Archived Workshops/References
Elkhorn Slough Water Quality
Description
Elkhorn Slough, on the coast of the Monterey Bay, is located in a watershed with diverse land uses. Approximately 25% of the land in the immediate watershed of the slough is in farm or ranch use. Strawberries in particular are farmed on the terraces and slopes surrounding the estuary. Moreover, the estuary receives inflow from the adjacent Tembladero and lower Salinas watersheds, through drainages that ultimately enter the estuary in south Moss Landing harbor. Researchers at the Monterey Bay Aquarium Research Institute have documented that nutrients flowing from the old Salinas River channel through Moss Landing Harbor are swept up into the six-mile channel of the Elkhorn Slough estuary on incoming tides, accounting for the majority of nutrients detected there (Jannasch et al. 2008). Nutrient concentrations in the estuary have been documented for decades, and at some sites near Moss Landing have exceeded levels detected in any other estuary worldwide. While the ultimate solution to the effects of excess nutrients on the estuary is to reduce nutrient inputs, wetland managers can enhance local water quality by increasing tidal exchange to sites with tide gates or other water control structures.
The Coastal Training Program hopes that this portion of its website will serve as a clearinghouse on peer-reviewed literature relevant to the decision making on water quality in the Elkhorn Slough. If you have suggestions to improve the website, please feel free to contact our office.
Training Programs
Documents and Publications
| TITLE DATE ADDED |
AUTHOR SOURCE |
DESCRIPTION |
|---|---|---|
| WORKSHOP MATERIALS | ||
| Presentation: Water Quality: Trends and Concerns PPT, 4.4MB Mar 23 12 |
John Haskins Elkhorn Slough National Estuarine Research Reserve March 2012 |
Power Point presentation 3/19/2012 |
| PEER-REVIEWED PUBLICATIONS | ||
| Coastal eutrophication as a driver of salt marsh loss PDF, 1.3MB Dec 13 13 |
Deegan, L.A., Johnson, D.S., Warren, R.S., Peterson, B.J., Fleeger, J.W., Fagherazzi, S. & Wollheim, W.M. Nature 490:388-392 2012 |
Here we present data from a nine year whole-ecosystem nutrient-enrichment experiment. Our study demonstrates that nutrient enrichment, a global problem for coastal ecosystems, can be a driver of salt marsh loss. |
| Diel Biogeochemical Cycling in a Hyperventilating Shallow Estuarine Environment PDF, 1.6MB Jan 04 12 |
Nicole G. Beck
Kenneth W. Bruland Estuaries 23(2):177-187 April 2000 |
The elevated biogeochemical cycling of oxygen, nitrogen, phosphorus, iodine, manganese, and iron found in this shallow estuarine environment suggest that tidal restrictions and anthropogenic nutrient enrichments can amplify diel variations and potentially hinder the functional and ecological stability of these systems. These data suggest that accurate chemical monitoring of the health of an estuarine ecosystem must account for the diel variability inherent in these highly productive environments. |
| Effects of upwelling on short-term variability in microbial and biogeochemical processes in estuarine sediments from Elkhorn Slough, California, USA PDF, 502KB Jan 04 12 |
Jane M. Caffrey, James T. Hollibaugh, Nasreen Bano, John Haskins Aquatic Microbial Ecology 58:261-271 February 11, 2010 |
We examined short-term variability in sediment microbial processes and biogeochemistry in response to decreased irradiance accompanying an upwelling event. |
| High nutrient pulses, tidal mixing and biological response in a small California estuary: Variability in nutrient concentrations from decadal to hourly time scales PDF, 653KB Jan 04 12 |
Jane M. Caffrey, Thomas P. Chapin, Hans W. Jannasch, John C. Haskins Estuarine, Coastal and Shelf Science 71:368-380 2007 |
Biological processes had the greatest effect on nitrate concentrations during the dry season and were less important during the rainy season. While primary production was enhanced by nutrient pulses, chlorophyll a concentrations were not. We believe that the generally weak biological response compared to the strong physical forcing in Elkhorn Slough occurred because the short residence time and tidal mixing rapidly diluted nutrient pulses. |
| Identifying factors that influence expression of eutrophication in a Central California estuary PDF, 390KB Nov 03 11 |
Brent B. Hughes,
John C. Haskins,
Kerstin Wasson,
Elizabeth Watson Marine Ecology Progress Series 439: 31-43 October 20, 2011 |
Virtually every portion of the estuary shows impacts of over-enrichment by the high nutrient loads, ranging from thick algal mats to low night-time oxygen levels. The sites that show the most extreme symptoms are upstream of water control structures that restrict tidal exchange. These sites have low biodiversity, lacking the large fish or abundant shorebirds found in nearby sites with more tidal exchange. While the ultimate solution to the effects of excess nutrients on the estuary is to reduce nutrient inputs, wetland managers can enhance local water quality by increasing tidal exchange to sites with tide gates or other water control structures. |
| Nitrate Sources and Sinks in Elkhorn Slough, California: Results from Long-term Continuous in situ Nitrate Analyzers PDF, 678KB Jan 04 12 |
Thomas P. Chapin; Jane M. Caffrey; Hand W. Jannasch; Luke J. Coletti; John C.
Haskins; Kenneth S. Johnson Estuaries 27(5):882-894 Oct. 2004 |
The propagation of an internal wave carrying water from ~100 m depth up the Monterey Submarine Canyon and into the lower section of Elkhorn Slough on every rising tide was a major source of nitrate, accounting for 80-90% of the nitrogen load during the dry summer period. |
| Salt marshes and eutrophication: An unsustainable outcome PDF, 1.6MB Dec 13 13 |
Turner, R.E., Howes, B.L., Teal, J.M., Milan, C.S., Swenson, E.M. & Goehringer-Toner, D.D Limnology and Oceanography 54(5):1634-1642 2009 |
Enrichment reduces organic matter belowground and may result in a significant loss in marsh elevation equivalent to about half the average global sea level rise rates. Sustaining and restoring coastal emergent marshes is more likely if they receive less, not more, nutrient loading. |
| Signatures of restoration and management changes in the water quality of a central California estuary PDF, 2.1MB May 11 12 |
Gee, Alison
Wasson, Kerstin
Shaw, Susan
Haskins, John Estuaries and Coasts 33(4):1004-1024 2010 |
Coastalmanagers and policy-makers are concerned with tracking improvements to water quality linked to management changes. Long-term water quality data acquired from two wetland areas in the upper reaches of the Elkhorn Slough estuary in central California were analyzed for signatures of land restoration or water control structure management. Post-restoration averaged NO3, NH3, and PO4 concentrations were 50-70% less than before-restoration concentrations. Assessment of watershed-scale effects revealed that proximity of restoration to sampling locations had almost as strong an effect on water quality as the percentage of land restored relative to watershed size. Results also suggest that restoration of even 1% of an agriculturally intensive watershed such as that of the Elkhorn Slough may result in improvements to water quality. Finally, results indicate that tide gate function can dominate water quality in managed wetlands and must be carefully tracked and managed in the context of estuarine conservation targets. |
| Spatial Variability in Nitrification Rates and Ammonia-Oxidizing Microbial Communities in the Agriculturally Impacted Elkhorn Slough Estuary, California PDF, 1.1MB Jan 04 12 |
Scott D. Wankel; Annika C. Mosier; Colleen M. Hansel; Adina Paytan; Christopher A. Francis Applied and Environmental Microbiology 7(1):269-280 January 2011 |
Ammonia oxidation - the microbial oxidation of ammonia to nitrite and the first step in nitrification - plays a central role in nitrogen cycling in coastal and estuarine systems. |
| The Land/Ocean Biogeochemical Observatory: A robust networked mooring system for continuously monitoring complex biogeochemical cycles in estuaries PDF, 2.3MB Jan 04 12 |
Hans W. Jannasch, Luke J. Coletti, Kenneth S. Johnson, Stephen E. Fitzwater, Joseph A. Needoba, and Joshua N. Plant Limnology and Oceanography: Methods 6:263-276 2008 |
Up to five LOBO moorings have been simultaneously deployed and maintained in Elkhorn Slough, California, since November 2003. Continuous hourly data of biological, chemical, and physical properties are relayed to shore, processed, and disseminated to users through a web interface in near-real time. This article describes the design, implementation, and functionality of the LOBO monitoring system. |
| Using nitrate dual isotopic composition (d15N and d18O) as a tool for exploring sources and cycling of nitrate in an estuarine system: Elkhorn Slough, California PDF, 1.7MB Jan 04 12 |
Scott D. Wankel; Carol Kendall; Adina Paytan Journal of Geophysical Research 114 2009 |
This work expands our understanding of nitrogen and oxygen isotopes as biogeochemical tools for investigating NO3 sources and cycling in estuaries, emphasizing the role that cycling processes may play in altering isotopic composition. |
| OTHER INFORMATION | ||
| Effects of Low Oxygen on Pacific Staghorn Sculpins and Olympia Oysters PDF, 573KB May 10 12 |
Van Parys, J.
Rodriguez, M.
Preisler, R.
Haskins, J.
Hughes, B.
Wasson, K. Elkhorn Slough National Estuarine Research Reserve; California State University, Monterey Bay; Hartnell College October 2011 |
* Elkhorn Slough is an estuary in central California located in a productive agricultural watershed * The estuary hosts rich plant and animal communities, but monitoring has revealed that water quality at some sites is very impaired * Sites at Elkhorn Slough exceed limits for nutrient concentrations, algal cover, chlorophyll a, and dissolved oxygen (Hughes et. al) * A common ecosystem response from low dissolved oxygen is mortality of benthic organisms (Diaz and Rosenberg 2008) * For surviving organisms, they experience sublethal stressors including impacts on growth and reproduction (Vaguer-Sunyer and Duarte 2008) * No previous data has been collected linking water quality with estuarine species survival at Elkhorn Slough * We examined the effects of low dissolved oxygen on two common estuarine species |
| Nitrate Transport To Coastal Monterey Bay: Investigating Source Inputs From Elkhorn Slough PDF, 5.1MB Mar 27 12 |
Tanya Novak Moss Landing Marine Laboratories; California State University Monterey Bay Fall, 2011 |
Nitrate transport from Elkhorn Slough (ES) to the nearshore surface waters of Monterey Bay is examined using two years of time-series data from the Land-Ocean Biogeochemical Observatory (LOBO).....While rates of nitrate transport vary seasonally, assessment of nitrate transport mechanisms to coastal Monterey Bay in the summer to early fall is essential to understanding the dynamics of extreme algal blooms that typically occur during these months. |
| North Monterey County hydrogeologic study Volume II: Critical issues report and interim management plan PDF, 8.8MB Dec 18 13 |
Fugro West, Inc Monterey County Water Resources Agency 1996 |
The report describes the critical problems with water quality and quantity in the North Monterey County study area. |
| North Monterey County Hydrologic Study: Volume I Water Resources PDF, 24.9MB Jan 21 15 |
Fugro West, Inc Monterey County Water Resources Agency October 1995 |
|
| Patterns and Causes of Variability in the Cover, Biomass, and Total Abundance of Ulva spp. in Elkhorn Slough, California PDF, 655KB Jan 04 12 |
Timothy J. Schaadt M.S. Thesis from Moss Landing Marine Lab, Cal State Monterey Bay August 2005 |
Although the affect of tides was not consistent among regions, my data indicate that tidal range can play an important role in the regulation of Ulva mats. Seasonal variability in algal mat dynamics occurred in Elkhorn Slough and some of these factors were also observed varying sub-seasonally potentially due to the effect of tides on Ulva mats. |
| Presentation: Proposed Nutrient TMDLs Lower Salinas River & Reclamation Canal Basin, & the Moro Cojo Slough Subwatershed Monterey County PDF, 1.9MB Feb 21 13 |
Pete Osmolovsky & Chris Rose
Water Board TMDL Program Central Coast Regional Water Quality Control Board January 31, 2013 |
|
| Statistical Analysis of Sixteen Years of Water Quality Data Project PDF, 1.4MB Jan 04 12 |
Marc Los Huertos University of California at Santa Cruz November 5, 2008 |
Water quality within Elkhorn Slough varies on both temporal and spatial scales. The trends at individual sites provide resounding support that monitoring water quality is a sensitive method of tracking ecosystem health. The source of variability, increasing turbidity, and elevated nutrient concentrations remains unknown. |
| Synthesis for management of eutrophication issues in Elkhorn Slough PDF, 3.5MB Jan 04 12 |
Brent Hughes Elkhorn Slough Technical Report Series 2009:1 2009 |
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. The potential to reverse eutrophication through restoration projects in Elkhorn Slough remains uncertain, although limited data suggest some cause for optimism. |
| Water Quality Monitoring in Elkhorn Slough: a summary of results 1988-1996 PDF, 682KB Jan 04 12 |
Jane Caffrey, Sue Shaw, Mark Silberstein, Andrew De Vogelaere, and Michelle White Elkhorn Slough Technical Report Series 1997:1 May 25, 1997 |
Some trends we have observed from this data include: 1) a significant increase in nitrate concentrations since the 1970s 2) extraordinarily high nitrate concentrations in the lower Salinas River which may be the highest recorded in scientific literature for a river or estuary 3) concentrations of ammonium that are an order of magnitude lower (or more) than nitrate 4) low concentrations of dissolved oxygen in some areas which have restricted circulation 5) opening of the Salinas River lagoon leads to rapid increases in salinity in the lower river even during the rainy season when river discharge is high. |
Links
| TITLE | DATE ADDED |
|---|---|
| Researchers find high levels of mercury in coastal fog http://www.vcstar.com/news/2011/dec/10/researchers-find-high-levels-of-mercury-in-fog/#ixzz1h9Du6vTK |
Mar 30 12 |