In mountainous landscapes with high climatic and geomorphic variability, how do rural land uses and exurbanization alter hydrology and water quality? We evaluated effects of rural land use and exurbanization on streamflows, suspended sediment concentrations and loads, specific conductance, and summer water temperatures in 12 streams and rivers within the Upper Little Tennessee River basin in the southern Appalachian Mountains. Eleven streams featured low levels of development (>61% forest cover) but differed in land use patterning, basin size, annual precipitation, and watershed morphology. One urban stream, located within the largest town in the basin, provided the high development comparative endpoint. Even low levels of rural development and exurbanization were associated with substantial increases in suspended sediment concentrations, sediment loads, and summer stream temperature daily maxima and diurnal variation. Observed summer temperature increases were much larger than would be expected due to global climate change over the next century. Specific conductance was idiosyncratic among the smaller streams. These water quality changes were not accompanied by streamflow changes that were discernible amid the high natural variation in precipitation and geomorphology. The water quality findings suggest the need for applying the best management practices, including riparian buffers, to even low levels of rural development.
The objective of our study was to estimate total bycatch and mortality of shortnose sturgeon Acipenser brevirostrum in the anchored‐gill‐net portion of the commercial fishery for American shad Alosa sapidissima in the Altamaha River, Georgia, from 2007 to 2009. We conducted on‐the‐water counts of commercial nets to estimate total fishing effort. Catch per unit effort was estimated from log books and direct observations of net retrievals by randomly selected commercial fishermen. During the 3 years of the study, the total estimated bycatch of shortnose sturgeon was 71, 53, and 498 fish, respectively. Recent studies have estimated the abundance of adult shortnose sturgeon in the Altamaha River to be approximately 1,800 individuals. Our study showed that catch per unit effort was highest during January and February of 2009 in upriver areas where previous research had identified several spawning locations. Our results also showed that the mortality of captured shortnose sturgeon was low in all 3 years (<8%), although we did not assess postrelease survival. Although closure of critical habitats may or may not be an important component of protecting shortnose sturgeon spawning habitat, our results suggest that on the Altamaha River, delaying the opening of commercial American shad fishing in the upper river until after 1 March would almost completely eliminate bycatch of migrating shortnose sturgeon and result in a minor reduction in American shad landings.Received February 16, 2011; accepted February 16, 2012
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