Petri dishes were then placed on a metal tray and covered with 
black plastic to ensure darkness. All seeds were germinated in the 
dark with alternating thermal periods of 20° Celsius (16 hours) and 
30° Celsius (8 hours) in a consol germinator (Mooring, Cooper, and 
Seneca, 1971). The following variables were tested: (a) dry seeds 
in glumes collected 10 November 1973, (b) wet seeds in glumes collected 
10 November 1973, (c) dry caryopses (no glumes) collected 10 November 
1973, (d) wet seeds in glumes collected 1 December 1973, and (e) wet 
seeds with gibberellic acid collected 10 November 1973. 
A total of 33 soil samples (11 at each location) were collected 
20 June 1974 at the shoreline, 50 and 150 feet from the shore. These 
samples were placed in plastic bags for transport to the laboratory. 
The soil was spread on shallow trays and observations for seed germina- 
tion were made for 3 weeks. Soil was moistened as necessary with 
distilled water. 
Four soil samples from the upper and middle zones and three samples 
from the lower zone were collected in July 1974 and placed in shallow 
pans. Twenty-five seeds of smooth cordgrass were placed in each sample 
and the soil was moistened with seawater as necessary. Seed germination 
was recorded for a 3-week period. 
Smooth cordgrass seeds were planted 23 March 1974 in a 10- by 12- 
foot plot in a wave-protected area. Seeds were mixed with substrate 
by hand. 
An experiment to compare survival of different transplant heights 
(4 to 15, 16 to 30, and over 30 inches) for black mangrove (Avicennia 
germinans) was planted 17 October 1974 (Fig. 8). Three replications 
(Blocks VI, VII, and VIII) were established. Blocks were designed to 
allow two additional monthly plantings of each height classes. 
Block IX was designed to test the establishment and growth of 
plants when protected from wave action. A temporary wave-stilling 
device (Fig. 9) was constructed from baled hay, wire net, steel cable, 
and pipe. The maximum height of the device was about 36 inches. 
Twelve rows of black mangrove, saltgrass (Dtsttchlts spicata), 
needlegrass (Juneus roemertanus), common reed, smooth cordgrass, and 
big cordgrass were planted behind the wave-stilling device. 
IV. WATER SALINITY 
Water salinity was variable at all study locations during 1974 
(Fig. 10). Salinity at Block I was affected by influxes of freshwater 
from Oyster Bayou. Thus, the biweekly salinity values at this location 
were generally lower than for the others. An exception occurred in 
July, a period of low precipitation, when salinity was about 15,700 
ppm. Lowest values were during the winter and following a heavy pre- 
cipitation period in May. Salinity then was generally below 2,500 ppm. 
22 
