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Long-Term Study Of Benthic Communities On The Continental Shelf Off Cameron, Louisiana: A Review Of Brine Effects And Hypoxia, Gary R. Gaston, Kenneth A. Edds
Long-Term Study Of Benthic Communities On The Continental Shelf Off Cameron, Louisiana: A Review Of Brine Effects And Hypoxia, Gary R. Gaston, Kenneth A. Edds
Gulf and Caribbean Research
A long-term data set compiled from our studies and a variety of investigations was analyzed to determine the effects of nine years of discharged brine (concentrated salt water) on benthic organisms surrounding a brine diffuser off Cameron, Louisiana (USA). These investigations began three months before brine discharge was initiated in 1981. A preliminary summary by Giammona and Darnell (1990) relied on just three years of discharge data and gave misleading reports of brine impacts.
Brine effects over the nine years of study were minimal, in part because the fine sediments of the study area were numerically dominated by opportunistic species. …
Behavioral Ecology Of Two Teal Species (Blue-Winged Teal, Anas Discors, And Green-Winged Teal, Anas Crecca) Overwintering In Marshes Of Coastal Louisiana, Usa, Gary R. Gaston, Jeanne C. Nasci
Behavioral Ecology Of Two Teal Species (Blue-Winged Teal, Anas Discors, And Green-Winged Teal, Anas Crecca) Overwintering In Marshes Of Coastal Louisiana, Usa, Gary R. Gaston, Jeanne C. Nasci
Gulf and Caribbean Research
Feeding and other dominant activities of Blue-winged Teal (BWT, Anas discors) and Green-winged Teal (GWT, Anas crecca) were compared from October 1987 to March 1988 in southwestern Louisiana, USA. Three observation towers were constructed near similar intermediate marsh habitats in areas where BWT and GWT concentrated for feeding. These observation towers allowed activities of the two species to be compared throughout the nonbreeding season. Although BWT and GWT often fed together, time spent in various activities differed. Feeding was the most frequent activity of both BWT(64.5%) and GWT (55.3%), but BWT spent more time feeding (P < 0.01) and alert (P < 0.05), but spent less (P < 0.01) time resting than GWT. Within each species there were differences in activity budgets among daily time blocks and among months, but few differences among the three habitats studied. Temperature and light intensity were correlated with resting (+), feeding (-), locomotion (-), and preening (+). Daily and monthly activity budgets of BWT and GWT were similar, as were ingested foods, suggesting that these two species used the study areas primarily for foraging, and left the areas for other activities. Predation and diminished resources during late winter may have affected activities of BWT and GWT as well.
Historic Trends In The Secchi Disk Transparency Of Lake Pontchartrain, J.C. Francis, M.A. Poirrier, D.E. Barbe, V. Wijesundera, M.M. Mulino
Historic Trends In The Secchi Disk Transparency Of Lake Pontchartrain, J.C. Francis, M.A. Poirrier, D.E. Barbe, V. Wijesundera, M.M. Mulino
Gulf and Caribbean Research
A major environmental concern about Lake Pontchartrain is an assumed long-term increase in turbidity based on Secchi disk transparency observations. Regression of the available data on Secchi disk transparency versus time (1953 through 1990) reveals a statistically significant decrease in transparency of about 40%. However, the data set is biased in that it does not adequately represent the seasonal effects of salinity and wind speed. Two analytical procedures were undertaken to determine the extent to which the apparent long-term decrease in transparency was dependent on the seasonal bias. One procedure involved seasonal adjustment of the data for the effects of …