My interest is analyzing the annual migration that Sargassum seaweed takes from the North Atlantic’s Sargasso Sea, to the Caribbean, and eventually on to the beaches of Texas, for the Sargassum that does not make landfall and returns to the Atlantic Ocean through the Florida Straits. Previously, these Sargassum wrack landings had been a great mystery and occurred with little or no warning. It is believed that the driving mechanism for this occurrence is the Azores High pressure system. This weather phenomenon part of the North Atlantic Oscillation which helps predict the movement of this high pressure system. When it is a positive state (near the East coast of the US) it is theorized that the pressure system forces Sargassum windrows to enter into the North Caribbean Passes and eventually into the Gulf of Mexico. It is this high pressure system that is believed to be the main catalyst for the Sargassum loop system to begin the long trek of Sargassum to eventually making land fall on the Texas Gulf Coast or returning to the Gulf Stream to help stabilize the Sargassum population in the Sargasso Sea.
My interest within the SEAS program involves developing Phase 2 of the Operation. This includes surveying satellite images provided by NASA’s Landsat satellites that take images of the Caribbean Sea every eight days. Months before washing up on Texas shores, the seaweed journeys West from the North Atlantic, through the Northern Caribbean passages (Windward Passage, Mona Pass, and Anagada Pass) and then up the Yucatan Pass, and into the Gulf. By monitoring each the amount and the currents, the time it takes for it to potentially reach the Texas Coasts can be calculated.
In order to estimate the arrival time of the seaweed blooms, I analyze specific images looking for observable traces of Sargassum entering or exiting the Caribbean Sea. Once I locate a patch, I highlight and compare its location to ocean current data, gathered from HYCOM. Based on these currents, one can predict when and where the patch of seaweed is traveling. Once I have formulated a prediction, I create a graphic illustrating the patch and explaining potential movements and long term prediction. This critical data is uploaded to the TAMU website server where it is published for the public to view.
My research interest focuses on several aspects of Sargassum’s life cycle. As part of the Sargassum Early Advisory System I have assisted in the compilation of data that supports the existences of the Sargassum loop system including evidence of both wind shear and ocean currents that provide the energy for Sargassum transportation over long distances. My work with oceanic drifters has increased the accuracy of our predictive system by establishing a better defined expectation of Sargassum’s rate of movement through the loop system including the analysis of the Langmuir Circulation.
My latest efforts have been directed at the growth cycle of Sargassum as it travels through neritic waters near the coast line. We have found significant discrepancies between the large volume of Sargassum that makes landfall on the coast and the patches that can be seen using Landsat imagery. At some point during its movement from the gulf waters to the coasts, a large spirt of growth occurs. We have developed a floating device to measure Sargassum growth in variable ocean conditions and have begun to collect data on growth rates in the surf zone. These data sets have produced very promising information to support our theories on coastal growth rates.
I have been involved with the SEAS program since August 2012. My interest includes investigating the changes in the volume of visible Sargassum between the entrance point into the Gulf of Mexico from the Yucatán Strait to the exit point through the Florida Strait, back into the Atlantic Ocean and eventually returning to the Sargasso Sea. I have been analyzing USGS LANDSAT satellite imagery focusing on visible Sargassum slicks and mats. These images are logged into a data set for visible or non-visible Sargassum. The images are then categorized by amount per imagery and then compared between the two observation sites. The SEAS team’s theory is that as the Sargassum enters into the coastal waters and more importantly neritic waters and that’s where a significant growth spurt occurs for these brown algae. Using the satellite imagery we are able track Sargassum movements every 8 days. With the monitoring the gyres, eddies, wind currents, and water currents we are able to accurately track Sargassum as it passes through the Gulf of Mexico.
My interest with the SEAS program has been to historically investigate the accuracy and consistency of the Sargassum Early Advisory System (SEAS) model by applying back casting methods. Landsat satellite images and archived newspaper articles are meticulously cross-referenced for recordings of Srgassum events. The newspaper articles were retrieved from the Galveston’s Rosenberg Library from archives made up of complaints about seaweed overwhelming the beach from as far back as 1982. The satellite images provide a visual confirmation of sargassum moving throughout the loop system, as well as the landings upon the Texas coastline. Hundreds of images and newspapers have been analyzed allowing for the construction of a record that can provide vital information pertaining to the SEAS reliability. The records indicate that when complaints of Sargassum inundating the beach have arisen, the Sargassum can be seen in satellite images arriving on the Texas coast. Through these studies into the correlation between these two data records the methods employed by SEAS have been shown to be accurate and well founded.
My name is Captain Robert Webster; I am the pinnacle researcher of SEAS. My work began with my passion for the restoration Galveston’s beaches. I grew up coming to Galveston and I remember the beaches with their hardy sandbars, natural beach face and vegetated dunes; characteristics that our sand-starved beaches of today are now lacking. I began investigating Sargassum’s use in beach remediation and simultaneously discovered that through scientific efforts it could be forecast. My main interest lies in investigating the best practices for beach management. I have strove to expand my knowledge base; to seek out answers to achieve equilibrium between a tourist industry accommodating beach and a long lasting environment that will be accessible for future generations to enjoy. I am interested in employing methods that will create less of a negative footprint on our beaches. I am particularly emphatic about using smaller equipment to clean our beaches, utilizing the excess Sargassum to fortify natural dune systems, and implementing split barges to inject dredge sediment into our system as naturally as possible. I remember the healthy landscape of Texas’ shoreline and I want to ensure that we leave that same beautiful environment for generations to come.