In:
Canadian Journal of Fisheries and Aquatic Sciences, Canadian Science Publishing, Vol. 52, No. 6 ( 1995-06-01), p. 1247-1256
Abstract:
On July 14, 1991, approximately 70 000 L of the soil fumigant Vapam ® , metam sodium, was spilled into the upper Sacramento River, California. Twelve hours before this spill reached Shasta Lake we sampled several sites in a subsequently impacted area and two control stations. Thereafter, samples were collected at approximately 5-d intervals for 26 d. We observed an almost immediate and subsequent 99.9% decrease in zooplankton biomass within 2.0 km of the river inflow. Lake-water chlorophyll concentrations crashed immediately to 20% of prespill values, but rebounded to approximately 750% prespill values after 9 d as a result of a spill-driven diatom bloom. Dissolved inorganic nitrogen and phosphorus concentrations increased severalfold immediately after the spill but returned to prespill concentrations as the algal bloom peaked. Effects of the spill were clearly related to distance from the river inflow with strong effects observed within 2.0 km, and weak or no effects observed at 8.0 km into the reservoir. A dilution experiment, using varying mixtures of contaminated and control station lake water, strongly confirmed the principal findings of the field study. Our field and experimental data showed far more severe effects of the spill than single species bioassays and lake pesticide concentrations predicted.
Type of Medium:
Online Resource
ISSN:
0706-652X
,
1205-7533
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
1995
detail.hit.zdb_id:
7966-2
detail.hit.zdb_id:
1473089-3
SSG:
21,3
SSG:
12
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