Biologists assessing Hurricane Harvey impacts to oysters

HOUSTON – The Texas Parks and Wildlife Department (TPWD) has completed oyster restoration efforts at four areas in Galveston Bay to enhance public oyster reefs and benefit recreational anglers.

The current restoration work began in September 2016. This year TPWD is using cultch mounds to make the reefs more resilient to storm surges and commercial fishing gear. By the end of September 2017 fresh cultch was planted over 41.5 acres. This work adds to the TPWD oyster restoration efforts begun in 2008, bringing the total oyster reef restored through cultch planting to over 480 acres.

Oyster restoration locations include Todd’s Dump Reef, South Redfish Reef and two locations on the north side of the Texas City Dike. About 9,670 cubic yards (11,604 tons) of reef building materials (known as cultch) was placed at the four locations.

The Texas City Dike sites specifically include Mosquito Island, a sand/shell bar extending north from the Dike just east of the hurricane protection levee, and an area adjacent to the Dike’s new fishing pier which is located approximately 1.75 miles east of the levee.

The current work, which will cost about $1.1 million, is being funded through a variety of sources including the Texas General Land Office’s Coastal Impact Assessment Program, TPWD’s Oyster Shell Recovery Fund and Texas City government funds. The TPWD Oyster Shell Recovery Fund is made up of proceeds from a fee attached to every sack of oysters harvested in Texas. This year marks the first time these funds have been used for oyster reef restoration. The $200,000 donation from Texas City was generated by Texas City Dike entrance fees.

Besides the economic benefits for commercial and recreational fishermen, restoring oyster reefs has environmental benefits. These benefits include water filtration and provision of food and habitat for numerous fish and invertebrates.

In addition to restoration efforts, TPWD is assessing impacts to oysters from Hurricane Harvey. Over 30 inches of rain fell on the Houston metropolitan area, and the associated runoff dropped salinities to near 0, resulting in wide-spread mortality of oysters in Galveston Bay. Shell from these dead oysters along with the cultch provided by this restoration project will be critical for recovery as larval oysters must have a clean, hard surface to attach to and grow.

Research shows prolonged low-salinity events can cause oysters to die, but it can also benefit the fishery by reducing the presence of pathogens and predators that threaten oyster populations.

“The full impact of Hurricane Harvey on Texas oyster populations will depend on factors such as how long salinities level remain low, the quantity and quality of the remaining oyster habitat and the ability of the surviving oysters to spawn before water temperatures drop,” said Lance Robinson, Coastal Fisheries Division Deputy Director. “The TPWD Coastal Fisheries Division continues to assess the impact on oysters and will have a better understanding of the how this resource is impacted in the coming months.”

For more information about oyster restoration efforts, contact Bill Rodney, (281) 534-0127, Bill.Rodney@tpwd.texas.gov, or Emma Clarkson, (361) 825-3380 Emma.Clarkson@tpwd.texas.gov.