diatom associated with
organically polluted water. Overflows from combined stormwater-sanitar
y sewers, within the Akron metropolitan area are the most probable cau
se of the continued suppression of diatom species diversity.