We are an undergraduate-driven research lab based at St. Mary’s College of Maryland (SMCM) located on the St. Mary’s River, just across the Southern Maryland peninsula from Chesapeake Bay. Our area of focus is ecosystem ecology, which takes a holistic approach in studying the environment. It involves integrated investigation of living and nonliving components of ecosystems, how those components interact, and how those interactions affect ecosystem structure and function.
The SMCM Coastal Ecosystem Ecology Lab investigates how human stressors, like climate change and nutrient pollution, affect coastal foundation species, such as seagrass (also known as submersed aquatic vegetation, or SAV) and salt marshes. We also investigate how changes in marsh and SAV abundance, in turn, affect coastal ecosystem processes. Our goal is to understand the underlying mechanisms of coastal ecosystem decline, recovery, and resilience, and to quantify the effects of ecological change on ecosystem functions, such as nutrient cycling.
This is important work because many of the functions that SAV and marshes carry out are valuable to people. For example, in the Chesapeake Bay region, federal, state, and local jurisdictions are spending a lot of time and money to reduce nutrient inputs to the estuary through one of the most ambitious coastal restoration programs in the world. Research that aims to understand how human activities affect marshes and SAV, and how these systems, in turn, affect estuarine nutrient cycling, informs these restoration efforts.
Because our home institution is a small, teaching-centered liberal arts college, the lab’s emphasis is on undergraduate student research training. Funded research projects involve student research assistants, who play an integral role in coordating and completing field and lab work. We also support a diverse range of coastal science-focused senior research projects (known as St. Mary’s Projects, or SMPs), directed research projects completed for course credit, and SMCM-funded St. Mary’s Undergraduate Research Fellow (SURF) projects.
Salt marshes protect coastal infrastructure from sea level rise and storm events associated with climate change. However, they are also vulnerable to climate change if environmental forcings overwhelm stabilizing feedbacks between marsh vegetation and the environment. For example, rapid marsh loss has occurred in regions of Chesapeake Bay and the New England coast due to edge erosion and interior drowning. However, other studies suggest that marshes are largely stable or can even increase in area due to accretion or transgression into uplands.
Although nutrient load reductions have been a primary management strategy for Chesapeake Bay restoration, internal ecological processes, such as seasonal nutrient retention in submersed aquatic vegetation (SAV) beds, may also play an important, complementary role. For example, if SAV increasingly retain nitrogen and phosphorus as they recover, they could potentially limit regional phytoplankton production, thereby decreasing the magnitude of seasonal bottom-water hypoxia. However, we lack sufficient details about the factors controlling the magnitude of an important mechanism of SAV-mediated nutrient sequestration–particulate nutrient trapping–to make inferences about its importance relative to total loads to the system.
My PhD dissertation focused on the dynamics of a large bed of submersed aquatic vegetation (SAV) in the upper Chesapeake Bay. What makes this particular SAV bed so special is 1) it’s huge (in fact it’s the largest SAV bed in the Bay) and 2) it suddenly recovered about 10 years ago. My goal was to identify factors that contributed to its recovery and resilience. I used a variety of approaches to answer these questions, including retrospective data analysis, observational and experimental fieldwork, and numerical simulation modeling.
SMCM student Chelsea English
Susquehanna Flats SAV bed
UMCES grad student Miles Bolton
Cassie and Miles collecting
an SAV biomass core
Cassie sampling SAV biomass
deploying a water quality
programming the water quality
(left: Cassie Gurbisz
right: REU student
Cassie in the field
Cassie pulling the boat
at low tide
SMCM student lab volunteer
not a bad view
from the office
SMCM student Kajsa Newton
SMCM student Dylan Powell
SMCM students Kevin Glotfelty (left)
and Isaac Hersh (right)
presenting their SMP documentary film
SMCM student Tyler Scott
presenting his SMP poster