Benjamin M. Jones Krista K. Bartz Daniel Young Christian E. Zimmerman Carson Baughman 2015 <p><span>Lake Clark is an important nursery lake for sockeye salmon (</span><i>Oncorhynchus nerka</i><span>) in the headwaters of Bristol Bay, Alaska, the most productive wild salmon fishery in the world. Reductions in water clarity within Alaska lake systems as a result of increased glacial runoff have been shown to reduce salmon production via reduced abundance of zooplankton and macroinvertebrates. In this study, we reconstruct long-term, lake-wide water clarity for Lake Clark using the Landsat TM and ETM+ surface reflectance products (1985–2014) and</span><i><span>&nbsp;</span>in situ</i><span>water clarity data collected between 2009 and 2013. Analysis of a Landsat scene acquired in 2009, coincident with</span><i><span>&nbsp;</span>in situ<span>&nbsp;</span></i><span>measurements in the lake, and uncertainty analysis with four scenes acquired within two weeks of field data collection showed that Band 3 surface reflectance was the best indicator of turbidity (</span><i>r²<span>&nbsp;</span></i><span>= 0.55,</span><i>RMSE<span>&nbsp;</span></i><span>&lt;&lt; 0.01). We then processed 151 (98 partial- and 53 whole-lake) Landsat scenes using this relation and detected no significant long-term trend in mean turbidity for Lake Clark between 1991 and 2014. We did, however, detect interannual variation that exhibited a non-significant (</span><i>r</i>^{2<span>&nbsp;</span>}<span>= 0.20) but positive correlation (</span><i>r</i>^{<span>&nbsp;</span>}<span>= 0.20) with regional mean summer air temperature and found the month of May exhibited a significant positive trend (</span><i>r²<span>&nbsp;</span></i><span>= 0.68,<span>&nbsp;</span></span><i>p<span>&nbsp;</span></i><span>= 0.02) in turbidity between 2000 and 2014. This study demonstrates the utility of hindcasting turbidity in a glacially influenced lake using the Landsat surface reflectance products. It may also help land and resource managers reconstruct turbidity records for lakes that lack</span><i><span>&nbsp;</span>in situ</i><span><span>&nbsp;</span>monitoring, and may be useful in predicting future water clarity conditions based on projected climate scenarios.</span></p> application/pdf 10.3390/rs71013692 en MDPI Reconstructing turbidity in a glacially influenced lake using the Landsat TM and ETM+ surface reflectance climate data record archive, Lake Clark, Alaska article