Station II 



Batis maritima — Batis maritima percent cover at 

 Station II exhibited a different pattern than the other 

 two stations (Figure 6-8a). Cover of this species 

 peaked at 16% in November 1995 but then decreased 

 by 11% from November 1995 to May 1996. The 

 decrease began following three months (August 1995 

 through November 1995) during which about 42.8 cm 

 (17 inches) of rain fell. The drop in percent cover was 

 Kkely the result of direct precipitation, since similar but 

 smaller scale declines were seen at the other two 

 stations during this time. On November 7, 1995, all 

 three transects were flooded with 15.1 to 25.2 cm (6 to 

 10 inches) of water as a result of about 25.2 cm 

 (10 inches) of rain that fell in one day (October 26, 

 1995) approximately two weeks earlier. 



Batis maritima cover increased 9.5% from May to 

 November 1996. During this rime, a positive net flow 

 of over 308 10' m' (250 acre-ft) passed dirough 

 Nueces Overflow Channel (Events 11 through 14). 

 However, the diverted water was derived from 

 primarily small exchanges, and the Rincon Overflow 

 Channel was not activated. Furthermore, the majority 

 of the flow was during late October, which was not 

 sufficient to account for significant changes in percent 

 cover. Therefore, the observed increase was more 

 likely correlated to precipitation which occurred during 

 the late summer (i?.^., > 22.7 cm (9 inches) fell during 

 August and September). Cover remained near 

 constant for close to a year, then declined by 9.5% 

 firom August 1997 to June 1998. The decline occurred 

 immediately following the July 1997 event. During the 

 period between the June and August sampling dates, a 

 total of 9.0 cm (3.55 inches) of rain fell and a positive 

 net flow of 1,902 10' m' (1,542 acre-ft) passed into 

 Rincon Bayou. During Event 16, Rincon Overflow 

 Channel was activated, and it was suspected that this 

 was also the case with Event 17 (Chapter 3). 



Afterwards, cover leveled off and remained relatively 

 stable, until it began to gradually increase in December 

 1999 near the end of the study period. It should be 

 noted that the major hydrographic events in October 

 1998 and the precipitation direcdy falling on the station 

 during the spring and summer of 1999 (> 35 cm, or 



14 inches) had no effect on cover. This was most 

 likely a result of cover already being relatively low. An 

 increase in cover began following the September 1999 

 event, which deposited 15 cm (6 inches) of rain in one 

 day and had a positive net inflow through the Nueces 

 Overflow Channel of 1,012 10' m' (820 acre-ft) 

 between the September and December sampling dates 

 in 1999. During this period. Event 36 was also 

 suspected to have activated the Rincon Overflow 

 Channel (Chapter 3). 



Borrichia frutescens - A correlation between Borricbia 

 frutescens and Batis maritima was not seen at Station II 

 (r^ = 0.16). At Station II, B. frutescens cover declined 

 slighdy (5%) from the beginning of the study period to 

 the end (Figure 6-8b). 



Distichlis spicata - At Station II, Distichlis spicata 

 cover decreased gradually from May 1996 (14%) to 

 June 1997 (< 1%) and remained relatively low (2 to 

 5%) for the remainder of the study period 

 (Figure 6-8c). Cover fell to almost 0% following the 

 October 1998 composite hydrographic event but 

 increased in cover from 0% to 10% from December 

 1998 to December 1999. 



Monanthodoe littoralis - At Station II, Monanthocloe 

 littoralis cover remained relatively constant between 

 June 1995 and November 1996 (about 20%) 

 (Figure 6-8d). Cover declined sharply from November 

 1996 (17%) to February 1997 (6%). Cover increased 

 (12%) until December 1998 when it dropped 

 continuously to 3% in September 1999. The decrease 

 during the October 1998 event, and the lowest cover 

 recorded (September 1999) and coincided with the 

 flooding of the transect after a tidal surge which 

 occurred due to the passing of Hurricane Bret. This 

 decrease corresponded to decreases seen in M. littoralis 

 cover at the Reference Station. Cover then increased 

 by 5% in December 1999, after Event 36, which 

 activated the Rincon Overflow Channel and flooded 

 the transect with fresh water. 



Salicornia bigelovii — The most significant changes 

 in percent cover were seen in the annual succulent 

 Salicornia bigelovii At Station II, the species was 

 basically non-existent until June 1998, when cover 



Chapter Six ♦ 6-19 



