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Contaminant exposure of willets feeding in agricultural drainages of the lower Rio Grande valley of south Texas

Environmental Monitoring and Assessment

By:
and

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Abstract

Willets (Catoptrophorus semipalmatus) were collected in June and August 1986 at the outlets of two agricultural drainages into the Lower Laguna Madre of South Texas and at two other Texas coastal sites. Mean liver concentration of arsenic was higher in August than June. Over 20% of the livers had arsenic concentrations elevated above a suggested background level of 5.0 ppm dry weight (DW), but concentrations (maximum 15 ppm) were below those associated with acute toxicity. Selenium concentration in livers varied from 2.3 to 8.3 ppm DW for all locations and represented background levels. Mercury concentrations in livers for all locations (means = 2.0 to 3.4, maximum 17 ppm DW) were below those associated with avian mortality and similar to levels found in other estuarine/marine birds. DDE in carcasses was higher in adults (mean = 1.0 ppm wet weight) than juveniles (0.2 ppm), and higher in August (1.0 ppm) than June (0.5 ppm); however, DDE concentrations were generally at background levels. Based on brain cholinesterase activity, willets were not recently exposed to organophosphate pesticides.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Contaminant exposure of willets feeding in agricultural drainages of the lower Rio Grande valley of south Texas
Series title:
Environmental Monitoring and Assessment
Volume
16
Issue:
2
Year Published:
1991
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
189-200
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Environmental Monitoring and Assessment
First page:
189
Last page:
200
Number of Pages:
12