Geology topics

Christopher E. Walker

Publications and source records attributed to Christopher E. Walker.

4 recordsLinked to original sources

USGS2012

Developing a quality assurance plan for telemetry studies: A necessary management tool for an effective study

Telemetry has been used to answer various questions associated with research, management, and monitoring programs and to monitor animal behavior and population dynamics throughout the world. Many telemetry projects have been developed to study the passage, behavior, and survival of migrating adult and juvenile salmonids at hydroelectric projects on the mainstem Columbia and Snake rivers (Skalski et al. 2001a, 2001b; Skalski et al. 2002; Keefer et al. 2004; Goniea et al. 2006; Plumb et al. 2006). Telemetry based field evaluations of the survival of salmon through hydroelectric projects are costly because of the technology (tags, telemetry systems, infrastructure, etc.) and personnel required to conduct the evaluations. Given the cost of implementing these projects, and the financial and conservation implications of the decisions made from the research results (e.g., forgone electricity production and conservation of threatened and endangered animals), ensuring quality data are collected by documenting all procedures, training, data checks, and that sound protocols and quality assurance and control procedures are in place is paramount. Telemetry studies can pose unique data collection, processing, and analysis challenges. For instance, inferences about entire populations of animals are made from study animals that are captured, held, and tagged at disparate locations. Consequently great care must be taken to ensure that any potential biases that could arise from field procedures must be minimized (Peven et al. 2005). Interrogations of released study animals are remotely conducted by telemetry systems throughout the study area. The continuous recording of telemetry systems can result in large numbers of detections over a short time frame and the potential for false positive detections from records that are weak or erroneous. Thus, there is the potential to generate large data sets (many thousands of lines) that require significant postprocessing. Data reduction can be done using software or programming code within a software package or manually to discern noise from valid data and pull out the pertinent information for analysis. In either case, consistent well-documented procedures need to be in place to ensure quality results and allow for repeatability of study methods.

Book chapter↗

USGS2010

Assessing survival of Mid-Columbia River released juvenile salmonids at McNary Dam, Washington, 2008-09

Few studies have evaluated survival of juvenile salmon over long river reaches in the Columbia River and information regarding the survival of sockeye salmon at lower Columbia River dams is lacking. To address these information gaps, the U.S. Geological Survey was contracted by the U.S. Army Corps of Engineers to evaluate the possibility of using tagged fish released in the Mid-Columbia River to assess passage and survival at and downstream of McNary Dam. Using the acoustic telemetry systems already in place for a passage and survival study at McNary Dam, fish released from the tailraces of Wells, Rocky Reach, Rock Island, Wanapum, and Priest Rapids Dams were detected at McNary Dam and at the subsequent downstream arrays. These data were used to generate route-specific survival probabilities using single-release models from fish released in the Mid-Columbia River. We document trends in passage and survival probabilities at McNary Dam for yearling Chinook and sockeye salmon and juvenile steelhead released during studies in the Mid-Columbia River. Trends in the survival and passage of these juvenile salmonid species are presented and discussed. However, comparisons made across years and between study groups are not possible because of differences in the source of the test fish, the type of acoustic tags used, the absence of the use of passive integrated transponder tags in some of the release groups, differences in tagging and release protocols, annual differences in dam operations and configurations, differences in how the survival models were constructed (that is, number of routes that could be estimated given the number of fish detected), and the number and length of reaches included in the analysis (downstream reach length and arrays). Despite these differences, the data we present offer a unique opportunity to examine the migration behavior and survival of a group of fish that otherwise would not be studied. This is particularly true for sockeye salmon because little information is available about their survival as they pass hydroelectric dams in the lower Columbia River. Collecting information on fish released in the Mid-Columbia River, as well as on fish released 8 kilometers upstream of McNary Dam, allowed us to evaluate similarities and differences in passage and survival probabilities. In general, juvenile salmonids released in the Mid-Columbia River and detected at and downstream of McNary Dam showed trends in passage and survival probabilities that were similar to fish released 8 kilometers upstream of McNary Dam. This suggests that increased migration time or length of migration had little effect on behavior and survival of Mid-Columbia River released juvenile salmonids detected at McNary Dam.

Open-File Report↗

USGS2008

Survival and migration behavior of juvenile salmonids at Lower Granite Dam, 2006

We described behavior and estimated passage and survival parameters of juvenile salmonids during spring and summer migration periods at Lower Granite Dam in 2006. During the spring, the study was designed to examine the effects of the Behavioral Guidance Structure (BGS) by using a randomized-block BGS Stored / BGS Deployed treatment design. The summer study was designed to compare passage and survival through Lower Granite Dam using a randomized-block design during two spill treatments while the BGS was in the stored position. We used the Route Specific Survival Model to estimate survival and passage probabilities of hatchery yearling Chinook salmon, hatchery juvenile steelhead, and hatchery and wild subyearling Chinook salmon. We also estimated fish guidance efficiency (FGE), fish passage efficiency (FPE), Removable Spillway Weir passage effectiveness (RPE), spill passage effectiveness (SPY), and combined spill and RSW passage effectiveness.

Idaho, Oregon,Washington↗

USGS2006

Occurrence of diatoms in lakeside wells in northern New Jersey as an indicator of the effect of surface water on ground-water quality

In a novel approach for detecting ground-water/surface-water interaction, diatoms were used as an indicator that surface water affects ground-water quality in lakeside communities in northern New Jersey. The presence of diatoms, which are abundant in lakes, in adjacent domestic wells demonstrated that ground water in these lakeside communities was under the direct influence of surface water. Entire diatom frustules were present in 17 of 18 water samples collected in August 1999 from domestic wells in communities surrounding Cranberry Lake and Lake Lackawanna. Diatoms in water from the wells were of the same genus as those found in the lakes. The presence of diatoms in the wells, together with the fact that most static and stressed water levels in wells were below the elevation of the lake surfaces, indicates that ground-water/surface-water interaction is likely. Ground-water/surface-water interaction also probably accounts for the previously documented near-ubiquitous presence of methyl tertiary-butyl ether in the ground-water samples. Recreational use of lakes for motor boating and swimming, the application of herbicides for aquatic weed control, runoff from septic systems and roadways, and the presence of waterfowl all introduce contaminants to the lake. Samples from 4 of the 18 wells contained Navicula spp., a documented significant predictor of Giardia and Cryptosporidium. Because private well owners in New Jersey generally are not required to regularly monitor their wells, and tests conducted by public-water suppliers may not be sensitive to indicators of ground-water/surface-water interaction, these contaminants may remain undetected. The presence of diatoms in wells in similar settings can warn of lake/well interactions in the absence of other indicators.

New Jersey↗