Kerstin Wasson
Elkhorn Slough National Estuarine Research Reserve

SYMPOSIUM OVERVIEW: UNDERSTANDING THE VALUES OF ELKHORN SLOUGH AND HOW THEY ARE THREATENED

This presentation briefly reviews the ways in which humans value Elkhorn Slough, from its benefit to the local economy and to health, to its beauty and richness which attract thousands of recreational visitors each year. Rareness of estuarine ecosystems, diversity of habitats and richness of biological communities help to explain Elkhorn Slough's special appeal. The estuary has been highly altered by humans over the past centuries, and some of these alterations threaten the beauty and richness of its ecosystems. Rivers have been diverted, freshwater inputs decreased, water control structures built to block tidal exchange, and a large artificial mouth to the estuary maintained, leading to tidal scour. All these changes have altered habitats, in particular leading to conversion of salt marshes to mudflats. Introductions of non-native species have greatly changed biological communities. Pollution, especially from agricultural sources, has severely degraded water quality, particularly in areas without full tidal exchange. Despite the variety and magnitude of these alterations, Elkhorn Slough ecosytems still host diverse plants and animals and beautiful habitats. Through a better understanding of the estuary's values, and the threats to them, strengthened by research such as that which is presented at this symposium, we can work together to protect and conserve this gem that is Elkhorn Slough.

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Rikk Kvitek, R. E. Direen, J. M. Frame, J. Galvan, G. M. Gonzalez, A. Hall, C. R. Hosler, A. M. Jones, M. R. Sandersfeld, K. J. Stoner & K. R. Wrubel.
California State University Monterey Bay

ELKHORN SLOUGH: COMING OR GOING? REMOTE SENSING TIME SERIES TRACKS TIDAL SCOUR AND HABITAT CHANGE IN A NATIONAL ESTUARINE RESEARCH RESERVE.

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Charlie Endris and Ivano Aiello
Moss Landing Marine Laboratories

LIMTS AND POTENTIALS OF HIGH-RESOLUTION TERRESTRIAL LASER SCANNING TECHNOLOGY IN MONITORING ESTUARINE GEOMORPHOLOGIC VARIABILITY

We present a novel investigation on geomorphologic variability in response to changing hydrologic conditions over various temporal scales in the wetlands of Elkhorn Slough, California.  Serial, high-resolution (<5 cm) surveys of the marsh and mudbank environments of this rapidly degrading estuary have been obtained using a state-of-the-art terrestrial laser scanner (TLS). New techniques were developed to collect, post-process, and analyze the geospatial data.  Factors that can lead to errors in TLS data measurements and to potential misinterpretations of surface variability were identified.  Long-term monitoring, spanning 15 months at four key sites, revealed a 30% increase in the widths of mudflat creeks and localized episodes of failure and slope retreat at the pickleweed edges.  Additionally, small-scale erosive events were identified along the edges of tidal creeks during a major spring tidal cycle and as a consequence of increased tidal flow caused by the opening of a culvert.

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Brian Spear1, Douglas Smith1, & Eric Van Dyke2
1Science and Environmental Policy, California State University Monterey Bay
2 Elkhorn Slough National Estuarine Research Reserve

29 YEARS OF GEOMORPHIC CHANGE AT ELKHORN SLOUGH, CA
This study utilized high-precision surveys to estimate 29 years of elevation change on the Elkhorn Slough marsh plain. There were 3 objectives to this study:  1) characterize the spatial variation in rates of net erosion/deposition and net vertical change with respect to the benchmark, 2) compare net vertical change rates to estimates of projected rate of sea-level rise in the region, and 3) determine linkages between land cover type and rate of net vertical change.  We resurveyed 11 of the 13 original transects using the same methodology to collect new surface elevations for comparison with the original 1980 dataset.  Overall, the survey points on the marsh plain averaged 5 mm/yr of accretion (SD = 4 mm/yr), while overall vertical movement was upward at 1 mm/yr given an estimated rate of regional subsidence of 4.1 mm/yr across the slough.  When compared to even the low sea level rise scenario of 2.5 mm/yr, rapid marsh deterioration will result if no management actions mitigate a rising sea.  Only 26 of the 149 survey points (17%) contain vertical change rates that will outcompete a 2.5 mm/yr sea level rise scenario.  Additionally, mudflat and tidal creek categories had erosion rates relative to the benchmarks of 7 mm/yr and 16 mm/yr, respectively.  Respective net vertical loss becomes 11 mm/yr and 20 mm/yr, with the estimated 4.1 mm/yr subsidence rate.  Further study is needed to identify and quantify individual components of benchmark movement to be able to quantify observed subsidence at each cross section.

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Elizabeth Burke Watson1,2 , Greg Pasternack2 , Andrew Gray2 , Miguel Goni3, and Robert Wheatcroft3, Nadine B. Quintana Krupinski4,  Joseph Street5, Adina Paytan5
1 Elkhorn Slough National Estuarine Research Reserve
2 Land, Air & Water Resources, University of California, Davis
3 College of Oceanic and Atmospheric Sciences, Oregon State University
4 Department of Earth and Planetary Sciences, University of California, Santa Cruz
5 Institute of Marine Sciences, University of California, Santa Cruz

PREHISTORIC ENVIRONMENTAL CONDITIONS IN ELKHORN, MORO COJO AND TEMBLADERO SLOUGH WETLANDS
Central Monterey Bay historically supported extensive slough networks (e.g. Harkins Slough, Watsonville Slough, Elkhorn Slough, Tembladero Slough, etc.) in the lower Pajaro and Salinas River Valleys, and in area connecting these two valleys.  The goal of the research presented here was to characterize pre-historic environmental conditions at Elkhorn, Moro Cojo, and Tembladero Sloughs, with respect to wetland plant distribution patterns, tidal and freshwater influences, and organic and lithic sediment sources.  To accomplish this research objective, sediment cores were collected from two areas of wetlands in Elkhorn Slough, two areas of wetlands in Moro Cojo Slough, and one area of wetlands at Tembladero Slough.  A chronology was established for these sediment cores using radiocarbon and radiocesium determinations.  Sediments were analyzed for fossil pollen abundance, bulk sediment geochemistry (using ICP-AES), lithic grain size distribution, and organic content, while a subset of cores were analyzed for carbon and nitrogen stable isotopes, and carbon and nitrogen content (%OC, %IC, %ON, %IN; C:N and OC:ON ratios).  We found a strong gradient of marine to fluvial influences reflected in these sediment cores throughout prehistoric times, with the Tembladero coring site supporting the freshest conditions, and clearest fluvial influence, the Elkhorn Slough coring site supporting the most saline conditions and clearest influence of marine and estuarine processes, while the Moro Cojo coring sites showed more of a mixture of influences.

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Catalina E. Reyes
Moss Landing Marine Laboratories

EFFECTS OF EROSION ON DISTRIBUTION OF SUBTIDAL COMMUNITIES IN ELKHORN SLOUGH, MONTEREY COUNTY, CALIFORNIA
The overall goal of this study was to investigate the effects of erosion on distribution of subtidal habitats in Elkhorn Slough.  Comparison of bathymetric data from 2001 to 2005 showed changes in amount of erosion and deposition across the study area.  Four erosion classes were identified: deposition, no change, low erosion, and high erosion.  Benthic images were collected seasonally to determine the percent occurrence and cover of habitat forming species for each erosion class during a one year period.  Sediment samples were also collected from consolidated features previously referred to as clay, in order to describe them geologically.  Green algae were associated with all erosion classes, whereas red algae and seagrasses were generally limited to areas that experienced minimal erosion, typical of low energy regimes.  High flow, high erosion areas experienced an increase in exposed substrate and shell debris.  Clay-like features were also generally limited to high erosion areas, but were predominantly moderately indurated siltstone with a grain size diameter of 5.04 to 17.42 µm, rather than clay.  In general, this study predicts that moderately indurated siltstone, shell, green algae, and exposed substrates will likely expand in coverage in Elkhorn Slough if erosion continues, whereas seagrasses and red algae have the potential to decrease if erosion expands.

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Alexis Hall1 & Krystle Gomez
Division of Science and Environmental Policy at California State University Monterey Bay

IMPACTS OF TIDAL EROSION ON THE DISTRIBUTION AND ABUNDANCE OF EXOTIC EPIFAUNA SPECIES IN ELKHORN SLOUGH
In this study, we examined the relationship of tidal erosion to temporal and spatial patterns of epifaunal species distribution and abundance at Elkhorn Slough. The temporal variation and spatial patterns of tidal erosion were examined using geospatial analyses of change over time of the main channel. Surveys from 1993 through 2007 were compared with a 2009 survey collected using multibeam sonar and vessel-mounted topographic LIDAR. Results were used for multiple high-resolution bathymetry mapping and digital elevation model raster subtraction analysis to quantify change over time in the depth of the main channel.  Changes in the spatial distribution and abundance of five exotic epifauna species have been previously related to this erosion gradient. Each species were assessed for recent percent cover changes by analyzing their changes of tidal scour rate, substrate, depth, and distance using video surveys conducted in 2003 and 2009. Distribution and abundance of epifaunal species show possible relation to a low erosion gradient at the middle of the slough, specifically Didemnum vexillum, an exotic colonial species commonly found on hard substrates. As tidal erosion increased, soft muddy sediment was exported and shell debris was exposed, which provided prime habitat for exotic species. The spatial distribution and high abundance of exotic epifauna species suggest invasion at areas of an abundance of shell debris, shallower depths and low erosion.

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Taewon Kim & Fiorenza Micheli
 Hopkins Marine Station, Stanford University, Pacific Grove

GLOBAL DIMMING OR WARMING: THE EFFECT OF SOLOR RADIATION AND TEMPERATURE VARIABILITY ON THE INVASION OF MARINE FOULING SPECIES
Climate change can alter the community structure as species which have adapted to the changed climate can compete better with other species. It can also influence the recruitment and invasion success of marine introduced species. Climate change involves not only global warming but also global dimming. However, it was not tested which of warming or dimming factors more significantly influences the invasion of marine species. To test this, we manipulated both temperature variability and light radiation by deploying different shading devices (black, white, transparent, and no treatment) for recruitment tiles in the warmer region where the species invasion rate is high. We compared the species frequency and coverage between shaded and non-shaded treatments. Interestingly, under opaque white plates where light radiation is lower than under transparent plates but the temperature is higher than under black plates, had the highest frequency and coverage of invasive fouling species. The recruitment tiles under black plates got second higher invasion of exotic species. We also deployed recruitment tiles in 14 different sites to determine if temperature influences the success of invasive species. The coverage of invasive species over native species increased significantly with increasing temperature. The results suggest that both low radiation and higher temperature facilitates the success of species invasion in the intertidal region.

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Brent Hughes, Kerstin Wasson, John Haskins
Elkhorn Slough National Estuarine Research Reserve

PATTERNS AND FILTERS OF EUTROPHICATION ENDPOINTS IN ELKHORN SLOUGH

Elkhorn Slough is an estuary that has been undergoing significant changes in the last 100 years due to anthropogenic effects. These changes in the slough include the opening of the Moss Landing Harbor in 1946, the construction of dikes, culverts and flood gates, and eutrophication from increased agricultural practices.  Elkhorn Slough has seen dramatic increases in the amount of dissolved nutrients during the last 70 years, and it has some of the highest nitrogen, phosphate and ammonia levels reported in the world.  Elkhorn Slough has overwhelming indications of eutrophication and even hypertrophication, due to elevated levels of chl a, the presence of blooms of ephemeral algae, and periods of hypoxic and at times anoxic conditions. The degree of eutrophication varies by location and is dependent on depth and tidal range.  The ecological effects due to this alteration to the water chemistry of Elkhorn Slough are beginning to unravel.  Evidence from other estuaries combined with data and observations from Elkhorn Slough over the last 40 years supports the idea that eutrophication is changing biological communities in Elkhorn Slough.  High abundances of persistent macroalgae coupled with anoxic sediments has limited available habitat for benthic communities, as well as benthic diversity.  This negative effect of eutrophication to benthic communities can also have negative consequences to higher trophic species, such as sharks and shorebirds, due to limited prey availability.

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William Berkeley Kauffman
Moss Landing Marine Laboratories

ANALYSIS OF PROKARYOTIC COMMUNITY SHIFT IN ANOXIC ESTUARINE SEDIMENT
Prokaryotes mediate reduction-oxidation reactions resulting in the biological fluxes of hydrogen, carbon, nitrogen, oxygen, and sulfur, cumulatively representing five of the six major elements that serve as building blocks for biological macromolecules.  In estuarine systems, prokaryotes are responsible for driving biogeochemical cycles and aid in the breakdown of pollutants in both the water column and the sediment.  Understanding the microbial ecology of estuarine systems will elucidate the microbes’ role in chemical cycling and estuarine health, thereby providing a mechanism for evaluating the effectiveness of restoration efforts.  In this study, denaturing gradient gel electrophoresis (DGGE) analysis of the 16S rRNA gene indicates a distinct shift in the sedimentary bacterial community at approximately 1 meter below the sediment-water interface at the head of Elkhorn Slough, the second largest estuary in California.

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Megan Wehrenberg
Moss Landing Marine Laboratories

ALTERNATE LIFE HISTORY OF Gracilariopsis andersonii (Rhodophyta)WITHIN THE DYNAMIC SUBSTRATE REGIME OF THE CENTRAL CALIFORNIA ESTUARY
Gracilariopsis andersonii is a common red alga of the central Californian intertidal. Its tolerance of physical stressors and its psammophytic nature make it well suited to a suite of environments, including the exposed rocky coast and the protected flats of estuaries and bays.  The purpose of this project was to examine and compare the mechanisms for growth and reproduction of G. andersonii found within two sites with differing environmental conditions, specifically an exposed rocky coast and an estuarine sand flat.  Biomass and reproductive capacity were measured within permanent plots at Pigeon Point (Pescadero, CA) and in the Elkhorn Slough (Moss Landing, CA) for one year.  The rocky coast population relied heavily upon sexual fertilization while the estuarine population relied almost solely upon vegetative fragmentation for propagation.  This result clearly indicates life history plasticity within this species.  Surprisingly, the algae within the Elkhorn Slough were found up to 45cm below the soft sediment surface during all winter months and much of the spring, yet the yearly biomass was nearly three times greater than the algae from the open coast. This suggests that sediment movement within the estuary may play an important role in the growth and reproductive cycles of these algae.  Additionally, I investigated the sediment composition in areas with and devoid of algae and found evidence indicating the alga as a sediment stabilizer and aiding in sedimentation. The results of this study indicate that variations in environmental conditions may control the life cycles and therefore demographics of these organisms.

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Nora E. Grant
Moss Landing Marine Laboratories

HABITAT USE OF EELGRASS (ZOSTERA MARINA) IN ELKHORN SLOUGH
Seagrasses provide an array of ecosystem services to the nearshore marine community. The goal of this study was to begin to determine the role of the seagrass, Zostera marina, in habitat provisioning within Elkhorn Slough, CA. Habitat use by fishes and some mobile epibenthic invertebrates was surveyed over time within and among Zostera, algae and bare habitats in the lower Elkhorn Slough region. Habitat use sampling was conducted from February 2008 to October 2008, split into the three sampling seasons winter, spring/summer, and fall. Zostera, algae and bare habitats were sampled each season using a 1m3 throw trap and a stratified random design.  Distribution, abundance and frequency of occurrence of species were compared across habitats and times using various metrics.  Species assemblages within each habitat type were compared by richness, heterogeneity, evenness and overlap metrics. Species distributions patterns indicated multiple potential habitat functions for Zostera. Species richness and diversity were highest in Zostera among the three habitats tested, and bare substrate was the most deplete of animals. Some species were exclusively found within Zostera while other species were distributed among all habitats. Trends in both size and abundance of particular fishes over time suggested Zostera beds provide nursery habitat for both permanent and migratory species within Elkhorn Slough.

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Rikke Preisler  and Kerstin Wasson
Elkhorn Slough National Estuarine Research Reserve and
Department of Ecology and Evolutionary Biology, University of California Santa Cruz

TEMPORAL AND SPATIAL PATTERNS OF THE GREEN CRAB INVASION AT ELKHORN SLOUGH
We investigated the temporal and spatial patterns of green crab abundance and body size at Elkhorn Slough. The globally invasive species the European green crab was first detected at Elkhorn Slough in 1994, and since 2000 we have monitored native and non-native crabs in the slough. While there is great annual variation in crab abundances there are some discernable temporal trends from the monitoring data. Native crab and non-native crab abundances are inversely proportional: when non-native crab abundance increases, native crab abundance decreases. Also, green crab abundance at Elkhorn Slough is current very low. In addition to tracking temporal trends, long-term monitoring data can facilitate detecting spatial trends in invasion success. In order to better understand the spatial patterns of the invasion we investigated whether specific habitats were particularly vulnerable to green crab invasion. To determine whether green crabs were more successful in certain habitats we measured green crab abundance and body size in the following three habitat pairs: areas closer to the head vs. closer to the mouth of the slough, tidally restricted vs. tidally non-restricted areas, and deep vs. shallow habitat. We found no effect of distance from the mouth of the slough on abundance but green crabs closer to the mouth of the slough were marginally larger. We also found an effect of tidal exchange on green crab abundance and size: green crabs were more abundant and smaller at sites with no tidal restriction. Finally, we found an effect of dept: green crabs were more abundant and larger at deeper sites. Temporal trajectories and spatial patterns of invasions can be used to inform management. Although it is too early to predict the final outcome of the invasion it is certainly still possible that this invader will become well established. Our data show potential for high abundance and rapid population growth particularly in areas with no tidal restriction and deeper habitat available.

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Daniela Maldini, Ron Eby, Robert Scoles and Mark P. Cotter
Okeanis

Roger Bland1,2 Karen Crow2,4 & Newell Garfield2,3
1 Physics and Astronomy Department, San Francisco State University
2 Romberg Tiburon Center, San Francisco State University
3 Geosciences Department, San Francisco State University
4 Biology Department, San Francisco State University

SHIPPING NOISE AND CALLING PATTERNS OF PORICHTHYS NOTATUS IN SAN FRANCISCO BAY
We have studied underwater sounds recorded over the last year with a hydrophone deployed from the Romberg Tiburon Center sampling pier in San Francisco Bay.  The dominant sounds are the mating hum of the plainfin midshipman (Porichthys notatus) (during the summer spawning season) and noise generated by marine traffic.  The power generated by midshipmen in the "toadfish band" (near 100 Hz) peaks during the summer months, and shows a pronounced diel variation, strongest at night and practically absent during the day.  The shipping noise is quite strong near 100 Hz, and shows just the opposite dependence on the hour of the day;  At six in the morning the ferries start running, and the midshipman stops humming.  We are interested in observing midshipman humming in Elkhorn Slough, where underwater noise from ferries and tankers should be much less than in San Francisco Bay.  If we find that calling patterns are different in Elkhorn Slough, it may turn out that the midshipman can provide a means of assessing the effect of anthropogenic underwater noise pollution on animal life.

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Randy Holloway
CSUMB, Coastal and Watershed Science and Policy M.S. Program

SEDIMENT DYNAMICS AND HYDRAULIC RESIDENCE TIME ON CARNEROS CREEK AT TRIPLE M RANCH
Carneros Creek flows into the top of Elkhorn Slough and is a contributor of fresh water and sediment to the Elkhorn Slough, but it also transports detrimental components associated with agricultural runoff. ALBA has an ongoing project at the site to improve water quality while protecting endangered species and preserving habitat.  The goals of my investigation are to 1) investigate hydrologic and sediment dynamics occurring at Triple M Ranch in order to inform adaptive management at the site and in the region, 2) quantify a sediment budget with inputs, outputs, and storage at Triple M Ranch, and 3) determine travel time of water and suspended sediment pulses through Triple M Ranch at varied flows.  My research will determine how much suspended and bedload sediment the wetlands are trapping, how much bedload is being trapped that could possibly be allowed to move downstream to the slough, and find the appropriate time lag for sampling the same bolus of water entering and leaving the property..  Furthermore, the sedimentation rate can be compared to predicted sea level rise for determination of the project’s longevity, and the residence time data for the site can be used for modeling of wetland functions such as nitrate and pesticide reductions.  Concurrent flow, suspended sediment, and bedload sediment measurements are used to construct the sediment budget in the form of * or input minus output equals the change in storage plus uncertainty.  Checks of the sediment storage will be serial surveying and sediment trap experiments.

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N. J. Nidzieko1, S. G. Monismith and C. A. Francis
Stanford University
1 Woods Hole Oceanographic Institution

EXAMINING THE LINK BETWEEN TIDAL CURRENTS AND MICROBIALLY-MEDIATED NITROGEN REMOVAL IN AN INTERTIDAL CHANNEL
We have conducted a manipulative experiment in a tidal creek of Elkhorn Slough, California, to relate physical processes to the microbially-mediated removal of nitrogen from the water column. Specifically, we examined the connection between tidal current strength, residence time, and the microbial community assemblage in the mud. Our working hypothesis is that the effectiveness of nitrogen removal in an estuary is closely tied to the spring-neap cycle, because of the feedback between the depth of the anoxic layer and the strength of tidal currents. Nitrogen removal--either via denitrification or anaerobic oxidation of ammonium (anammox)--occurs primarily under suboxic conditions, however stronger tidal currents increase the thickness of the upper oxygenated layer, potentially inhibiting the delivery of dissolved inorganic nitrogen from the water column to where it could be removed in the sediment. A confounding factor in this process is the residence time of water within the creek. As part of this study, we installed a low sill in the tidal creek midway through the experiment, in order to change the hydrodynamic conditions and residence time within the creek. This change was monitored continuously by a in-situ instrument array consisting of a current profiler, turbulence, oxygen, nitrate, salinity, and temperature measurements.

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Tanya Novak1, Dr. Erika McPhee-Shaw1, Dr. Ken Johnson2
1 Moss Landing Marine Laboratories
2 Monterey Bay Aquarium Research Institute

SUMMER NUTRIENT DELIVERY TO COASTAL MONTEREY BAY: INVESTIGATING SOURCE INPUTS FROM ELKHORN SLOUGH
The significance of nutrient delivery from Elkhorn Slough to the coastal waters of Monterey Bay is examined using two summers of time series data from the Land Ocean Biogeochemical Observatory (LOBO).  Nitrate, temperature and salinity data from offshore moorings 1km north (2008) and 1 km south (2009) of the Moss Landing Harbor entrance at 20-m depth were monitored with the objective of observing high nitrate events associated with transport from the slough to the coast.  Quantification of nitrate flux from the slough is based on bulk estimates of volume transport and average nitrate concentrations observed on the ebbing tide at slough mooring locations.  Preliminary results show that potential contributions from Elkhorn Slough are small relative to other transport mechanisms such as upwelling and internal waves, even during high stream-flow events.  One distinct runoff event, October 13-14, 2009, was observed during our two summer study period.  Data from the offshore mooring array as well as from the slough LOBO network are used to assess the impact of this winter-type event compared to our longer time-series of summer conditions.  While rates of nutrient transport vary seasonally, assessment of nitrate delivery to coastal Monterey Bay in the summer to early fall is essential to understanding the dynamics of large algal bloom events that typically occur during these months.

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Sonia Sankaran
Moss Landing Marine Laboratories

TRACE METAL BURDEN IN ULVA SPECIES IN THE OLD SALINAS RIVER, MOSS LANDING HARBOR, AND ELKHORN SLOUGH, CALIFORNIA
The objective of this study was to examine whether Ulva spp. growing in the Old Salinas River Channel, Moss Landing Harbor and Elkhorn Slough, California reflect a different trace metal burden than populations at the mouth of the harbor that are exposed to greater tidal flux from the Monterey Bay.  Tissue concentrations of Ag, Al, As, Cd, Cr, Cu, Mn, Ni, Pb, Se, and Zn were determined for Ulva spp. growing at sites in the Old Salinas River Channel, Moss Landing Harbor, Elkhorn Slough and the protected side of the north Moss Landing Harbor jetty.  Overall, samples from the Salinas Channel had the highest concentrations of trace metals of all sites, except for cadmium which was greatest at the north jetty.  There were significant differences in trace metal concentrations between sites.  The ratios of different metal to aluminum concentrations in Ulva samples was compared to ratios of crustal abundances of those metals to the crustal abundance of aluminum to look for discrepancies between metal content in the algae and crustal concentrations.  Samples from the Moss Landing jetty revealed the greatest differences in metal concentrations from crustal abundances.

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Kristina L. Schmit
Civil and Environmental Engineering, Stanford University

ENVIRONMENTAL TRIGGERS OF HYPOXIA IN THE ELKHORN SLOUGH RESERVE
The Elkhorn Slough Reserve, located just east of Moss Landing, is one of California’s few remaining coastal wetlands. The reserve is dedicated to research including ecological studies, weather, water quality, erosion as well as other areas of environmental concern. As with many other estuarine environments, the Elkhorn Slough experiences variations in dissolved oxygen content, sometimes entering the hypoxic range. Hypoxia is an important measure of water quality because of its effect on fish and other benthic organisms. This papers look at the effects of meteorological data on hypoxia in the Elkhorn Slough. Although there are many factors that influence dissolve oxygen content, it appears water temperature is one variable that is significantly correlated to hypoxia.  A model is created that may be used to input daily weather forecast information and output a warning signal when it appeared that conditions might reach hypoxia.

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