Drought and salinity in brackish marshes

Since January 2009, we have been monitoring many biotic and abiotic characteristics of restored and reference brackish marshes near Port Arthur, Texas. For the first 2.5 years, the water salinity was always less than 15 ppt, but the exceptional drought last summer dramatically changed that. Salinities in June 2011 were near 25 ppt, nearly five times greater than typical June levels of about 5 ppt. This huge increase corresponded with the disappearance of most of the aquatic fish and invertebrates, and replacement with a few individuals of some marine species like white shrimp (Litopenaeus setiferus).

2012 has brought the return of more typical salinity levels. Will the fauna recover as well? We'll be monitoring that over the summer, so stay tuned...

Water column salinity from January 2009 through April 2012 at a brackish marsh near Port Arthur and Sabine Lake, Texas. We monitored four restored areas (excavated, filled, pumped, and terrace), and one reference area. All areas were similar to each other but showed very strong responses to the exceptional drought in Texas in summer 2011 (see map below).

Map showing drought levels in the U.S. on June 21, 2011 (see http://droughtmonitor.unl.edu/archive.html for archived maps). The darkest red color covering most of Texas represents the highest possible level of drought - "Exceptional Drought." In Texas, this condition persisted for months.