South-central California Research Articles

Geomorphology and dynamics of a coastal transgressive dune system, central California

ABSTRACT The Callendar dunes are located within the Santa Maria dune complex in south-central California and have been studied repeatedly since the pioneering work of Bowen and Inman in the 1960's. Previous conceptual models of the system’s Holocene evolution relate variations in dune morphologies to changes in sediment supply and sea level. In the years since their studies, conceptual frameworks of coastal and continental transgressive dune systems provide useful avenues for re-visiting the morphodynamic history of the Callendar dunes. Our study presents grain size and dune spacing data collected by Tchakerian and Mulligan in 1981, while working under Orme as graduate assistants. These data, when considered in light of the more recent conceptual frameworks mentioned above, suggest that the Callendar dunes may exhibit some elements of self-organization. With this in mind, we apply a conceptual model of coastal transgressive dune systems to help elucidate some of the historical morphodynamics influencing the modern arrangement of morphologies at the Callendar dunes.

Emigdiano Blues: The California Indigenous Pigment Palette and an In Situ Analysis of an Exotic Colour

Abstract The Native inhabitants of South Central California produced rock art containing red, orange, black, white, green and blue colours using a range of mineral and organic materials. Many of these same colours were used on material culture and body painting. This paper focuses on a sub-group of the Chumash, called the Emigdiano, who produced an enigmatic blue colour used in the creation of rock art. Here, we focus on the blue pigment at the rock shelter site of Three Springs in the Wind Wolves Preserve in South Central California. The composition of blue pigments has previously been the focus of discussion with suggestions that they were produced either using European pigments taken from Spanish missions, or that azurite from a local quarry was the source. Previous experimental work had demonstrated that it was possible for the blue to be produced from locally available azurite. Here we present the in situ analyses of these enigmatic blue pigments using handheld X-ray Fluorescence (pXRF). Results from pXRF analysis of rock art, quarried azurite samples and experimental rock art reconstructions showed that the Emigdiano Blue at Three Springs were not azurite based and was composed of optical blue (a mixture of black and white or grey materials which mimic the appearance of blue). This paper discusses the surprising implications of the use, given the availability of a ‘true’ blue pigment, and the wider ontological importance of combining multiple colours to produce the effect of blue in a rock art panel.

Investigating Pseudorabies Virus as a Mortality Factor for California Mountain Lions

Wild pigs in North America carry multiple pathogens capable of causing diseases in wildlife, people, and domestic animals. Wild pigs are the reservoir host of pseudorabies virus (PrV) which is a fatal infection in wild carnivores. We previously conducted surveillance for PrV in wild pigs from Kern County, California where the distribution of wild pigs overlaps with native mountain lion. We found that 100% of wild pigs were exposed to PrV, and 6% were shedding the virus. Black bears and pumas have been observed preying on wild pigs in the region suggesting that they are vulnerable to exposure to PrV from pigs. We conducted retrospective, post-mortem surveillance for PrV on 16 pumas from five counties in south central California. None of the pumas tested positive for PrV. In Florida, PrV is attributed to one-third of the deaths in Florida panthers. Wild pigs are a large portion of the diet of panthers in Florida, but studies in California suggest pigs may not be utilized as frequently. This difference in diet could account for the lack of evidence that PrV causes measurable mortality in California pumas. Nonetheless, in management areas with carnivores, wild pig management should be carefully considered.

Origins of The Santa Maria And Vandenberg Coastal Dune Sheets (~100-0 ka) Under Changing Sea Levels, Shoreline Orientations and Wave Directions: Long-Term Records of Coastal Sand Supply in South-Central California, USA

Two large coastal dune sheets, including the Santa Maria dune sheet and Vandenberg dune sheet, have been analyzed for late-Quaternary distributions, ages and volumes of dune sand deposition. Six new thermoluminescence (TL) ages establish the age range of dune sand deposition from >106±21 ka to <4.1 ka in the study area. Seven late-Pleistocene TL and 14C dated mid-depth samples (≤30 m depth subsurface), yield a mean of 33 ka for the late-Pleistocene dune deposits. Both TL and 14C dated Holocene dune deposits establish a transition from weathered middle-Holocene dune deposits to unweathered latest-Holocene dune deposits after 4 ka. Marine sand supply to the large dune sheets occurred by 1) cross-shelf eolian transport during late-Pleistocene marine low-stands (70–13 ka), 2) shoreward wave transport during slowing of the Holocene marine transgression (9–5 ka), and 3) longshore littoral transport during the latest-Holocene marine high-sand (3.5–0 ka). Measured and dated dune deposit sections (n=66, ranging from 2 to 60 m depth) demonstrate substantial differences in preserved sand volumes between the two adjacent dune sheets, Santa Maria (~ 2,300x106 m3) and Vandenberg (~430x106 m3). Asymmetric distributions of dune deposit volumes between and within the dune sheets show that long-term sand supply was locally controlled by paleo-shoreline orientations relative to corresponding deep-water wave propagation directions (260–290° TN) from the North Pacific Low Pressure Area. Recently declining sand supplies and/or -trapping efficiencies in the dune sheet littoral subcells led to ongoing shoreline retreat (≥ 200 m) and under-cutting of late- Holocene eolian sand ramps at the south ends of the Santa Maria and Vandenberg dune sheets. The termination of transgressive cross-shelf sand supply and locally variable longshore retention of littoral sand confirm previously reported framework models of regional coastal sand supply. Such models help to identify shorelines that are most susceptible to future beach erosion from predicted sea level rise following ongoing global warming.

Household networks and emergent territory: a GIS study of Chumash households, villages and rock-art in South-Central California

ABSTRACTElite households of the Californian Chumash have been studied in order to understand the development of Late Holocene hunter-gatherer alliance networks. Equally, models of what has been termed ‘tribelet territories’ have been used to describe land ownership within larger Californian concepts. Surprisingly little research has explicitly addressed issues of how such territories may have developed. In this article, we turn to DeLanda’s philosophy of social complexity to consider how Chumash households may have underpinned the development of tribelet territories and the political implications for their articulation with wider alliances. Importantly, utilizing Geographic Information Systems (GIS), we analyse potential mobility patterns in relation to households, villages and rock-art locales in a case from the Emigdiano Chumash. The results suggest that the painting of rock art was imbricated within processes of territorialization, and that the local placement of art reflects which villages were home to particularly high-status households.

Indigenous Landscapes and Spanish Missions: New Perspectives from Archaeology and Ethnohistory

Indigenous Landscapes and Spanish Missions: New Perspectives from Archaeology and Ethnohistory

Bartonella spp. exposure in northern and southern sea otters in Alaska and California.

Since 2002, an increased number of northern sea otters (Enhydra lutris kenyoni) from southcentral Alaska have been reported to be dying due to endocarditis and/or septicemia with infection by Streptococcus infantarius subsp. coli. Bartonella spp. DNA was also detected in northern sea otters as part of mortality investigations during this unusual mortality event (UME) in Kachemak Bay, Alaska. To evaluate the extent of exposure to Bartonella spp. in sea otters, sera collected from necropsied and live-captured northern sea otters, as well as necropsied southern sea otters (Enhydra lutris nereis) unaffected by the UME, were analyzed using an immunofluorescent antibody assay. Antibodies against Bartonella spp. were detected in sera from 50% of necropsied and 34% of presumed healthy, live-captured northern sea otters and in 16% of necropsied southern sea otters. The majority of sea otters with reactive sera were seropositive for B. washoensis, with antibody titers ranging from 1:64 to 1:256. Bartonella spp. antibodies were especially common in adult northern sea otters, both free-living (49%) and necropsied (62%). Adult stranded northern sea otters that died from infectious causes, such as opportunistic bacterial infections, were 27 times more likely to be Bartonella seropositive than adult stranded northern sea otters that died from noninfectious causes (p<0.001; 95% confidence interval 2.62-269.4). Because Bartonella spp. antibodies were detected in necropsied northern sea otters from southcentral (44%) and southwestern (86%) stocks of Alaska, as well as in necropsied southern sea otters (16%) in southcentral California, we concluded that Bartonella spp. exposure is widely distributed among sea otter populations in the Eastern Pacific, providing context for investigating future disease outbreaks and monitoring of Bartonella infections for sea otter management and conservation.

Drawing Upon the Past: Temporal Ontology and Mythological Ideology in South-central Californian Rock Art

The increasing influence of New Animism is providing useful ways of interpreting rock art as well as ways to move beyond generalizing models based upon Cartesian principles. However, the increasing attention to animism runs the risk of simply replacing one generalization with another. To avoid the pitfalls of generalization, this article sets out to explore the ways in which relational ontology may have been communicated throughout indigenous society in a specific case study from south-central California. To do this requires adopting a ‘third space’ approach (Porr &amp; Bell 2011) to detail the didactic and pedagogical narrative roles of rock art and mythology in south-central California. Paraphrasing Bird-David (2006), the goal is to understand how an animistic epistemology is enacted into an institutionalized way of knowing. To do this, I look closely at new information on rock-art chronology in conjunction with mythological narratives. It is suggested that the vibrant pictographs of the region drew upon ontological notions of the past embodied at specific places in the landscape and that the narrative structure of myth helps inform our understanding of the narrative structure of rock-art composition. This provides an appreciation of indigenous perceptions of time, which in turn shows that mythology was a template for human institutions while explaining rock art as another ontological institution that was part-and-parcel of relational ideologies associated with ‘delayed-return’ complex societies of south-central California.

Polyvalent Metaphors in South-Central California Missionary Processes

AbstractThe Spanish missionary entrada (A.D. 1769 to 1833) along the California coast created a series of complex encounters between multiple cultural discourses. The Franciscan mission system directly brought colonial and indigenous cultural metaphorical understandings into play. Missionary and indigenous discourse interacted largely via the media of material culture, animals, embellished architecture, and landscape—media interpreted through preexisting cultural metaphors and understandings. Investigating how metaphors played a role in constituting colonial entanglements is important in understanding cultural interactions and change. Metaphors structured colonial interactions, simultaneously hindering and enabling missionary–indigenous relationships. These relationships created parameters for unforeseen transitory configurations: a process best theorized under the term polyvalence. By adopting polyvalence, the processes of colonialism can be approached without usage of ethnic or racialized terms such as creolization, hybridity, or amalgamation. In the case of indigenous south-central California, it is suggested here that widely different forms of evidence can be better appreciated without recourse to terms laden with racial or ethnic connotations. The evidence suggests that while missions may have failed to create entirely new ethnic groups, missionary endeavors did result in unanticipated outcomes, presenting problems and creative opportunities for indigenous groups living within immediate coastal and extended interior populations.

The propagating response of coastal circulation due to wind relaxations along the central California coast

[1] Following relaxations of prevailing upwelling‐favorable winds, warm waters from the Santa Barbara Channel propagate poleward around Point Conception and along the south central California coast. We examined characteristics of these relaxation flows, including frontal propagation speed and temperature changes during the warm water arrivals, by using multiyear time series of currents and temperatures from four moorings along the ∼15 m isobath, surface current observations from high‐frequency radars, and satellite sea surface temperature images. Propagation speeds of the warm fronts relative to ambient waters ranged from 0.04 to 0.46 m s −1 . As the fronts arrived at the moorings, temperature increases ranged from 0.7°C to 4.2°C. In ensemble averages over many frontal arrivals, alongshore flow speeds increased by 0.1–0.2 m s −1 over the water column during arrivals. Cross‐shore flows were onshore near the surface and offshore near the bottom with speeds of 0.02–0.05 m s −1 . This cross‐shore flow structure persisted as temperature increased during arrivals and ceased when temperatures stopped increasing. Frontal propagation speeds were correlated with temperature increases at the moorings, consistent with forcing by baroclinic pressure gradients. Compared to other buoyant flows such as from the Chesapeake Bay where density contrasts with ambient waters are 2– 3k g m −3 , these relaxation flows are less buoyant with density contrasts of 0.1–0.9 kg m −3 . Consequently, the propagation of these flows is more affected by bottom friction and the speeds are closer to the “slope‐controlled” or “bottom‐advected” limit described in theoretical and laboratory work but not well studied in the ocean.

Placing Ideology

The inland and interior regions of south-central California are distinctive from the coastal plains in the numbers and distribution of rock art sites. Here I examine rock art in its landscape context in relation to village sites, seasonally occupied sites, and natural resources. In looking at three rock art rich landscapes, analysis demonstrates a pervasive association across inland and interior south-central California between bedrock mortars and rock art. The implications of this persistent correlation suggest something more than accidental sharing of space between ritual and subsistence activities. The employment of visual media within important subsistence and habitation contexts argues for an indigenous ideological expression related to vital inland and interior land-use practices. The nature of that ideological display remains fuzzy, but minimally this highly visible display of vibrant media in the form of pictographs should be seen as a projection of some form of authority at the most important locales within some terrestrial south-central California landscapes.

Landscape Archaeology in Southern and South-Central California

Landscape Archaeology in Southern and South-Central California

Treatment of Variable Water Sources: Adaptations for a Flexible Desalination System

There are a number of locations where a utility would want to be able to treat multiple sources of water with one treatment system. Those that the Bureau of Reclamation (Reclamation) has come across recently are:The Texas Gulf Coast where brackish surface or groundwater is available for much of the year but only seawater is available during dry seasons;South central California where the character of the irrigation drainage water changes with the intensity of irrigation;Inland desert areas where the composition of brackish surface and groundwater is significantly different when augmented with storm water. Reclamation assisted the US Office of Naval Research in development and demonstration of the Expeditionary Unit Water Purifier system which can produce 378 m3/day (100,000 gal/day) of potable water from any liquid source water up to 60 g/L TDS under 35°C. The system was tested under the Environmental Technology Validation (ETV) program overseen by NSF International for the US Environmental Protection Agency (EPA). Test water sources were seawater, turbid surface water, and tertiary wastewater. As a complete system, it performed well with each source. It was only capable of 50% recovery of water however. Because of this, the system has been turned down for potential emergency applications due to the excessive loss of water. This issue occurring at the same time as the three situations mentioned above prompted a proposal to design a flexible system that could be adapted to achieve high water recovery when the feed source allows while still maintaining the capability of recovering energy when the remaining concentrate pressure allows.

Land Use, Land Ideology: An Integrated Geographic Information Systems Analysis of Rock Art Within South-Central California

While rock art is global in distribution, it remains a media fix in placed within particular physical environments. Because of this, it can be examined using various spatial approaches and technologies. By integrating a variety of Geographic Information Systems (GIS) applications to examine the location and position of rock art in relation to both natural features and other archaeological deposits, a detailed understanding of the positioning of rock art can be advanced. In this case, I employ this methodology to address the presence that rock art exerted within the Emgidiano/HulkuhkuChumash landscape of South-Central California. In so doing, I demonstrate that specific research questions concerning rock art in public or private contexts can be addressed, and that in this example, the pictographs of theHulkuhkuwere visibly integrated within the intimate confines of the most important economic places in the landscape, showing that subsistence and symbolic practices were conjoined through ideological media.

Event-driven sediment flux in Hueneme and Mugu submarine canyons, southern California

Vertical sediment fluxes and their dominant controlling processes in Hueneme and Mugu submarine canyons off south-central California were assessed using data from sediment traps and current meters on two moorings that were deployed for 6 months during the winter of 2007. The maxima of total particulate flux, which reached as high as 300+ g/m 2/day in Hueneme Canyon, were recorded during winter storm events when high waves and river floods often coincided. During these winter storms, wave-induced resuspension of shelf sediment was a major source for the elevated sediment fluxes. Canyon rim morphology, rather than physical proximity to an adjacent river mouth, appeared to control the magnitude of sediment fluxes in these two submarine canyon systems. Episodic turbidity currents and internal bores enhanced sediment fluxes, particularly in the lower sediment traps positioned 30 m above the canyon floor. Lower excess 210Pb activities measured in the sediment samples collected during periods of peak total particulate flux further substantiate that reworked shelf-, rather than newly introduced river-borne, sediments supply most of the material entering these canyons during storms.

Wind relaxations and poleward flow events in a coastal upwelling system on the central California coast

When upwelling favorable winds weaken or relax in coastal upwelling systems, prevailing equatorward currents often weaken and then reverse to form propagating poleward currents. Here the statistics of wind relaxations and poleward flow events along the south central California coast are derived using meteorological and oceanographic times series during 2000–2006. Over the 7‐year record, 169 wind relaxations were observed (about 1 every 2 weeks) and 127 of these were followed by poleward flow events. Thermistor moorings and current profilers along the 15 m isobath at Alegria, Point Arguello, Point Purisima, and Point Sal recorded the poleward flows. The poleward flows propagate northward at 10–30 km d−1 and appear as sequential temperature increases at the moorings. Wind relaxations occur throughout the year but are most frequent in September and least frequent in April when upwelling winds are strong and persistent. Poleward flows follow wind relaxations frequently during May through November and rarely in December and January. Sea level differences between Santa Monica and Port San Luis, California, decreased as winds relaxed, consistent with forcing by alongshore pressure gradients. Temperature distributions at Point Arguello, Point Purisima, and Point Sal were skewed toward higher values because of the poleward flows. The alongshore distance traveled by the poleward flows increased with duration of the wind relaxations and magnitudes of alongshore temperature and sea level differences prior to the relaxations.

Osteology of the Graveldiver Scytalina cerdale (Perciformes: Zoarcoidei: Scytalinidae)

The Graveldiver, Scytalina cerdale, is a small, poorly known burrowing fish from the intertidal and subtidal zones of the west coast of North America, ranging from south-central California to Alaska. This is the sole member of the family Scytalinidae, which is included in the Zoarcoidei. Although it was described over 120 years ago, it is rare in natural history collections and its anatomy is only imperfectly known. This article describes and illustrates the skeletal anatomy of S. cerdale based on newly prepared cleared and stained specimens. Many points of its anatomy are clarified or corrected (e.g., presence of the intercalars and ribs, in contrast to their reported absence) or described for the first time (e.g., structure of its gill-arches). Previous hypotheses of its systematic placement within the Zoarcoidei are discussed. On the basis of preliminary comparisons, S. cerdale may have phylogenetic affinity with at least some members of the family Stichaeidae (e.g., Xiphister). However, further study is needed on the anatomy and inter-relationships of the families of the Zoarcoidei before any conclusions can be made.

Population genetic structure and ancestry of Oncorhynchus mykiss populations above and below dams in south-central California

Genetic analyses of coastal Oncorhynchus mykiss, commonly known as steelhead/rainbow trout, at the southern extreme of their geographic range in California are used to evaluate ancestry and genetic relationships of populations both above and below large dams. Juvenile fish from 20 locations and strains of rainbow trout commonly planted in reservoirs in the five study basins were evaluated at 24 microsatellite loci. Phylogeographic trees and analysis of molecular variance demonstrated that populations within a basin, both above and below dams, were generally each other’s closest relatives. Absence of hatchery fish or their progeny in the tributaries above dams indicates that they are not commonly spawning and that above-barrier fish are descended from coastal steelhead trapped at dam construction. Finally, no genetic basis was found for the division of populations from this region into two distinct biological groups, contrary to current classification under the US and California Endangered Species Acts.

SPATIAL AND TEMPORAL PATTERNS OF INVERTEBRATE RECRUITMENT ALONG THE WEST COAST OF THE UNITED STATES

Patterns of recruitment in marine ecosystems can reflect the distribution of adults, dispersal by ocean currents, or patterns of mortality after settlement. In turn, patterns of recruitment can play an important role in determining patterns of adult abundance and community dynamics. Here we examine the biogeographic structure of recruitment variability along the U.S. West Coast and examine its association with temperature variability. From 1997 to 2004 we monitored monthly recruitment rates of dominant intertidal invertebrates, mussels and barnacles, at 26 rocky shore sites on the West Coast of the United States, from northern Oregon to southern California, a span of 1750 km of coastline. We examined spatial variation in the dynamics of recruitment rates and their relationship to coastal oceanography using satellite-derived time series of monthly sea surface temperature (SST). Recruitment rates showed a biogeographic structure with large regions under similar dynamics delimited by abrupt transitions. The seasonal peak in recruitment rates for both mussels and barnacles changed from a late summer–early fall peak in Oregon to winter or early spring in northern California, and then back toward summer in southern California. Recruitment rates varied greatly in magnitude across the latitudinal range. The barnacle Balanus glandula and mussels (Mytilus spp.) showed a decline of two orders of magnitude south of Oregon. In contrast, recruitment rates of barnacles of the genus Chthamalus showed a variable pattern across the region examined. The spatial distribution of associations between raw SST and recruitment rates for all species showed positive associations, indicating recruitment during warm months, for all species in Oregon, northern California, and several sites in south-central California. By considerably extending the spatial and temporal scales beyond that of previous studies on larval recruitment rates in this system, our study has identified major biogeographic breaks around Cape Blanco and Point Conception despite considerable spatial and temporal variation within each region and among species. These large differences in recruitment rates across biogeographic scales highlight the need for a better understanding of larval responses to ocean circulation patterns in the conservation and management of coastal ecosystems.

Phylogeography of Diadophis punctatus: Extensive lineage diversity and repeated patterns of historical demography in a trans-continental snake

Dynamic climatic oscillations during the Pleistocene had profound effects on the distributions of species across North America. Although the role of historical climate change on speciation remains controversial, the impact on genetic variation within species has been well documented. We examined mtDNA sequences from the cytochrome b gene (1117 bp) and a portion of the NADH-4 gene (659 bp) for 286 individuals of Diadophis punctatus to infer phylogeographic patterns and population structure and to examine historical demographic patterns in both glaciated and unglaciated regions of North America. We inferred 14 lineages that replace each other geographically across the United States. Several of these lineages appear to be confined to specific habitats (floodplains, grasslands, montane environments) and traverse previously identified genetic barriers for terrestrial vertebrates including the Mississippi and Apalachicola Rivers, the Appalachian Mountains, and the western continental divide. We also observed overlapping ranges between some haplotype groups and several instances of secondary contact associated with ecological transition zones in eastern South Carolina, southern Oklahoma and central California. Within the US, diversification began during the late Miocene and continued into the mid-Pleistocene, suggesting these lineages pre-dated the last glacial maximum. Coalescent and non-coalescent demographic analyses indicate that independent lineages currently occupying previously glaciated or unsuitable areas in eastern, central and western US underwent post-glacial population expansion likely from southern refugia during the late Pleistocene/early Holocene. Conversely, southern lineages display patterns consistent with long-term population stability. Such long-term persistence of genetic structure may be due to the competitive effects between lineages or ecosystem stability in more southern latitudes.