A hydrographic survey of the Galveston Bay system, Texas, 1963-66

Water temp and salinity data, taken during 1963-66, and dissolved organic nitrogen, total phosphorus, and dissolved O sub(2) data taken during 1964-66 from Galveston Bay, Texas were analyzed by area and habitat (depth strata). Temps ranged from 0.4 degree C to 36.0 degree C during the study and averaged slightly higher in the peripheral than the open-water or channel habitat, Between years, water temp averages varied as much as 7 degree C between coldest months, and 3 degree C between warmest months. Salinities ranged from 0.1 to 36.6ppt and increased from the peripheral to the channel habitats, Gradients of increasing salinities occurred from east to west and north to south in the system. Salinities decreased from 1963 to 1966 with the smallest difference between years occurring in March and April and the greatest difference between years in May and June. Minimum salinities always occurred during periods of high stream discharge in the winter and spring and maximum salinities during periods of low stream discharge in the late summer and fall. Dissolved organic nitrogen concs ranged from 1 to 300 mu g at/l. Nitrogen concs decreased from the upper to the lower bays. Nitrogen values were similar seasonally and between years. High river flow was correlated with an increase of nitrogen in the lower bay areas. Total phosphorus concs ranged from 0.1 to 47.5 mu g at/l. Phosphorus concs diminished from upper to lower bays, and from west to east in the system. Seasonal concs of phosphorus were similar from 1964 through the spring of 1966. In June 1966, concs increased, reaching an all years' maximum in the fall. River discharge was not correlated to phosphorus concs, although nitrogen and phosphorus values were positively correlated. Dissolved O sub(2) concs ranged from 0.2 to 13.6 ml/l. Lowest O sub(2) concs were in the channels and highest and similar concs were in the peripheral and openwater habitats. O sub(2) values were inversely correlated with water temps