Predictive Modeling of Selenium Accumulation in Brine Shrimp in Saline Environments Earl R. Byron,*y Harry M. Ohlendorf,y Aaron Redman,z William J. Adams,§ Brad Marden,k Martin Grosell,# and Marjorie L. Brooksyy yCH2M Hill, 2485 Natomas Park Drive, Suite 600, Sacramento, California 95833, USA zHydroqual, Providence, Utah, USA §Rio Tinto, Murray, Utah, USA kParliament Fisheries, Ogden, Utah, USA #University of Miami, Miami, Florida, USA yyDepartment of Zoology, Southern Illinois University, Carbondale, Illinois, USA (Submitted 6 September 2010; Returned for Revision 11 October 2010; Accepted 5 January 2011) ABSTRACT Great Salt Lake, Utah, is a large, terminal, hypersaline lake consisting of a northern more saline arm and a southern arm that is less saline. The southern arm supports a seasonally abundant fauna of low diversity consisting of brine shrimp (Artemia franciscana), 7 species of brine flies, and multiple species of algae. Although fish cannot survive in the main body of the lake, the lake is highly productive, and brine shrimp and brine fly populations support large numbers of migratory waterfowl and shorebirds, as well as resident waterfowl, shorebirds, and gulls. Selenium and other trace elements, metals, and nutrients are contaminants of concern for the lake because of their concentrations in municipal and industrial outfalls and runoff from local agriculture and the large urban area of Salt Lake City. As a consequence, the State of Utah recently recommended water quality standards for Se for the southern arm of Great Salt Lake based on exposure and risk to birds. The tissue-based recommendations (as measured in bird eggs) were based on the understanding that Se toxicity is predominately expressed through dietary exposure, and that the breeding shorebirds, waterfowl, and gulls of the lake are the receptors of most concern. The bird egg– based recommended standards for Se require a model to link bird egg Se concentrations to their dietary concentrations and water column values. This study analyzes available brine shrimp tissue Se data from a variety of sources, along with waterborne and water particulate (potential brine shrimp diet) Se concentrations, in an attempt to develop a model to predict brine shrimp Se concentrations from the Se concentrations in surrounding water. The model can serve as a tool for linking the tissue-based water quality standards of a key dietary item to waterborne concentrations. The results were compared to other laboratory and field-based models to predict brine shrimp tissue Se concentrations from ambient water and their diet. No significant relationships were found between brine shrimp and their dietary Se, as measured by seston concentrations. The final linear and piecewise regression models showed significant positive relationships between waterborne and brine shrimp tissue Se concentrations but with a very weak predictive ability for waterborne concentrations <10 mg/L. Integr Environ Assess Manag 2011;7:478–482. ß 2011 SETAC Keywords: Selenium Brine shrimp Bioaccumulation Great Salt Lake INTRODUCTION Great Salt Lake, Utah, is a large, terminal, hypersaline lake consisting of a northern more saline arm and a southern arm that is less saline (although currently between 85 and 165 g/L total dissolved solids) because it receives most of the freshwater drainage entering the lake (Gwynn 2002; Brix et al. 2004). The 2 arms are incompletely separated by a Southern Pacific Railroad causeway and embedded culverts. The southern arm supports a seasonally abundant community of low diversity consisting of brine shrimp (Artemia francis- cana), 7 species of brine flies (Ephydra sp.), and multiple species of algae dominated by 2 species of the green alga, Dunaliella (Marden 2008). Although fish can not survive in the main body of the lake, the lake is highly productive and brine shrimp and brine fly populations support large numbers of migratory waterfowl and shorebirds, as well as resident waterfowl, shorebirds, and gulls. In addition, the harvest of brine shrimp cysts (encysted brine shrimp embryos) for aquaculture is a multimillion dollar industry (Kuehn 2002; Marden 2008). Selenium and other trace elements, metals, and nutrients are contaminants of concern for Great Salt Lake because of inputs from municipal and industrial point sources and runoff from local agriculture and the large urban area of Salt Lake City, which borders the southeastern end of the lake. Generic, national recommended water quality criteria (USEPA 2009) have not been applied to the hypersaline waters of the lake, although recommendations for the possible development of site-specific standards for Se were proposed in the past (Brix et al. 2004). Driven by ongoing concerns related to increasing discharges of Se to the lake from mining, agriculture, and urban sources, the State of Utah recently recommended water quality stand- ards for Se for the southern arm of Great Salt Lake (Utah 2010) based on exposure and risk to birds. The tissue-based recommendations (as measured in bird eggs) are based on the understanding that Se toxicity occurs predominately through dietary exposure, and that the breeding shorebirds, waterfowl, Integrated Environmental Assessment and Management — Volume 7, Number 3—pp. 478–482 478 ß 2011 SETAC * To whom correspondence may be addressed: ebyron@ch2m.com Published online 31 January 2011 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/ieam.179 Case Study