Graduate Student Spotlight

Unexploded Ordnance

 

 

I’m McKensie Daugherty, your host for on the ocean. Some people are worried about UFO’s, but even fewer are concerned with UXO’s. UXO stands for Unexploded Ordnance: unused military-grade explosives and chemicals. Once they became too old to use, banned by treaty or law, or simply rendered obsolete, these dangerous UXOs were deposited onto the ocean floor by governments all over the world as recently as 1970. Unfortunately, the amount and extent of UXO deposits currently lying on the ocean floor are poorly understood. Oceanographers at Texas A&M University are pushing to change this. In the new millennium, human activity has exploded on offshore seabeds, especially due to the energy and fishing industries. A pair of professors is encouraging the Department of Defense to undertake a comprehensive study of UXO sites in the Gulf of Mexico. In August 2015, an unexploded, armed World War II era seamine washed up on a Florida beach. No one was injured, but it underscored the need to understand and dispose of UXO’s along US coastlines. A complete understanding of the type and amount of unexploded ordnance is essential to protect the well-being of the environment, offshore workers, tourists, and those who live on the shoreline. A full deployment of SONAR echo-sounders and remotely operated vehicles will be needed to fully assess the situation. Overall the technology and willpower are becoming more and more available to make our oceans safer and healthier. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Niall Slowey

Script Author and Contributing Graduate Student: Vance Nygard

 Unexploded bomb on Florida Beach
Calcium Carbonate Saturation Horizons

I’m McKensie Daugherty, your host for on the ocean. Calcium carbonate is a chalk-like mineral that makes up the shells of many different oceanic organisms including corals, plankton, and mollusks. In order for these organisms to build their shells, they need both calcium and carbonate to be abundant within the water. And the limiting factor for these organisms is carbonate. Surface waters, where most of these organisms live, are supersaturated in terms of calcium carbonate. This means that there is sufficient carbonate available for the organisms to thrive and build shells. Ocean acidification, a process where oceans are acidified due to absorption of excess atmospheric carbon dioxide, can limit the availability of carbonate as well as lead to the dissolution of calcium carbonate structures. With increasing depth, there is less and less available carbonate in the water, and the water becomes undersaturated. The depth where the water transitions from supersaturated to undersaturated is called the saturation horizon. These horizons are getting shallower in all the major ocean basins due to the excess carbon dioxide from the atmosphere. Researchers at Texas A&M University are mapping these saturation horizons in the Gulf of Mexico. By monitoring the changes in the ocean basin closest to us, we can understand what is changing and learn how to protect these economically important areas. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Shari Yvon-Lewis

Script author/Contributing Graduate Student: Connie Previti

gra greCoccolithophore, a type of shelled phytoplankton that requires calcium carbonate to create its shell.

Images:Google images

 

Coastal Erosion

 

 

I’m McKensie Daugherty, your host for on the ocean. Coastal erosion (the removal of beaches) is one of the most important problems we are facing in the 21st century. Populations around the world are becoming increasingly dense around the coastlines and the income of many countries depends on tourists attracted to their beaches. Losing beaches will not only result in loss of land, but also a decline in the economy. Many factors can contribute to local erosion issues. These include limited sediment supply, human interventions, and meteorological events like storms or weather fronts. Research institutions study meteorological events and try to understand how they affect currents, waves, and sediment transport along coastlines, and what the best way is to reduce or control the erosion. Texas A&M University was a part of multi-institutional field campaign conducted along the Yucatán Peninsula in México. The field campaign examined the cold front and local wind system effects on near shore currents, waves, grain size variability, and sediment transport. Field data were obtained using more than 50 instruments measuring waves, currents, wind, and sediment concentrations. The study has concluded that during an increase in onshore wind velocity, erosion of the beach and sandbar migration occurred. In addition, the cumulative effect of intense onshore winds  had the same relative erosion effect as cold fronts have on the beach. Overall, many factors increase coastal erosion including weather patterns and human-induced activities. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Jens Figlus

Script Author/Contributing Graduate Student: Tariq AlrushaidArctic Coastal Erosion Modeling

Photo credit: uaa.alaska.edu

Classifying Phytoplankton

 

 

I’m McKensie Daugherty, your host for On the Ocean. Harmful Algal Blooms are major threats to human health, marine ecosystems, and coastal economies.  These blooms are the result of a rapid increase in algae that either produce toxins or consume resources that other animals need.  By gathering data on single-celled algae, or phytoplankton, scientists are able to understand how these natural hazards occur. Scientists at Texas A&M University are using a technique called imaging in-flow cytometry to record and classify millions of images of phytoplankton cells per year in the Gulf of Mexico. Since 2007, they have used an instrument known as the Imaging FlowCytobot to continuously image  the phytoplankton,  which gives a better picture of the dynamics of phytoplankton populations than a single sample once a month.  All the imaging data is available to the public and can be accessed from the Gulf of Mexico Coastal Ocean Observing System.  Using the Imaging FlowCytobot, a toxic algae species, called Dinophysis ovum, was reported for the first time in 2008 near Texas’ shores. These algae concentrated in oysters and cause Diarrhetic Shellfish Poisoning if oysters are eaten by humans.  The aim for classifying so many phytoplankton is to find not only familiar species but also novel species that are toxic and to know where they appear to bloom. Finding such species is important for Texas Parks and Wildlife and the Department of Health to protect human health. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Lisa Campbell

Script Author/Contributing Graduate Student: Bryan Demapan

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Dinophysis ovum photo from Imaging FlowCytobot in Port Aransas, Tx

Influence of Kuroshio Eddies on North Pacific Weather Patterns

 

 

I’m McKensie Daugherty, your host for On the Ocean. Did you know that the ocean surface near Japan can affect the rainfall patterns in the United States? Well it can! Scientists at Texas A&M University have found a correlation between the variability in ocean surface temperatures associated with the Kuroshio current and rain patterns along the Northern Pacific coast of the U.S.. The Kuroshio is a warm ocean current, similar to the warm Gulf Stream along the North Atlantic coast of the United States. Ocean eddies, which are known as “storms of the oceans” because of their circular currents, often pinch off from the Kuroshio and can create small-scale regions of abnormally warm or cold ocean surface temperatures. In order to study how these Kuroshio eddies affect weather patterns, scientists at Texas A&M University have conducted numerical experiments using high-resolution regional climate models. These computer model simulations, supported by observations, show that weak Kuroshio eddy activity increases winter precipitation along the U.S. Northern Pacific coast. Strong Kuroshio eddy activity reduces this precipitation.  These results have important implications for improving forecasts of winter storm systems, and projections of their response to future climate change. These improved forecasts are known to have major social and economic impacts, by improving the representation of ocean eddy-atmosphere interaction in forecasting and climate model predictions. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Ping Chang

Script Author/Contributing Graduate Student: Laura Farris

 

eddy 1 eddy 3 eddy 2

Microbial secretions in the degradation of oil and dispersant

I’m McKensie Daugherty, your host for On the Ocean. Shortly after the Deep Water Horizon oil spill, people observed a profuse formation of slime-like ooze on the surface water, which was referred to by National Geographic as “marine snot”. However, it is actually called marine snow, and it plays an important role in the organic material transport from the surface water to the sediments of the ocean floor. Marine snow acts as a microhabitat for organisms such as diatoms and bacteria, which secrete a dense, sticky, transparent material. These secretions consist of complex threads of carbohydrates, known as microbial exopolymers, which are incredibly sticky. It was hypothesized that these compounds contributed to the removal of oil in the Gulf of Mexico during the Deep Water Horizon spill. Gulf of Mexico Research Initiative funded a consortium called Aggregation and Degradation of Dispersants and Oil by Microbial Exopolymers. This research was done at Texas A&M University in Galveston. Large tanks were filled with seawater mixed with oil, and dispersants, followed by the addition of a plankton concentrate sample from Galveston Bay. Less than 10 hours later the exopolymers had formed in the tanks. The amount of oil was measured every six hours and it actually decreased over time when it was with the exopolymers. This supports that exopolymers aid in the sinking of oil in the water column. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Terry Wade

Script Author/Contributing Graduate Student: Maya Morales-McDevit

Exopolymeric Substances (EPS) formation in mesocosm tanks

Photo credit: Terry Wade

EPS in control
Average oil equivalent concentration in triplicates of WAF tanks as a function of time. The blue curve is a LOESS estimator of the fit and the grey band is the 95%  confidence interval.
waf eoe
Martian Meteorites
I’m McKensie Daugherty, your host for On the Ocean. Looking within our own ocean can give us clues about water on other worlds. Expeditions to Antarctica have found meteorites that lay exposed on the snow. As the meteorites lay in Antarctica, carbonate minerals form on their outer surface. These minerals can be analyzed using methods to study carbonate minerals commonly found within ocean sediments here on Earth. Though ordinary meteorites can contain carbonate materials formed before the meteorites reached Earth, the meteorites chosen for this research contain only carbonate minerals that formed since they landed in Antarctica. NASA scientists working together with researchers at Texas A&M University are determining the types of carbonate minerals and their chemical compositions, then relating this information to conditions in the Antarctic environment where the minerals formed. The cold, arid Antarctic environment can be used as an analog for Mars’ environment. The next step will be to study Martian meteorites that have carbonate minerals that formed on Mars. This will allow scientists to identify those carbonate minerals that formed before these meteorites fell to Earth. This will help scientists better understand the Martian environment, and how these minerals may have formed. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professors: Dr. Niall Slowey, Dr. Piers Chapman

Script Author/Contributing Graduate Student: Katherine Crabill

Contributing Graduate Student: Michael Evans

Researchers camping while collecting meteorites:

antarctica camping

Sargassum Overload

 

 

I’m McKensie Daugherty, your host for On the Ocean. You’re likely to find more than sand and seashells, beach combing in the North Atlantic. Seaweeds of all shapes, sizes, and colors wash ashore everyday, but one of these types is not like the others. Unlike most seaweeds, which are usually found on the seafloor, the golden-colored Sargassum or “Gulf weed” can be found floating on the surface waters of the Caribbean, Gulf of Mexico, and Sargasso Sea. By using gas filled floats, Sargassum flourishes at the surface where it supports a diverse community of fauna. Sargassum provides a protective home for a wide range of animals ranging from small invertebrates, like shrimp and crabs, to juvenile sea turtles and serves as hunting grounds for predators like seabirds, tuna, and mahi mahi. When Sargassum washes ashore in small amounts, it provides nutrients to beaches and helps prevent erosion. However, in the last five years, much larger quantities of Sargassum have been washing ashore with disastrous effects. Cleanup of Sargassum from beaches is expensive and is often damaging. For sea turtles, blooms of Sargassum and subsequent cleanup efforts can destroy their nests. Scientists do not yet know why these blooms are occurring, but their consequences are far reaching. To understand why these blooms are happening, scientists are using satellites and Sargassum collections to determine where it’s coming from. Recent findings suggest that these large blooms originate in North equatorial waters, further south than Sargassum is usually seen. More research is needed to understand why these blooms began, and how they will affect other natural and human communities. Sargassum plays a unique role in our oceans and we must understand in order to predict and mediate future changes to this vital ecosystem. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Amy Siuda

Script Author/Contributing Graduate Student: Lindsay Martin

 

A juvenile sea turtle uses a Sargassum mat as a nursery habitat in the Gulf of Mexico.

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MantaSargassum-12

Thousands of fish school beneath a mat of Sargassum in the Gulf of Mexico.

© Lindsay Martin 2015

Color Maps

 

 

I’m McKensie Daugherty, your host for on the ocean. Meteorologists on  television often display temperature on a map with reds depicting warm temperatures, going towards blues, which depict cold temperatures, and the other colors between the two. This color gradient from red to blue is known as a color map. Oceanographers typically use a rainbow color map to analyze their data for trends in temperature, salinity, flow fields, and other parameters. Reading these maps can be difficult with the rainbow coloring because it highlights yellow and cyan areas to human eyes. To aid in reducing these arbitrary highlights in data, oceanography researchers developed superior color maps specific to each parameter to minimize interpretation errors. Hypoxia, the lack of oxygen in the water, is one parameter oceanographers study. To show these regions, they highlight oxygen rich areas as yellow and oxygen poor areas as red with grey scale in the middle for areas with normal oxygen levels. All of the newly made color maps are color-blind friendly. And are also translated to better gray scale printing. The new color maps mostly go from dark shades of a color up to light shades of the color, since that is what people are best able to associate with regular changes in data.  Overall using more specific color maps reduces interpretation errors and facilitate better science communication to the public and among scientists. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Kristen Thyng

Contributing Graduate Student/Author: Emily Lewis

 

First figure:
The left hand column utilizes specially-designed colormaps for oceanography properties and the right hand column shows the commonly-used but perceptually-challenging jet colormap. Example model output of the sea surface (top row, from Dr. Rob Hetland, Texas A&M) and data from an undulating towed vehicle along the ship track (bottom three rows, from Dr. Steve DiMarco, Texas A&M) are shown. 
 
 Image from:
Thyng, K. M., Hetland, R. D., Zimmerle, H. M., DiMarco, S. F. (in revision). Choosing good colormaps: accurate and effective data visualization. Oceanography.
 
Carbon Tetrachloride In the Oceans

I’m McKensie Daugherty, your host for on the ocean. Global climate change is the result of more than just carbon dioxide in the atmosphere. Carbon Tetrachloride, also known as carbon tet, is a man-made compound, made up of one carbon and four chlorine atoms, and is known to play a part in climate change, by destroying the ozone layer. It is also a significantly more potent green-house gas then carbon dioxide. After it is released into the atmosphere, it can go to the stratosphere where the ozone layer is, soils, or the oceans where the large scale destruction occurs. In science, there is a mathematical way to quantify this process using a value that is unique for every compound and each specific path to destruction, called a rate loss constant. Back in the 90’s the countries from around the world collaborated to prevent future damage from Ozone depleting substances by enacting the international treaty called the Montreal Protocol. This effectively banned Carbon Tet and required its usage and emissions to be reported. So by using the reported emissions and the known rate loss constants for each place of destruction, scientists have predicted there to be about a 4% per year decrease in atmospheric Carbon Tet concentrations. However, it was observed that it is decreasing at a rate of only about 1% per year. Scientists at Texas A&M University are trying to obtain a more accurate value for the rate loss constant for the ocean, since many components of this value are still unknown. Hopefully, this research will lead to closing the gap between the expected decline, and observed decline of this dangerous compound from the atmosphere. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.Contributing Professor: Dr. Shari Yvon-Lewis

Contributing Graduate Student/Author: Stanford Goodwin

ccl4 lifetime graph

Hemispheric concentrations since the early 1900’s.

ccl4 decline graph

Concentration after the Montreal Protocol

ccl4 rate loss

How the rate loss for the ocean is calculated mathematically.