海角社区

Estuarine fisheries to models of ecosystem services, CC&E graduate students conduct research with real world impacts. Take a peek at what they've been up to lately.

 

Wading into Louisiana's estuaries

Department of Oceanography & Coastal Sciences, or DOCS, Masters student Howard Dunleavy works in fisheries, examining the effects of the opening of the Bonnet Carre Spillway diversions on the brackish ecosystems and fisheries in the lake.

鈥淚 want to find out how these freshwater introduction events are impacting the local fish communities鈥攂oth in short and long term鈥攁nd explore whether the influence of spillway openings is negative, positive, or potentially neutral when observed at a full-estuary scale,鈥� Howard says. 

He says that fisheries in areas like Lake Ponchartrain can be very resilient, even in the face of a 鈥渕assive man-made change to their environment like a freshwater diversion.鈥� 

鈥淓stuaries, like Lake Pontchartrain, offer a wide range of niches to fill which enables them to host an incredibly diverse group of species, all of which respond to ecological change in unique ways. It has excited me to discover that while some fishes may flee from the spillway plume when the diversion is open, others have the tolerance to stay in their habitat and wait it out, and it all depends on the species being observed.鈥�

 

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Building Reliable Ecosystem Services Models

Department of Environmental Sciences, or DES, student Mariam Valladares-Castellanos, is a 4th year PhD in Dr. Tom Douthat's lab. She is investigating the connections between land use, land cover and water quality. She recentlyin the journal Science of the Total Environment.

How does this paper fit in with the rest of your research? 
This study builds directly on the overall objective of my dissertation, which is to understand the effects of land-use regulation changes on water quality ecosystem services and their implications for coastal watersheds. This is particularly important for Puerto Rico, my study area, where land use and land cover transitions from extensive agriculture to forest recovery and rapid urban growth have significantly impacted water quality.

What do you think is the biggest takeaway from this research?
Reliable ecosystem service models are essential for understanding water quality and guiding decisions that affect both ecosystems and people. But in many places, especially where monitoring data is scarce, building and validating these models has been a major challenge. Our study shows that by combining machine learning with hydrogeological similarity, we can overcome this barrier. Our framework makes it possible to apply water quality ecosystem service models even in data-limited regions, like Puerto Rico, where we tested it, helping identify areas that need water quality conservation or management. In short, this work opens the door to scalable, evidence-based water quality management in places where decisions matter most, but data are hardest to find.

 

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Studying Sediment

DOCS Masters student Amber Tymul works with Dr. Giulio Mariotti, studying sediment dynamics and the processes that affect the stability of the marsh. 

鈥淚 enjoy studying sediment dynamics because of the role sediments play in shaping the coast and building landscapes,鈥� she says. 鈥淥ne thing I think people should know about estuaries is that they provide valuable coastal protection, shielding inland areas against flood events and preventing erosion.鈥�

As part of her research she is modeling South Carolina鈥檚 ACE Basin to better understand the use of thin layer placements, or TLP 鈥� the application of dredged material to the surface of a marsh. 

She hopes to discover how the sites respond to TLP 鈥� 鈥渋f it builds elevation, promotes vegetation, prevents flooding,鈥� she says. 鈥淭his connects with the rest of my work because the model I use evaluates the long-term geomorphology changes of an area, so by applying TLP in the model, I am able to observe if a specific site will successfully maintain the TLP given its sediment dynamics, hydrodynamics, and other parameters.鈥�