This study aims to review thirteen coastal restoration projects considering the various ecosystem services provided by restoration and estimates the economic value of one of the ecosystem services of restoration. These ecosystem services include water quality improvement, fish and benthic species productivity, shoreline stabilization, oyster abundance, and marsh growth. The projects represent a set of large-scale projects within Alabama and Mississippi, with construction and monitoring costs ranging from $2.3 million to $50 million per project. To determine the economic value of one of the ecosystem services of coastal restoration projects, I used the meta-analysis method to estimate the willingness to pay (WTP) for coastal water quality improvements. The estimated function from the meta-analysis is applied to parameters specific to the study area. The WTP for improved coastal water quality, from a baseline of fishable but likely to degrade, to an improved fishing catch rate, is $203 per household annually among residents of Alabama and Mississippi.

Marshes and seagrass beds have been widely recognized as important habitat for estuarine species, but less has been done on how these habitats interact and function together, thereby limiting understanding of the variability of juvenile recruitment to coastal systems. Therefore, the objective of this study was to assess the interaction between fringing marsh and adjacent seagrass for the provision of habitat for juvenile nekton. Weekly seine net and benthic seagrass core sampling from June to November 2020 determine the relationship between nekton and marsh-edge and seagrass habitat. This study shows disparate results, in terms of the effects of proximity to marsh edge and seagrass biomass on nekton abundance and size, pointing to different selectivity of marsh edge versus seagrass by different species. In addition, there are no effects of proximity to marsh edge and seagrass biomass on community composition, but an interactive effect on community dispersion.

Nature-based solutions (NBS) are promising strategies for protecting vulnerable coasts in the context of climate change, utilizing the coastal protection capabilities of natural ecosystems for engineering applications. The ability of coastal marsh vegetation to attenuate wave energy and prevent coastal erosion has been acknowledged for decades, however, consideration for their use in coastal protection strategies is presently limited, particularly in Canada due to a lack of engineering guidelines and limited available research considering region-specific variables. Physical modelling presents a useful tool for investigating the coastal protection function provided by marsh vegetation in a controlled, repeatable environment, which can ultimately inform the design of nature-based coastal protection strategies. To date, such studies have investigated the influence of plant biophysical parameters (stem flexibility, width, and height) and hydrodynamic conditions (wave height, wave period, and plant submergence) on wave attenuation. These studies have used either live vegetation, requiring full-scale wave testing, or surrogate vegetation, which allows simplified testing at either full- or reduced-scale. Overall, live vegetation studies have been limited in the variety of saltmarsh plants considered, with few studies considering plant species native to the Canadian coastline. Several physical modelling studies have been performed using surrogate plants, however, methods of surrogate development for flexible vegetation or reduced-scale testing are not yet well developed. This thesis aims to address knowledge gaps pertaining to the use of marsh vegetation in coastal protection strategies, particularly through the development of experimental methods with both live and surrogate plants. A full-scale flume study with live vegetation was performed to develop fundamental knowledge of wave-vegetation interactions for Spartina alterniflora and Spartina patens, two salt marsh species native to Canada’s Atlantic coast. S. alterniflora was observed to demonstrate a resistance strategy in response to hydrodynamic forcing, versus the avoidance strategy of S. patens, supporting complementary functioning of the two species if utilized together in coastal protection schemes. Observations of plant properties and stem bending from live plant tests were subsequently applied in the development of a small-scale flume study, which examined wave attenuation associated with a downscaled S. alterniflora meadow in the configuration of a “living dyke” structure. Wave damping induced by surrogate vegetation was observed to be minimal for the tested wave conditions (0.073 m < Hm0 < 0.225 m, 2.0 < Tp < 3.2 s, 1:4 scale) and beach slope (1V:20H), with wave height evolution dominated by wave shoaling and breaking. Several methods were considered for modelling the S. alterniflora meadow at reduced scale, and results demonstrated a sensitivity to surrogate diameter but not flexibility. The development of robust experimental methods for investigating the performance of nature-based coastal infrastructure is essential for the establishment of appropriate design conditions. The scale series approach of this thesis supports such methodological advancements and is expected to make preliminary contributions to design guidance on coastal marsh-based NBS and provide critical direction for future studies.

Acrocephalus warblers have gone through the adaptive radiation during last severalmillion years, which gave rise to thirty one species occupying mainly Eurasia,Africa and Australia. The majority of species are morphologically very similar,however, they differ in ecological requirements, migration strategy, and song.Interspecific hybridization seems to be quite common among Acrocephaluswarblers, not only between sister species, but also between more distantly relatedtaxa. The main goal of this study was to determine whether this hybridization leadsto gene flow between species and which factors affect the rate of interspecific geneflow. For this purpose we conducted population-genetic analysis in three Europeanspecies of the Acrocephalus warblers of the subgenus Notiocichla: reed warbler (A.scirpaceus), marsh warbler (A. palustris), and blyth's reed warbler (A. dumetorum).Our results based on the analysis of sequence data from eight nuclear loci indicate,that gene flow between the studied species occurs, but only in one direction. Thegene flow is higher between genetically more related species than betweenecologically more similar species. We also estimated that the reed warbler and themarsh warbler diverged approximately 1,1 million years ago. The blyth's warblerand ancestor of the reed and marsh warbler...

This research investigated the feasibility and benefits of integrating geospatial technology with traditional ecological knowledge (TEK) of an indigenous Louisiana coastal population in order to assess the impacts of current and historical ecosystem change to community viability. The primary goal was to provide resource managers with a comprehensive method of assessing localized ecological change in the Gulf Coast region that can benefit community sustainability. Using Remote Sensing (RS), Geographic Information Systems (GIS), and other geospatial technologies integrated with a coastal community's TEK to achieve this goal, the objectives were (1) to determine a method for producing vulnerability/sustainability mapping products for an ecosystem-dependent livelihood base of a coastal population that results from physical information derived from RS imagery and supported, refined, and prioritized with TEK, and (2) to demonstrate how such an approach can engage affected community residents who are interested in understanding better marsh health and ways that marsh health can be recognized, and the causes of declining marsh determined and addressed. TEK relevant to the project objectives collected included: changes in the flora and fauna over time; changes in environmental conditions observed over time such as land loss; a history of man-made structures and impacts to the area; as well as priority areas of particular community significance or concern. Scientific field data collection measured marsh vegetation health characteristics. These data were analyzed for correlation with satellite image data acquired concurrently with field data collection. Resulting regression equations were applied to the image data to produce estimated marsh health maps. Historical image datasets of the study area were acquired to understand evolution of land change to current conditions and project future vulnerability. Image processing procedures were developed and applied to produce maps that detail land change in the study area at time intervals from 1968 to 2009. This information was combined with the TEK and scientific datasets in a GIS to produce mapping products that provide new information to the coastal restoration decision making process. This information includes: 1) what marsh areas are most vulnerable; and 2) what areas are most significant to the sustainability of the community.

This thesis investigates whether lead mining can be detected using palaeoenvironmental data recovered from freshwater loch and marsh sediment. Using radiometric time-frames and geochernical analyses the environmental impact of 18th and 19th century mining on Islay, Inner Hebrides, Scotland, has been investigated. The model of known mining events thus produced has been used to assess previously unrecorded (early) lead mining activity. Previous mining in the area is suggested by 18th century accounts that record the presence of 1,000 "early" workings scattered over the north-east limestone region. While there is little to support the often repeated assertion that lead mining dates back to the Norse Period (circa lOll th centuries) it is clear that it may well have been an established industry prior to the time of the first historical records in the 16th century. In order to use a palaeoenvironmental approach to the question of mining history and its impact, the strategy has been to use integrated loch and catclunent units of study. The areas considered are; Loch Finlaggan, Loch Lossit, Loch Bharradail and a control site at Loch Leathann. Soil and sediment geochemical mapping has been used to assess the distribution of lead, zinc and copper within the catchments. Environmental pathways have been identified and influx of lead, zinc and copper to the loch sediment has been detennined through the analyses of cores from each loch basin. Archaeological fieldsurvey and the re-examination of the results from mineral prospecting data across the study region provides new evidence on the geographical extent and contaminatory effects of leadmining in this area. This study shows how the effect of lead mining can be identified in the palaeoenvironrnental record from circa 1367 AD onwards, so mining in Islay does indeed predate the earliest known archaeological and historical records.

Spartina anglica est une espèce exotique hybride qui peuple les zones humides littorales. Elle s’est installée dans le Bassin d’Arcachon au cours des années 1980, envahissant fortement les prés salés et les platiers vaseux préalablement occupés par, respectivement, Spartina maritima et Zostera noltei. Face aux inquiétudes suscitées par cette installation, cette thèse vise à comprendre, par une approche pluridisciplinaire, les mécanismes d’invasion et ses conséquences sur le milieu physique et sur les espèces végétales natives. L’objectif de ce travail est d’étudier l’occupation de niche par S. anglica et ses interactions avec deux espèces intertidales natives : S. maritima et Z. noltei.L’analyse d’images aériennes et satellitales a montré que, 30 ans après l’invasion, dans une zone densément peuplée par la Spartine native, la zone haute des prés salés a peu changé : la Spartine anglaise a occupé des niches vides et n’a pas remplacé la végétation native. Une expérience de transplantation réciproque et de mesures de biomasses confirment ce résultat, en montrant que l’espèce native offre une résistance à la colonisation de l’espèce exotique. L’expansion de la Spartine anglaise vers les replats de marée de l’intérieur du Bassin serait ainsi liée à sa capacité à tolérer les perturbations physiques, à sa forte plasticité de croissance en milieu oxygéné et riche en nutriments et à son comportement auto-facilitateur. Sa forte capacité d’ingénieur d’écosystèmes semble être liée à son système racinaire très développé, qui améliore l’aération des sols fortement anoxiques.Les effets de la colonisation par l’espèce exotique des zones intertidales basses à subtidales sur la Zostère naine sont importants sur le long-terme (dizaines d’années). En tant qu’ingénieur d’écosystèmes, la Spartine exotique favorise l’élévation du sol par sédimentation, entrainant une dessiccation du sédiment, peu favorable à la Zostère. Des mesures physiques au sein de patchs de l’espèce exotique suggèrent que l’élévation du sédiment est toutefois lente, surtout liée à une allocation de biomasse spécifique aux racines ainsi qu’à des rhizomes qui permettent de résister à l’érosion.En termes de gestion et de conservation des prés salés du Bassin d’Arcachon, ces résultats indiquent l’importance de limiter les perturbations physiques et les apports nutritifs qui pourraient rompre la résistance à l’invasion de la Spartine native. Ils supportent aussi l’idée que la Spartine anglaise pourrait être un allié robuste face à l’élévation du niveau de la mer. / Spartina anglica is a hybrid exotic cordgrass that inhabits coastal salt marshes. This species arrived in the Bay of Arcachon in the 1980s and since has importantly colonized the salt marshes and tidal flats formerly only occupied by the native Spartina maritima and Zostera noltei, respectively. This work aims at understanding, with an interdisciplinary perspective, the invasion mechanisms of this exotic cordgrass and the outcoming changes of its introduction in the Bay, both to the physical environment and to the native vegetation. Different approaches were considered in order to assess the niche occupancy by the exotic Spartina and its interactions with the native intertidal species, Spartina maritima and Zostera noltei.The analysis of aerial and satellite images has shown that, in about 30 years after the invasion, within a zone densely populated by the native Spartina, the global high marsh zone did not suffer significant changes with the arrival of the invasive species. Spartina anglica did not replace the existent marsh vegetation, it occupied empty niches along the intertidal area instead. Additionally, experimental works of cross transplantation and biomass measurements have corroborated that the native Spartina maritima offers resistance to the colonization by the exotic Spartina. It was also shown that the invasive occupies the same intertidal niche along the elevation and anoxic gradient than the native. The successful extension of Spartina anglica into the mudflat towards the inner Bay was related to its likely ability to tolerate physical disturbances, its strong growth plasticity in nutrient- and oxygen- rich patches and its self-facilitator behaviour. This latter trait is related to its strong ecosystem-engineering ability due to its prominent root system and consequent ability to ameliorate the oxygenation of highly anoxic soils.The main effect of the exotic Spartina species on the seagrass is related to its stronger ecosystem-engineering ability, favouring bed accretion up to levels that are not favourable to Z. noltei through enhancement of desiccation stress. However, hydrodynamic and altimetry measurements have shown that the process of bed accretion is slow and, due to the cordgrass’ specific preferential biomass allocation to roots, its efficiency is more linked to its resistance to erosion rather than sediment trapping.The results of this study provide relevant information for the definition of appropriate action and conservation strategies of marsh zones in the Bay of Arcachon, and in particular the importance of limiting physical disturbance and nutrient pollution that could disrupt the biotic resistance of the native cord grass. They also suggest a potentially important role of the exotic species in facing increasing Sea Level Rise.

Wildlife biologists and land managers tasked with the recovery of the endangered Lower Keys marsh rabbit (LKMR; Sylvilagus palustris hefneri) were in need of a current population estimate as well as a method to estimate the LKMR population annually. Habitat loss and fragmentation from population growth and development have threatened the existence of the LKMR. Establishing and understanding long-term habitat availability for the LKMR is important for determining causes of historical population declines as well as designing and implementing successful recovery plans. I conducted a range-wide pellet survey and a mark-recapture study to estimate the LKMR population. I evaluated the fit of 5 models and considered the variation in behavioral response model the best model. I correlated (r2 = 0.913) this model's rabbit abundance estimates to pellet density in 11 patches and generated a range-wide population estimate of 317, a western clade population of 257, an eastern clade population of 25, and translocated LKMR populations of 35 and 0 on Little Pine and Water keys, respectively. This prediction equation provides managers a quick, efficient, and non-invasive method to estimate LKMR abundance from pellet counts. To quantify the amount of habitat loss and fragmentation that occurred over the last 50 years, I systematically delineated and compared potential LKMR habitat using 1959 and 2006 aerial photographs. Additionally, I investigated if other factors could have reduced the amount of suitable habitat available for the LKMR with a comparison of habitat loss and fragmentation on a developed island and an undeveloped island. Range-wide, I found that number of habitat patches increased by 38, total class area decreased by 49.0%, and mean patch size decreased by 44.3%. Mean shape index increased by 4.2% and mean proximity index decreased by 13%. Both the 1959 and 2006 connectance indices were low while the 2006 set decreased 12.1%. I observed the same patterns of habitat loss and fragmentation on both the developed and undeveloped islands as I did in the range-wide landscape analysis. I found that LKMR habitat has declined in area and become more fragmented over the last 50 years. Habitat loss and fragmentation by development have directly endangered the LKMR; however, sea level rise and woody encroachment also could have historically caused habitat loss and fragmentation. Although development in LKMR habitat was halted, sea-level rise and woody encroachment could continue to alter LKMR habitat.

The numerous benefits that wetlands provide make them essential to ecosystem services and ecological functions. Historically, wetland losses have been caused by natural and anthropogenic changes. In Texas, nearly 50% of coastal wetland habitat has been lost since the 1930s and losses in the Lower Neches watershed have been some of the most extensive. Restoration is a way to mitigate these losses and can be accomplished in many ways. Each restoration design creates different aquatic habitats that can influence both submerged aquatic vegetation (SAV) and faunal communities. The restoration of the Lower Neches Wildlife Management Area (LNWMA) has created the conditions for the growth of the invasive submerged macrophyte, Myriophyllum spicatum (Eurasian watermilfoil) which may be competing with the native aquatic grass, Ruppia maritima (widgeongrass) for essential nutrients. In this study, an attempt was made to link restoration design with both SAV and aquatic fauna community structures by using a throw trap to characterize assemblages observed in three different types of restored marshes. We also performed two controlled mesocosm experiments in 0.5 gal aquariums to determine growth inhibition by M. spicatum on R. maritima. Analyses using Kruskal-Wallis non-parametric test determined that temporal variations in fauna and SAV community composition was greater than any restoration effect. Discriminant Function Analyses (DFAs) determined two to three key faunal species that best predicted association among restoration designs, but linear regressions could not determine any consistent relationship between individual species density and biomass of the dominant SAV species, M. spicatum. For the mesocosm experiments, M. spicatum inhibited the biomass production and branch count of R. maritima when the two species are grown together (ANOVA, p = 0.004 and 0.003, respectively). Changes in SAV assemblages due to competition and habitat characteristics could play a major role in determining faunal community. In order to minimize the temporal effect observed and better determine any habitat pattern that may be present, a much longer study is necessary.

Cattle ranching in Vermilion Parish is a social-techno-ecological system (STES) that is currently vulnerable due to changing social, technological and ecological conditions. In addressing ways to increase the adaptive capacity of cattle ranching in Vermilion Parish, I used a multiple, mixed method approach grounded in a critical constructivist framework. Constructivism is the idea that our relationship to facts is constructed by our social context. It is these perceptions that shape people’s actions. By looking at these perceptions through an emancipatory frame I was able to understand multiple interpretations of meaning, consciously address them, consider how they may have shaped our actions, and then alter those meanings and power relationships. In an effort to increase the adaptive capacity of cattle ranching in Vermilion Parish, my research focused on actions, why people perform those actions, and how to change them. This research connected the physical landscape of the marshes, the individual landscape of perception, and the conceptual landscape of resilience. If resilience is the ability of a system (cattle ranching in vermilion parish) to recover after a disturbance, adaptive capacity is when the actors within the system can influence that system’s resilience. I explored the history of cattle ranching in Vermilion Parish from three different, but overlapping perspectives – environmental, social, and technological. These perspectives compliment the information from interviews and 3CM sessions. These 15 interviews revealed the perception of 11 types of threats facing cattle ranching in Vermilion Parish. The body of literature surrounding resilience theory identifies traits of highly adaptive systems. The recommendations and suggestions outlined in Chapter 6 exist at the intersection of the actors’ perception of specific threats and the decidedly generalized traits of highly adaptive systems. These suggestions were geared towards increasing the adaptive capacity of cattle ranching in Vermilion Parish. Given these layered landscapes and their complexity, my recommendations were subject to feedback loops and long periods of integration. These recommendations contribute to the theoretical foundation detailed in Chapter 3 by identifying specific ways that the actors of this particular system may be able increase their own adaptive capacity. / text