PAT-UC Covers - California Sea Grant - UC San Diego

Water Quality and Clean Beaches
Beaches are serious stuff in Southern California–not just because they are the core
of the region’s lifestyle, but also because they are a major economic engine. Beaches,
through tourism, for example, generated about $17 billion in direct revenues in
1998, eclipsing other marine-related industries such as commercial fishing and
aquaculture. The following projects focus on beach water quality – a major issue in
California both because of new regulations on beach monitoring and because of a
series of highly publicized beach closures in Orange County in 1999 and 2000.
MODELING WATER QUALITY AND POLLUTION TRANSPORT
By modifying a regional ocean circulation model for the U.S. West Coast, Keith
Stolzenbach and James McWilliams of UCLA created a high-resolution coastal
circulation model for Santa Monica Bay. This Sea Grant-funded model resolves
water movements on a 1-kilometer scale, making it possible to answer fundamental
and detailed questions about pollution and sediment transport. The scientists
learned that the residence time of pollutants is closely linked to the action of giant
eddies shed from larger currents offshore. When an eddy sweeps through the bay,
the entire bay is flushed. In the absence of eddies, pollutants stagnate. The findings
have implications for how to best handle and control municipal waste and runoff.
Currently, the model is being programmed to simulate the dispersion of runoff; the
dispersion, deposition and re-suspension of sediments; and the origin and evolution
of toxic algal blooms (see project R/CZ-171).
IDENTIFYING SOURCES OF BACTERIAL CONTAMINATION
In this Sea Grant project, Cliff Brunk of UCLA developed a set of DNA markers
that make it possible to track sources of fecal bacterial contamination, e.g., whether
bacteria are from storm drains, sewage effluent or animal and bird feces. This
is important because current water-quality tests are based on measurements of
“indicator” bacteria, which provide no information on the origins of potentially
harmful bacteria. Hopefully, municipalities
will use the markers to track bacterial
pollution along the coast to its upstream
sources.
The Orange County Water District has
already used the markers to help it identify
the sources of problematic films on the
local water filtration system (see projects
R/CZ-153 & 167).
MEASURING VIRAL LOADS IN COASTAL
WATERS
Waterborne viruses pose a well-recognized
health risk. Viral contamination, however,
is not monitored because of the difficulty
in measuring very low concentrations of
these pathogens. In this Sea Grant project,
Sunny Jiang of UC Irvine developed a
method for detecting the presence of
the human adenovirus, a cousin of the
hepatitis A virus. The method was used
to show that human viruses frequently
contaminate coastal waters near river
mouths in Southern California. These areas
often have normal bacterial levels. The
absence of a correlation between bacterial
and viral contamination highlights the
limitations of current bacteria-based
health standards. The Public Facilities and
Resources Department in Orange County
has used Jiang’s method to help it find the
sources of contamination in the highly
polluted Aliso Creek watershed (see project
R/C-46PD).
SUBLETHAL EFFECTS OF COPPER ON
MARINE SPECIES
In this project, toxicologist Ronald
Tjeerdema of UC Davis exposed abalone to
low levels of copper and wood preservative
to study the effects of chronic pollution.
The experiments required designing
nuclear magnetic resonance (NMR)
instrumentation suitable for imaging
animals that need to be kept in water.
Contaminants were shown to reduce
adenosine triphosphate production in an
California Sea Grant: 1998-2003
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