Coastal Alabama Research Articles

Microsite Habitat, Species Associations, and Habitat Suitability Model of a Globally Imperiled Shrub

Miller's witch-alder (Fothergilla milleri, Hamamelidaceae) is a newly described globally imperiled shrub that is known from disjunct populations in coastal Alabama, the panhandle of Florida, and one location in Georgia. Little is currently known about the natural history or ecology of the species. We conducted inventories of three populations of F. milleri in Alabama and Florida. A total of 3060 ramets were found; 45% were in one subpopulation ≤0.5 ha in area and 79% were in one population within an area of 4.5 ha. Low ramet counts in few locations makes the species particularly vulnerable to extinction due to stochastic events. Also, all seed capsules found within the surveys were infected by an aphid, which is possibly preventing sexual reproduction within the populations. Microsite habitat data indicated F. milleri grows in a unique transitional habitat between upland conifer forest and wetlands. The sites where extant populations of F. milleri inhabit tend to have acidic and well-drained soils with a high sand content. Further, many populations were under thick midstory vegetation. Thus, fire or other forms of removal may be needed to release those subpopulations before they may become shaded out. Lastly, a habitat suitability model was developed to better facilitate conservation efforts. However, only 0.5% of the study area was within the highest level of suitability. Fothergilla milleri is facing multiple threats that could lead to its extirpation from the wild, and direct and intense conservation action may be necessary to ensure F. milleri remains on the landscape.

Hybridization and low genetic diversity in the endangered Alabama red-bellied turtle (Pseudemys alabamensis).

Pseudemys alabamensis is one of the most endangered freshwater turtle species in the United States due to its restricted geographic distribution in coastal Alabama and Mississippi. Populations of P. alabamensis are geographically isolated from one another by land and saltwater, which could act as barriers to gene flow. It is currently unknown how differentiated these populations are from one another and whether they have experienced reductions in population size. Previous work found morphological differences between Alabama and Mississippi populations, suggesting that they may be evolutionarily distinct. Other Pseudemys turtles such as P. concinna and P. floridana occur naturally within the same geographic area as P. alabamensis and are known to hybridize with each other. These more abundant species could threaten the unique genetic identity of P. alabamensis through introgression. In order to evaluate the endangered status of P. alabamensis and the level of hybridization with other species, we used mitochondrial and nuclear microsatellite markers to assess genetic variation within and among populations of P. alabamensis throughout its range and estimate admixture with co‐occurring Pseudemys species. In P. alabamensis, we found no variation in mitochondrial DNA and an excess of homozygosity in microsatellite data. Our results show genetic differentiation between Alabama and Mississippi populations of P. alabamensis, and low estimated breeding sizes and signs of inbreeding for two populations (Fowl River, Alabama and Biloxi, Mississippi). We also found evidence of admixture between P. alabamensis and P. concinna/P. floridana. Based on our results, P. alabamensis is highly endangered throughout its range and threatened by both low population sizes and hybridization. In order to improve the species’ chances of survival, focus should be placed on habitat preservation, maintenance of genetic diversity within both the Mississippi and Alabama populations, and routine population‐monitoring activities such as nest surveillance and estimates of recruitment.

Do Wind Hazard Mitigation Programs Affect Home Sales Values?

The FORTIFIED Home Program is a voluntary construction and re-roofing program designed to strengthen residential properties to withstand damages from severe weather events. The FORTIFIED designation framework can accommodate sustainable new home construction and existing property retrofitting efforts. Applying a two-state utility framework to Zillow’s ZTRAX and IBHS’s FORTIFIED designation data, we estimate the effect of a FORTIFIED Home designation on residential property values using sales transactions for coastal Alabama from 2011 to 2021. We add to the growing body of literature examining the relationship between eco-friendly construction applications and home prices by deriving the contribution of a FORTIFIED designation to enhanced risk reduction and lowered insurance costs. The results of our full- and nearest-neighbor-matched sample design suggest a likely price premium significance on the order of 2-4% for FORTIFIED homes.

‘Swallow medicine, eat rice, pray about health’: health, health care and health-seeking experiences of South-East Asian older refugees

AbstractSouth-East Asian refugees have lived in the United States of America for nearly four decades, with early refugee immigrants experiencing ageing and later life within the refugee context. As refugees age, health concerns of this older population grow, highlighting the need for ongoing assessment of refugee health and health-seeking behaviours. This study builds on previous literature that assessed the health and health-seeking patterns of South-East Asian refugees in the early years following resettlement, exploring how health and health-seeking is understood among older refugees 40 years after immigration. This paper includes a subset of 37 older refugees from a larger, community-based participatory, mixed-methods intergenerational study of Cambodian and Laotian refugee families conducted over four years (quantitative N = 433; qualitative N = 183). Thematic analysis of 34 semi-structured interviews with these older refugees in coastal Alabama revealed trends in health and health-seeking practices. Older refugees reported high rates of diabetes and hypertension within their generational cohort, and indicated a shift in health-seeking behaviours, whereby Western biomedicine is sought first for such chronic concerns, followed by traditional medicines for mild ailments such as headaches or colds. Older refugees underscored barriers of language, finances and transportation as limiting access to Western health care. Implications for engaging in community health practices and incorporating services to specifically meet the needs of the ageing refugee population are discussed.

The Potential of Wave Energy Conversion to Mitigate Coastal Erosion from Hurricanes

Wave energy conversion technologies have recently attracted more attention as part of global efforts to replace fossil fuels with renewable energy resources. While ocean waves can provide renewable energy, they can also be destructive to coastal areas that are often densely populated and vulnerable to coastal erosion. There have been a variety of efforts to mitigate the impacts of wave- and storm-induced erosion; however, they are either temporary solutions or approaches that are not able to adapt to a changing climate. This study explores a green and sustainable approach to mitigating coastal erosion from hurricanes through wave energy conversion. A barrier island, Dauphin Island, off the coast of Alabama, is used as a test case. The potential use of wave energy converter farms to mitigate erosion due to hurricane storm surges while simultaneously generating renewable energy is explored through simulations that are forced with storm data using the XBeach model. It is shown that wave farms can impact coastal morphodynamics and have the potential to reduce dune and beach erosion, predominantly in the western portion of the island. The capacity of wave farms to influence coastal morphodynamics varies with the storm intensity.

Habitat selection and abundance of West Indian manatees Trichechus manatus at the margins of their expanding range

Habitat selection and abundances at range margins during geographic expansion may influence movement into new areas, shaping the trajectory of climate-driven changes in species distribution. The West Indian manatee is an ideal species to study how habitat selection influences range expansion because its presence has rapidly increased during the past 2 decades in the northern Gulf of Mexico (nGoM), a region outside its historical range. We estimated the habitat selection and abundances of manatees in coastal Alabama waters along the nGoM coast using resource selection functions and N-mixture models, respectively. Warm season (May-Nov) manatee abundances were estimated at 25 and 34 manatees at any given time in coastal Alabama waters in 2010 and 2019, respectively. Manatees primarily used the Mobile-Tensaw River Delta and Dog River areas, selecting nearshore shallow water habitats proximate to submerged aquatic vegetation. Distance to boat ramps and human population density had stronger effects on opportunistic sighting data but remained important for tagged data, indicating that manatee habitat selection overlapped with humans. Temperature strongly predicted manatee sightings; most sightings occurred when temperatures were >20°C. Our data indicate that the key interacting factors likely to moderate manatee range expansion, and therefore be important to management and conservation of this species, include increased sea temperature, availability of nearshore habitat with submerged aquatic vegetation, and regional manatee population dynamics. As environmental conditions at the range margins continue to become more favorable to manatees and areas within the range core decline in quality, areas at the range margins may become increasingly important.

Psychological Effect of Anti-Asian Attitudes by COVID-19 on Asian Americans in Coastal Alabama

This study aimed to understand how the anti-Asian attitude due to the COVID-19 affected Asian American communities in Alabama. We asked whether Asian Americans were worried about going out due to the anti-Asian attitude due to COVID-19. This study conducted online surveys to Cambodians or Laotians, who were 18 years and older, were living in Coastal Alabama, in May 2020. To avoid in-person contact, respondents answered questions online. A total of 353 respondents participated in the survey. In the Cambodian community, more younger adults participated in the survey, while more middle-aged adults participated from the Laotian community. Laotians had longer educational attainment and watched multiple media to obtain COVID-19 related information. Cambodians (72%) were afraid of COVID-19 infection more than Laotians (53%). More Cambodians (73%) were afraid to go out because of the anti-Asian attitude than Laotians (52%). The logistic regression analysis presented that people worried more about the COVID-19 infection were less likely to go out due to anti-Asian attitudes. Educational attainment did not have a protective effect. Watching multiple media sources decreased the worry about the anti-Asian attitude for Laotians. The age cohort showed both a protective and exacerbate the effect. Cambodians, who were in their thirties, were worried about going out. However, Laotian fifties and over did not worry about going out. This difference might be related to the length of the stay in the U.S. Hanks et al. found that Cambodians, compared to Laotians, had more new immigrants who recently came to the community to marry.

Aphyllon ludovicianum (Orobanchaceae), newly reported in coastal Alabama and Florida, U.S.A.

We describe the first records of the parasitic plant Aphyllon ludovicianum in Alabama and Florida, a range extension and disjunction of over 400 miles eastward and over 500 miles southward. A key to the two species of Aphyllon in Alabama and Florida is included.

Range expansion and complete mitochondrial genome of the highfin blenny (Lupinoblennius nicholsi).

The highfin blenny, Lupinoblennius nicholsi, is a marine fish species reported in reef and rocky inshore habitats with a disjunct distribution in the southern Gulf of Mexico. Overall, there are very few studies on this species and there is a scarcity of molecular resources for genetic comparisons. We set out to report the first mitochondrial genome for L. nicholsi and report a range expansion for the species. An individual of L. nicholsi was collected from the coast of Dauphin Island, Alabama. The mitochondrial genome was sequenced, assembled, and annotated. The fragment corresponding to cytochrome oxidase I (COI) was used to compare this sample to other cryptobenthic species of the Atlantic. Finding a mature individual in the coast of Alabama implies this species has a continuous distribution throughout the northern Gulf of Mexico. The mitochondrial genome of L. nicholsi is 16,416bp in length and comprised of 13 protein coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a non-coding D-loop. Comparisons using COI support the species is L. nicholsi and separate it from other cryptobenthic fishes found in the area. This study represents the first mitochondrial genome for this L. nicholsi, serving as a reference for future comparative studies with marine fishes. By reporting the range expansion of this species, this study provides insights on the fish diversity of the Gulf of Mexico.

Our Wastewater Footprint

Collaboration among scientists and stakeholders is increasingly valued in research to coproduce knowledge and research products that better inform decision making and enact meaningful change. We present an example of effective coproduction of knowledge to protect water quality along the Mississippi–Alabama coast using a comprehensive approach that tracked progress from initial research through product assessment. We coproduced an education and decision support tool known as “Our Wastewater Footprint” and engaged communities through a variety of public outreach efforts, adapting the product to meet the needs of individual end users. We assessed the effectiveness of our efforts by tracking attendance at outreach activities, measuring website traffic, and collecting survey data from end users after product use. Data from >9,900 users indicated that presentations at community events and print and social media posts most efficiently reached large audiences using limited resources, and social media posts were most effective in promoting changes in behavior and attitudes on a social level. This case study exemplifies how involving stakeholders in research and product development can increase community engagement in stewardship and prompt change to enhance water quality. Our results tangibly demonstrate that meaningful assessment of the administrative and social impacts of coproduced knowledge is feasible and can be accomplished in a short period of time.

Intergenerational Transmission of Traumatic Stress and Resilience Among Cambodian Immigrant Families Along Coastal Alabama: Family Narratives.

Purpose: Intergenerational transmission of psychological trauma is an ongoing global public health concern. Cambodia experienced ∼4 years of genocide, causing about 2 million deaths. Many survivors fled and resettled in the United States where they continued to face the psychological and relational consequences of forced displacement, with limited access to mental health treatment. This study employed an ecological social determinants of health framework to explore how resettled families discussed traumatic experiences and resilience transmitted across three generations.Methods: Narrative inquiry-guided, in-depth semistructured interviews were conducted with intergenerational families: five grandparents, six parents, and nine adult children. The interview protocol included developing detailed family genograms that facilitated the sharing of experiences of living through the Cambodian genocide (1975–1979) and resettlement to the United States in the 1980s. A thematic data analysis was conducted across individual and family experiences before, during, and after the genocide and resettlement.Results: The findings highlight parent–child relationships as the primary mechanism of intergenerational transmission of traumatic stress and resilience among Cambodian immigrant families. Specifically, high parental expectations, authoritarian parenting, corporal punishment, and submissive communication styles were reported. On the other hand, strong bonds and less hierarchy between parents and children were found to be resilience factors among this population.Conclusions: The results of this qualitative study underscore the need for a systemic mental health conceptualization for practitioners working with resettled Cambodian families to overcome the cycle of intergenerational transmission of traumatic stress and promote resilience postresettlement.

Dynamics of Mud Blister Worm Infestation and Shell Repair by Oysters.

AbstractMud blister worms bore into oyster shells; and oysters respond to shell penetration by secreting new layers of shell, resulting in mud blisters on inner surfaces of oyster shells. We conducted two experiments in off-bottom oyster farms along Alabama's coast in summer 2017 to explore the dynamics of worm infestation, blister formation, and shell repair. Results support our hypothesis that only a small proportion of worms that bore into oysters cause blisters. Triploid oysters had fewer blisters than diploids, likely because of faster growth and shell repair. We treated oysters to remove mud blister worms, redeployed them at intertidal and subtidal sites for nine weeks, and found that reinfestation by worms occurred only in subtidal oysters. Intertidally deployed oysters showed no visible blister coverage, indicating recovery, whereas blister coverage increased in subtidal oysters. Reinfestation of subtidal oysters was correlated with previous burrow damage, visualized with X-ray images, thus supporting our hypothesis that worms preferentially settle in previously infested shells. Forces required to break blisters, measured with a custom-built shucking knife with an integrated force sensor, were low relative to forces required to shuck oysters, possibly because our experiment was conducted when worm infestation was increasing. Higher forces were required to break smaller, lighter-colored blisters, consistent with blister recovery; but results were highly variable and not consistent across sites and sampling times, suggesting that size and color of blisters alone did not explain shell strength. Our results indicate that oysters repair shells slowly relative to more dynamic patterns of worm infestation.

Older Adult Refugees’ Roles in Creating Partnerships for Culturally Responsive Healthcare

The aim of this presentation is to reveal the importance of engaging older refugee community members in creating partnerships with local healthcare providers to implement culturally responsive interventions. Such engagement invites older refugees’ participation and encourages continued connection to country of origin beliefs and culture, particularly within the sphere of healthcare and medical family therapy. Cambodian and Laotian refugee families in coastal Alabama were interviewed via qualitative community-based participatory research and ethnographic, in-depth interviews focused on familial and communal processes. Local healthcare providers engaged in focus group discussions regarding cultural processes associated with health beliefs and behaviors and in periodic outreach through culturally responsive health fairs. We found that older adults play important roles in refugee populations as community leaders, problem-solvers, and legacy-carriers upholding traditional values and cultural continuity. They also maintain and promote continuity by employing traditional, complementary, or alternative medicine (TCAM). Recursive processes also emerged as older individuals sought care from younger community members in times of sickness, including having younger generations provide language translation and transportation to local healthcare centers and hospitals and in navigating the United States healthcare system. In addition, community members joined with local healthcare providers to aide in health and healthcare literacy among refugees and to educate local physicians on culturally responsive interventions. Implications include the inclusion of older adults in health decisions and the promotion and maintenance of community partnerships with health agencies that both encourage TCAM utilization and also allow for access to ongoing, appropriate treatment within the US healthcare system.

Gaseous Elemental Mercury Concentrations along the Northern Gulf of Mexico Using Passive Air Sampling, with a Comparison to Active Sampling

Mercury is a toxic element that is dispersed globally through the atmosphere. Accurately measuring airborne mercury concentrations aids understanding of the pollutant’s sources, distribution, cycling, and trends. We deployed MerPAS® passive air samplers (PAS) for ~4 weeks during each season, from spring 2019 to winter 2020, to determine gaseous elemental mercury (GEM) levels at six locations along the northern Gulf of Mexico, where the pollutant is of particular concern due to high mercury wet deposition rates and high concentrations in local seafood. The objective was to (1) evaluate spatial and seasonal trends along the Mississippi and Alabama coast, and (2) compare active and passive sampling methods for GEM at Grand Bay National Estuarine Research Reserve, an Atmospheric Mercury Network site. We observed higher GEM levels (p < 0.05) in the winter (1.53 ± 0.03 ng m−3) compared to other seasons at all sites; with the general pattern being: winter > spring > summer ≈ fall. Average GEM levels (all deployment combined) were highest at Bay St. Louis (1.36 ± 0.05 ng m−3), the western-most site nearest the New Orleans metropolitan area, and lowest at Cedar Point (1.07 ± 0.09 ng m−3), a coastal marsh with extensive vegetation that can uptake GEM. The MerPAS units compared reasonably well with the established active monitoring system, but gave slightly lower concentrations, except in the winter when the two methods were statistically similar. Both the passive and active sampling methods showed the same seasonal trends and the difference between them for each season was <15%, acceptable for evaluating larger spatial and temporal trends. Overall, this work demonstrates that PASs can provide insight into GEM levels and the factors affecting them along coastal regions.

Movement patterns of red snapper Lutjanus campechanus based on acoustic telemetry around oil and gas platforms in the northern Gulf of Mexico

Offshore oil and gas platforms in the northern Gulf of Mexico are known aggregation sites for red snapper Lutjanus campechanus. To examine habitat use and potential mortality from explosive platform removals, fine-scale movements of red snapper were estimated based on acoustic telemetry from March 2017 to July 2018. Study sites in the northern Gulf of Mexico, USA, included one platform off coastal Alabama (30.09°N, 87.88°W) and 2 platforms off Louisiana (28.81°N, 91.97°W; 28.92°N, 93.15°W). Red snapper (n = 59) showed a high affinity for platforms, with most (94%) positions being recorded within 95 m of the platforms. Home range areas were correlated with water temperature and inversely correlated with dissolved oxygen concentrations. During summer and fall, red snapper used larger areas and many fish (54%) emigrated from their platforms but most (83%) returned in ≤3 d. Site fidelity for red snapper was 31% yr-1 and residency time was 7 mo, but the probability-of-presence at platforms was 70% after 1 yr, indicating the importance of platforms for this species. Overall fishing mortality was high for platforms (F = 0.86, 95% CL = 0.47-1.40), but since the stock is managed on a quota basis this high mortality should have little effect on total stock abundance. Thus, platforms can still provide an important habitat for red snapper, and consideration of area use patterns, fishing mortality and environmental factors can reduce red snapper mortality when scheduling explosive platform removals. As such, the present study indicates that an optimum time for explosive removal would be in late summer after the red snapper fishing season is completed.

Disturbance-driven changes to northern Gulf of Mexico nekton communities following the Deepwater Horizon oil spill

The 2010 Deepwater Horizon (DwH) oil spill in the Gulf of Mexico discharged ~3.19 million barrels of oil into Gulf waters, making it one of the largest marine disasters in history in terms of volume. We report on the results of a study to assess oil impacts to coastal fishes and invertebrates. Using two-decades of fisheries-independent data in coastal Alabama and Mississippi, we document variability following both natural and anthropogenic disturbances from two periods pre-DwH (1997–2001 and 2007–2009), one intra-spill period for acute DwH effects (2010–2012) and one period post-spill for chronic, longer-term impacts (2014–2017). Results indicated significant changes to community structure, relative abundance, and diversity in the intra-spill period. Causation for changes is confounded by variables such as behavioral emigration, altered freshwater inflow, death of consumers, and the mandated fishery closure. Results highlight the need for long-term, comprehensive monitoring/observing systems to provide adequate background for assessing future disturbances.

Characterizing nitrogen attenuation by headwater slope wetlands across different land uses

Rapidly increasing population pressure and land conversion from forests to urban and agricultural uses have been important stressors on coastal wetlands. Headwater wetlands in the southeast U.S. are particularly vulnerable because of their small size- they are easily filled or impacted through ditching, piping or impoundments. Since headwater areas have a disproportionately high influence on watershed flow and nutrient flux, alterations to their functionality can have impacts to downstream and coastal waters. Although headwater wetlands are generally understood to support water quality, the magnitude and mechanisms for this function are often uncertain. We compared flow, NO2−-N + NO3−-N (NO2 + NO3) concentrations, and NO2 + NO3 loads at the inlet and outlet of four headwater slope wetlands across common land covers/uses (i.e., commercial-urban, residential-suburban, agriculture, and forested) in coastal Alabama, USA. Watershed sizes draining to wetlands ranged from 0.5–1.8 km2 and each wetland showed distinct and shared trends. Measured NO2 + NO3 concentrations were typically low (<0.4 mg L−1) in all wetlands except for the agricultural watershed. The wetland in the residential watershed experienced high NO2 + NO3 loading rates into the wetland (21.6 kg ha−1 yr−1) however this was because of unusually high discharge to the wetland relative to its watershed size (overall mean: 0.13 m3 sec−1). Annual NO2 + NO3 loading rates from the forested and commercial-urban lands were much lower (<1.0 kg ha−1 yr−1). Despite drainage alterations at all sites, wetlands still provided annual NO2 + NO3 load reductions ranging from 13.1–62.0% although the commercial-urban wetland achieved reductions primarily through hydrologic recharge. Evidence from this study and others along the northern Gulf of Mexico coast indicate that low-order stream discharge can be relatively high and in some cases may drive high nutrient loading rates. Even though the natural drainage to most headwater wetlands has changed, they still can provide reliable attenuation of nitrate and other nutrients particularly where efforts are made to maintain a more natural wetland hydroperiod.

Habitat-Suitability Model for the Yellow Rail (Coturnicops noveboracensis) in the Northern Gulf Coast of Alabama and Mississippi, USA

The yellow rail (Coturnicops noveboracensis) is a migratory bird of high conservation priority throughout its range and winters across the Atlantic and Gulf Coastal Plains regions of the southeastern United States. Although the winter ecology of this species has been recently explored, no studies have addressed their distribution and abundance in relation to suitable habitat capable of supporting this species during winter along the northern Gulf Coast of Alabama and Mississippi. The objectives of this study were to develop a habitat-suitability model for yellow rail wintering in the northern Gulf Coast of Alabama and Mississippi. We then used this model to evaluate the distribution of habitat suitable for supporting yellow rail in this geographic area. Using a multivariate approach that makes use of presence-only data through a maximum entropy framework we compared the distribution of where the focal species was observed to a reference set of the whole study area. Of the 784,657 ha over which our model was applied, only 1% (8643 ha) of this area was predicted suitable in its present condition, for supporting yellow rail in winter. Our analysis indicates that the yellow rail along the northern Gulf Coast of Alabama and Mississippi occupy a very narrow range of environmental conditions highlighting need for specific management actions to maintain and conserve suitable winter landscapes for this habitat-restricted species.

Habitat Associations and Co‐Occurrence Patterns of Two Estuarine‐Dependent Predatory Fishes

AbstractEstuarine‐dependent fishes experience a wide range of environmental conditions, and most species exhibit distinct associations with particular habitats. However, similar species or multiple conspecifics often overlap spatiotemporally, which can result in ecological interactions that have consequences for behaviors that can shape the structure and function of ecosystems. We used a long‐term gill‐net data set (2001–2015) to investigate the habitat associations and co‐occurrence patterns of two estuarine‐dependent predatory fishes, Red Drum Sciaenops ocellatus and Spotted Seatrout Cynoscion nebulosus, in coastal Alabama, USA. Both species were associated with similar environmental conditions, primarily low dissolved oxygen and low salinity, especially when temperature was low. However, differences emerged between the species with respect to the effects of interacting environmental variables on their habitat use patterns, which were likely driven by physiological, biological, and ecological dissimilarities between them. Concerning their biogenic habitat use, extensive submerged aquatic vegetation (SAV) was an important habitat for both species, but Spotted Seatrout appeared to prefer high‐salinity SAV beds, while Red Drum associated with SAV regardless of salinity. Spotted Seatrout were associated with extensive emergent marsh edges, and the positive relationship between Red Drum and SAV was diminished when marsh edge was abundant. Co‐occurrence was observed primarily in habitats with which both species were associated, most frequently in shallow, prey‐rich marsh edges and high‐salinity seagrass beds. These observed habitat use patterns elucidate the subtle differences in resource use that allow these species to coexist and suggest potential areas where interactions between them may shape their roles as predators.

The Propagation of Fluvial Flood Waves Through a Backwater‐Estuarine Environment

AbstractCoastal cities and ports are located along estuaries and deltas where flooding from rivers can be as devastating as storm surges. Precise river discharge measurements are taken far inland of marine influences and backwater environments, creating large timing and magnitude uncertainties downstream at the coast. Long‐term discharge, water level, velocity, and salinity measurements in coastal Alabama were used to observe the timing and magnitude of discharge events flowing 238 km from rivers to the Gulf of Mexico as river flood (fluvial) waves. Waves were described and simplified using a momentum balance, phasing techniques, and wave theory from inland rivers. Results showed the coastal backwater environment transitioned to a drawdown (i.e., plunging water profile) at bankfull discharge and suggested the drawdown location and intensity was strongly influenced by the frictional transition of the delta from tupelo‐cypress forest to oligohaline marsh. The horizontal (velocity) and vertical (water level) components of fluvial waves were observed propagating through this dynamic deltaic‐estuarine environment transitioning from in phase diffusive waves to out of phase dynamic waves. The wave celerity increased with surface water slope and decreased with cross‐sectional area. Instead of larger events propagating faster, the geometry (i.e., levees and floodplains) and flooding significantly delayed and attenuated the magnitude of discharge reaching the gulf. This flooding downstream of discharge measurements modulated the estuarine water level, velocity, and flushing of salt. The use of fluvial wave theory will increase the precision of coastal flooding predictions for stakeholders and research now, as well as under future sea level rise.