Daniel Welsh - Academia.edu (original) (raw)

Papers by Daniel Welsh

Research paper thumbnail of Duck and shorebird reproduction in the grasslands of central California

California Fish and Game, 1994

Research paper thumbnail of Reproductive Performance of Ashy Storm-Petrels(Oceanodroma hornochroa) at Santa Cruz Island, California, in 1995-2007

Porceedings of the …, 2009

Page 1. Pages 269–281 in Damiani, CC and DK Garcelon (eds.). 2009. Proceedings of 269 the 7th Cal... more Page 1. Pages 269–281 in Damiani, CC and DK Garcelon (eds.). 2009. Proceedings of 269 the 7th California Islands Symposium. Institute for Wildlife Studies, Arcata, CA. REPRODUCTIVE PERFORMANCE OF ASHY STORM ...

Research paper thumbnail of Removal of contaminant organic gases from air in closed systems by soil

Soil Biology and Biochemistry, 1992

The effect of air flow rate and prior conditioning of soil on the removal of contaminant organic ... more The effect of air flow rate and prior conditioning of soil on the removal of contaminant organic gases from air by soil bed reactors (SBRs) was experimentally tested in closed systems. Removal rates of methane, ethane and propane were not significantly different from controls indicating that no net removal of these gases occurred during the experiments. Carbon monoxide removal was complete and rapid, while the removal of ethylene appeared to be accelerated with prior exposure of the soil to ethylene (conditioning). suggesting that the induction of microbial populations may be involved. The amount of contaminant gases removed from the air did not significantly change with changes in air flow rate.

Research paper thumbnail of Ashy Storm-Petrel Contaminants

Research paper thumbnail of Arsenic, Mercury, Selenium, and Organochlorines and Reproduction of Interior Least Terns in the Northern Great Plains, 1992-1994

Colonial Waterbirds, 1998

Research paper thumbnail of Copper, cadmium, and zinc concentrations in juvenile chinook salmon and selected fish-forage organisms (aquatic insects) in the upper Sacramento River, California

Water, Air, & Soil Pollution, 2001

This study assessed the downstream extent and severity of copper (Cu), cadmium (Cd), and zinc (Zn... more This study assessed the downstream extent and severity of copper (Cu), cadmium (Cd), and zinc (Zn) contamination from acid mine drainage on juvenile chinook salmon (Oncorhynchus tshawytscha) and aquatic insects over a roughly 270-km reach of the Sacramento River below Keswick Reservoir. During April-May 1998, salmon were collected from four sites in the river and from a fish hatchery that receives water from Battle Creek. Salmon from river sites were examined for gut contents to document their consumption of various invertebrate taxa, whereas salmon from river sites and the hatchery were used for metal determinations. Midge (Chironomidae) and caddisfly (Trichoptera) larvae and mayfly (Ephemeroptera) nymphs were collected for metal determinations during April-June from river sites and from Battle and Butte creeks. The fish hatchery and Battle and Butte creeks served as reference sites because they had no history of receiving mine drainage. Salmon consumed mostly midge larvae and pupae (44.0%, damp-dry biomass), caddisfly larvae (18.9%), Cladocera (5.8%), and mayfly nymphs (5.7%). These results demonstrated that insects selected for metal determinations were important as fish forage. Dry-weight concentrations of Cu, Cd, and Zn were generally far higher in salmon and insects from the river than from reference sites. Within the river, high metal concentrations persisted as far downstream as South Meridian (the lowermost sampling site). Maximum concentrations of Cd (30.7 µg g −1 ) and Zn (1230 µg g −1 ), but not Cu (87.4 µg g −1 ), in insects exceeded amounts that other investigators reported as toxic when fed for prolonged periods to juvenile salmonids.

Research paper thumbnail of Extra-Pair Copulations in Black Brant

The Condor, 1990

... 5) 1986 27 May 10 June 30 May-5 June 26 May-4 Junea (n = 6) (n = 13) aOne copulation that occ... more ... 5) 1986 27 May 10 June 30 May-5 June 26 May-4 Junea (n = 6) (n = 13) aOne copulation that occurred on the date that the pair's eggs pipped (28 June) is excluded because it could not possibly have resulted in fertilization. ...

Research paper thumbnail of Nest Success, Cause-Specific Nest Failure, and Hatchability of Aquatic Birds at Selenium-Contaminated Kesterson Reservoir and a Reference Site

The Condor, 1989

ABSTRACT During 1983-1985, we studied the reproductive success of several species of aquatic bird... more ABSTRACT During 1983-1985, we studied the reproductive success of several species of aquatic birds (coots, ducks, shorebirds, and grebes) nesting at two sites in Merced County, California: a selenium-contaminated site (Kesterson Reservoir) and a nearby reference site (Volta Wildlife Area). We used a computer program (MICROMORT) developed for the analysis of radiotelemetry data (Heisey and Fuller 1985) to estimate nest success and cause-specific failure rates, and then compared these parameters and hatchability between sites and among years. Nest success and causes of failure varied by species, site, and year. The most important causes of nest failure were usually predation, desertion, and water-level changes. However, embryotoxicosis (mortality, deformity, and lack of embryonic development) was the most important cause of nest failure in Eared Grebes (Podiceps nigricollis) at Kesterson Reservoir. Embryotoxicosis also reduced the hatchability of eggs of all other species at Kesterson in one or more years; embryonic mortality occurred rarely at Volta, and abnormalities were not observed.

Research paper thumbnail of Concentrations of selenium in biota, sediments, and water at Cibola National Wildlife Refuge

Archives of Environmental Contamination and Toxicology, 1994

Selenium contamination was studied at Cibola National Wildlife Refuge (Cibola NWR) in the lower C... more Selenium contamination was studied at Cibola National Wildlife Refuge (Cibola NWR) in the lower Colorado River Valley, California and Arizona, USA. The objective was to determine whether local irrigation practices resulted in exposure of fish to toxic concentrations of selenium.

Research paper thumbnail of Organochlorine Contaminants in Ashy Storm-Petrel Eggs from Santa Cruz Island, California, in 1992-2008: preliminary findings

Research paper thumbnail of Duck and shorebird reproduction in the grasslands of central California

California Fish and Game, 1994

Research paper thumbnail of Reproductive Performance of Ashy Storm-Petrels(Oceanodroma hornochroa) at Santa Cruz Island, California, in 1995-2007

Porceedings of the …, 2009

Page 1. Pages 269–281 in Damiani, CC and DK Garcelon (eds.). 2009. Proceedings of 269 the 7th Cal... more Page 1. Pages 269–281 in Damiani, CC and DK Garcelon (eds.). 2009. Proceedings of 269 the 7th California Islands Symposium. Institute for Wildlife Studies, Arcata, CA. REPRODUCTIVE PERFORMANCE OF ASHY STORM ...

Research paper thumbnail of Removal of contaminant organic gases from air in closed systems by soil

Soil Biology and Biochemistry, 1992

The effect of air flow rate and prior conditioning of soil on the removal of contaminant organic ... more The effect of air flow rate and prior conditioning of soil on the removal of contaminant organic gases from air by soil bed reactors (SBRs) was experimentally tested in closed systems. Removal rates of methane, ethane and propane were not significantly different from controls indicating that no net removal of these gases occurred during the experiments. Carbon monoxide removal was complete and rapid, while the removal of ethylene appeared to be accelerated with prior exposure of the soil to ethylene (conditioning). suggesting that the induction of microbial populations may be involved. The amount of contaminant gases removed from the air did not significantly change with changes in air flow rate.

Research paper thumbnail of Ashy Storm-Petrel Contaminants

Research paper thumbnail of Arsenic, Mercury, Selenium, and Organochlorines and Reproduction of Interior Least Terns in the Northern Great Plains, 1992-1994

Colonial Waterbirds, 1998

Research paper thumbnail of Copper, cadmium, and zinc concentrations in juvenile chinook salmon and selected fish-forage organisms (aquatic insects) in the upper Sacramento River, California

Water, Air, & Soil Pollution, 2001

This study assessed the downstream extent and severity of copper (Cu), cadmium (Cd), and zinc (Zn... more This study assessed the downstream extent and severity of copper (Cu), cadmium (Cd), and zinc (Zn) contamination from acid mine drainage on juvenile chinook salmon (Oncorhynchus tshawytscha) and aquatic insects over a roughly 270-km reach of the Sacramento River below Keswick Reservoir. During April-May 1998, salmon were collected from four sites in the river and from a fish hatchery that receives water from Battle Creek. Salmon from river sites were examined for gut contents to document their consumption of various invertebrate taxa, whereas salmon from river sites and the hatchery were used for metal determinations. Midge (Chironomidae) and caddisfly (Trichoptera) larvae and mayfly (Ephemeroptera) nymphs were collected for metal determinations during April-June from river sites and from Battle and Butte creeks. The fish hatchery and Battle and Butte creeks served as reference sites because they had no history of receiving mine drainage. Salmon consumed mostly midge larvae and pupae (44.0%, damp-dry biomass), caddisfly larvae (18.9%), Cladocera (5.8%), and mayfly nymphs (5.7%). These results demonstrated that insects selected for metal determinations were important as fish forage. Dry-weight concentrations of Cu, Cd, and Zn were generally far higher in salmon and insects from the river than from reference sites. Within the river, high metal concentrations persisted as far downstream as South Meridian (the lowermost sampling site). Maximum concentrations of Cd (30.7 µg g −1 ) and Zn (1230 µg g −1 ), but not Cu (87.4 µg g −1 ), in insects exceeded amounts that other investigators reported as toxic when fed for prolonged periods to juvenile salmonids.

Research paper thumbnail of Extra-Pair Copulations in Black Brant

The Condor, 1990

... 5) 1986 27 May 10 June 30 May-5 June 26 May-4 Junea (n = 6) (n = 13) aOne copulation that occ... more ... 5) 1986 27 May 10 June 30 May-5 June 26 May-4 Junea (n = 6) (n = 13) aOne copulation that occurred on the date that the pair's eggs pipped (28 June) is excluded because it could not possibly have resulted in fertilization. ...

Research paper thumbnail of Nest Success, Cause-Specific Nest Failure, and Hatchability of Aquatic Birds at Selenium-Contaminated Kesterson Reservoir and a Reference Site

The Condor, 1989

ABSTRACT During 1983-1985, we studied the reproductive success of several species of aquatic bird... more ABSTRACT During 1983-1985, we studied the reproductive success of several species of aquatic birds (coots, ducks, shorebirds, and grebes) nesting at two sites in Merced County, California: a selenium-contaminated site (Kesterson Reservoir) and a nearby reference site (Volta Wildlife Area). We used a computer program (MICROMORT) developed for the analysis of radiotelemetry data (Heisey and Fuller 1985) to estimate nest success and cause-specific failure rates, and then compared these parameters and hatchability between sites and among years. Nest success and causes of failure varied by species, site, and year. The most important causes of nest failure were usually predation, desertion, and water-level changes. However, embryotoxicosis (mortality, deformity, and lack of embryonic development) was the most important cause of nest failure in Eared Grebes (Podiceps nigricollis) at Kesterson Reservoir. Embryotoxicosis also reduced the hatchability of eggs of all other species at Kesterson in one or more years; embryonic mortality occurred rarely at Volta, and abnormalities were not observed.

Research paper thumbnail of Concentrations of selenium in biota, sediments, and water at Cibola National Wildlife Refuge

Archives of Environmental Contamination and Toxicology, 1994

Selenium contamination was studied at Cibola National Wildlife Refuge (Cibola NWR) in the lower C... more Selenium contamination was studied at Cibola National Wildlife Refuge (Cibola NWR) in the lower Colorado River Valley, California and Arizona, USA. The objective was to determine whether local irrigation practices resulted in exposure of fish to toxic concentrations of selenium.

Research paper thumbnail of Organochlorine Contaminants in Ashy Storm-Petrel Eggs from Santa Cruz Island, California, in 1992-2008: preliminary findings