The Grand Bay National Estuarine Research Reserve (GNDNERR) is a retrograding delta in the northern Gulf of Mexico with a variety of habitats for resident and transient fish. To understand seasonal habitat use, fish communities were sampled seasonally by seining five nearshore habitat types, including replicate sites representing depositional edge (n=2), erosional edge (n=3), seagrass (n=3), shell midden (n=3), and beach (n=2) from 2005 – 2014. Data was analyzed using Analysis of Similarity (ANOSIM), Non-Metric Multidimensional Scaling (NMDS), and Similarity of Percentages (SIMPER) to quantify differences in fish communities among habitat types for each season across the period of record. A total of 532 samples and 111,563 fish were collected across the study period and the top three most abundant species were Anchoa mitchilli (32.9%), Leiostomus xanthurus (15.6%), and Menidia beryllina (12.5%). Total species richness was highest at erosional edges in spring (50 species) and lowest at shell middens in winter (13 species). Community analyses showed that several species were associated with certain habitat types for a given season. For example, 94% of Fundulus similis sampled during summer were found at beaches and 81% of Lagodon rhomboides sampled in spring were found at seagrass habitats. Further, 93%, 87%, and 62% of sampled Brevoortia patronus were found at erosional edges during winter, fall, and summer, respectively, which is an ecologically and commercially important species in this region. These associations can be used to inform restoration and/or conservation of habitat types within the GNDNERR in the coming years.

Coastal upland forests are home to a variety of flora and fauna, including forest-dwelling bats. Bats play a crucial role within forested ecosystems as the primary predators of night-flying insects, but global declines in some bat populations have reduced many of the ecological and economic services bats provide. As threats increase, coastal forests have the potential of being a vital refugia for their residential and migrating bats. Many forested areas are managed in an effort to improve overall forest habitat quality and increase biodiversity. Understanding how bats respond to land management-induced changes within forest habitats is necessary for the conservation of these species. Leveraging the large-scale land management projects at the Grand Bay National Estuarine Research Reserve (GNDNERR) in Jackson County, Mississippi, this project will determine if the activity and diversity of bats and their insect prey is affected by different coastal upland land habitat management techniques, such as prescribed fire and mechanical clearing. Analysis of bat species presence and activity was assessed using acoustic surveys. Passive insect traps were used to trap flying insects for analysis of abundance and diversity relationships among potential bat prey between the land management techniques. Findings from this study could be used to inform land managers of the potential benefits and impacts of land management practices on forest bats and their insect prey.

To effectively restore habitats in ways that benefit fisheries, managers must understand how fisheries species use those habitats. We used fine-scale acoustic telemetry to track the movements of sportfish and make inferences about their use of various microhabitats associated with restored shorelines. Arrays of closely spaced acoustic receivers were deployed along two shorelines in Mississippi Sound, Alabama: Lightning Point/Little Bay Peninsula, a reconstructed marsh and lagoon protected by riprap and concrete pyramid breakwaters; and Point aux Pins Peninsula, a complex seascape of mudflats, seagrass, marsh edge, and oyster beds also protected by breakwater pyramids. We used the receiver arrays to triangulate the positions of acoustically tagged fish with an accuracy on the order of 1-2 m. The distance and turning angle between consecutive positions was then calculated and used as a quantitative proxy of behavior. We interpreted meandering tracks made up of medium length steps as indicative of foraging, single direction tracks of long steps as indicative of travel, and relatively stationary tracks of very short steps as indicative of sheltering. We have tagged and tracked three sportfish species, Red Drum, Speckled Seatrout, and Sheepshead, in both arrays. Preliminary results show Sheepshead sheltering near breakwater pyramids at night and foraging widely during the day. Red Drum and Speckled Seatrout appear to shelter along the marsh edge at night and forage over oyster reefs during the day. Understanding how habitats within existing restored shorelines are used by fisheries species can help inform the design of future restoration projects.

Seagrass beds support high biodiversity and animal abundance, serve as feeding grounds for a variety of nearshore animals, offer shelter from predation, and act as a nursery habitat for juveniles. The species composition of seagrass beds can impact habitat use by animals. Two common species of seagrass in the Gulf of Mexico are Ruppia maritima (widgeon grass) and Halodule wrightii (shoal grass). The shallow coastal waters of the Grand Bay National Estuarine Research Reserve (GNDNERR) support both of these species, but the habitat use of each by nekton is poorly understood, which limits management. Nekton communities were sampled in May, July, and September 2022 in GNDNERR within R. maritima and H. wrightii-dominated seagrass beds and unvegetated habitat. All nekton were collected, identified to species, weighed, and measured to quantify density, species richness, and species diversity within each habitat. Seagrass cores were also collected to quantify above and below-ground biomass, leaf area index, and epiphyte load. Juveniles of several commercially fished nekton species including blue crabs (Callinectes sapidus), white shrimp (Litopenaeus setiferus), and brown shrimp (Farfantepenaeus aztecus) were collected, with higher density and greater species diversity in seagrass compared to unvegetated bottom. These results reinforce the importance of seagrass within GNDNERR as essential nursery habitat and can be used to inform management and long-term planning.

The increase in extent of the competitive Phragmites australis in several of Mississippi's coastal marsh areas raises questions about how these marshes may develop, in terms of both spatial extent and ecosystem function. To better characterize tolerance limits of P. australis and estimate future spread potential, we are investigating the elevation range, topography, and surface-water salinity in P. australis-dominated areas. Vegetation and salinity measurements were collected during the 2022 growing season in the Pascagoula River, Jourdan River, and Hancock County Coastal Preserves. Two P. australis-dominated and two adjacent non-P. australis dominated transects were surveyed (RTK GNSS, Trimble R12i) at each site to record elevation and species presence at 0.5m intervals. Transects began in the water 1.5m before the shoreline and continued landward perpendicular to the shoreline, traversing the entire width of the P. australis patch at each site. Surface salinity was recorded at 15min intervals (Star-Oddi CT/CTD) beginning in August 2022. While maximum elevations of occurrence were similar among P. australis, Juncus roemerianus, and Spartina cynosuroides, minimum elevations for P. australis were the lowest among all species sampled at all sites. Additionally, the lowest-salinity site (Pascagoula) exhibited lower elevations for P. australis, J. roemerianus, S. cynosuroides, and Sagittaria lancifolia than the two higher-salinity sites. Data from these and additional sites will be synthesized with aerial image data documenting historical trends in P. australis distribution to assess the impacts of several physical environmental variables on inundation tolerance and rate of spread.

Long-term monitoring of wildlife populations is necessary to detect population changes over time and apply necessary conservation measures. The benefits of long-term monitoring are most noticeable in dynamic ecosystems with numerous ecological stressors, such as tidal marshes. Along the Northern Gulf of Mexico, secretive tidal marsh birds are understudied, despite their role as bio-indicators of marsh ecosystem health. Furthermore, the Gulf and its bird communities face myriad disturbances such as hurricanes, oil spills, land use change, and sea-level rise. Long-term monitoring strategies are crucial for assessing tidal marsh bird populations and associated distributions. We generated preliminary species-specific population estimates of secretive marsh birds across the Mississippi Gulf Coast in 2019 and 2021 utilizing a robust sampling design, standardized monitoring protocol, and spatially explicit abundance modeling. The most abundant species included Red-winged Blackbirds, Clapper Rails, Seaside Sparrows, Common Yellowthroats, Boat-tailed Grackles, and Least Bitterns. We estimated a total of 32,635 ± 1,196 Clapper Rails, our most abundant species, across 264 points distributed among 12 marsh complexes. Clapper Rail abundance was negatively impacted by percent of developed land and distance from the marsh-water edge. Using this multi-faceted framework, we demonstrate the importance of investigating site-level and landscape-level variables that affect species-specific abundance. We also propose further application of abundance and distribution estimates including projecting the effects of sea-level rise and urbanization on future populations to help identify best practices for conserving species of concern.