Temperature and Water Depth Monitoring Within Chum Salmon Spawning Habitat Below Bonneville Dam -- Annual Report -- October 2007-September 2008

Arntzen, Evan

doi:10.2172/967225

Cited by 1 publication

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

Section: Discussionmentioning

confidence: 99%

“…Using the model developed in this report, Arntzen and Murray (2011) predicted that emergence would be 13 days earlier if 825ATUs were used as the threshold for emergence instead of 932 ATUs. The 825-ATU value has been used in the past as representative of the earliest onset of emergence in the Ives Island area (personal communication with Todd Hillson, WDFW, as cited in Arntzen and Murray 2011). We chose to use 932 ATUs as the threshold of emergence because it represented when 50% of the fry from a local chum salmon stock emerged in a controlled study conducted in our laboratory in 2007 and 2008 (Arntzen et al 2008a(Arntzen et al , 2009b.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Development of a Conceptual Chum Salmon Emergence Model for Ives Island

Murray¹,

Geist²,

Arntzen³

et al. 2011

View full text Add to dashboard Cite

SummaryThe objective of this project was to develop a conceptual model for the U.S. Army Corps of Engineers, Portland District, that can be used to predict the timing of chum salmon (Oncorhynchus keta) emergence in the Ives Island area. Researchers at the Pacific Northwest National Laboratory developed the model using real-time hourly temperature data from three locations in the Ives Island spawning area that were instrumented with paired hyporheic and river sensors beginning in 2003. These data were supplemented by additional temperature data collected in the Ives Island area during 2006-2007, including 5 additional paired hyporheic and river sensors and 32 hyporheic sensors that measured temperature at approximately 15 cm below the bed surface of the Columbia River.Using these data, we calculated accumulated thermal units (ATUs) for each sensor location; we assumed emergence occurred at 932 ATUs based on the time to 50% emergence in previous laboratory studies. We found that mixing various proportions of hyporheic and river temperature data from the realtime sensors could be used to reproduce the number of days to emergence for the full range of sensor locations in [2006][2007]. The number of days to emergence that were mapped in the Ives Island area were spatially coherent, with much shorter time to emergence in the western part of the channel relative to more easterly parts of the channel. These results are similar to those of earlier studies showing that bed temperatures in the Ives Island area tend to be spatially continuous and mappable and that cooler hyporheic water is found in the eastern part of the channel.A pre-season estimate of emergence dates is determined by interpolating the days to emergence for each redd location from the map of 2006-2007 redds and temperatures. The map is then used to identify the mixture of hyporheic and river temperature data from the real-time system that would provide the closest match for the estimated days to emergence for each redd location. The identified mixture is then used to update the emergence estimates for each redd during the incubation season as new hyporheic and river temperature data become available from the real-time system. This method assumes that the spatial distribution of areas with warm and cool hyporheic temperatures near Ives Island tends to be relatively constant, as suggested by the results of earlier mapping studies. A case study was prepared using redd location data from 2009-2010 to illustrate use of the conceptual model. The case study showed differences in emergence estimates resulting from variations in the river and hyporheic temperatures from year to year.

show abstract

Section: Discussionmentioning

confidence: 99%