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USGS2015

Science foundation Chapter 5 Appendix 5.1: Case study shore birds: Western sandpipers ( Calidris mauri ) and American avocets ( Recurvirostra Americana )

Western sandpipers ( Calidris mauri ) are small (22-35 g) sexually dimorphic sandpipers, with males typically smaller than females. Western sandpipers frequently occur in mixed species flocks along with other Calidris species, including least sandpipers ( Calidris minutilla ) and dunlin ( Calidris alpina ), in the San Francisco Bay Estuary (SFBE) and are the most abundant shorebird species found from fall to spring. Western sandpipers are one of the most common shorebird species in SFBE, the Pacific Flyway, and North America overall. The largest concentrations of western sandpipers, and of most shorebirds, are found in the South Bay where large expanses of mudflats are exposed at low tide and managed and/or salt ponds are available for high tide roosting and feeding habitat (Warnock et al 2002, Warnock and Takekawa 1995). In recent years, there is some evidence that there has been a shift in shorebird numbers towards the North Bay, perhaps as large salt pond restoration projects provide interim mud flat habitat during the evolution towards tidal marsh habitat (Pitkin and Wood, 2011).

California↗

USGS1968

Variation of Nb-Ta, Zr-Hf, Th-U and K-Cs in two diabase-granophyre suites

Concentrations of Nb, Ta, Zr, Hf, Th, U and Cs have been determined in samples of igneous rocks representing the diabase-granophyre suites from Dillsburg, Pennsylvania, and Great Lake, Tasmania. Niobium and tantalum have a three to fourfold increase with differentiation in each of the suites. The chilled margin of the Great Lake intrusion contains half the niobium and tantalum content (5.3 ppm and 0.4 ppm, respectively) of the chilled basalt from Dillsburg (10 ppm and 0.9 ppm, respectively). The twofold difference between the suites is correlated with differences in their titanium content. The average Nb Ta "> NbTa ratios for each suite are similar: 13.5 for the Great Lake suite, and 14.4 for the Dillsburg suite. The zirconium content of the two suites is essentially the same and increases from 50 to 60 ppm in the chilled margins to 240–300 ppm in the granophyres. Hafnium is low in the early formed rocks (0.5 –1.5 ppm and achieves a maximum in the granophyres (5–8 ppm). The Zr Hf "> ZrHf ratio decreases from 68 to 33 with progressive differentiation. In the Dillsburg suite thorium and uranium increase from 2.6 ppm and 0.6 ppm, respectively, in the chilled samples to 11.8 ppm and 3.1 ppm in the granophyres. The chilled margin of the Great Lake suite contains 3.2 ppm thorium and 9.8 ppm uranium; the granophyre contains 11.2 ppm thorium and 2.8 ppm uranium. The average Th U "> ThU ratios of the Dillsburg and Great Lake suites are nearly the same—4.1 and 4.4, respectively. Within each suite the Th U "> ThU ratio remains quite constant. Cesium and the K Cs "> KCs ratio do not vary systematically in the Dillsburg suite possibly because of redistribution or loss of cesium by complex geologic processes. Except for the chilled margin of the Great Lake suite, the variation of Cs and the K Cs "> KCs ratio are in accord with theoretical considerations. Cesium increases from about 0.6 ppm in the lower zone to 3.5 ppm in the granophyre; the K Cs "> KCs ratio varies from 10 × 10 3 in the lower zone to 6 × 10 3 in the granophyre. A comparison of the abundance of some of these elements is made with those reported on oceanic tholeiites from the Atlantic and Pacific oceans. Trace elements with large ionic radii (Th, U, Cs) are present in significantly greater concentrations in the two continental tholeiitic series than in the oceanic tholeiites. However, this does not seem to be true for lithophilic elements of smaller ionic radii (Zr and Nb). These trace element distribution patterns, when considered with other minor element and isotopic studies, indicate that 1. crustal contamination does not entirely account for differences between continental and oceanic tholeiites, and 2. the oceanic tholeiites do not necessarily delimit the geochemical characteristics of the mantle.

Geochimica et Cosmochimica Acta↗

USGS1993

Neogene folding and faulting in southern Monterey Bay, Central California, USA

The goal of this study was to determine the Neogene structural history of southern Monterey Bay by mapping and correlating the shallow tectonic structures with previously identified deeper occurring structures. Side scan sonographs and Uniboom seismic reflection profiles collected in the region suggest that deformation associated with both compressional and transcurrent movement is occurring. Strike-slip movement between the North American and Pacific plates started as subduction ceased 21 Ma, creating the San Andreas fault system. Clockwise rotation of the Pacific plate occurred between 3.4 and 3.9 Ma causing orthogonal convergence between the two plates. This plate rotation is responsible for compressional Neogene structures along the central California coast. Structures exhibit transpressional tectonic characteristics such as thrust faulting, reverse faulting and asymmetrical folding. Folding and faulting are confined to middle Miocene and younger strata. Shallow Mesozoic granitic basement rocks either crop out or lie near the surface in most of the region and form a possible décollement along which the Miocene Monterey Formation has decoupled and been folded. Over 50% of the shallow faults strike normal (NE-SW) to the previously identified faults. Wrench fault tectonics complicated by compression, gradual uplift of the basement rocks, and a change in plate convergence direction are responsible for the observed structures in southern Monterey Bay.

Marine Geology↗

USGS2016

Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes

Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish.

Environmental Pollution↗

USGS2017

Paleowetlands and regional climate change in the central Atacama Desert, northern Chile

Widespread, organic-rich diatomaceous deposits are evidence for formerly wetter times along the margins of the central Atacama Desert, one of the driest places on Earth today. We mapped and dated these paleowetland deposits at three presently waterless locations near Salar de Punta Negra (24.5°S) on the western slope of the Andes. Elevated groundwater levels supported phreatic discharge into wetlands during two periods: 15,900 to ~ 13,800 and 12,700 to ~ 9700 cal yr BP. Dense concentrations of lithic artifacts testify to the presence of paleoindians around the wetlands late in the second wet phase (11,000?–9700 cal yr BP). Water tables dropped below the surface before 15,900 and since 8100 cal yr BP, and briefly between ~ 13,800 and 12,700 cal yr BP. This temporal pattern is repeated, with some slight differences, in rodent middens from the study area, in both paleowetland and rodent midden deposits north and south of the study area, and in lake level fluctuations on the adjacent Bolivian Altiplano. The regional synchroneity of these changes points to a strengthening of the South American Monsoon — which we term the "Central Andean Pluvial Event" — in two distinct intervals (15,900–13,800 and 12,700–9700 cal yr BP), probably induced by steepened SST gradients across the tropical Pacific (i.e., La Niña-like conditions).

Atacama Desert;Andes Mountains↗

USGS1969

Aeromagnetic investigation of crustal structure for a strip across the western United States

This report represents part of a larger study undertaken to interpret the gross features of the earth's crust by aeromagnetic methods. The larger survey covers a 100-mile-wide strip along a great circle arc from Washington, D.C., to San Francisco, California. The area considered extends from about 200 miles east of the Rocky Mountains to 150 miles west of the coast of the Pacific Ocean. Inferences on gross structure and lithology are made from the magnetic patterns and trends shown on the map. At the continental margin, the magnetic data strongly suggest that the oceanic crust becomes much more deeply buried as the continent is approached. A large magnetic anomaly extending northwestward along the center of the Great Valley is probably caused by mafic intrusive rocks.

California, Colorado, Kansas, Nebraska, Nevada, Ut↗

USGS2020

Focused fluid flow and methane venting along the Queen Charlotte fault, offshore Alaska (USA) and British Columbia (Canada)

Fluid seepage along obliquely deforming plate boundaries can be an important indicator of crustal permeability and influence on fault-zone mechanics and hydrocarbon migration. The ~850-km-long Queen Charlotte fault (QCF) is the dominant structure along the right-lateral transform boundary that separates the Pacific and North American tectonic plates offshore southeastern Alaska (USA) and western British Columbia (Canada). Indications for fluid seepage along the QCF margin include gas bubbles originating from the seafloor and imaged in the water column, chemosynthetic communities, precipitates of authigenic carbonates, mud volcanoes, and changes in the acoustic character of seismic reflection data. Cold seeps sampled in this study preferentially occur along the crests of ridgelines associated with uplift and folding and between submarine canyons that incise the continental slope strata. With carbonate stable carbon isotope (δ 13 C) values ranging from −46‰ to −3‰, there is evidence of both microbial and thermal degradation of organic matter of continental-margin sediments along the QCF. Both active and dormant venting on ridge crests indicate that the development of anticlines is a key feature along the QCF that facilitates both trapping and focused fluid flow. Geochemical analyses of methane-derived authigenic carbonates are evidence of fluid seepage along the QCF since the Last Glacial Maximum. These cold seeps sustain vibrant chemosynthetic communities such as clams and bacterial mats, providing further evidence of venting of reduced chemical fluids such as methane and sulfide along the QCF.

Alaska, British Columbia↗

USGS2012

Predation rates, timing, and predator composition for Scoters ( Melanitta spp.) in marine habitats

Studies of declining populations of sea ducks have focused mainly on bottom-up processes with little emphasis on the role of predation. We identified 11 potential predators of White-winged Scoters ( Melanitta fusca (L., 1758)) and Surf Scoters ( Melanitta perspicillata (L., 1758)) in North American marine habitats. However, of 596 Scoters marked with VHF transmitters along the Pacific coast, mortalities were recovered in association with just two identifiable categories of predators: in southeast Alaska recoveries occurred mainly near mustelid feeding areas, while those in southern British Columbia and Washington occurred mainly near feeding areas of Bald Eagles ( Haliaeetus leucocephalus (L., 1766)). Determining whether marked Scoters had been depredated versus scavenged was often not possible, but mortalities occurred more frequently during winter than during wing molt (13.1% versus 0.7% of both species combined, excluding Scoters that died within a postrelease adjustment period). In two sites heavily used by Scoters, diurnal observations revealed no predation attempts and low rates of predator disturbances that altered Scoter behavior (≤ 0.22/h). These and other results suggest that predation by Bald Eagles occurs mainly at sites and times where densities of Scoters are low, while most predation by mustelids probably occurs when Scoters are energetically compromised.

Canadian Journal of Zoology↗

USGS2012

Low-level copper exposures increase visibility and vulnerability of juvenile coho salmon to cutthroat trout predators

Copper contamination in surface waters is common in watersheds with mining activities or agricultural, industrial, commercial, and residential human land uses. This widespread pollutant is neurotoxic to the chemosensory systems of fish and other aquatic species. Among Pacific salmonids (Oncorhynchus spp.), copper-induced olfactory impairment has previously been shown to disrupt behaviors reliant on a functioning sense of smell. For juvenile coho salmon (O. kisutch), this includes predator avoidance behaviors triggered by a chemical alarm cue (conspecific skin extract). However, the survival consequences of this sublethal neurobehavioral toxicity have not been explored. In the present study juvenile coho were exposed to low levels of dissolved copper (5-20 microg/L for 3 h) and then presented with cues signaling the proximity of a predator. Unexposed coho showed a sharp reduction in swimming activity in response to both conspecific skin extract and the upstream presence of a cutthroat trout predator (O. clarki clarki) previously fed juvenile coho. This alarm response was absent in prey fish that were exposed to copper. Moreover, cutthroat trout were more effective predators on copper-exposed coho during predation trials, as measured by attack latency, survival time, and capture success rate. The shift in predator-prey dynamics was similar when predators and prey were co-exposed to copper. Overall, we show that copper-exposed coho are unresponsive to their chemosensory environment, unprepared to evade nearby predators, and significantly less likely to survive an attack sequence. Our findings contribute to a growing understanding of how common environmental contaminants alter the chemical ecology of aquatic communities.

Ecological Applications↗

USGS2020

Sediments and the sea floor of the continental shelves and coastal waters of the United States—About the usSEABED integrated sea-floor-characterization database, built with the dbSEABED processing system

Since the second half of the 20th century, there has been an increase in scientific interest, research effort, and information gathered on the geologic sedimentary character of the continental margins of the United States. Data and information from thousands of sources have increased our scientific understanding of the character of the margin surface, but rarely have those data been combined and integrated. Initially, the U.S. Geological Survey (USGS), in cooperation with the Institute of Arctic and Alpine Research at the University of Colorado Boulder, created the usSEABED database to provide surficial sea-floor-characterization data for USGS assessments of marine-based aggregates and for studies of sea-floor habitat. Since then, the USGS has continued to build up the database as a nationwide resource for many uses and applications. Previously published data derived from the usSEABED database have been released as three USGS data series publications containing data covering the U.S. Atlantic margin, the Gulf of Mexico and Caribbean regions, and the Pacific coast. An updated USGS data release unifies the three publications, incorporates additional data and sources including data from Alaska, Hawaii, and U.S. overseas territories, and provides revised output files that fix known errors and add known or inferred sampling dates. This report accompanies the data release and contains information on the methodology and products of the usSEABED database.

Open-File Report↗

USGS1999

Publications of the Western Geologic Mapping Team 1997-1998

The Western Geologic Mapping Team (WGMT) of the U.S. Geological Survey, Geologic Division (USGS, GD), conducts geologic mapping and related topical earth-science studies in the western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues such as ground-water quality, potential geologic hazards, and land-use decisions. Areas of primary emphasis currently include southern California, the San Francisco Bay region, the Pacific Northwest, the Las Vegas urban corridor, and selected National Park lands. The team has its headquarters in Menlo Park, California, and maintains smaller field offices at several other locations in the western United States. The results of research conducted by the WGMT are released to the public as a variety of databases, maps, text reports, and abstracts, both through the internal publication system of the USGS and in diverse external publications such as scientific journals and books. This report lists publications of the WGMT released in calendar years 1997 and 1998. Most of the publications listed were authored or coauthored by WGMT staff. However, the list also includes some publications authored by formal non-USGS cooperators with the WGMT, as well as some authored by USGS staff outside the WGMT in cooperation with WGMT projects. Several of the publications listed are available on the World Wide Web; for these, URL addresses are provided. Most of these Web publications are USGS open-file reports that contain large digital databases of geologic map and related information. For these, the bibliographic citation refers specifically to an explanatory pamphlet containing information about the content and accessibility of the database, not to the actual map or related information comprising the database itself.

Open-File Report↗

USGS2014

Tsunami vertical-evacuation planning in the U.S. Pacific Northwest as a geospatial, multi-criteria decision problem

Tsunami vertical-evacuation (TVE) refuges can be effective risk-reduction options for coastal communities with local tsunami threats but no accessible high ground for evacuations. Deciding where to locate TVE refuges is a complex risk-management question, given the potential for conflicting stakeholder priorities and multiple, suitable sites. We use the coastal community of Ocean Shores (Washington, USA) and the local tsunami threat posed by Cascadia subduction zone earthquakes as a case study to explore the use of geospatial, multi-criteria decision analysis for framing the locational problem of TVE siting. We demonstrate a mixed-methods approach that uses potential TVE sites identified at community workshops, geospatial analysis to model changes in pedestrian evacuation times for TVE options, and statistical analysis to develop metrics for comparing population tradeoffs and to examine influences in decision making. Results demonstrate that no one TVE site can save all at-risk individuals in the community and each site provides varying benefits to residents, employees, customers at local stores, tourists at public venues, children at schools, and other vulnerable populations. The benefit of some proposed sites varies depending on whether or not nearby bridges will be functioning after the preceding earthquake. Relative rankings of the TVE sites are fairly stable under various criteria-weighting scenarios but do vary considerably when comparing strategies to exclusively protect tourists or residents. The proposed geospatial framework can serve as an analytical foundation for future TVE siting discussions.

Washington↗

USGS2010

Patterns of use and distribution of king eiders and black scoters during the annual cycle in northeastern Bristol Bay, Alaska

Northeastern Bristol Bay, Alaska, which includes three large estuaries, is used by multiple sea duck species during the annual cycle. Limited aerial surveys indicate that this area supports tens of thousands of king eiders and black scoters during spring migration and the autumn molt. Existing satellite telemetry data were used to assess the temporal patterns of habitat use and spatial distribution of king eiders and black scoters in northeastern Bristol Bay throughout the annual cycle. King eiders used northeastern Bristol Bay during all months of the annual cycle and black scoters used the area during spring through fall. Both species exhibited a similar seasonal pattern of use that corresponded with the timing of life-cycle stages. Abundance of both species was highest during spring migration and the autumn molting period and lowest during summer. Use by king eiders did not occur during all winter months in every year of the study. King eiders were more broadly distributed than black scoters and were located farther from shore in deeper water. Core use areas had minimal overlap, suggesting a degree of spatial segregation between species and a preference for different habitats in northeastern Bristol Bay. Further study of potential variation in invertebrate community structure that may correlate with the observed interspecific spatial segregation in habitat use is needed to determine preferred forage and describe habitat requirements for each species. Such information is necessary to assess the potential impact that future anthropogenic or environmental changes may have on habitat quality of northeastern Bristol Bay and demography of Pacific sea duck populations that use this area.

Alaska↗

USGS2000

Publications of the Western Earth Surface Processes Team, 1999

The Western Earth Surfaces Processes Team (WESPT) of the U.S. Geological Survey, Geologic Division (USGS, GD), conducts geologic mapping and related topical earth- science studies in the western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues such as ground-water quality, potential geologic hazards, and land-use decisions. Areas of primary emphasis currently include southern California, the San Francisco Bay region, and the Pacific Northwest. The team has its headquarters in Menlo Park, California, and maintains field offices at several other locations in the western United States. The results of research conducted by the WESPT are released to the public as a variety of databases, maps, text reports, and abstracts, both through the internal publication system of the USGS and in diverse external publications such as scientific journals and books. This report lists publications of the WESPT released in 1999 as well as additional 1997 and 1998 publications that were not included in the previous list (USGS Open-file Report 99-302). Most of the publications listed were authored or coauthored by WESPT staff. The list also includes some publications authored by non-USGS cooperators with the WESPT, as well as some authored by USGS staff outside the WESPT in cooperation with WESPT projects.

Open-File Report↗

USGS2001

Publications of the Western Earth Surface Processes Team 2000

The Western Earth Surface Processes Team (WESP) of the U.S. Geological Survey (USGS) conducts geologic mapping and related topical earth science studies in the western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues such as ground-water quality, potential geologic hazards, and land-use decisions. Areas of primary emphasis in 2000 included southern California, the San Francisco Bay region, the Pacific Northwest, the Las Vegas urban corridor, and selected National Park lands. The team has its headquarters in Menlo Park, California, and maintains smaller field offices at several other locations in the western United States. The results of research conducted by the WESPT are released to the public as a variety of databases, maps, text reports, and abstracts, both through the internal publication system of the USGS and in diverse external publications such as scientific journals and books. This report lists publications of the WESPT released in 2000 as well as additional 1999 publications that were not included in the previous list (USGS Open-file Report 00-215). Most of the publications listed were authored or coauthored by WESPT staff. The list also includes some publications authored by non-USGS cooperators with the WESPT, as well as some authored by USGS staff outside the WESPT in cooperation with WESPT projects. Several of the publications listed are available on the World Wide Web; for these, URL addresses are provided. Many of these Web publications are USGS open-file reports that contain large digital databases of geologic map and related information.

Open-File Report↗

USGS2017

Genetic structure among greater white-fronted goose populations of the Pacific Flyway

An understanding of the genetic structure of populations in the wild is essential for long-term conservation and stewardship in the face of environmental change. Knowledge of the present-day distribution of genetic lineages (phylogeography) of a species is especially important for organisms that are exploited or utilize habitats that may be jeopardized by human intervention, including climate change. Here, we describe mitochondrial (mtDNA) and nuclear genetic (microsatellite) diversity among three populations of a migratory bird, the greater white-fronted goose ( Anser albifrons ), which breeds discontinuously in western and southwestern Alaska and winters in the Pacific Flyway of North America. Significant genetic structure was evident at both marker types. All three populations were differentiated for mtDNA, whereas microsatellite analysis only differentiated geese from the Cook Inlet Basin. In sexual reproducing species, nonrandom mate selection, when occurring in concert with fine-scale resource partitioning, can lead to phenotypic and genetic divergence as we observed in our study. If mate selection does not occur at the time of reproduction, which is not uncommon in long-lived organisms, then mechanisms influencing the true availability of potential mates may be obscured, and the degree of genetic and phenotypic diversity may appear incongruous with presumed patterns of gene flow. Previous investigations revealed population-specific behavioral, temporal, and spatial mechanisms that likely influence the amount of gene flow measured among greater white-fronted goose populations. The degree of observed genetic structuring aligns well with our current understanding of population differences pertaining to seasonal movements, social structure, pairing behavior, and resource partitioning.

Ecology and Evolution↗

USGS2019

A natural‐origin steelhead population's response to exclusion of hatchery fish

It is asserted that reduction or elimination of hatchery stocking will increase natural‐origin salmon Oncorhynchus spp. and steelhead O. mykiss production. We conducted an analysis of steelhead population census data (1958–2017) to determine whether elimination of summer steelhead stocking in the upper Clackamas River in 1998 increased the productivity of natural‐origin winter steelhead. A Bayesian state–space stock–recruitment model was fitted to the adult steelhead data set, and productivity was estimated as a function of hatchery‐origin spawner abundance as well as other environmental factors. When used as a predictive variable in our model, the abundance of hatchery summer steelhead spawners (1972–2001) did not have a negative effect on winter steelhead recruitment. However, spill at North Fork Dam (the gateway to the upper Clackamas River basin) and the Pacific Decadal Oscillation (an index of ocean conditions) were both negatively associated with winter steelhead recruitment. Moreover, winter steelhead abundance in the upper Clackamas River basin failed to rebound to abundances observed in years prior to the hatchery program, and fluctuations in winter steelhead abundance were correlated with those of other regional winter steelhead stocks. Our assessment underscores the need for studies that (1) directly quantify the effects of hatchery fish on the production of natural‐origin salmon and steelhead, (2) empirically test published theories about mechanisms of hatchery fish impacts on natural‐origin populations, and (3) document population responses to major changes in hatchery programs.

Oregon↗

USGS2011

Growth anomalies on the coral genera Acropora and Porites are strongly associated with host density and human population size across the Indo-Pacific

Growth anomalies (GAs) are common, tumor-like diseases that can cause significant morbidity and decreased fecundity in the major Indo-Pacific reef-building coral genera, Acropora and Porites. GAs are unusually tractable for testing hypotheses about drivers of coral disease because of their pan-Pacific distributions, relatively high occurrence, and unambiguous ease of identification. We modeled multiple disease-environment associations that may underlie the prevalence of Acropora growth anomalies (AGA) (n = 304 surveys) and Porites growth anomalies (PGA) (n = 602 surveys) from across the Indo-Pacific. Nine predictor variables were modeled, including coral host abundance, human population size, and sea surface temperature and ultra-violet radiation anomalies. Prevalence of both AGAs and PGAs were strongly host density-dependent. PGAs additionally showed strong positive associations with human population size. Although this association has been widely posited, this is one of the first broad-scale studies unambiguously linking a coral disease with human population size. These results emphasize that individual coral diseases can show relatively distinct patterns of association with environmental predictors, even in similar diseases (growth anomalies) found on different host genera (Acropora vs. Porites). As human densities and environmental degradation increase globally, the prevalence of coral diseases like PGAs could increase accordingly, halted only perhaps by declines in host density below thresholds required for disease establishment.

PLoS ONE↗