| dc.description.abstract | During the growing seasons of 1999 and 2000 five experiments were performed to
test growth of the seagrass Halodule beaudettei (shoal-grass) in nursery pond conditions.
Sediment oxidation state, sediment source, container type, flow regime, and light
transmittance were tested to improve nursery pond cultivation techniques and to test
assumptions about the decline of seagrasses in Galveston Bay, Texas. Oxidized and reduced
sediments exhibited no statistical difference as mean percent change in the number of stems
of shoal-grass, after 47 days. Sediment from three source locations, West Bay, East Beach
Lagoons, and the experimental pond bottoms, showed no significant difference in the mean
percent change in the number of stems of shoal-grass at 48 and 95 days. A statistical
difference was seen in the container type experiment, trays versus pots, at 48 days where
shoal-grass had double the number of stems produced in trays; however no significant
difference was found at 93 days. A significant difference was found in the flow regime
experiment, no-flow versus flow, at 47 days in the mean percent change of shoal-grass with
double the number of stems produced in the flow regime. Significant differences were
observed between the low light and high light treatments with shoal-grass, widgeongrass (Ruppia maritima), star grass (Halophila engelmannii), and turtlegrass (Thalassia
testudinum), with survival and growth occurring in the high light treatment and decline and
death occurring in the low light treatment. The importance of reduced sediment may have
been overstated in the past as sediment reduction occurs rapidly with submersion. It appears
that while West Bay sediment did not have a deleterious effect on shoal-grass, West Bay
simulated light conditions did. Container type seems to be important at first but not so
much in the long term. Some flow, water movement, or current appears to be important. | en |
