Chemical and Physical Parameters at a Shallow-Littoral Site and a Pelagial Site on Lake Ray Roberts, Denton County, Texas (United States)

This research directly supported the author’s thesis work in partial fulfilment of Master of Science in biology from the University of North Texas (United States) from August 1996 to September 1997. Two sites at Lake Ray Roberts, Denton County, Texas (United States) were examined and contrasted for productivity. The site located in the pelagic zone exhibited a slight, thermal gradient with no stratification, and a slightly stratified clinograde oxygen profile which is typical for summer-stratified eutrophic lakes. The site located in the shallow, littoral zone exhibited high, increasing turbidity with depth, marked by shallow light attenuation through the water column. Temperature was constant at every depth in the littoral site, with a slight, clinograde oxygen profile, typical for shallow, littoral areas subject to wind-induced mixing. Volume estimations of chlorophyll-a shows a strong presence in the euphotic zone, indicating photosynthesis occurs until approximately 2.2 m below the surface. The shallow, littoral site showed the basic signs of higher productivity than the open, pelagic site.