Evaluating Reproductive Timing, Population Genetics, and Disease Load in Texas Oysters

The Texas oyster industry is in a state of flux. As the productivity of the wild fishery declines due to
habitat loss, exploitation, and a changing climate, there is increasing interest in activities to restore
habitat and relieve the pressure on wild populations, namely reef restoration and commercial
aquaculture. Both reef restoration and aquaculture of oysters require an in-depth understanding of the
state of wild populations throughout the year.

For restoration purposes, an understanding of population structure, levels of genetic diversity, disease loads, and timing of reproduction are necessary to match wild and augmented oysters and to maximize the effectiveness of habitat restoration. For commercial aquaculture, this same information helps to minimize aquaculture-wild interactions and inform farm stocking decisions, broodstock sourcing, and farm-siting policies. Understanding reproductive timing of wild oysters is especially important, as it is essential for consistent and reliable hatchery-based production of eyed-larvae and spat, an activity that is central to both activities.

A two-year project is proposed to fill existing knowledge gaps for oyster populations in Texas, which can
lead to advancement of both restoration and oyster aquaculture efforts.

The proposed project consists of two components:

1. A field-monitoring trial of wild oysters in eight Texas bays to collect critical data
   regarding population structure, genetic diversity, reproductive status, and Dermo load over time
2. A conditioning trial to develop a protocol for off-season conditioning of North Texas oysters to promote
   year-round hatchery production,
3. Larval and spat growth trials to establish best practices for maximizing efficiency of Texas hatcheries. The Texas A&M AgriLife Research Mariculture Laboratory at Flour Bluff in Corpus Christi has the facilities and expertise needed to begin the research.