Bridgeport Reservoir
- Lake name:
- Bridgeport Reservoir
- Location:
- California
- HydroLAKE ID:
- 112483
- GRanD ID:
- 546
- Latitude:
- 38.325225
- Longitude:
- -119.212814
- Surface area (km2):
- 9.3
- Basin type:
- reservoir
- Dam completion date:
- 1924
- Primary emergent vegetation:
- water smartweed
- Primary vegetation for nesting:
- water smartweed
- Management agency:
- Walker River Irrigation District
- Lake use:
- irrigation
- Region associations:
- Walker River; Topaz Lake; Antelope Valley
- Comments:
- Large mountain lake that can be 50 feet deep when full. Most of the marshes have been heavily grazed by cattle. Has had toxic algae warnings.
Summary of Surveys (5)
Survey Citation:
Ackerman, J. T., C. A. Hartman, C. A. Eagles-Smith, M. P. Herzog, J. Davis, G. Ichikawa, and A. Bonnema. 2015. Estimating mercury exposure of piscivorous birds and sport fish using prey fish monitoring. Environmental Science & Technology 49:13596–13604.
-
Type
boat -
Time period
April 2012, October 2013 -
Source
Peer-reviewed -
Both Western and Clarks?
N/A
| Count Type | Range | Max | Year |
|---|---|---|---|
| Max Adults | 1 to 100 | presence? | 2012 |
| Most Recent Adults | 1 to 100 | presence? | 2012 |
| Max Nests | N/A | N/A | N/A |
| Most Recent Nests | N/A | N/A | N/A |
| Max Chicks | N/A | N/A | N/A |
| Most Recent Chicks | N/A | N/A | N/A |
Comments:
Not a survey but grebes were sampled at 25 lakes in CA from April to October of 2012 (13 lakes) and 2013 (12 lakes). An average of 14 grebes per lake (from 2 to 38 grebes) were captured at night with night-lights. No breakdown of actual numbers captured per lake was provided. Morphometry and molt data, along with blood was collected from each bird for mercury analysis, and sex determination via genetic analysis. From 7 out of the 25 lakes, an average of 14 grebe eggs (from 6 to 23 eggs) were collected. An egg from each randomly sampled nest was collected either from an active nest (random egg) or from an abandoned nest (abandoned egg). Prey fish and sport fish were also sampled an average of 11 days after grebe sampling. At Bridgeport Reservoir, no grebe eggs were collected in 2012 (Figure SI). 354 grebes were captured total from the 25 lakes, 71% were Western grebes, 29% were Clark's, 48% were female, 52% were male. 101 grebe eggs were collected from 7 lakes, of which 62% were Western grebes, 15% were Clark's grebes, 23% were unidentified which. Grebe blood, eggs, and sport fish mercury concentrations were strongly correlated to mercury concentrations in prey fish at the lakes. Grebe mercury concentrations were also strongly correlated with sport fish mercury concentrations. This study showed that prey fish monitoring can estimate mercury exposure of grebes and other piscivorous birds if these birds can't be sampled directly.
Survey Citation:
Ivey, G. L. 2004. Conservation assessment and management plan for breeding Western and Clark’s Grebes in California. Unpublished technical report. American Trader Trustee Council, California. . Accessed 15 January 2020.
-
Time period
1990s -
Source
Conservation Assessment, Management Plan -
Both Western and Clarks?
N/A
| Count Type | Range | Max | Year |
|---|---|---|---|
| Max Adults | 1 to 100 | presence | 1990s |
| Most Recent Adults | 1 to 100 | presence | 1990s |
| Max Nests | 1 to 100 | presence | 1990s |
| Most Recent Nests | 1 to 100 | presence | 1990s |
| Max Chicks | N/A | N/A | N/A |
| Most Recent Chicks | N/A | N/A | N/A |
Comments:
This entry to capture historical record of breeding grebes in CA prior to 2002. There were breeding grebes and noted as colony site in Bridgeport Reservoir in the 1990s, no numbers or other details. Source is D. Shuford, pers. comm.
Survey Citation:
Ivey, G. L. 2004. Conservation assessment and management plan for breeding Western and Clark’s Grebes in California. Unpublished technical report. American Trader Trustee Council, California. . Accessed 15 January 2020.
-
Type
shore -
Time period
21 September 2003 -
Source
Conservation Assessment, Management Plan -
Both Western and Clarks?
N/A
| Count Type | Range | Max | Year |
|---|---|---|---|
| Max Adults | 101 to 500 | 225 | 2003 |
| Most Recent Adults | 101 to 500 | 225 | 2003 |
| Max Nests | 1 to 100 | 80 | 2003 |
| Most Recent Nests | 1 to 100 | 80 | 2003 |
| Max Chicks | 101 to 500 | 128 | 2003 |
| Most Recent Chicks | 101 to 500 | 128 | 2003 |
Comments:
Seems only survey was from shore on 80% of Bridgeport Reservoir on September 21, 2003 but due to long distance viewing, chick sizes and species were not differentiated. Table 3 population estimate is the # of nests (80) x 2 for 160. However, the actual adult count of 225 is entered here. Moderate amounts of nesting occurred here in 2003 with 2.2% of the selected sites and 1.0% of the grebe population of the Intermountain West (Ivey and Herziger in prep.). Relatively good productivity in 2003 (0.56). Cattle grazing has reduced some marsh habitat (Cooper 2004).
Survey Citation:
Ivey, G.L., and C.P. Herziger. 2006. Intermountain west waterbird conservation plan, version 1.2. A plan associated with the Waterbird Conservation for the Americas Initiative. Published by U.S. Fish and Wildlife Service Pacific Region, Portland, Oregon.
-
Time period
N/A -
Source
Conservation Plan -
Both Western and Clarks?
N
| Count Type | Range | Max | Year |
|---|---|---|---|
| Max Adults | 101 to 500 | 160 | 2003 |
| Most Recent Adults | 101 to 500 | 160 | 2003 |
| Max Nests | 1 to 100 | 80 | 2003 |
| Most Recent Nests | 1 to 100 | 80 | 2003 |
| Max Chicks | N/A | N/A | N/A |
| Most Recent Chicks | N/A | N/A | N/A |
Comments:
Appendix D, Table D-2, data is from 2003: 80 nests, 160 area population estimate (nests x 2), population data source is Ivey 2004. Ivey 2004 does an actual adult count, this 160 estimate is less than that. Ivey Region 1 Non Game CA Waterbird Atlas spreadsheet says this is both Western and Clark's but the Ivey 2006 has it as just Western. Leaving it as Western.
Survey Citation:
Robison, K., R. Weems, and D. Anderson. 2008. Western and Clark's Grebe conservation and management in California. Annual report for year three (2007). Report for American Trader and Kure/ Stuyvesant Trustee Councils and National Fish and Wildlife Foundation, California.
-
Type
shore -
Time period
16 August 2007 -
Source
Report -
Both Western and Clarks?
Y
| Count Type | Range | Max | Year |
|---|---|---|---|
| Max Adults | 1 to 100 | 100 | 2007 |
| Most Recent Adults | 1 to 100 | 100 | 2007 |
| Max Nests | N/A | N/A | N/A |
| Most Recent Nests | N/A | N/A | N/A |
| Max Chicks | 1 to 100 | 10 | 2007 |
| Most Recent Chicks | 1 to 100 | 10 | 2007 |
Comments:
No nests found. Multiple adults attending and feeding a brood of 2 chicks. Adults with stained plumage, possible evidence of oil exposure, were observed. Subsequent reports have their own entries.
Sources of Information
- Messager, M. L., B. Lehner, G. Grill, I. Nedeva, and O. Schmitt. 2016. Estimating the volume and age of water stored in global lakes using a geo-statistical approach. Nature Communications 7:13603. Data is available at www.hydrosheds.org.; Lehner, B., C. Reidy Liermann, C. Revenga, C. Vorosmarty, B. Fekete, P. Crouzet, P. Doll, M. Endejan, K. Frenken, J. Magome, C. Nilsson, J.C. Robertson, R. Rodel, N. Sindorf, and D. Wisser. 2011. Global Reservoir and Dam Database, Version 1 (GRanDv1): Dams, Revision 01. Palisades, New York: NASA Socioeconomic Data and Applications Center (SEDAC).
- Lehner, B., C. Reidy Liermann, C. Revenga, C. Vorosmarty, B. Fekete, P. Crouzet, P. Doll, M. Endejan, K. Frenken, J. Magome, C. Nilsson, J.C. Robertson, R. Rodel, N. Sindorf, and D. Wisser. 2011. Global Reservoir and Dam Database, Version 1 (GRanDv1): Dams, Revision 01. Palisades, New York: NASA Socioeconomic Data and Applications Center (SEDAC).
- Bridgeport Reservoir Information
- Bridgeport Valley Important Bird Areas (IBA) Information
- Bridgeport Reservoir Toxic Algae Warning