Responses of freshwater plants and invertebrates to acidification

Conference · Tue Jan 01 04:00:00 UTC 1980

OSTI ID:7033261

Hendrey, G R; Yan, N D; Baumgartner, K J

Acidic, oligotrophic, clear waters often have strong similarities among their biota. In the phytoplankton, Dinophyceae, and to a lesser extent Chrysophyceae tend to dominate. Production of 25 Canadian Shield lakes (pH 6.1-7.1) ranged from 25 to 240 mg C m/sup -2/ d/sup -1/. Both biomass and production appear to be controlled by the supply and bio-availability of phosphorus rather than pH per se. We found little evidence of possible C limitation in acidified lakes. There does not appear to be a direct relationship between (H/sup +/) and biomass density in lakes, as illustrated by whole-lake manipulations of (H/sup +/) and total phosphorus (TP). These studies, however, do not examine effects of acidification on the whole lake-watershed system. It is suggested that watershed acidification processes such as leaching of Al may reduce TP loading to lakes. Zooplankton community biomass appears to be reduced at low pH and small-bodied forms may dominate. Among the zoobenthos, biomass does appear to be reduced in some lakes but not others. Various studies found shredders; collectors and scrapers to be reduced more than raptorial species. We hypothesize that removal of fish predation on benthos allows a relative increase in the invertebrate predators, reduction of herbivores (chironomids are relatively abundant) and the subsequent increase in benthic algae observed in many waters.

• Research Organization: Brookhaven National Lab., Upton, NY (USA); Ontario Ministry of the Environment, Toronto (Canada); Dartmouth Coll., Hanover, NH (USA). Dept. of Biological Sciences
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 7033261
• Report Number(s): BNL-28534; CONF-8009120-1
• Country of Publication: United States
• Language: English

Related Subjects

520200* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACIDIFICATION
AQUATIC ORGANISMS
BENTHOS
BIOMASS
ENERGY SOURCES
ENVIRONMENTAL EFFECTS
LAKES
NUTRIENTS
PH VALUE
PHYTOPLANKTON
PLANKTON
POPULATION DYNAMICS
PRODUCTIVITY
RENEWABLE ENERGY SOURCES
SURFACE WATERS
ZOOPLANKTON