HOUSTON – Texas Parks and Wildlife Department (TPWD) has hired Apollo Environmental Strategies of Beaumont to distribute more than 70,000 cubic yards of oyster reef building materials (called “cultch”) over six natural, publicly owned oyster reefs in Galveston Bay.
This work is part of ongoing efforts to restore oyster reef habitats which were severely impacted by Hurricane Ike-induced sedimentation in September 2008. Starting in August and finishing in October 2011, cultch materials (river rock and/or crushed limestone) will be spread over 178 acres of public oyster reef.
These “cultch plantings” will attract planktonic oyster larvae that will settle on the cultch and grow into adult oysters thus helping to re-establish previously productive oyster reefs. Oyster reefs selected for cultch plantings are: Frenchy’s Reef, Middle Reef and Hanna Reef in East Bay and Dollar Reef, East Redfish Reef and South Redfish Reef in Galveston Bay. Reefs were selected for cultch plantings based on the depth of overlying sediments, water depth, and proximity to oil and gas pipelines and private oyster leases.
This work will cost $3.8 million, primarily funded through federal fisheries disaster grants awarded to TPWD to address impacts from hurricanes Rita and Ike. After Hurricane Ike struck the Texas coast in September 2008, TPWD side scan sonar surveys found that about 50 percent of oyster reef habitats in Galveston Bay and about 80 percent of oyster reef habitats in East Bay were covered in sediment deposited by the hurricane’s storm surge.
In addition to benefiting the commercial oyster industry, the restoration will provide numerous ecological benefits. One of the primary ecological functions of oyster reefs is water filtration. Oysters feed by filtering tiny plants known as phytoplankton from the water and a single oyster can filter up to 50 gallons of water in a day. This filter feeding also removes silt and some contaminants from the water, thus making oyster reefs nature’s bio-filters. At a minimum density of 10 oysters per square meter, the restored 178 acres of oyster habitat will be capable of filtering approximately 360 million gallons of water per day. By comparison, the average daily flow rate for Houston’s 39 wastewater treatment plants in 2009 was 252 million gallons per day (Greater Houston Partnership, http://www.houston.org/economic-development/facts-figures/utilities/index.aspx).
Oyster reefs also provide habitat for numerous bottom dwelling fish and invertebrates which are in turn food for larger game fish. Therefore, this project is expected to indirectly benefit the recreational fishing community. Scientists refer to these various functions of oyster reefs, including providing product for the commercial fishing industry, as “ecosystem services”.
Prior to this year’s restoration work, TPWD restored five acres of oyster reef off of Eagle Point near San Leon in 2009/2010, and 20 acres of oyster reef on Middle Reef in East Bay in 2009. This year’s work represents a seven fold increase in acres of oyster reef restored by TPWD. East Bay, which has been closed to commercial oyster fishing for the last two years, will re-open to commercial harvest on Nov. 1.