Trace-Element Accumulation by Hygrohypnum Ochraceum in the Upper Rio Grande Basin, Colorado and New Mexico, Usa

Abstract

Abstract-Accumulation of 12 trace elements by transplanted aquatic bryophytes (Hygrohypnum ochraceum) was determined at 13 sites in the Rio Grande and tributary streams in southern Colorado and northern New Mexico as part of the U.S. Geological Survey's National Water-Quality Assessment Program. The purposes of the study were to determine the spatial distribution of trace elements in relation to land-use practices in the upper Rio Grande Basin, compare accumulation rates of metals in bryophytes at sites contaminated by trace elements, and evaluate transplanted aquatic bryophytes as a tool for examining the bioavailability of trace elements in relation to concentrations in water and bed sediment.Concentrations of Cd, Cu, Pb, and Zn in bryophytes, water, and bed sediment were significantly higher at sites that receive drainage from mining areas than at sites near agricultural or urban activities. Concentrations of most trace elements were lower in a tributary stream below an urban source than at sites near mining or agricultural use. Concentrations of Cu and Zn in bryophytes correlated with concentrations in water and bed sediment. In addition, bryophyte concentrations of As, Cd, and Pb correlated with concentrations in bed sediment.Transplanted bryophytes can provide an indication of bioavailability. Rates of accumulation were related to the magnitude of ambient trace-element concentrations; maximal uptake occurred during the first 10 d of exposure. Trace-element concentrations in transplanted bryophytes could potentially be used to predict water and sediment concentrations that represent an integration of conditions over short to intermediate lengths of time, rather than instantaneous conditions as measured using water samples.

Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental contaminants and their effects on fish in the Rio Grande Basin

“…1), has been contaminated by molybdenum mine tailings. Elevated concentrations of Cd, Pb, and Cu in sediments and Se, Cd, As, and Zn in fish and other biota in the Red River have been documented (Carter and Porter, 1997;Roy and others, 1992). Some gold and silver mining also occurred historically in Trans-Pecos Texas.…”

“…The NASQAN program periodically collected water samples, which were analyzed for a large number of dissolved and suspended constituents including pesticides, nutrients, and trace elements, at six RGB sites sampled in our study (Stations 511-516; Table 1) beginning in 1996 (Wells and Reutter, 1996). In the early 1990s, the NAWQA pro gram studied the upper RGB from its headwaters to El Paso, Texas; the study included the measurement of waterborne pesticides and metals as well as contaminant concentrations in sediments, fish livers (inorganic contaminants), whole fish (organochlorine chemicals) (Carter and Anderholm, 1997;Levings and others, 1998), and bryophytes (Carter and Porter, 1997). White and others (1983) investigated toxaphene and p,p'-DDE concentrations in RGB fish and avian wildlife in the late 1970s; this study included collection sites at Alamosa, Colorado (Station 64), Falcon and Amistad International Res ervoirs (Stations 513 and 514), and the AC at Harlingen, Texas (Station 511).…”

“…In Colorado, historical silver mining and related activities in the Creede Mining District polluted two RG tributaries, Willow Creek and the Alamosa River. Willow Creek has been contaminated by a variety of elemental contaminants (Carter and Porter, 1997;Levings and others, 1998) and has been listed as an impaired waterway due to low pH (Colorado Department of Public Health and Environment (CDPHE), Water Quality Control Division, 2002). The RG from its confluence with Willow Creek to Wagon Gap [about 8 mi (13 km )] is also listed as impaired due to elevated Zn, and from Willow Creek to the City of Del Norte [about 30 mi (48 km)] it is considered impaired due to elevated cadmium (Cd).…”

Relations of benthic macroinvertebrates to concentrations of trace elements in water, streambed sediments, and transplanted bryophytes and stream habitat conditions in nonmining and mining areas of the upper Colorado River basin, Colorado, 1995-98

“…To evaluate environmental variability, three bags per site were placed in riffle areas in the stream reach, including the Nate Creek ditch site, for a 15-day exposure period. According to Carter and Porter (1997), the maximum rate of uptake occurs during the first 10-day exposure for most trace elements, and significant differences in bryophyte trace-element concentrations can be found after as few as 10 days of exposure to ambient conditions. Bags were collected and bryophytes were removed and washed again, as described previously, and analyzed for trace elements (Nelson and Camp-bell, 1995;Nelson, 1996).…”

Summary of information on synthetic organic compounds and trace elements in tissue of aquatic biota, Clark Fork-Pend Oreille and Spokane River basins, Montana, Idaho, and Washington, 1974-96

“…The use of aquatic bryophytes (mosses) as bioindicators could provide information about the occurrence and bioavailability of trace elements around mining areas. Carter and Porter (1997) found that bryophytes were useful for discriminating stream sites contaminated with arsenic, cadmium, copper, lead, manganese, molybdenum, and zinc, and that they can integrate temporal variations in concentration.…”