Cedar Bayou

About this Project

The tidal inlets that flow between our bays and estuaries and the Gulf of Mexico are essential for the survival of many commercially and recreationally significant marine species, including Red Drum, Southern Flounder, and Blue Crab, which rely on these passages to spawn and then grow in fertile sheltered waters. The Center for Sportfish Science and Conservation (CSSC) is studying how reopening Cedar Bayou, a natural tidal inlet between Matagora and San Jose islands that has been closed since 1979, impacts the population densities of juvenile fish within Mesquite Bay’s seagrass nursery habitat. Quantifying the relationship between tidal inlets and juvenile fish populations is crucial to sustainable fish management along the Texas coast.

Cedar Bayou was re-opened in September 2014. Researchers at the CSSC gathered baseline data on the environment adjacent to the waterway for two years prior to its opening, and monitored seasonal changes in the abundance of fish and crustaceans for a year. The resulting analysis found that densities of sportfish and forage species increased significantly following the reopening of Cedar Bayou, including Red Drum, Atlantic Croaker, Penaeid Shrimp, and Blue Crab. The increases in these species were so remarkable that the overall species assemblage in Mesquite Bay changed statistically following reopening. In addition, acoustic tracking data strongly indicated that adult Red Drum used the freshly opened Cedar Bayou inlet to migrate to spawning grounds within months of reopening. Since the 2014 reopening, Hurricane Harvey impacted the inlet’s tidal exchange and caused a dramatic reduction in flow. However, work to again open Cedar Bayou is scheduled to begin in May 2021.

Research Objectives

Establish pre-opening baseline data on nekton assemblages and abundance in habitats adjacent to Cedar Bayou seasonally two years prior to the opening of the inlet.
Monitor seasonal changes to fish and crustacean abundance and recruitment for one year after Cedar Bayou has been opened.
Determine if adult Red Drum are using Cedar Bayou as a migration route between the estuarine wetlands and breeding grounds in the Gulf of Mexico using acoustic telemetry

(cover photo courtesy of L. Laskowski)

Publications

Hall, Q.A., J.M. Curtis, J. Williams, G.W. Stunz. 2019. The importance of newly-opened tidal inlets as spawning corridors for adult Red Drum (Sciaenops ocellatus). Fisheries Research 212: 48-55. doi:10.1016/j.fishres.2018.12.002.

PDF

Hall, Q.A., M.M. Reese Robillard, J.A. Williams, M.J. Ajemian, and G.W. Stunz. 2016. Reopening of a remote tidal inlet increases recruitment of estuarine-dependent nekton. Estuaries and Coasts 39:1769-1784. doi: 10.1007/s12237-016-0111-3

PDF

After nearly 30 years of planning and 4 months of dredging, Cedar Bayou was officially reopened in September 2014. This is the first water to flow through what eventually became the main channel.

Map of the study area where samples have been collected since 2012

No juvenile Red Drum were found near Cedar Bayou in the two years of pre-opening samples. These juveniles were found near the bayward mouth of the inlet less than a month after it reopened.

Juvenile fish, shrimp, and crabs are collected using a special net called an epibenthic sled.

Rinsing the cod end of an epibenthic sled

Sampling small nekton at Cedar Bayou tidal inlet. We strain the sample using small nets before they are preserved and brought back to the lab.

These juvenile Southern Flounder found during the post-opening surveys suggest that flatfish species are also taking advantage of Cedar Bayou's reopening.

All organisms collected are identified, counted and measured by hand. So far our team has counted nearly 160,000 organisms!

CSSC staff at the reopening of Cedar Bayou