Santa Barbara Coastal Research Articles

A tool for detecting giant kelp canopy biomass decline in the Californias.

Kelp species provide many ecosystem services associated with their three-dimensional structures. Among these, fast-growth, canopy-forming species, like giant kelp Macrocystis pyrifera, are the foundation of kelp forests across many temperate reefs. Giant kelp populations have experienced regional declines in different parts of the world. Giant kelp canopy is very dynamic and can take years to recover from disturbance, challenging comparisons of standing biomass with historical baselines. The Santa Barbara Coastal LTER (SBC LTER), curates a time series of Landsat sensed surface cover and biomass for giant kelp in the west coast of North America. In the last decade, this resource has been fundamental to understanding the species' population dynamics and drivers. However, simple ready-to-use summary statistics aimed at classifying regional kelp decline or recovery are not readily available to stakeholders and coastal managers. To this end, we describe here two simple metrics made available through the R package kelpdecline. First, the proportion of Landsat pixels in decline (PPD), in which current biomass is compared with a historical baseline, and second, a pixel occupancy trend (POT), in which current year pixel occupancy is compared to the time-series long probability of occupancy. The package produces raster maps and output tables summarizing kelp decline and trends over a 0.25 × 0.25° scale. Using kelpdecline, we show how sensitivity analysis on PPD parameter variation can increase the confidence of kelp decline estimates.

Phytoplankton transport out of the euphotic zone by frontal subduction and gravitational sinking in the Santa Barbara Channel, CA, USA

Production of particulate organic carbon (POC) in nutrient-rich coastal waters over continental shelves, its export to depth, and its transport to deeper ocean waters is a poorly quantified component of the global carbon cycle. A critical step in quantifying this vertical transport is identifying shelf processes that export phytoplankton out of the euphotic zone. During cruises of the Santa Barbara Coastal Long Term Ecological Research project, we discovered substantial chlorophyll a (chl a) below the euphotic zone in the Santa Barbara Channel, a part of the southern California Current System. Observations from towed, undulating vehicles revealed deep chlorophyll layers near fronts where upwelled waters from central California converged with lower-density waters from the Southern California Bight. The mean fraction ± 1 standard deviation (SD) of chlorophyll biomass below the euphotic zone spanning the entire Santa Barbara Channel was ~7 ± 9% during 13 cruises averaged across all seasons. In one spring cruise, the fraction was ~30%, and in other cruises the layers were absent. Phytoplankton export out of the euphotic zone by subduction was indicated by spatial coherence between chl a and sloping density surfaces. Vertical plumes of chl a crossing density surfaces indicated enhanced gravitational export within cyclonic eddies. Chl a in water samples below the euphotic zone, away from fronts and cyclonic flows, suggested additional phytoplankton export. Our results emphasize the importance of subduction in the export of phytoplankton and POC out of the euphotic zone in coastal upwelling systems.

Connectivity: insights from the U.S. Long Term Ecological Research Network

AbstractEcosystems across the United States are changing in complex and surprising ways. Ongoing demand for critical ecosystem services requires an understanding of the populations and communities in these ecosystems in the future. This paper represents a synthesis effort of the U.S. National Science Foundation‐funded Long‐Term Ecological Research (LTER) network addressing the core research area of “populations and communities.” The objective of this effort was to show the importance of long‐term data collection and experiments for addressing the hardest questions in scientific ecology that have significant implications for environmental policy and management. Each LTER site developed at least one compelling case study about what their site could look like in 50–100 yr as human and environmental drivers influencing specific ecosystems change. As the case studies were prepared, five themes emerged, and the studies were grouped into papers in this LTER Futures Special Feature addressing state change, connectivity, resilience, time lags, and cascading effects. This paper addresses the “connectivity” theme and has examples from the Phoenix (urban), Niwot Ridge (alpine tundra), McMurdo Dry Valleys (polar desert), Plum Island (coastal), Santa Barbara Coastal (coastal), and Jornada (arid grassland and shrubland) sites. Connectivity has multiple dimensions, ranging from multi‐scalar interactions in space to complex interactions over time that govern the transport of materials and the distribution and movement of organisms. The case studies presented here range widely, showing how land‐use legacies interact with climate to alter the structure and function of arid ecosystems and flows of resources and organisms in Antarctic polar desert, alpine, urban, and coastal marine ecosystems. Long‐term ecological research demonstrates that connectivity can, in some circumstances, sustain valuable ecosystem functions, such as the persistence of foundation species and their associated biodiversity or, it can be an agent of state change, as when it increases wind and water erosion. Increased connectivity due to warming can also lead to species range expansions or contractions and the introduction of undesirable species. Continued long‐term studies are essential for addressing the complexities of connectivity. The diversity of ecosystems within the LTER network is a strong platform for these studies.

The value of a broad temporal and spatial perspective in understanding dynamics of kelp forest ecosystems

Many ecological processes play out over longer time scales and larger spatial scales than can be studied in a traditional 2–4-year grant cycle. Uncertainties in future funding hinder efforts to implement comprehensive research programs that integrate coupled time series observations of physical variables and ecological responses, manipulative experiments and synthetic analyses over the long term. Such research is essential for advancing our understanding of ecological responses associated with climate change, and the physical and biological processes that control them. This need is perhaps greatest for ecosystems that display highly dynamic and spatially complex patterns that are difficult to explain with short-term, small-scale studies. Such is the case for kelp forest ecosystems, which often show tremendous spatial and temporal variability in resource supply, consumer control and physical disturbance across spatial scales of metres to hundreds of kilometres and temporal scales of hours to decades. Here we present four examples from the Santa Barbara Coastal Long-term Ecological Research project that demonstrate the value of a broad temporal and spatial perspective in understanding the causes and ecological consequences of short-term local dynamics of giant kelp forests of California, USA.

Stratigraphic Revelations Regarding the Rincon Shale (Lower Miocene) in the Santa Barbara Coastal Area, California: ABSTRACT

Stratigraphic Revelations Regarding the Rincon Shale (Lower Miocene) in the Santa Barbara Coastal Area, California: ABSTRACT

Rock-Eval Pyrolysis and Vitrinite Reflectance Results from Lower Miocene Strata in the Onshore Santa Maria Basin and Santa Barbara Coastal Area, California

Rock-Eval Pyrolysis and Vitrinite Reflectance Results from Lower Miocene Strata in the Onshore Santa Maria Basin and Santa Barbara Coastal Area, California

Observations and Numerical Model Simulations of the Atmospheric Boundary Layer in the Santa Barbara Coastal Region

Abstract Observations of boundary-layer flow within the Santa Barbara region taken on 20 September 1985 revel the presence of a wide variety of flow features, including mesoscale wind vortices sea/land breezes, and thermally driven upslope/downslope winds. Details of these features, in particular the mesoscale vortices, are documented with dual-Doppler radar, Doppler sodar, aircraft, surface mesonet, and rawinsonde data. Numerical simulations of flow in the region using a mixed-layer model show good agreement with the observations. Model simulations indicate that sea-/land-roughness differences and planetary vorticity are of minor importance in forming the midchannel eddy (MCE), an eddy that is observed in the channel during the early morning hours. MCE formation is, however, shown to be strongly dependent on the initial stratification of the atmosphere, with more intense eddies forming as the stability increases. A second independent mechanism for MCE formation appears to be the interaction of drainage f...

Geology of Northern Santa Rosa Island: ABSTRACT

The stratigraphy of the northern part of Santa Rosa Island is somewhat similar to that of the Santa Barbara Coastal district. These two areas represent, respectively, the southern and northern margins of the Ventura Basin. The Island area mapped offered a section from Pleistocene to Eocene, with Pliocene evidently absent. Formations recognized include marine terraces, Santa Margarita sandstone, Monterey shale, Rincon shale, Vaqueros sandstone, Sespe, Cozy Dell(?) shale, and Matilija(?) sandstone. An interesting time equivalence between the Vaqueros and upper Sespe formations is indicated. The Santa Rosa fault is the dominant structural feature of the Island. It trends east-west and divides the Island in half. A horizontal displacement of nearly five miles is indicated. Other significant but smaller faults are the Sandy Point, Garanon, and Arlington. Important folds are the Garanon, Tecolote, and Soledad anticlines and the West End and Becher's Bay synclines. Five wells have been drilled and abandoned on the Island and a sixth is now being drilled. End_of_Article - Last_Page 2062------------