24727

200301700 EXP WENATCHEE RM&E PILOT - UNIV OF ALASKA, FAIRBANKS

10/1/2005

9/30/2006

156. Develop RM&E Methods and Designs

Work Element Usage Report

A: 156 - Development of methods for monitoring low order drainages

Develop and test methods for monitoring subcatchment and stream condition of low-order drainages.

Headwater stream sampling

We will continue to sample our 60 stream sites located within the Wenatchee subbasin starting in October 2006. Half (30) of these streams are located in Ecological Sub-Region (ESR) 4 (wet ecoregion) with the other 30 in ESR 11 (dry ecoregion). In both ecoregions, 15 low (little past logging and presence of roads) and high impact (recent logging and roads) sites have been chosen. Of the ESR 11 sites, 10 occur in the Mission Creek and 20 occur in the Peshastin Creek drainages. In ESR4, six occur in the Icicle, nine in Nason Creek, 10 in Little Wenatchee, and five in the White River drainages.

Invertebrates (aquatic and terrestrial) and organic detritus (i.e., particulate organic matter =250-µm) will be collected with a 250-µm net attached to one end of a 75-cm long, 10-cm diameter plastic pipe frame, which will rest on the stream bottom. One frame per stream with attached net will be secured with sandbags in the middle of each stream. Because the sampler will be placed on the stream bottom, seston will be captured (suspended particulate organic matter) as well as bedload particulate organic matter, which will be collectively labeled detritus, and macroinvertebrates in the drift as well as those moving downstream along the streambed. Facilitated by high stream gradient, the downstream end of each horizontal pipe will rest above the stream surface; discharge through the sampler will be determined by recording the time taken to fill a container of known volume. Discharge will be measured during each sampling period, a mean calculated, and this value used to determine the density of invertebrates (individuals m-3) and detritus (= 250-µm diameter, g m-3). Most of the streams are expected to be sufficiently small to allow for the entire stream flow to pass through the pipes. If not, the percentage relative to the total stream flow will be estimated. This fraction will be used to extrapolate the transport measured through the net for the whole stream. Replicates will be streams within each land-use and ecoregion (n = 15). Streams will be sampled continuously for invertebrates and detritus over a 24-h period once every two months, October through August, for all sites.

Invertebrates will be sorted from detritus after being placed in 70% EtOH in the field. They will be identified to the lowest reliable taxon, their body lengths measured, and dry mass determined using taxon-specific length-mass regression equations (Rogers et al. 1977; Smock 1980; Meyer 1989; Sample et al. 1993; Burgherr and Meyer 1997). Invertebrates will be categorized as either aquatic or terrestrial if they were a product of aquatic or terrestrial secondary production, respectively (Wipfli 1997). The remainder of the sample (detritus component) will be oven-dried, weighed, ashed (at 500º C for 5 h), and reweighed to determine ash-free dry mass (AFDM).

Additionally, we will measure several other physical and biological variables in the streams to link the productivity measures with causal factors in the subcatchments, including periphyton development on rock surfaces, and stream temperature, pH, and conductivity at all sites.

By measuring invertebrate, detritus and nutrient transport from headwaters (surrogates of headwater production) at a point along the length of a stream, we can assess the level of productivity, and therefore health and condition of a headwater subcatchment upstream of the sampling site. We intend to test methods i n the Wenatchee River Basin for monitoring headwater subcatchment condition that were developed by Wipfli and Gregovich (2002) for southeastern Alaska streams. Data suggest this technique holds promise as a surrogate of headwater subcatchment productivity, can serve as a tool for assessing the cumulative impacts of multiple stressors in subcatchments, and can be used as an indicator of watershed condition and health.

A draft monitoring protocol for the Wenatchee sub-basin will be produced focusing on how techniques developed for southeastern Alaska can by applied to our study area.

$80,000

63.24%

10/01/2005

10/06/2006

09/29/2006

Concluded

[Unassigned]

[Unassigned]

Finite