Home | << 1 2 >> |
![]() |
Arpan, L. M., Xu, X., Raney, A. A., Chen, C. -fei, & Wang, Z. (2018). Politics, values, and morals: Assessing consumer responses to the framing of residential renewable energy in the United States. Energy Research & Social Science, 46, 321–331.
Abstract: Despite growing availability of renewable energy or "green pricing" programs for residential use, consumer adoption in the U.S is limited. Existing data indicate that consumer values and political orientation-both of which reflect moral considerations-are associated with interest in renewable energy policies and use. An online experiment (n = 317) tested whether promotional messages framing renewable energy as consistent with participants' primary moral concerns, as delineated by moral foundations theory, would indirectly lead to more positive message evaluation and greater willingness to pay for such programs. Specifically, the interactions of framing effects with participants' political orientation were examined, as were the mediating roles of message-induced hope and personal moral norms. Results indicated political orientation was the most consistent predictor of message-induced hope, personal moral norms, and willingness to pay. Message framing did not interact with political orientation to influence mediating or outcome variables. Main effects of framing on hope were identified. Implications for promotion and adoption of residential renewable energy programs are discussed.
|
Bolson,, Sukop,, Arabi,, Pivo,, & Lanier,. (2018). A Stakeholder-Science Based Approach Using the National Urban Water Innovation Network as a Test Bed for Understanding Urban Water Sustainability Challenges in the U.S. Water Resour. Res., 54(5), 3453–3471.
Abstract: Urban water systems across the United States are struggling to adapt to an evolving set of threats. Understanding specific pressures and the regional responses to those pressures requires input from practitioners with knowledge of sociotechnological aspects of urban water systems. The Urban Water Innovation Network (UWIN), a consortium of academic institutions and partners supported by the National Science Foundation Sustainability Research Network program, provides a unique opportunity to engage stakeholder and research communities across the U.S. Interactions between UWIN researchers and water stakeholders from five regions (Southeast Florida, Sun Corridor, Mid-Atlantic, Pacific Northwest, and Front Range) form the basis for case studies on transitions toward sustainability. Analysis of qualitative data on pressures, states, and responses collected during interactions provides insight into the challenging context of urban water management. Top pressures identified include climate change, aging infrastructure, water quality impairments, and funding limitations. Additionally, stakeholders described resistance to change and short-term perspectives among elected officials, limited understanding/ awareness of water systems among decision makers, and lack of leadership on water issues as contributing to pressures. More than technological solutions, practitioners call for improved coordination in water management, strengthened communication with elected officials, and behavioral change among citizens. Regarding stakeholder-scientist interactions, participants sought practical outcomes, such as the organization of seemingly abundant scientific products into usable products. The utility of the pressure-state-response model as a framework for data collection and analysis in the context of understanding transitions toward urban water sustainability is discussed and recommendations for future studies are presented.
Keywords: NATURAL-RESOURCE MANAGEMENT; CLIMATE-CHANGE; SYSTEMS; POLICY; TRANSITIONS; PERSPECTIVE; TYPOLOGY; CITIES
|
Bruno, J. F., Bates, A. E., Cacciapaglia, C., Pike, E. P., Amstrup, S. C., van Hooidonk, R., et al. (2018). Climate change threatens the world's marine protected areas. Nature Climate Change, 8(6), 499.
Abstract: Marine protected areas (MPAs) are a primary management tool for mitigating threats to marine biodiversity1,2. MPAs and the species they protect, however, are increasingly being impacted by climate change. Here we show that, despite local protections, the warming associated with continued business-as-usual emissions (RCP8.5)3 will likely result in further habitat and species losses throughout low-latitude and tropical MPAs4,5. With continued business-as-usual emissions, mean sea-surface temperatures within MPAs are projected to increase 0.035 °C per year and warm an additional 2.8 °C by 2100. Under these conditions, the time of emergence (the year when sea-surface temperature and oxygen concentration exceed natural variability) is mid-century in 42% of 309 no-take marine reserves. Moreover, projected warming rates and the existing ‘community thermal safety margin’ (the inherent buffer against warming based on the thermal sensitivity of constituent species) both vary among ecoregions and with latitude. The community thermal safety margin will be exceeded by 2050 in the tropics and by 2150 for many higher latitude MPAs. Importantly, the spatial distribution of emergence is stressor-specific. Hence, rearranging MPAs to minimize exposure to one stressor could well increase exposure to another. Continued business-as-usual emissions will likely disrupt many marine ecosystems, reducing the benefits of MPAs.
|
Burris, G., Elsner, J., & Doel, R. E. (2018). Plantation Records as a Source of Historical Weather and Agricultural Data. Southeastern Geographer, 58(4), 348–364.
Abstract: Plantation records from the southeastern United States have long been an important source for historical, social, and cultural narratives. However, they also represent an underutilized source for meteorological, environmental, and agricultural data from the antebellum period. This study has two goals. Firstly, we advocate for a more systematic application of these records for quantitative analysis. Secondly, we present some early results from such a study using the records of Shirley Plantation in Virginia. We show how these records can be mined for data on weather and agricultural activity and how their broader usefulness is extended with the inclusion of appropriate meta-data. Observations of weather conditions and crop responses to seasonal changes lend themselves to quantitative analysis that can improve our understanding of the local weather and climate of that period. We present a case study comparing last spring freeze date in this region from the late 1820s to 2010s and suggest that last spring freeze now occurs approximately 23 days earlier compared to approximately 200 years ago. We also include summaries of the response of specific crops and cultivars since this knowledge may help the farmers' of today adapt to changing weather conditions. While individual plantation records may have idiosyncratic limitations, plantation records, along with other types of detailed historical records, can still provide rich detail for specific locations or events. Plantation records are not limited to the southeastern US and include diverse geographic locations in less developed areas which were often the same areas were enslaved labor was exploited under the plantation system.
Keywords: CLIMATE-CHANGE; ENSO; VARIABILITY; PHENOLOGY; IMPACTS; SUGAR
|
Campbell, L. G., Campbell LG, Thrash, J. C., Thrash JC, Rabalais, N. N., Rabalais NN, et al. (2019). Extent of the annual Gulf of Mexico hypoxic zone influences microbial community structure. PLoS One, 14(4), e0209055.
Abstract: Rich geochemical datasets generated over the past 30 years have provided fine-scale resolution on the northern Gulf of Mexico (nGOM) coastal hypoxic (</= 2 mg of O2 L-1) zone. In contrast, little is known about microbial community structure and activity in the hypoxic zone despite the implication that microbial respiration is responsible for forming low dissolved oxygen (DO) conditions. Here, we hypothesized that the extent of the hypoxic zone is a driver in determining microbial community structure, and in particular, the abundance of ammonia-oxidizing archaea (AOA). Samples collected across the shelf for two consecutive hypoxic seasons in July 2013 and 2014 were analyzed using 16S rRNA gene sequencing, oligotyping, microbial co-occurrence analysis, and quantification of thaumarchaeal 16S rRNA and archaeal ammonia-monooxygenase (amoA) genes. In 2014 Thaumarchaeota were enriched and inversely correlated with DO while Cyanobacteria, Acidimicrobiia, and Proteobacteria where more abundant in oxic samples compared to hypoxic. Oligotyping analysis of Nitrosopumilus 16S rRNA gene sequences revealed that one oligotype was significantly inversely correlated with DO in both years. Oligotyping analysis revealed single nucleotide variation among all Nitrosopumilaceae, including Nitrosopumilus 16S rRNA gene sequences, with one oligotype possibly being better adapted to hypoxia. We further provide evidence that in the hypoxic zone of both year 2013 and 2014, low DO concentrations and high Thaumarchaeota abundances influenced microbial co-occurrence patterns. Taken together, the data demonstrated that the extent of hypoxic conditions could potentially drive patterns in microbial community structure, with two years of data revealing the annual nGOM hypoxic zone to be emerging as a low DO adapted AOA hotspot.
|
Cazenave, A., Meyssignac, B., Ablain, M., Balmaseda, M., Bamber, J., Barletta, V., et al. (2019). Global sea-level budget 1993present. Earth Syst. Sci. Data, 10(3), 1551–1590.
Abstract: Global mean sea level is an integral of changes occurring in the climate system in response to unforced climate variability as well as natural and anthropogenic forcing factors. Its temporal evolution allows changes (e.g.,acceleration) to be detected in one or more components. Study of the sea-level budget provides constraints on missing or poorly known contributions, such as the unsurveyed deep ocean or the still uncertain land water component. In the context of the World Climate Research Programme Grand Challenge entitled "Regional Sea Level and Coastal Impacts", an international effort involving the sea-level community worldwide has been recently initiated with the objective of assessing the various datasets used to estimate components of the sea-level budget during the altimetry era (1993 to present). These datasets are based on the combination of a broad range of space-based and in situ observations, model estimates, and algorithms. Evaluating their quality, quantifying uncertainties and identifying sources of discrepancies between component estimates is extremely useful for various applications in climate research. This effort involves several tens of scientists from about 50 research teams/institutions worldwide (www.wcrp-climate.org/grand-challenges/gc-sea-level, last access: 22 August 2018). The results presented in this paper are a synthesis of the first assessment performed during 2017-2018. We present estimates of the altimetry-based global mean sea level (average rate of 3.1 +/- 0.3mm yr(-1) and acceleration of 0.1 mm yr(-2) over 1993-present), as well as of the different components of the sea-level budget (http://doi.org/10.17882/54854, last access: 22 August 2018). We further examine closure of the sea-level budget, comparing the observed global mean sea level with the sum of components. Ocean thermal expansion, glaciers, Greenland and Antarctica contribute 42%, 21%, 15% and 8% to the global mean sea level over the 1993-present period. We also study the sea-level budget over 2005-present, using GRACE-based ocean mass estimates instead of the sum of individual mass components. Our results demonstrate that the global mean sea level can be closed to within 0.3 mm yr(-1) (1 sigma). Substantial uncertainty remains for the land water storage component, as shown when examining individual mass contributions to sea level.
|
Convertino, M., Foran, C. M., Keisler, J. M., Scarlett, L., LoSchiavo, A., Kiker, G. A., et al. (2013). Enhanced Adaptive Management: Integrating Decision Analysis, Scenario Analysis and Environmental Modeling for the Everglades. Sci. Rep., 3.
Abstract: We propose to enhance existing adaptive management efforts with a decision-analytical approach that can guide the initial selection of robust restoration alternative plans and inform the need to adjust these alternatives in the course of action based on continuously acquired monitoring information and changing stakeholder values. We demonstrate an application of enhanced adaptive management for a wetland restoration case study inspired by the Florida Everglades restoration effort. We find that alternatives designed to reconstruct the pre-drainage flow may have a positive ecological impact, but may also have high operational costs and only marginally contribute to meeting other objectives such as reduction of flooding. Enhanced adaptive management allows managers to guide investment in ecosystem modeling and monitoring efforts through scenario and value of information analyses to support optimal restoration strategies in the face of uncertain and changing information.
|
Dai, H., Ye, M., Hu, B. X., Niedoroda, A. W., Zhang, X., Chen, X., et al. (2019). Hierarchical sensitivity analysis for simulating barrier island geomorphologic responses to future storms and sea-level rise. Theor Appl Climatol, 136(3-4), 1495–1511.
Abstract: This paper presents a new application of an advanced hierarchical sensitivity analysis of a new climate model of barrier island geomorphological evolution. The implemented sensitivity analysis in this study integrates a hierarchical uncertainty framework with a variance-based global sensitivity analysis to decompose the different model input uncertainties. The analysis can provide quantitative and accurate measurements for the relative importance of uncertain model input factors while considering their dependence relationships. The climate model used in this research was the barrier island profile (BIP) model, which is a new computer code developed to simulate barrier island morphological evolution over periods ranging from years to decades under the impacts of accelerated future sea-level rise and long-term changes in the storm climate. In the application of the model, the BIP model was used to evaluate the responses of a series of barrier island cross-sections derived for Santa Rosa Island, Florida, to random storm events and five potential accelerated rates of sea-level rise projected over the next century. The uncertain model input factors thus include the scenario uncertainty caused by alternative future sea-level rise scenarios and the parametric uncertainties of random storm parameters and dune characteristics. The study results reveal that the occurrence of storms is the most important factor for the evolution of sand dunes on the barrier island and the impact of sea-level rise is essential to the morphological change of the island backshore environment. The analysis can provide helpful insights for coastal management and planning. This hierarchical sensitivity analysis is mathematically general and rigorous and can be applied to a wide range of climate models.
Keywords: PARAMETRIC UNCERTAINTY; CLIMATE-CHANGE; MODEL; FLOW; EVOLUTION; TRANSPORT; RECOVERY; EROSION; SCALE; BEACH
|
Fu, X., & Peng, Z. - R. (2019). Assessing the sea-level rise vulnerability in coastal communities: A case study in the Tampa Bay Region, US. Cities, 88, 144–154.
Abstract: Sea-level rise (SLR) has drawn unprecedented attention from coastal communities around the world. In fact, many are already being affected and, in response, SLR vulnerability assessments have increasingly emerged in the US as the local communities' first attempt on the adaptation planning agenda. However, to date, little is known about these early planning endeavors in terms of how vulnerability is conceptualized and operationalized. By reviewing the current local SLR vulnerability assessments in the US, we find that most are only focusing on their biophysical exposure to SLR overlooking other important vulnerability factors including sensitivity and adaptive capacity. The limited number of SLR scenarios and the lack of consideration for extreme events are also considered as the major deficiencies. To fill these gaps, we propose a conceptual vulnerability assessment framework to operationalize the full concept of vulnerability and test it through a case study in the Tampa Bay region, Florida. By comparing the vulnerability results of the common practice with our proposed framework, we find large variances in the resulting findings stressing the importance of selecting the proper assessment approach. This paper finally concludes with urban planning and governance implications and future research directions. Coastal planner and managers wanting to improve their understanding of the communities' vulnerability to SLR will benefit from this study.
Keywords: CLIMATE-CHANGE; ADAPTIVE CAPACITY; LOCAL ADAPTATION; TIPPING POINTS; STRATEGIES; PATHWAYS; IMPACT
|
Fu, X., Sun, B., Frank, K., & Peng, Z. - R. (2019). Evaluating sea-level rise vulnerability assessments in the USA. Climatic Change, 155(3), 393–415.
Abstract: Many coastal communities around the world are increasingly faced with pressure from sea level rise (SLR). Adapting to the impacts of SLR is now considered inevitable. Many coastal communities in the USA have started to invest in vulnerability assessments that seek to identify the degree of future risk induced by SLR and key vulnerable sectors as well as to provide a sound factual basis for designing and implementing adaptations. However, no study has systematically analyzed the content of these emerging assessments and their quality. This study aims to address this gap by evaluating 64 SLR vulnerability assessments in the USA using an established multi-criteria evaluation framework and by identifying governance factors that affect assessment quality. This study is the first baseline study to understand how the vulnerability of SLR has been assessed by US governments and, more importantly, shed light on pathways for their future improvement. Our analysis finds that the content and quality of the existing assessments vary widely. One-sided assessments that only consider physical exposure are common, and most assessments do not include plans for adaptations. The wealth of the area, amount of funding, mainstreaming efforts, and public awareness are all positively correlated with the assessment quality. We also find that assessments primarily authored by planning staff are lower in quality than those conducted through collaboration. Our findings offer comparative, empirical knowledge for urban planners and coastal managers to improve future vulnerability assessments and adaptation planning for SLR.
|
Ghanbari, M., Arabi, M., & Obeysekera, J. (2020). Chronic and Acute Coastal Flood Risks to Assets and Communities in Southeast Florida. J. Water Resour. Plann. Manage., 146(7).
Abstract: Chronic and acute coastal flood risks in Miami-Dade County are assessed over the range of sea-level rise (SLR) scenarios for the coming decades. The HAZUS-MH coastal flood hazard modeling and loss estimation tool are used to determine flood extent and depth and corresponding monetary losses to buildings associated with different sea water levels (SWLs). The frequency of SWLs is estimated using a nonstationary mixture normal-generalized Pareto distribution under current condition and future SLR scenarios. Also, the least adaptation level to cope with SLR-induced amplification of coastal flooding is assessed in terms of an increase in flood threshold. The results indicate that under current sea-level conditions, coastal flood risks are predominantly from exposure to acute extreme events. However, chronic risks from repetitive nonextreme flooding may exceed those from extreme floods under future SLR scenarios. Therefore, adaptation strategies may incorporate consideration about chronic flooding to avoid increasing cumulative losses under future SLR scenarios.
Keywords: SEA-LEVEL RISE; CLIMATE-CHANGE; STORM-SURGE; TIPPING POINTS; EXTREME EVENTS; ADAPTATION; HAZARD; DECISIONS; FREQUENCY; PATHWAYS
|
Ghanbari, M., Arabi, M., Obeysekera, J., & Sweet, W. (2019). A Coherent Statistical Model for Coastal Flood Frequency Analysis Under Nonstationary Sea Level Conditions. Earth's Future, 7(2), 162–177.
Abstract: Flood exposure is increasing in coastal communities due to rising sea levels. Understanding the effects of sea level rise (SLR) on frequency and consequences of coastal flooding and subsequent social and economic impacts is of utmost importance for policymakers to implement effective adaptation strategies. Effective strategies may consider impacts from cumulative losses from minor flooding as well as acute losses from major events. In the present study, a statistically coherent Mixture Normal-Generalized Pareto Distribution model was developed, which reconciles the probabilistic characteristics of the upper tail as well as the bulk of the sea level data. The nonstationary sea level condition was incorporated in the mixture model using Quantile Regression method to characterize variable Generalized Pareto Distribution thresholds as a function of SLR. The performance validity of the mixture model was corroborated for 68 tidal stations along the Contiguous United States (CONUS) coast with long-term observed data. The method was subsequently employed to assess existing and future coastal minor and major flood frequencies. The results indicate that the frequency of minor and major flooding will increase along all CONUS coastal regions in response to SLR. By the end of the century, under the "Intermediate" SLR scenario, major flooding is anticipated to occur with return period less than a year throughout the coastal CONUS. However, these changes vary geographically and temporally. The mixture model was reconciled with the property exposure curve to characterize how SLR might influence Average Annual Exposure to coastal flooding in 20 major CONUS coastal cities.
Keywords: EXTREME-VALUE ANALYSIS; MAXIMUM WATER LEVELS; CLIMATE-CHANGE; RISE; VARIABILITY; EVENTS; BOSTON; IMPACT; HAZARD; SURGE
|
Kiskaddon, E., Kiskaddon E, Chernicky, K., Chernicky K, Bell, S., & Bell S. (2019). Resource use by and trophic variability of Armases cinereum (Crustacea, Brachyura) across human-impacted mangrove transition zones. PLoS One, 14(2), e0212448.
Abstract: In Florida, resource use patterns by Armases cinereum (Armases), a highly abundant crab in coastal habitats, may serve as important indicators of habitat condition. Here we investigated feeding patterns of Armases in coastal palm scrub forest to intertidal mangrove forest transition zones (transitions) as well as the relationship between habitat disturbance and Armases' trophic position across three pairs of geographically separated populations in Tampa FL, USA. Each pair of sites represented an unmodified "natural" location as well as a "disturbed" location lacking upland terrestrial palm scrub forested habitat. Laboratory experiments established a baseline understanding of feeding preference of Armases offered strictly mangrove material as well as sources abundant at the transition. In-situ feeding behavior was examined using MixSIAR mixing models with delta13C and delta15N stable isotope tracers. Armases showed a strong preference for consuming partially-decomposed mangrove material from Avicennia germinans and an equally strong preference for Iva frutescens. Armases also displayed predatory behavior under laboratory conditions, confirming omnivory in the presence of mangrove material. Stable isotopes revealed a pattern of elevated trophic position of Armases in disturbed habitats over paired natural locations. Diet reconstruction provided coarse resolution of in-situ feeding and results show high spatial variation: in natural habitats, Armases appears to rely heavily upon upland plant material compared to disturbed habitats where it may consume more animal prey. Combined, these findings support that Armases trophic position and diet may indicate habitat quality in mangrove transitions in the southeastern United States.
|
Lapointe, B. E., Brewton, R. A., Herren, L. W., Porter, J. W., & Hu, C. (2019). Nitrogen enrichment, altered stoichiometry, and coral reef decline at Looe Key, Florida Keys, USA: a 3-decade study. Mar Biol, 166(8).
Abstract: Increased loadings of nitrogen (N) from fertilizers, top soil, sewage, and atmospheric deposition are important drivers of eutrophication in coastal waters globally. Monitoring seawater and macroalgae can reveal long-term changes in N and phosphorus (P) availability and N:P stoichiometry that are critical to understanding the global crisis of coral reef decline. Analysis of a unique 3-decade data set for Looe Key reef, located offshore the lower Florida Keys, showed increased dissolved inorganic nitrogen (DIN), chlorophyll a, DIN:soluble reactive phosphorus (SRP) ratios, as well as higher tissue C:P and N:P ratios in macroalgae during the early 1990s. These data, combined with remote sensing and nutrient monitoring between the Everglades and Looe Key, indicated that the significant DIN enrichment between 1991 and 1995 at Looe Key coincided with increased Everglades runoff, which drains agricultural and urban areas extending north to Orlando, Florida. This resulted in increased P limitation of reef primary producers that can cause metabolic stress in stony corals. Outbreaks of stony coral disease, bleaching, and mortality between 1995 and 2000 followed DIN enrichment, algal blooms, and increased DIN:SRP ratios, suggesting that eutrophication interacted with other factors causing coral reef decline at Looe Key. Although water temperatures at Looe Key exceeded the 30.5 degrees C bleaching threshold repeatedly over the 3-decade study, the three mass bleaching events occurred only when DIN:SRP ratios increased following heavy rainfall and increased Everglades runoff. These results suggest that Everglades discharges, in conjunction with local nutrient sources, contributed to DIN enrichment, eutrophication, and increased N:P ratios at Looe Key, exacerbating P limitation, coral stress and decline. Improved management of water quality at the local and regional levels could moderate N inputs and maintain more balanced N:P stoichiometry, thereby reducing the risk of coral bleaching, disease, and mortality under the current level of temperature stress.
|
Liu, B., Asseng, S., Müller, C., Ewert, F., Elliott, J., Lobell, D. B., et al. (2016). Similar estimates of temperature impacts on global wheat yield by three independent methods. Nature Climate change, 6(12).
Abstract: The potential impact of global temperature change on global crop yield has recently been assessed with different methods. Here we show that grid-based and point-based simulations and statistical regressions (from historic records), without deliberate adaptation or CO2 fertilization effects, produce similar estimates of temperature impact on wheat yields at global and national scales. With a 1 °C global temperature increase, global wheat yield is projected to decline between 4.1% and 6.4%. Projected relative temperature impacts from different methods were similar for major wheat-producing countries China, India, USA and France, but less so for Russia. Point-based and grid-based simulations, and to some extent the statistical regressions, were consistent in projecting that warmer regions are likely to suffer more yield loss with increasing temperature than cooler regions. By forming a multi-method ensemble, it was possible to quantify �method uncertainty� in addition to model uncertainty. This significantly improves confidence in estimates of climate impacts on global food security.
Keywords: Agriculture; Climate-change impacts
|
Macreadie, P. I., Anton, A., Raven, J. A., Beaumont, N., Connolly, R. M., Friess, D. A., et al. (2019). The future of Blue Carbon science. Nat Commun, 10, 3998.
Abstract: The term Blue Carbon (BC) was first coined a decade ago to describe the disproportionately large contribution of coastal vegetated ecosystems to global carbon sequestration. The role of BC in climate change mitigation and adaptation has now reached international prominence. To help prioritise future research, we assembled leading experts in the field to agree upon the top-ten pending questions in BC science. Understanding how climate change affects carbon accumulation in mature BC ecosystems and during their restoration was a high priority. Controversial questions included the role of carbonate and macroalgae in BC cycling, and the degree to which greenhouse gases are released following disturbance of BC ecosystems. Scientists seek improved precision of the extent of BC ecosystems; techniques to determine BC provenance; understanding of the factors that influence sequestration in BC ecosystems, with the corresponding value of BC; and the management actions that are effective in enhancing this value. Overall this overview provides a comprehensive road map for the coming decades on future research in BC science.
|
Moore, J. F., Pine III, W. E., Frederick, P. C., Beck, S. /, Moreno, M., Dodrill, M. J., et al. (2020). Trends in Oyster Populations in the Northeastern Gulf of Mexico: An Assessment of River Discharge and Fishing Effects over Time and Space. Mar Coast Fish, 12(3), 191–204.
Abstract: Within the Big Bend region of the northeastern Gulf of Mexico, one of the least developed coastlines in the continental USA, intertidal and subtidal populations of eastern oysterCrassostrea virginica(hereafter referred to as "oyster") are a critical ecosystem and important economic constituent. We assessed trends in intertidal oyster populations, river discharge, and commercial fishing activity in the Suwannee River estuary within the Big Bend region using fisheries-independent data from irregular monitoring efforts and publicly available environmental data. We used generalized linear models to evaluate counts of oysters from line-transect surveys over time and space. We assessed model performance using simulation to understand potential bias and then evaluated whether these counts were related to freshwater inputs from the Suwannee River and commercial oyster fishing effort and landings at different time lags. We found that intertidal oyster counts have declined over time and that most of these declines are found in inshore intertidal oyster bars, which are becoming degraded. We also found a significant relationship between oyster counts and a 1-year lag on mean daily Suwannee River discharge, but including commercial fishery trips or landings did not improve model fit. It is unclear whether declines in intertidal oyster bars are offset by formation of new oyster reefs elsewhere. These results quantify rapid declines in intertidal oyster reefs in a region of coastline with high conservation value that can be used to inform ongoing and proposed restoration projects in the region.
|
Purtlebaugh, C. H., Martin, C. W., & Allen, M. S. (2020). Poleward expansion of common snook Centropomus undecimalis in the northeastern Gulf of Mexico and future research needs. PLoS One, 15(6), e0234083.
Abstract: Globally, rising temperatures have resulted in numerous examples of poleward shifts in species distribution patterns with accompanying changes in community structure and ecosystem processes. In the Gulf of Mexico, higher mean temperatures and less frequent winter freezes have led to the expansion of tropics-associated marine organisms. Our objectives were to quantify changing environmental conditions and the poleward expansion of the common snook Centropomus undecimalis into the Cedar Keys area of Florida, USA (29 deg N). The snook is an economically and recreationally important sport fish found from southern Brazil to south Florida. Cedar Key and the Lower Suwannee River are north of the snook's historically documented range, likely due to lethal water temperatures during winter. Using data from a long-term monitoring program, we report an increase in catches of snook in this area since 2007. The spatial and temporal expansion of the species began with adult fish in 2007. By 2018, snook of all sizes were found in the region, and we found strong evidence of local reproduction during 2016-2018. The locations of nursery habitat and winter thermal refuges (e.g., freshwater springs) need to be identified and have implications for land-use policy and minimum-flow regulations for rivers. The arrival of the snook in the northern Gulf of Mexico could affect food web ecology and habitat interactions among estuarine predators, and future studies should evaluate snook's food habits and competitive interactions with resident fishes in this expanded range. Our study provides an example of how species range expansions due to changing temperatures should result in new research priorities to evaluate impacts of climate change on coastal systems.
|
Pusack, T. J., Kimbro, D. L., White, J. W., & Stallings, C. D. (2019). Predation on oysters is inhibited by intense or chronically mild, low salinity events: Low salinity stress reduces predation. Limnol Oceanogr, 64(1), 81–92.
Abstract: Environmental stress gradients can affect species distributions and interspecific interactions. Because environmental stress depends on both intensity and duration, understanding the consequences of stress requires experiments that simultaneously manipulate both dimensions. In Apalachicola Bay, Florida (U.S.A.) the southern oyster drill (Stramonita haemastoma) is a major predator of the eastern oyster (Crassostrea virginica). Drill predation appears to be salinity-dependent: in a recent field study, predation rates were positively correlated with salinity. Salinity in the bay is typically high (> 20) during the dry summer months, conditions that favor both oysters and the drill. However, periodic freshets can dramatically reduce salinity, which inhibits (or kills) drills, but not oysters. In this study, we used field measurements of salinity and drill densities to inform mesocosm experiments. We investigated the specific combinations of intensity and duration of low-salinity stress that inhibit drill predation. In these experiments, more intense salinity reductions reduced feeding both during and after the low-salinity stress event. During the event, longer durations (15 d) were necessary for mild salinity reductions (-5) to reduce the feeding rate by the same amount as a short (5 d) exposure of more intense (-10 or -15) salinity reduction. Both conditions may create a predation refuge for oysters, consistent with field observations. Given that the recent collapse of the Apalachicola Bay oyster population was preceded by several years without low-salinity events to inhibit predation, our results provide a mechanism by which a predator may have contributed to the loss of a historically productive and sustainable fishery.
|
Raymond, C., Horton, R. M., Zscheischler, J., Martius, O., AghaKouchak, A., Balch, J., et al. (2020). Understanding and managing connected extreme events. Nat. Clim. Chang., 10(7), 611–621.
Abstract: Extreme weather and climate events and their impacts can occur in complex combinations, an interaction shaped by physical drivers and societal forces. In these situations, governance, markets and other decision-making structures-together with population exposure and vulnerability-create nonphysical interconnections among events by linking their impacts, to positive or negative effect. Various anthropogenic actions can also directly affect the severity of events, further complicating these feedback loops. Such relationships are rarely characterized or considered in physical-sciences-based research contexts. Here, we present a multidisciplinary argument for the concept of connected extreme events, and we suggest vantage points and approaches for producing climate information useful in guiding decisions about them.
The impacts of extreme weather and climate can be amplified by physical interactions among events and across a complex set of societal factors. This Perspective discusses the concept and challenge of connected extreme events, exploring research approaches and decision-making strategies.
Keywords: CLIMATE-CHANGE IMPACT; STORM-SURGE; DROUGHT; RISK; CHALLENGES; SCIENCE; UNCERTAINTY; LESSONS; PRECIPITATION; AMPLIFICATION
|
Copyright © Florida Climate Institute. All rights reserved.