FIRST QUARTER 2013
Page 5
Good News from the Stream!
Every August a group of biologists with GEI Consultants come to Wharf to collect aquatic data in the streams surrounding Wharf and Golden Reward. One of the conditions in our Surface Water Discharge Permit is that we collect this data annually. They go to the same locations every year and assess the changes in habitat, fish populations, benthic invertebrate populations, and Periphyton populations. To assess the changes in habitat they measure the stream width, depth, bank condition, and structure at each location. At each location they install a net at the up-stream and down-stream ends of a 100 meter section of stream. They make three passes in the 100 meter section of stream with an electro-fish device to collect all of the fish. They determine species, density, biomass, size, and condition of the fish prior to returning them to the stream. Benthic invertebrates are the insects that live in the streams. They collect the invertebrates by using a 500 micrometer mesh kick net. The organisms are preserved in 95 % alcohol and sent to a lab for identification. It takes the lab from August until late December or early January to complete the arduous task of identifying all of the invertebrates. Periphyton are very small microscopic aquatic plants such as algae and diatoms. They are collected by essentially scrubbing pieces of the bottom substrate with a wire brush in a bucket. The method is really much more scientific though so that the results are comparable. These samples are also sent to various laboratories for identification, enumeration, and determination of chlorophyll a and biomass. This work also takes the labs a long time to complete as everything has to be done under microscopic examination.
Ron Waterland Environmental Manager
By collecting and identifying all of these organisms they can assess the health of the streams because there are certain organisms that are very sensitive to pollution and there are certain organisms that tolerate pollution. They also collect the same data in reference streams that are not near our mining operations. They take all of this information and put it into a report for us to send to the South Dakota Department of Environment and Natural Resources. We also send the report to the South Dakota Game Fish and Parks Department. The following paragraph is taken directly from the report and shows that streams around Wharf and Golden Reward are healthy and in good shape.
GEI Consultant, Lee Bergstedt, and assistant.
Overall, aquatic biological data collected in 2012 indicated the benthic invertebrate population in Annie Creek appears recovered from the 2007 release of high BOD water. Mountain suckers have been absent or collected only in low abundances from the middle reaches of Annie Creek since 2007, although healthy trout populations are present within the lower reaches of Annie Creek. Healthy trout populations are also present in other streams within the study area, including Deadwood Creek, Stewart Gulch, and Whitetail Creek. Trout inhabit False Bottom Creek as well, but successful recruitment may be limited in some years. Periphyton densities were relatively low at all sites in 2012, and diversity and richness metrics were generally lower than corresponding reference sites. However, tolerance and trophic metrics, which are indicators of poor water quality and siltation, were generally more favorable at the Wharf and Golden Reward sites than at the reference sites. Periphyton metrics and habitat characteristics at the Whitetail Creek reference site indicate this site appeared stressed from sedimentation in 2012. Factors such as low and intermittent flows appear to limit the composition of the aquatic communities at the sites Lost Camp Gulch and Cleopatra Creek.