Fall 2012

Experimental Seagrass Mapping in Redfish Bay, Texas By Dr. Michael Starek, Associate Research Professor Dr. Michael Starek (left) and Dr. Lihong Su (right) acquiring radiometer readings in Redfish Bay on 10 September 2012. Photo by: Alistair Lord On 10 September, Coastal and Marine Geospatial Lab (CMGL) researchers and the University of Houston (UH) conducted a coordinated airborne and ground-based survey of the Redfish Bay State Scientific Area as part of a pilot study to investigate the capabilities of airborne bathymetric light detection and ranging (lidar) and hyperspectral imaging for seagrass mapping. Monitoring seagrass habitat is an important environmental initiative in the state of Texas. However, accurate discrimination of different seagrass species over large areas via remote sensing has proved very difficult. Hyperspectral imaging measures the radiation emitted from the earth's surface across a wide range of the electromagnetic spectrum. This information can be used to identify characteristic spectral signatures of objects within the imaged scene. This technology, in combination with 3D measurements of the sea floor provided by bathymetric lidar, can be applied to map the location and potentially the type of seagrass in an area. The ultimate goal of the CMGL/UH pilot study is to provide a proof of concept for bathymetric lidar and hyperspectral data fusion for seagrass discrimination along the Texas coast. The National Center for Airborne Laser Mapping (NCALM) of the University of Houston flew the mission using their Cessna 337 Skymaster airplane and a suite of state-of-the-art airborne lidar and spectral imaging sensors. Traditional bathymetric lidar systems have been limited in their ability to map within the shallow water zone (<1 m) where seagrass can occur due to limitations in receiver response and laser pulse length. For this survey, UH acquired data using their new bathymetric lidar system designed for mapping shallow-water depths, the Optech Aquarius 532 nm system. UH also collected data with their 288 band hyperspectral imaging sensor, the CASI 1500. The ground campaign was led by CMGL using an airboat to collect in-situ radiometer measurements of sky irradiance and above water reflectance at different locations within the bay. The radiometer data is used for airborne sensor calibration. The team also collected salinity measurements, water samples, GPS position, and depth. A c-up survey acquired ground-verification data of bottom type and seagrass cover at over 80 locations within the bay. Collectively, the data will be used for development and validation of seagrass classification algorithms using the lidar and hyperspectral sensor data. The CMGL survey team included Dr. Mike Starek and Dr. LiHong Su, research analyst Alistair Lord, Ph.D. candidate Anthony Reisinger, and current Ph.D. graduate John Wood. Rick Kalke, from the Ecosystems and Modeling group captained the airboat enabling a successful field campaign. After data processing is completed, work will be directed towards seagrass classification algorithm development. The work will extend upon seagrass mapping research conducted in the region by John Wood. Furthermore, Dr. Su obtained a Texas Research and Development Foundation grant to explore the feasibility of high-resolution multi-spectral satellite imagery for seagrass discrimination, and this study will provide a comparative assessment.

Summer 2012

GRIIDC Meeting and New Hires Project Scoping and Teambuilding GRIIDC Group (pictured above). Front row: Susan Rogers, Julie Lann, Jennifer Page, Lauren Showalter, Jim Gibeaut, Felimon Gayanilo, Fabio Moretzsohn, William Nichols. Back row: Michael van den Eijnden, Dave Reed, James Davis, Matthew Howard and Patrick Krepps. Photo by: Diana Del Angel The Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC) is the vehicle by which the Gulf of Mexico Research Initiative (GoMRI) is implementing the Research Database, and which will help address the data and information needs of GoMRI. GRIIDC will serve GoMRI by assisting researchers with data archiving and ensuring data and information legacy that promotes continual scientific discovery and public awareness of the Gulf of Mexico ecosystem. GRIIDC held its Project Scoping, Visioning, and Teambuilding (PSVT) meeting at the Harte Research Institute for Gulf of Mexico Studies, Texas A&M University-Corpus Christi, on July 12-13, 2012. This meeting signified the completion of the hiring process leading to the formulation of the GRIIDC team. This event was held to kick-start the project and set procedures, tasking strategy, address prevailing issues, and build a cohesive data management team. This was attended by all members of GRIIDC including subject matter experts from Texas A&M University-College Station and from Florida Fish and Wildlife Conservation Commission. The event was started with a re-introduction of the GoMRI and GRIIDC missions and organizational structure by the Director of the Project, Dr. James Gibeaut, HRI Endowed Chair of Geospatial Sciences. Six breakout sessions were held addressing issues related to large scale data management. The second day focused on project planning and it was concluded with a better picture as to the tasks ahead. HRI student receives award Reisinger earns prestigious fellowship Anthony Reisinger, PhD. Anthony Reisinger, PhD candidate and graduate assistant working under HRI?s Endowed Chair Dr. Jim Gibeaut, was awarded the prestigious NASA Earth and Space Science Fellowship (NESSF). This fellowship will provide funding for his dissertation work on ?Suspended Sediment Dynamics of Shallow Wind-Driven Estuaries: A Remote Sensing Approach?. Reisinger?s dissertation work focuses on suspended sediments within Texas estuaries. His research methods involve satellite remote sensing, a major field campaign, and modeling and analyses of physical processes affecting estuarine sedimentary processes. NASA received a total of 287 applications in Earth Science Research and selected 54 for the award. NOAA-NGI Intern Njagi Researches data crosswalks Nyambura Njagi Nyambura Njagi, a graduate student in Geospatial Surveying Engineering at Texas A&M University Corpus Christi, was awarded a summer internship through the NOAA-NGI Diversity Internship Program this year. During her internship, she worked in HRI's Coastal and Marine Geospatial Lab with Endowed Chair Dr. Jim Gibeaut on a data crosswalk using the Coastal and Marine Ecological Classification Standard (CMECS). CMECS is the national system for organizing coastal, marine, and living ecosystems. This classification system was approved by Federal Geographic Data Committee in early June and since, the need for conversion or crosswalk from other classification systems to CMECS has emerged. While many crosswalks will involve conversion between different classification systems, Nyambura?s project aimed to develop a crosswalk between a fisheries dataset coded in an early version of CMECS to the newly approved CMECS.  A key conclusion of her work is that data crosswalking will often require decision-making from the user and/or software in order to resolve complicated unit conversions from one classification system to another. She presented her work in August at NASA?s John C. Stennis Space Center in Hancock County, Mississippi.

Spring 2012

New method of studying marsh Team experiments with red brick dust Over the past two years HRI's Coastal and Marine Geospatial Lab (CMGL) has studied marsh accretion on Mustang Island on the Texas coast using Cesium-137 geochronology. "Accretion" describes the net change in the relative elevation of the marsh surface in the tidal frame. This work was part of a thesis project by HRI Master's Student Boris Radosavljevic. From his work, only 13 accretion rates could be determined in low-marshes and tidal flats where intense bioturbation complicated the determination of the Cesium peak. Because there is ambiguity in the data related to accretion in tidal flats and low marshes, before Radosavljevic left for Germany in March, he began an experiment that will hopefully shed some light on this matter. With the help of Greg Hauger of Conrad Blucher Institute and HRI Research Technician Alistair Lord the researchers spread red brick dust at 167 locations over the surfaces of salt marsh and wind tidal flat environments in Mustang Island State Park. Then in May, the team conducted elevation surveys at each of the marker horizons. These horizons serve to record the surface elevation at the time they were deployed. Sampling these sites in the years to come will provide a much more detailed and accurate picture of salt marsh and tidal flat accretionary dynamics in south Texas. HRI develops interactive maps Showing susceptibility to sea-level rise Barrier islands Barrier islands are highly vulnerable to relative sea-level rise, erosion and tropical storms, but simply categorizing their entire extent as a risky place to live would not help guide ongoing urban development. HRI’s Coastal and Marine Geospatial Lab has developed interactive coastal geohazards maps of 3 barrier islands on the Texas coast (Galveston Island, Mustang Island and South Padre Island). These maps show areas that vary in their susceptibility to, and function for, mitigating the effects of geological processes including relative sea-level rise, erosion and storm-surge flooding and washover. These interactive maps provide tools and resources to help land planners, coastal managers and citizens understand the potential changes that wetlands, dunes and beaches could undergo in the decades to come. Geohazards maps have been developed for Galveston Island and South Padre Island Texas, and work is ongoing for Mustang Island near Corpus Christi, Texas.