Galveston Bay oyster reef survey. Volume I: Technical reports. Volume II: Map atlas.




Powell, Eric N.
Song, J.
Ellis, M.
Choi, K.

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Galveston Bay National Estuary Program


Report I: Oyster reefs make up one of the primary geological features of Galveston Bay. They affect current flow and salinity and provide a primary substrate for a wide variety of hard-bottom invertebrates and fish. The commercial oyster fishery in Galveston Bay is one of the more important ones in the U.S. and the private (or noncommercial) harvest of shellfish in Texas ranks third in the country. Accordingly, the oyster reefs play a pivotal geological, ecological and commercial role in Galveston Bay. The purpose of this study was to survey the oyster reefs of Galveston Bay and compare them to earlier surveys. Of particular importance were concerns about the perceived loss of reef area and the lowering of relief on the remaining reefs. The primary objectives of this study were to resurvey the aerial extent and relief of the principal reefs in Galveston Bay.; Report II: Oysters are generally considered to respiratory best at moderate salinities (12-20 ppt). Factors restricting oyster production outside this salinity range include increased respiratory demand, decreased filtration rate, and mortality at lower salinity and predation and disease at higher salinities. Production on reefs, however, is significantly affected by variables like food supply and rate of recruitment that might follow salinity in a more complex way. In addition, the direct affect of the commercial fishery is poorly known. Some reefs are heavily fished, others are less so, in the same salinity regime. Accordingly, the production of oyster populations might not be a simple function of salinity, and, indeed, the accompanying survey of reef accretion and loss over a 20 year interval in Galveston Bay did not reveal a clear trend with the prevailing salinity gradient over that time. Moderate salinity areas, on the average, accreted more new reef, however areas of similar salinity accreted and lost reef area during this time over much of the salinity gradient in the bay.


2 volumes; available for download at the link below.


oyster reefs, oyster fisheries, accretion, circulation, salinity effects, subsidence, habitat loss, habitat restoration, habitat modification, habitat degradation, habitat improvement, population dynamics, food availability, currents, inflow, biological production, perkinsus marinus, biogeography, rangia cuneata, oyster culture, fishery management, monitoring, artificial reefs