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At least 1,531 records · Page 85Linked to original sources
USGS2016

Coseismic slip and early afterslip of the 2015 Illapel, Chile, earthquake: Implications for frictional heterogeneity and coastal uplift

Great subduction earthquakes are thought to rupture portions of the megathrust, where interseismic coupling is high and velocity-weakening frictional behavior is dominant, releasing elastic deformation accrued over a seismic cycle. Conversely, postseismic afterslip is assumed to occur primarily in regions of velocity-strengthening frictional characteristics that may correlate with lower interseismic coupling. However, it remains unclear if fixed frictional properties of the subduction interface, coseismic or aftershock-induced stress redistribution, or other factors control the spatial distribution of afterslip. Here we use interferometric synthetic aperture radar and Global Position System observations to map the distribution of coseismic slip of the 2015 M w 8.3 Illapel, Chile, earthquake and afterslip within the first 38 days following the earthquake. We find that afterslip overlaps the coseismic slip area and propagates along-strike into regions of both high and moderate interseismic coupling. The significance of these observations, however, is tempered by the limited resolution of geodetic inversions for both slip and coupling. Additional afterslip imaged deeper on the fault surface bounds a discrete region of deep coseismic slip, and both contribute to net uplift of the Chilean Coastal Cordillera. A simple partitioning of the subduction interface into regions of fixed frictional properties cannot reconcile our geodetic observations. Instead, stress heterogeneities, either preexisting or induced by the earthquake, likely provide the primary control on the afterslip distribution for this subduction zone earthquake. We also explore the occurrence of coseismic and postseismic coastal uplift in this sequence and its implications for recent hypotheses concerning the source of permanent coastal uplift along subduction zones.

Journal of Geophysical Research B: Solid Earth↗
USGS2017

Reexamination of the magnitudes for the 1906 and 1922 Chilean earthquakes using Japanese tsunami amplitudes: Implications for source depth constraints

Far-field tsunami records from the Japanese tide gauge network allow the reexamination of the moment magnitudes ( M w ) for the 1906 and 1922 Chilean earthquakes, which to date rely on limited information mainly from seismological observations alone. Tide gauges along the Japanese coast provide extensive records of tsunamis triggered by six great ( M w >8) Chilean earthquakes with instrumentally determined moment magnitudes. These tsunami records are used to explore the dependence of tsunami amplitudes in Japan on the parent earthquake magnitude of Chilean origin. Using the resulting regression parameters together with tide gauge amplitudes measured in Japan we estimate apparent moment magnitudes of M w 8.0–8.2 and M w 8.5–8.6 for the 1906 central and 1922 north-central Chile earthquakes. The large discrepancy of the 1906 magnitude estimated from the tsunami observed in Japan as compared with those previously determined from seismic waves ( M s 8.4) suggests a deeper than average source with reduced tsunami excitation. A deep dislocation along the Chilean megathrust would favor uplift of the coast rather than beneath the sea, giving rise to a smaller tsunami and producing effects consistent with those observed in 1906. The 1922 magnitude inferred from far-field tsunami amplitudes appear to better explain the large extent of damage and the destructive tsunami that were locally observed following the earthquake than the lower seismic magnitudes ( M s 8.3) that were likely affected by the well-known saturation effects. Thus, a repeat of the large 1922 earthquake poses seismic and tsunami hazards in a region identified as a mature seismic gap.

Journal of Geophysical Research B: Solid Earth↗
USGS2016

Constraining the relative importance of raindrop- and flow-driven sediment transport mechanisms in postwildfire environments and implications for recovery time scales

Mountain watersheds recently burned by wildfire often experience greater amounts of runoff and increased rates of sediment transport relative to similar unburned areas. Given the sedimentation and debris flow threats caused by increases in erosion, more work is needed to better understand the physical mechanisms responsible for the observed increase in sediment transport in burned environments and the time scale over which a heightened geomorphic response can be expected. In this study, we quantified the relative importance of different hillslope erosion mechanisms during two postwildfire rainstorms at a drainage basin in Southern California by combining terrestrial laser scanner-derived maps of topographic change, field measurements, and numerical modeling of overland flow and sediment transport. Numerous debris flows were initiated by runoff at our study area during a long-duration storm of relatively modest intensity. Despite the presence of a well-developed rill network, numerical model results suggest that the majority of eroded hillslope sediment during this long-duration rainstorm was transported by raindrop-induced sediment transport processes, highlighting the importance of raindrop-driven processes in supplying channels with potential debris flow material. We also used the numerical model to explore relationships between postwildfire storm characteristics, vegetation cover, soil infiltration capacity, and the total volume of eroded sediment from a synthetic hillslope for different end-member erosion regimes. This study adds to our understanding of sediment transport in steep, postwildfire landscapes and shows how data from field monitoring can be combined with numerical modeling of sediment transport to isolate the processes leading to increased erosion in burned areas.

California↗
USGS2016

GDGT and alkenone flux in the northern Gulf of Mexico: Implications for the TEX 86 and U K 1 37 paleothermometers

The TEX 86 and molecular biomarker proxies have been broadly applied in down-core marine sediments to reconstruct past sea surface temperature (SST). Although both TEX 86 and have been interpreted as proxies for mean annual SST throughout the global ocean, regional studies of GDGTs and alkenones in sinking particles are required to understand the influence of seasonality, depth distribution and diagenesis on downcore variability. We measure GDGT and alkenone flux, as well as the TEX 86 and indices in a 4-year sediment trap time series (2010-2014) in the northern Gulf of Mexico (nGoM), and compare these data with core-top sediments at the same location. GDGT and alkenone fluxes do not show a consistent seasonal cycle, however the largest flux peaks for both occurs in winter. co-varies with SST over the 4-year sampling interval, but the -SST relationship in this data set implies a smaller slope or non-linearity at high temperatures when compared with existing calibrations. Furthermore, the flux-weighted value from sinking particles is significantly lower than that of underlying core-top sediments, suggesting preferential diagenetic loss of the tri-unsaturated alkenone in sediments. TEX 86 does not co-vary with SST, suggesting production in the subsurface upper water column. The flux-weighted mean TEX 86 matches that of core-top sediments, confirming that TEX 86 in the nGoM reflects local planktonic production rather than allochthonous or in-situ sedimentary production. We explore potential sources of uncertainty in both proxies in the nGoM, but demonstrate that they show nearly identical trends in 20 th century SST, despite these factors.

Paleoceanography↗
USGS2016

Observed and simulated hydrologic response for a first-order catchment during extreme rainfall 3 years after wildfire disturbance

Hydrologic response to extreme rainfall in disturbed landscapes is poorly understood because of the paucity of measurements. A unique opportunity presented itself when extreme rainfall in September 2013 fell on a headwater catchment (i.e., <1 ha) in Colorado, USA that had previously been burned by a wildfire in 2010. We compared measurements of soil-hydraulic properties, soil saturation from subsurface sensors, and estimated peak runoff during the extreme rainfall with numerical simulations of runoff generation and subsurface hydrologic response during this event. The simulations were used to explore differences in runoff generation between the wildfire-affected headwater catchment, a simulated unburned case, and for uniform versus spatially variable parameterizations of soil-hydraulic properties that affect infiltration and runoff generation in burned landscapes. Despite 3 years of elapsed time since the 2010 wildfire, observations and simulations pointed to substantial surface runoff generation in the wildfire-affected headwater catchment by the infiltration-excess mechanism while no surface runoff was generated in the unburned case. The surface runoff generation was the result of incomplete recovery of soil-hydraulic properties in the burned area, suggesting recovery takes longer than 3 years. Moreover, spatially variable soil-hydraulic property parameterizations produced longer duration but lower peak-flow infiltration-excess runoff, compared to uniform parameterization, which may have important hillslope sediment export and geomorphologic implications during long duration, extreme rainfall. The majority of the simulated surface runoff in the spatially variable cases came from connected near-channel contributing areas, which was a substantially smaller contributing area than the uniform simulations.

Water Resources Research↗
USGS2017

Steady state fractionation of heavy noble gas isotopes in a deep unsaturated zone

To explore steady state fractionation processes in the unsaturated zone (UZ), we measured argon, krypton, and xenon isotope ratios throughout a ∼110 m deep UZ at the United States Geological Survey (USGS) Amargosa Desert Research Site (ADRS) in Nevada, USA. Prior work has suggested that gravitational settling should create a nearly linear increase in heavy-to-light isotope ratios toward the bottom of stagnant air columns in porous media. Our high-precision measurements revealed a binary mixture between (1) expected steady state isotopic compositions and (2) unfractionated atmospheric air. We hypothesize that the presence of an unsealed pipe connecting the surface to the water table allowed for direct inflow of surface air in response to extensive UZ gas sampling prior to our first (2015) measurements. Observed isotopic resettling in deep UZ samples collected a year later, after sealing the pipe, supports this interpretation. Data and modeling each suggest that the strong influence of gravitational settling and weaker influences of thermal diffusion and fluxes of CO 2 and water vapor accurately describe steady state isotopic fractionation of argon, krypton, and xenon within the UZ. The data confirm that heavy noble gas isotopes are sensitive indicators of UZ depth. Based on this finding, we outline a potential inverse approach to quantify past water table depths from noble gas isotope measurements in paleogroundwater, after accounting for fractionation during dissolution of UZ air and bubbles.

Nevada↗
USGS2017

Hydrologic impacts of changes in climate and glacier extent in the Gulf of Alaska watershed

High‐resolution regional‐scale hydrologic models were used to quantify the response of late 21st century runoff from the Gulf of Alaska (GOA) watershed to changes in regional climate and glacier extent. NCEP Climate Forecast System Reanalysis data were combined with five Coupled Model Intercomparison Project Phase 5 general circulation models (GCMs) for two representative concentration pathway (RCP) scenarios (4.5 and 8.5) to develop meteorological forcing for the period 2070–2099. A hypsographic model was used to estimate future glacier extent given assumed equilibrium line altitude (ELA) increases of 200 and 400 m. GCM predictions show an increase in annual precipitation of 12% for RCP 4.5 and 21% for RCP 8.5, and an increase in annual temperature of 2.5°C for RCP 4.5 and 4.3°C for RCP 8.5, averaged across the GOA. Scenarios with perturbed climate and glaciers predict annual GOA‐wide runoff to increase by 9% for RCP4.5/ELA200 case and 14% for the RCP8.5/ELA400 case. The glacier runoff decreased by 14% for RCP4.5/ELA200 and by 34% for the RCP8.5/ELA400 case. Intermodel variability in annual runoff was found to be approximately twice the variability in precipitation input. Additionally, there are significant changes in runoff partitioning and increases in snowpack runoff are dominated by increases in rain‐on‐snow events. We present results aggregated across the entire GOA and also for individual watersheds to illustrate the range in hydrologic regime changes and explore the sensitivities of these results by independently perturbing only climate forcings and only glacier cover.

Alaska, British Columbia, Yukon↗
USGS2017

Noble gas signatures in the Island of Maui, Hawaii: Characterizing groundwater sources in fractured systems

Uneven distribution of rainfall and freshwater scarcity in populated areas in the Island of Maui, Hawaii, renders water resources management a challenge in this complex and ill-defined hydrological system. A previous study in the Galapagos Islands suggests that noble gas temperatures (NGTs) record seasonality in that fractured, rapid infiltration groundwater system rather than the commonly observed mean annual air temperature (MAAT) in sedimentary systems where infiltration is slower thus, providing information on recharge sources and potential flow paths. Here we report noble gas results from the basal aquifer, springs, and rainwater in Maui to explore the potential for noble gases in characterizing this type of complex fractured hydrologic systems. Most samples display a mass-dependent depletion pattern with respect to surface conditions consistent with previous observations both in the Galapagos Islands and Michigan rainwater. Basal aquifer and rainwater noble gas patterns are similar and suggest direct, fast recharge from precipitation to the basal aquifer. In contrast, multiple springs, representative of perched aquifers, display highly variable noble gas concentrations suggesting recharge from a variety of sources. The distinct noble gas patterns for the basal aquifer and springs suggest that basal and perched aquifers are separate entities. Maui rainwater displays high apparent NGTs, incompatible with surface conditions, pointing either to an origin at high altitudes with the presence of ice or an ice-like source of undetermined origin. Overall, noble gas signatures in Maui reflect the source of recharge rather than the expected altitude/temperature relationship commonly observed in sedimentary systems.

Hawaii↗
USGS2018

Numerical models of pore pressure and stress changes along basement faults due to wastewater injection: Applications to the 2014 Milan, Kansas Earthquake

We have developed groundwater flow models to explore the possible relationship between wastewater injection and the 12 November 2014 M w 4.8 Milan, Kansas earthquake. We calculate pore pressure increases in the uppermost crust using a suite of models in which hydraulic properties of the Arbuckle Formation and the Milan earthquake fault zone, the Milan earthquake hypocenter depth, and fault zone geometry are varied. Given pre‐earthquake injection volumes and reasonable hydrogeologic properties, significantly increasing pore pressure at the Milan hypocenter requires that most flow occur through a conductive channel (i.e., the lower Arbuckle and the fault zone) rather than a conductive 3‐D volume. For a range of reasonable lower Arbuckle and fault zone hydraulic parameters, the modeled pore pressure increase at the Milan hypocenter exceeds a minimum triggering threshold of 0.01 MPa at the time of the earthquake. Critical factors include injection into the base of the Arbuckle Formation and proximity of the injection point to a narrow fault damage zone or conductive fracture in the pre‐Cambrian basement with a hydraulic diffusivity of about 3–30 m 2 /s. The maximum pore pressure increase we obtain at the Milan hypocenter before the earthquake is 0.06 MPa. This suggests that the Milan earthquake occurred on a fault segment that was critically stressed prior to significant wastewater injection in the area. Given continued wastewater injection into the upper Arbuckle in the Milan region, assessment of the middle Arbuckle as a hydraulic barrier remains an important research priority.

Kansas↗
USGS2017

Natural and human-induced variability in barrier-island response to sea level rise

Storm-driven sediment fluxes onto and behind barrier islands help coastal barrier systems keep pace with sea level rise (SLR). Understanding what controls cross-shore sediment flux magnitudes is critical for making accurate forecasts of barrier response to increased SLR rates. Here, using an existing morphodynamic model for barrier island evolution, observations are used to constrain model parameters and explore potential variability in future barrier behavior. Using modeled drowning outcomes as a proxy for vulnerability to SLR, 0%, 28%, and 100% of the barrier is vulnerable to SLR rates of 4, 7, and 10 mm/yr, respectively. When only overwash fluxes are increased in the model, drowning vulnerability increases for the same rates of SLR, suggesting that future increases in storminess may increase island vulnerability particularly where sediment resources are limited. Developed sites are more vulnerable to SLR, indicating that anthropogenic changes to overwash fluxes and estuary depths could profoundly affect future barrier response to SLR.

New Jersey↗
USGS2017

Connecting crustal seismicity and earthquake-driven stress evolution in Southern California

Tectonic stress in the crust evolves during a seismic cycle, with slow stress accumulation over interseismic periods, episodic stress steps at the time of earthquakes, and transient stress readjustment during a postseismic period that may last months to years. Static stress transfer to surrounding faults has been well documented to alter regional seismicity rates over both short and long time scales. While static stress transfer is instantaneous and long lived, postseismic stress transfer driven by viscoelastic relaxation of the ductile lower crust and mantle leads to additional, slowly varying stress perturbations. Both processes may be tested by comparing a decade-long record of regional seismicity to predicted time-dependent seismicity rates based on a stress evolution model that includes viscoelastic stress transfer. Here we explore crustal stress evolution arising from the seismic cycle in Southern California from 1981 to 2014 using five M ≥6.5 source quakes: the M 7.3 1992 Landers, M6.5 1992 Big Bear, M 6.7 1994 Big Bear, M 7.1 1999 Hector Mine, and M 7.2 2010 El Mayor-Cucapah earthquakes. We relate the stress readjustment in the surrounding crust generated by each quake to regional seismicity using rate-and-state friction theory. Using a log likelihood approach, we quantify the potential to trigger seismicity of both static and viscoelastic stress transfer, finding that both processes have systematically shaped the spatial pattern of Southern California seismicity since 1992.

California↗
USGS2017

Delayed seismicity rate changes controlled by static stress transfer

On 15 June 2010, a M w 5.7 earthquake occurred near Ocotillo, California, in the Yuha Desert. This event was the largest aftershock of the 4 April 2010 M w 7.2 El Mayor-Cucapah (EMC) earthquake in this region. The EMC mainshock and subsequent Ocotillo aftershock provide an opportunity to test the Coulomb failure hypothesis (CFS). We explore the spatiotemporal correlation between seismicity rate changes and regions of positive and negative CFS change imparted by the Ocotillo event. Based on simple CFS calculations we divide the Yuha Desert into three subregions, one triggering zone and two stress shadow zones. We find the nominal triggering zone displays immediate triggering, one stress shadowed region experiences immediate quiescence, and the other nominal stress shadow undergoes an immediate rate increase followed by a delayed shutdown. We quantitatively model the spatiotemporal variation of earthquake rates by combining calculations of CFS change with the rate-state earthquake rate formulation of Dieterich (1994), assuming that each subregion contains a mixture of nucleation sources that experienced a CFS change of differing signs. Our modeling reproduces the observations, including the observed delay in the stress shadow effect in the third region following the Ocotillo aftershock. The delayed shadow effect occurs because of intrinsic differences in the amplitude of the rate response to positive and negative stress changes and the time constants for return to background rates for the two populations. We find that rate-state models of time-dependent earthquake rates are in good agreement with the observed rates and thus explain the complex spatiotemporal patterns of seismicity.

California↗
USGS2017

A decade of induced slip on the causative fault of the 2015 Mw 4.0 Venus earthquake, northeast Johnson County, Texas

On 7 May 2015, a M w 4.0 earthquake occurred near Venus, northeast Johnson County, Texas, in an area of the Bend Arch-Fort Worth Basin that reports long-term, high-volume wastewater disposal and that has hosted felt earthquakes since 2009. In the weeks following the M w 4.0 earthquake, we deployed a local seismic network and purchased nearby active-source seismic reflection data to capture additional events, characterize the causative fault, and explore potential links between ongoing industry activity and seismicity. Hypocenter relocations of the resulting local earthquake catalog span ~4–6 km depth and indicate a fault striking ~230 ° , dipping to the west, consistent with a nodal plane of the M w 4.0 regional moment tensor. Fault plane solutions indicate normal faulting, with B axes striking parallel to maximum horizontal compressive stress. Seismic reflection data image the reactivated basement fault penetrating the Ordovician disposal layer and Mississippian production layer, but not displacing post-Lower Pennsylvanian units. Template matching at regional seismic stations indicates that low-magnitude earthquakes with similar waveforms began in April 2008, with increasing magnitude over time. Pressure data from five saltwater disposal wells within 5 km of the active fault indicate a disposal formation that is 0.9–4.8 MPa above hydrostatic. We suggest that the injection of 28,000,000 m 3 of wastewater between 2006 and 2015 at these wells led to an increase in subsurface pore fluid pressure that contributed to inducing this long-lived earthquake sequence. The 2015 M w 4.0 event represents the largest event in the continuing evolution of slip on the causative fault.

Texas↗
USGS2017

Shallow marine response to global climate change during the Paleocene-Eocene Thermal Maximum, Salisbury Embayment, USA

The Paleocene-Eocene Thermal Maximum (PETM) was an interval of extreme warmth that caused disruption of marine and terrestrial ecosystems on a global scale. Here we examine the sediments, flora, and fauna from an expanded section at Mattawoman Creek-Billingsley Road (MCBR) in Maryland and explore the impact of warming at a nearshore shallow marine (30–100 m water depth) site in the Salisbury Embayment. Observations indicate that at the onset of the PETM, the site abruptly shifted from an open marine to prodelta setting with increased terrestrial and fresh water input. Changes in microfossil biota suggest stratification of the water column and low-oxygen bottom water conditions in the earliest Eocene. Formation of authigenic carbonate through microbial diagenesis produced an unusually large bulk carbon isotope shift, while the magnitude of the corresponding signal from benthic foraminifera is similar to that at other marine sites. This proves that the landward increase in the magnitude of the carbon isotope excursion measured in bulk sediment is not due to a near instantaneous release of 12 C-enriched CO 2 . We conclude that the MCBR site records nearshore marine response to global climate change that can be used as an analog for modern coastal response to global warming.

Maryland, New Jersey, Pennsylvania, Virginia↗
USGS2017

Disturbance hydrology: Preparing for an increasingly disturbed future

This special issue is the result of several fruitful conference sessions on disturbance hydrology, which started at the 2013 AGU Fall Meeting in San Francisco and have continued every year since. The stimulating presentations and discussions surrounding those sessions have focused on understanding both the disruption of hydrologic functioning following discrete disturbances, as well as the subsequent recovery or change within the affected watershed system. Whereas some hydrologic disturbances are directly linked to anthropogenic activities, such as resource extraction, the contributions to this special issue focus primarily on those with indirect or less pronounced human involvement, such as bark-beetle infestation, wildfire, and other natural hazards. However, human activities are enhancing the severity and frequency of these seemingly natural disturbances, thereby contributing to acute hydrologic problems and hazards. Major research challenges for our increasingly disturbed planet include the lack of continuous pre- and post-disturbance monitoring, hydrologic impacts that vary spatially and temporally based on environmental and hydroclimatic conditions, and the preponderance of overlapping or compounding disturbance sequences. In addition, a conceptual framework for characterizing commonalities and differences among hydrologic disturbances is still in its infancy. In this introduction to the special issue, we advance the fusion of concepts and terminology from ecology and hydrology to begin filling this gap. We briefly explore some preliminary approaches for comparing different disturbances and their hydrologic impacts, which provides a starting point for further dialogue and research progress.

Water Resources Research↗
USGS2024

A decade of curtailment studies demonstrates a consistent and effective strategy to reduce bat fatalities at wind turbines in North America

There is a rapid, global push for wind energy installation. However, large numbers of bats are killed by turbines each year, raising concerns about the impacts of wind energy expansion on bat populations. Preventing turbine blades from spinning at low wind speeds, referred to as curtailment, is a method to reduce bat fatalities, but drawing consistent inference across studies has been challenging. We compiled publicly available studies that evaluated curtailment at six wind energy facilities in North America across 10 years. We used meta-regression of 29 implemented treatments to determine fatality reduction efficacy as well as sources of variation influencing efficacy. We also estimated species-specific fatality reduction for three species that comprise most fatalities in North America: hoary bat ( Lasiurus cinereus ), eastern red bat ( Lasiurus borealis ) and silver-haired bat ( Lasionycteris noctivagans ). We found that curtailment reduced total bat fatalities by 33% with every 1.0 ms −1 increase in curtailment wind speed. Estimates of the efficacy for the three target species were similar (hoary bats: 28% per ms −1 , 95% CI: 0.4%–48%, eastern red bats: 32% per ms −1 , 95% CI: 13%–47% and silver-haired bats: 32% per ms −1 , 95% CI: 3%–53%). Across multiple facilities and years, a 5.0 ms −1 cut-in speed was estimated to reduce total bat fatalities by an average of 62% (95% CI: 54%–69%). Mortality reductions at individual facilities in any given year were estimated to fall between 33%–79% (95% prediction interval). Inter-annual differences rather than inter-site or turbine characteristics accounted for most of the variation in efficacy rates. Species-specific average mortality reduction at 5.0 ms −1 curtailment wind speed was 48% (95% CI: 24%–64%) for hoary bats, 61% (95% CI: 42%–74%) for eastern red bats and 52% (95% CI: 30%–66%) for silver-haired bats. Practical implication . curtailment reduced bat mortality at wind turbines in this North American study. Efficacy increased proportionally as curtailment speed is raised, and patterns and rates of efficacy were similar across species. This indicates that curtailment is an effective strategy to reduce bat fatalities at wind energy facilities, but exploration of further refinements could both minimize bat mortality and maximize energy production.

Ecological Solutions and Evidence↗
USGS2014

Change detection using vegetation indices and multiplatform satellite imagery at multiple temporal and spatial scales

This chapter describes emerging methods for using satellite imagery across temporal and spatial scales using a case study approach to illustrate some of the opportunities now available for combining observations across scales. It explores the use of multiplatform sensor systems to characterize ecological change, as exemplified by efforts to scale the effects of a biocontrol insect (the leaf beetle Diorhabda carinulata ) on the phenology and water use of Tamarix shrubs (Tamarix ramosissima and related species and hybrids) targeted for removal on western U.S. rivers, from the level of individual leaves to the regional level of measurement. Finally, the chapter summarizes the lessons learned and emphasize the need for ground data to calibrate and validate remote sensing data and the types of errors inherent in scaling point data over wide areas, illustrated with research on evapotranspiration (ET) of Tamarix using a wide range of ground measurement and remote sensing methods.

Book chapter↗
USGS2014

Vaccination against bacterial kidney disease

Bacterial kidney disease (BKD) of salmonid fishes, caused by Renibacterium salmoninarum , has been recognized as a serious disease in salmonid fishes since the 1930s. This chapter discusses the occurrence and significance, etiology, and pathogenesis of BKD. It then describes the different vaccination procedures and the effects and side-effects of vaccination. Despite years of research, however, only a single vaccine has been licensed for prevention of BKD, and has demonstrated variable efficacy. Therefore, in addition to a presentation of the current status of BKD vaccination, a discussion of potential future directions for BKD vaccine development is included in the chapter. This discussion is focused on the unique characteristics of R. salmoninarum and its biology, as well as aspects of the salmonid immune system that might be explored specifically to develop more effective vaccines for BKD prevention.

Book chapter↗