Fragile ecosystems | Mirage News

A university doctorate. the candidate studies how different shoreline types affect fish populations along Biscayne Bay.

Ellery Lennon will never forget the day she spotted a young lemon shark swimming in the shade of the mangroves along Biscayne Bay. Claiming to be a “fat shark nerd”, Lennon says the surprise sighting was an important discovery that ties directly to her thesis work and the research she is conducting this summer.

Lennon uses a refractometer to record water salinity in Biscayne Bay.

“Spotting juvenile sharks was a really important discovery,” says Lennon, who holds a Ph.D. from the University of Miami. candidate in the Department of Biology, who earned her undergraduate double major in marine science and biology from the College of Arts and Sciences and the Rosenstiel School of Marine and Atmospheric Science in 2016. “Not only does this show that populations of Mangrove-dwelling fish and invertebrates may harbor a predatory species like a shark, but the observation also illustrates how healthy mangroves provide important nursery habitat for juvenile fish.

Over the next two months, Lennon and his undergraduate research assistant, Alexis Carrasquillo, will use an underwater video camera to capture images of fish along different shorelines of Biscayne Bay in hopes of determining how coastal shielding (man-made structures like levees, for example) affect coastal fish assemblages.

Although used to mitigate the effects of climate change, the construction of seawalls can contribute to pollution and loss of habitat for fish and corals. By using the underwater cameras along the shorelines of the mangroves, seawalls, and in areas where both seawalls and mangroves exist, Lennon hopes to show how important mangroves are to the Bay ecosystem. Biscayne by the number of fish captured on video with underwater cameras.

parrot fish
Rainbow parrotfish captured with an underwater camera.

“I’m very interested in studying fish populations and want to know how different types of shorelines can support fish assemblages,” says Lennon. “A diverse fish population is an important indicator of a healthy ecosystem and can increase the ecosystem’s ability to function and provide beneficial services. Not only are mangrove ecosystems home to other fish and predators, such as sharks lemon that I spotted, but also bird populations, nutrient cycling, and recreational activities, like snorkeling.

Biology professor Kathleen Sealey, whose life’s work is devoted to coastal restoration ecology, particularly coastal system management in South Florida, guides them through the research. Sealey has worked on similar projects with colleagues and university students in the Bahamas and the Caribbean, and participated in a local initiative with Monroe County and the Florida Department of Environmental Protection to study water in and around 13 different canal sites across the Florida Keys. .

“Our research is designed to better understand ecological responses to coastal management,” says Sealey. “Applied ecological research can help us make the most of environmental management expenditures to improve the functioning of our coastal ecosystems.”

Before Lennon can really dive into her research, she must determine if underwater cameras are an appropriate method for characterizing fish in front of mangrove shores. “We also need to determine how many hours of video are enough to characterize the fish at each site. That’s what Alexis is going to help me with this summer,” says Lennon.

To do this, they deploy cameras at two sites that the National Oceanic and Atmospheric Administration (NOAA) has been monitoring for years. NOAA monitors fish by snorkeling along transects in front of mangrove habitats. Carrasquillo will help Lennon’s research by comparing their fish video data to NOAA snorkeling fish data to see if they find similar species and abundances.

“I’m so excited to get started,” says Carrasquillo, who specializes in marine biology and ecology. “Ellery was my teacher’s assistant when I started my second semester in first grade, so I was interested in the project when she discussed it with the class. I love being outdoors and regularly go kayaking or fishing with my dad and brother, so now doing research related to my personal interests it’s an amazing experience that I’m happy to have found.

mangrove
Lennon created a diagram showing the importance of fish to coastal systems and humans

Lennon’s research for his dissertation correlates with a collaborative U-LINK project with Professor Sealey and other UM faculty members from disciplines including civil engineering, sculpture, architecture, architecture, and architecture. economy and marine ecosystems. The U-LINK Next Generation of Coastal Structures team has combined its expertise to develop the next generation of coastal design structures that are durable, multi-functional and provide aesthetic value to a region’s culture.

“The U-LINK team has come up with many ideas on how to improve the ecological function of coastal structures, but now we need ecological measurements to see if these ideas produce the results we expect,” adds Sealey. “The underwater video system could be the rapid assessment method we need to compare different types of nature-based coastal structures.”

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