An Assessment of Little Bay Water Quality and Seagrass Monitoring Program




Mission-Aransas National Estuarine Research Reserve

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The University of Texas Marine Science Institute




Little Bay is a small, semi-enclosed estuary located in the heart of Rockport, Texas. Estuaries are where freshwater from rivers and streams mixes with salt water from the oceans. Estuaries are extremely productive and valuable ecosystems that provide flood protection, filter nutrients and contaminants, and provide valuable habitats for wildlife, including nursery areas for many commercially and recreationally important fishes and invertebrates. Little Bay has been an important part of the Rockport community for many years. It not only provides the important ecological functions mentioned above, but it also supports the local tourism industry by providing opportunities for both residents and visitors to fish, kayak, boat, jet-ski, and watch birds. For the last few years, there has been growing concern about the “health” of Little Bay. Many long-term residents and visitors have noted marked changes in the habitats and wildlife of Little Bay. They are worried about Little Bay’s ability to function properly and to continue to support the recreational activities which have made it such a popular destination for both residents and visitors. Various monitoring programs, including seagrass and water quality monitoring projects and water quality monitoring in the streams that flow into Little Bay, have been conducted to try and understand the recent decline in environmental quality. However, definitive explanations for the declines witnessed in Little Bay have not been found and further long-term monitoring efforts would be useful. In 2012, the Mission-Aransas National Estuarine Research Reserve proposed the idea of establishing a quarterly “Report Card” to monitor the long-term health of Little Bay. Report cards are an effective way to portray the changing conditions of the estuary and have been used in several bays throughout the United States, including the heavily-impacted Chesapeake Bay system. The Little Bay Report Card includes measurements of water quality and is based on the following parameters: temperature, salinity, dissolved oxygen, turbidity, and chlorophyll. Water quality is compared to measurements taken in Aransas Bay. This comparison with Aransas Bay will be used to provide a “grade” for each parameter and will be factored into an annual score. Aransas Bay is generally regarded as a “healthy” bay with good water quality and productive habitats. Details on the Report Card measurements and “grades” can be found in Appendix A. The information provided in this report includes an annual review of all water quality parameters, including nutrients, chlorophyll a, microplankton sampling, and seagrass extent monitoring in Little Bay and nearby Aransas Bay. The Mission-Aransas Reserve manages five data-logging stations throughout the Mission-Aransas Estuary and one in Little Bay. Each site contains a data logger that collects water quality information at 15 minute intervals throughout the year. The data for five stations, not including Little Bay, are available online at: The microplankton samples were counted and analyzed by Cammie Hyatt, Mission-Aransas Reserve scientist. The seagrass monitoring was performed by Dr. Ken Dunton’s laboratory at the University of Texas Marine Science Institute. Dr. Dunton’s laboratory have extensive experience with seagrass monitoring on the Texas coast. Currently, they monitor seagrass within the Reserve, Corpus Christi Bay, and the upper and lower Laguna Madre.

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