Elkhorn Slough (ELK) NERR Water Quality Metadata January - December, 1999 Last updated June 22, 2001

Water quality monitoring is conducted at 26 National Estuarine Research Reserves (NERR)
at four locations within or adjacent to the reserve. The following parameters are collected at
least every 30 minutes: water temperature, specific conductivity, salinity, percent saturation,
dissolved oxygen concentration, water depth, pH and turbidity. All water quality data loggers
will be deployed from a known depth from the bottom at each site. Research objectives
Measurements are taken every 30 minutes over a three to four week period at three sites in
Elkhorn Slough. One site South Marsh (SM) is in a relatively unimpacted side channel of the
slough and the second, Azevedo Pond (AP) is in a pond that receives fertilizer and pesticide
runoff from an adjoining strawberry field. The third site, North Marsh (NM), was added in April
1999 and is located in an area where there is both agricultural and non-agricultural runoff. The
purpose of this research is to identify the base parameters for Elkhorn Slough by using South
Marsh as the control site and the other two sites are impacted sites and monitored for possible
future problems.SUPPLEMENTAL INFORMATION: Associated researchers and projects The following are
brief descriptions of research projects in Elkhorn Slough as of June 1998. Elkhorn Slough
National Estuarine Research Reserve and the Elkhorn Slough Foundation have had an ongoing
program to monitor estuarine water quality in the central Monterey Bay region since 1988.
Currently, 24 stations are monitored monthly for temperature, salinity, dissolved oxygen, pH,
turbidity, nitrate, ammonium and dissolved inorganic phosphate concentrations. Two of these
stations on the Reserve are about 400 m from the SM site. Data collection began at these two
stations in September 1989. A monthly monitoring station is also located at Azevedo Pond within
10 m of the YSI deployment. Monthly data from the Azevedo Pond are available from March 1992.
The University of California Santa Cruz Agroecology Program has an ongoing project to examine
the effects of agricultural production on an adjacent wetland. Matthew Werner, Marc Los Huertos,
Felecia Rein, Sean Swezey, Mark Silberstein, Andrew De Vogelaere, Ron Tjeerdema have been the
principal investigators. The following is a list of student/research projects conducted in 1999:
Bane (Stout), Shannon; determine rates of erosion and whether they are related to Spheroma;
graduate student, SJSU. Braby, Caren; examine ecological consequences of physiological
differences between bay mussel species; graduate student, Stanford. Byers, Jeb; assess
interactions between native and introduced horn snail; graduate student, UCSB. Casper, David;
investigate toxicology, tagging methods of Slough sharks; campus vet, UCSC. Chapin, Thomas;
Jannasch, Hans; develop in-situ continuous nutrient monitoring system; Postdoc PI,
MBARI. Connors, Sarah; dynamics of shorebird habitat use as related to tidal flux; graduate
student, MLML. Fry, Brian; using 15-N to monitor N-loading at NERR sites; professor, UCSC.
Harrington, Neil; nitrification potential, bacterial abundance, and productivity; graduate
student, UCSC. Kao, Jon; diet, daily ration, and gastric evacuation in leopard sharks; graduate
student, MLML. Los Huertos, Marc; nitrogen dynamics in vegetated buffer strips between
agriculture and wetlands; researcher, UCSC. Lowe, Tricia; patterns and consequences of marsh
loss at the Slough; graduate student, MLML. Malzone, Chris; tidal scour, erosion, and sediment
transport in the Slough; graduate student, MLML. Potts, Don; Cochran, Susan; Siciliano, Daria;
remote-sensing of vegetation and habitats with hyperspectral aerial imagery; professor
graduate students, UCSC. Reis, Dawn Kathleen; demography of red-legged frog populations;
researcher. Woolfolk, Andrea; effects of human and cattle trampling on salt marsh assemblage;
graduate student, MLML. Other remarks/notes CURRENTNESS REFERENCE: ObservedSPATIAL DATA
ORGANIZATION INFORMATION Indirect Spatial Reference: Site location and character Elkhorn Slough
is located on the West Coast of the United States in Central California. It connects with the
Pacific Ocean in central Monterey Bay near Moss Landing, California. There are three sampling
sites. SM (South Marsh) is in a side channel of the slough and is relatively unimpacted by
anthropogenic influences. The YSI is located on the side of a bank in one of the secondary
slough channels. AP (Azevedo Pond) is in a pond that receives fertilizer and pesticide runoff
from a strawberry field in year-round production. The YSI is located about 10m from a culvert
connecting the pond to the slough. NM (North Marsh) is located in between South Marsh and
Azevedo Pond. This site is impacted by both agricultural and urban runoff. The tidal range at
Azevedo Pond approximately 1.1 m. Salinity ranges between 3 ppt during storm events to 40 ppt
during warm days with increased evaporation with an average 31 ppt. The average salinity for
this year was 31 ppt. Temperature ranged from 3 deg to 33 deg C with an average of 16 deg C. DO%
is highly variable ranging from 0 to 328% with an average of 80% saturation. PH ranges from 6.9
and 8.7 with an average of 7.8. Turbidity ranges from 0 to 211 NTU during rain events and has an
average of 11NTU for the year. The tidal range at South Marsh is approximately 2.75 m. Salinity
ranges from 17 ppt during a storm event to 35 ppt in summer with an average of 31 ppt.
Temperature ranged from 9 deg to 23 deg C with an average of 15 deg C. DO % ranges from 8% to
209% saturation with an average of 86%. PH ranges from 7.2 to 8.5 with an average of 7.8.
Turbidity ranges from 0 to 98 NTU and had an average of 7 NTU. The tidal range of North Marsh is
approximately 1 meter. Salinity ranges between 20 and 43 ppt and has an average of 34 ppt.
Temperature ranges from 8 deg to 28 deg C and had an average of 18 deg C. DO % ranges from 0 to
317% and had an average of 72 % saturation. PH ranged from 6.9 to 9.1 with an average of 8.0.
Turbidity ranged from 0 to 160 NTU with an average of 12 NTU.