No description available.

The Naples Bay Estuarine System, situated in southwest Florida, has undergone extensive modifications caused directly and indirectly by anthropogenic influences. These alterations include the substitution of mangrove-forested shorelines with concrete bulkheads, canalization of the watershed and along the bay shoreline, and navigational channel dredging. The system consists of northern Naples Bay, southern Naples Bay, and Dollar Bay, whose shorelines range from highly developed to undeveloped, respectively. This project explored the natural geological response of the system to these alterations using data from side scan sonar, sediment grab samples, and vibracores. In highly urbanized northern Naples Bay, benthic substrates consist primarily of muddy sands, with few oyster reefs. Southern Naples Bay and Dollar Bay, however, consist of coarser sediment, and are characterized by extensive mangrove shorelines and numerous oyster reefs. The impact of anthropogenic alterations has significantly shifted sediment distributions in northern Naples Bay from a coarser to a finer grained substrate. This shift has occurred to a lesser degree in southern Naples Bay, and Dollar Bay has not made this transition, due to the relative lack of anthropogenic modifications made to this part of the system.

Thesis (Ph. D.)--Washington State University, August 2006. / Includes bibliographical references (p. 64).

There is strong scientific consensus on the evidence of anthropogenic climate change which will increasingly present social, economic and institutional challenges. The Fifth Assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) established that ‘human influence on the climate system is clear’ and that ‘changes in many extreme weather and climate events have been observed since about 1950’ (IPCC 2014a). Associated impacts include sea level rise and increased likelihood of extreme weather worldwide such extreme rainfall, heat waves, hurricanes and tornados (IPCC 2014a; Klijn et al. 2015). Climate change adaptation is the adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects in order to minimise the impacts and to take advantage of new opportunities (IPCC 2007). Many vulnerable countries, regions and cities have accepted that some form of adaptation is inevitable (Swart et al. 2014). This thesis contributes to the research on decision-making for climate change adaptation in order to reduce vulnerability. Both bottom-up and top-down analyses are applied to complement one another with an application to flooding. Flood risk is expected to increase in the UK under climate change (Alfieri et al. 2016; Scottish Government 2016) associated significant economic damage (CEA 2007). From a top-down perspective, the thesis explores how to enhance economic decision-making under climate change uncertainty. In a situation of uncertainty the costs may be clear and immediate whereas the benefits are uncertain and often only realised in the distant future. This impedes the use of standard decision-making tools such as cost-benefit analysis that rely on the quantification of (expected) costs and benefits. The thesis begins on the macro scale with a taxonomy of economic decision-making tools for climate change adaptation, discusses the sector level and subsequently proceeds to the case study micro-scale with applications of adaptation decision-making. First, the potential of alternative decision-making tools, so-called robust decision-making approaches, is examined. The strengths and weaknesses of these tools relative to traditional decision-making processes such as CBA are explored and their future potential in the adaptation process evaluated. It is found that robust decision-making tools under uncertainty provide performance across a range of climate change scenarios, but they may yield lower overall performance if compared with the alternative strategy under the actual climate outturn. Furthermore, they are resource intense and decision makers need to balance the resources required for employing the methods with the added value they can offer. A flow-chart is developed to provide guidance on which decision-making tool should be applied depending on the scale and type of adaptation project. On the sector level, the economic appraisal of adaptation options for agriculture is explored. Agriculture is particularly vulnerable to climate change due to the direct impacts of weather and climate on agricultural output and the sector plays an indispensable role in providing (and improving) food security as well as creating employment. Many of the adaptation options in agriculture involve short-term managerial changes and can be appraised with standard economic decision-making and the options can be carried out after the climate signal has been observed. For those adaptations that do require a longer time to take effect or are long-lived and are (partly) irreversible in nature, robust approaches have a valuable role to play in decision-making. Suggestions are made regarding how robust decisionmaking tools under uncertainty can be practically applied to adaptations in agriculture, outlining the data needs and the steps of the data analysis for three different applications. On the micro level, for a case study in the Eddleston Water catchment in the Scottish borders, UK, two different economic appraisal tools are applied. These include a cost-benefit analysis of afforestation as a flood management measure under different climate change scenarios which can provide important insights for adaptation decisions when robust decision-making tools under uncertainty are not feasible due to resource constraints. It is found that the flood risk under climate change increases substantially in the case study area which needs to be taken into consideration for economic appraisal. The results of the CBA reveal that all modelled scenarios of afforestation have positive NPVs which are driven by further eco-system services (including climate regulation, water quality and recreation) rather than flood regulation benefits. It is concluded that eco-system services beyond flood regulation should be considered for the appraisal of NFM to enable policy-makers to make informed decisions. Second, the Expected values can be used in situations of quantifiable uncertainty, i.e risk. But for climate change we do not have a strong methodology to assess these subjective probabilities. They cannot be fully based on the past, because climate change is a new process for which we have no historical equivalent. Models share common flaws in their assumptions and their dispersion in results cannot be used to assess the real uncertainty (Hallegatte, 2012). The term deep uncertainty (Lempert et al., 2003) or severe uncertainty is used (Ben-Haim, 2006) in these contexts. Such uncertainty is characterised as a condition where decision makers do not know or cannot agree upon a model that adequately describes cause and effect or its key parameters (Walker et al., 2012). This leads to a situation where it is not possible to say with confidence whether one future state of the world is more plausible than another. The robust decision-making tool under uncertainty real option analysis is applied to the same case study to allow for adjusting adaptation options over time by integrating lessons learned about climate change in the appraisal process. A simplified ROA is presented to minimise the life cycle cost of a system that aims to prevent flooding of a return period of 1/20 using tools which should be available to most public authorities. This includes the use of UKCP09 climate data, analysis of changes of peak flow under the measure implemented, cost structures for the measure and damage cost under different outcomes. The analysis can be carried out in an excel spread sheet with the aforementioned types of input. The results of the analysis demonstrate that the obtained strategy is significantly cheaper than planting for the worst case scenario and presents the potential for learning under climate change uncertainty as a way to allocate resources in a more efficient way. The complementing bottom up approach investigates behavioural barriers to decisionmaking for adaptation. Standard economic theory tells us that self-interest will motivate most actors to engage in efficient private adaptation as long as the costs do not exceed the benefits. Thus, we would expect households at flood risk to invest in flood adaptation measures. However, it has been observed that households do not necessarily take action to protect themselves and their assets from flooding. In a study carried out in co-operation with 36 communities around Scotland, protection motivation theory is used to explain the uptake of household flood protection and whether community led flood action groups can increase uptake. It is found that flood action groups directly and indirectly influence the uptake of some flood protection measures positively in particular if tailored information is provided. Overall, it is concluded that both top-down and bottom-up approaches play an important role to move towards an economically efficient adaptation in the context of flooding. / From a top-down perspective, uncertainty should be explicitly acknowledged and included in economic decision-making for adaptation (to flooding) to make an informed decision. The type of analysis will depend on the adaptation project and resources at hand. Developing and fostering bottom-up tools such as flood action groups to increase the uptake of the type of household flood protection with a benefit-cost ratio above 1 may also contribute towards the more efficient allocation of resources.

No description available.

Habitat loss is one of the leading causes of species decline across all taxa and conservation practices require information on population trends. The Mescalero Sands ecosystem, New Mexico, USA, is experiencing landscape changes associated with oil and gas development. The dune-dwelling lizard community contains a habitat specialist, Sceloporus arenicolus, that is of particular interest because it has a very limited geographic distribution that is entirely subject to oil and gas development. Distance sampling is widely used to estimate population densities of many vertebrate taxa however assumptions can be difficult to satisfy with certain species or in certain habitats. Researchers must investigate the likelihood that assumptions can be satisfied before implementing any population sampling method. I had two objectives. First to investigate the precision of population densities of dune-dwelling lizards estimated via distance sampling that was coupled with double-observer surveys. Second to compare abundances of dune-dwelling lizards among sites that varied in oil and gas development. I conducted distance line transects and compared those density estimates to densities obtained from total removal plots. I quantified the amount of oil and gas development, habitat quantity and quality and correlated those to lizard abundances to investigate the effects of oil and gas development on lizard populations. I found large differences in density estimates from distance sampling and total removal plots that resulted from violation of distance sampling assumptions. Although distance sampling is a low cost method, it does not produce reliable density estimates for dune-dwelling lizards and is not an appropriate sampling method in this system. I did not find oil and gas development effects on the habitat quantity, quality or on the abundances of lizards. Lizard abundances were most strongly correlated to habitat quantity. Lizard abundances may be influenced by complex interactions between oil and gas development and habitat quantity and quality but controlling for those interactions was beyond the scope of my study. Before and after experiments and long-term studies at multiple sites would be required to more fully address the effects of oil and gas development on lizard populations in the Mescalero Sands.

Habitat loss is one of the leading causes of species decline across all taxa and conservation practices require information on population trends. The Mescalero Sands ecosystem, New Mexico, USA, is experiencing landscape changes associated with oil and gas development. The dune-dwelling lizard community contains a habitat specialist, Sceloporus arenicolus, that is of particular interest because it has a very limited geographic distribution that is entirely subject to oil and gas development. Distance sampling is widely used to estimate population densities of many vertebrate taxa however assumptions can be difficult to satisfy with certain species or in certain habitats. Researchers must investigate the likelihood that assumptions can be satisfied before implementing any population sampling method. I had two objectives. First to investigate the precision of population densities of dune-dwelling lizards estimated via distance sampling that was coupled with double-observer surveys. Second to compare abundances of dune-dwelling lizards among sites that varied in oil and gas development. I conducted distance line transects and compared those density estimates to densities obtained from total removal plots. I quantified the amount of oil and gas development, habitat quantity and quality and correlated those to lizard abundances to investigate the effects of oil and gas development on lizard populations. I found large differences in density estimates from distance sampling and total removal plots that resulted from violation of distance sampling assumptions. Although distance sampling is a low cost method, it does not produce reliable density estimates for dune-dwelling lizards and is not an appropriate sampling method in this system. I did not find oil and gas development effects on the habitat quantity, quality or on the abundances of lizards. Lizard abundances were most strongly correlated to habitat quantity. Lizard abundances may be influenced by complex interactions between oil and gas development and habitat quantity and quality but controlling for those interactions was beyond the scope of my study. Before and after experiments and long-term studies at multiple sites would be required to more fully address the effects of oil and gas development on lizard populations in the Mescalero Sands.

Empirical algorithms are developed using high-quality GO-SHIP hydrographic measurements of commonly measured parameters (temperature, salinity, pressure, nitrate, and oxygen) that estimate pH in the Pacific sector of the Southern Ocean. The coefficients of determination, R-2, are 0.98 for pH from nitrate (pH(N)) and 0.97 for pH from oxygen (pH(Ox)) with RMS errors of 0.010 and 0.008, respectively. These algorithms are applied to Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) biogeochemical profiling floats, which include novel sensors (pH, nitrate, oxygen, fluorescence, and backscatter). These algorithms are used to estimate pH on floats with no pH sensors and to validate and adjust pH sensor data from floats with pH sensors. The adjusted float data provide, for the first time, seasonal cycles in surface pH on weekly resolution that range from 0.05 to 0.08 on weekly resolution for the Pacific sector of the Southern Ocean.

The onset of agriculture about 12,000 years ago has had a major influence on the biodiversity of plants and animals. Unfortunately, the rapid changes in agricultural practices that has occurred in recent times has negatively affected many farmland species. One such species is the grass snake (Natrix natrix), which has been reported to decline in many parts of Europe, including Sweden. The grass snake is unique, not only in that it is the most northerly distributed oviparous reptile in the world, but also because of its habit of using anthropogenic heat sources such as manure heaps and composts as nesting-sites. Unfortunately changes in manure management and abandonment of farmlands have resulted in a decline and fragmentation of these environments. This may pose a threat for the northernmost populations of the grass snake, because natural nests in these areas may not provide sufficient heat for the eggs to hatch. The eggs and embryos of reptiles are highly sensitive to incubation temperatures, which can influence not only hatching success but also many phenotypic traits in the hatchlings. In this thesis I used a series of laboratory and field experiments to investigate the importance of anthropogenic heat sources for the reproductive ecology of cold-climate populations of grass snakes.  More specifically, I aimed to investigate thermal regimes of nests and how they influence embryonic development and offspring traits associated with survival and fitness. The results showed that manure heaps and composts are significantly warmer than potential natural nests and that natural nests do not provide sufficient heat to sustain embryonic development. Further, manure heaps were warmer and more constant in temperature than composts, resulting in higher hatching success and earlier hatching in manure heaps. The higher thermal variability in composts increased the frequency of abnormalities that are likely to negatively affect survival and fitness. In conclusion, this thesis shows that the use of anthropogenic heat sources has enabled grass snakes to expand their range farther north than any other oviparous reptile and that the thermal dichotomy in the primary nesting environments used by grass snakes contribute to important life-history variation in this species. These findings have important implications for conservation of reptile populations in general and grass snakes in particular.

Thesis advisor: Noah Snyder / While it has been shown that extensive sedimentation in historic millponds has greatly affected streams in the Mid-Atlantic Piedmont region (Walter and Merritts, 2008), much less is known about the phenomenon in the heavily dammed areas of post-glacial New England. Some research has found similar deposits behind breached historic dams in the Sheepscot River watershed in mid-coast Maine, but at a smaller scale than those seen in the Mid-Atlantic region (Strouse, 2013; Hopkins, 2014). I attempt to further explore millpond sedimentation in New England by quantifying the volume of millpond sediment, also called legacy sediment, in the 171.3 km² upper Charles River watershed in eastern Massachusetts. Twenty three milldams were located in the watershed on 1850s maps, giving a damming density of 0.177 dams/km². Each historic dam that had since breached, 14 in total, was visited in the field to identify possible legacy sediment deposits. Legacy sediments were identified by their meter or higher terraces made of fine sands and silt and verified by comparison to sedimentary patterns found in other legacy sediment deposits and radiocarbon dating of material both within the legacy sediment and in the underlying layer. Legacy sediment terraces with an area of 1.68*10⁴ m² and a total volume of 1.29 - 2.57*10⁴ m³ were found upstream of two adjacent breached historic dam sites on the Charles River in Medway, MA. Radiocarbon dates from a coarse sand and gravel lower at 1.8 m depth returned pre-settlement dates of 1281-1391 cal AD (two σ). These dams were immediately downstream of a large glacial feature with steep banks along the river. The lack of legacy sediment at other dam sites and the lack of sedimentation behind intact dams suggest that a low sediment supply to millponds prevented legacy sediment deposits from forming in most of the watershed. / Thesis (BS) — Boston College, 2016. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Earth and Environmental Sciences.