Sanctuary Integrated Monitoring Network
Monterey Bay National Marine Sanctuary

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Water Quality_ map
Figure 1. Zones of water quality monitoring within the Monterey Bay National Marine Sanctuary. [View Larger]

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The Monterey Bay National Marine Sanctuary provides habitat for a wealth of biological diversity, outstanding recreational opportunities and spectacular coastal scenery that is renowned on a world scale. Every organism that resides within or moves through the sanctuary depends upon clean water, as do all our commercial and recreational uses.

The sanctuary borders nearly 480 kilometers (300 miles) of California's coastline and receives runoff from watersheds that cover approximately 18,130 square kilometers (7,000 square miles) and support a variety of land uses. The sanctuary is fortunate to be in an area with relatively few impacts from industrial discharges and large point sources of pollution. However, being adjacent to such a large extent of coastline makes it susceptible to impacts from non-point, urban, rural and agricultural pollution sources.

By the time rainfall or irrigation runoff enters streams, rivers, wetlands, estuaries and ultimately the sanctuary, it may contain high levels of nutrients, sediments or dangerous chemicals that have been picked up during the journey from land to sea. Monitoring has shown that while the sanctuary's offshore areas are in relatively good condition, near-shore coastal areas, harbors, lagoons, estuaries and tributaries suffer from a number of problems, including elevated levels of nitrates, sediments, persistent pesticides, metals, bacteria, pathogens, detergents and oils.

These contaminants can have a variety of biological impacts, including bioaccumulation, reduced recruitment of anadramous species, algal blooms, mortality due to toxicity, transfer of pathogens to wildlife and humans, and interference with recreational use of the sanctuary.


To improve the water quality conditions in the sanctuary, it is important to understand fully where the pollution comes from, where it is going, what its impacts are and how water quality conditions are changing over time. To help address these issues, a number of ongoing water quality monitoring programs currently operate within the sanctuary and its watersheds. These include, among others:
Together, these programs are gathering the data managers need to target source reduction efforts, assess trends and determine impacts.

Bruckner Chase as he exits the ocean at San Carlos Beach after swimming 26 miles across Monterey Bay from Santa Cruz, CA.

Bruckner Chase answering questions from the media at San Carlos Beach in Monterey. He had just swam across Monterey Bay from Santa Cruz to bring awareness to the oceans.

The effects of human activities on water quality in Monterey Bay are both widespread and varied in the degree to which they disrupt the ecosystem and /or restrict water use. Monitoring and analysis have revealed high concentrations of nutrients, metals, pathogens, detergents and other contaminants in local creeks and rivers as well as in the numerous urban outfalls that drain into sanctuary waters.

As central coast populations grow, more pressure will be exerted on the sensitive ecosystems of Monterey Bay. Public awareness of these problems and an understanding of land use and management practices related to pollutant levels are important components of a strategy to improve water quality in these ecosystems.

The sanctuary's Water Quality Protection Program (WQPP) educates the public about water quality issues and facilitates implementation of marine, urban and agricultural management practices to improve water quality. SIMoN has partnered with other monitoring organizations in the region to create an ongoing framework for data integration, regional water quality assessments and evaluation of management practice effectiveness.

Persistent Pesticides
Persistent pesticides are known to concentrate in the fats of wildlife; in high concentrations they can cause disease, lack of reproductive potential or mortality.

Toxic conditions that result from persistent pesticides have been shown to exist in the Pajaro River watershed (Hunt et. al., 1999), Salinas River watershed (Anderson et al., 2003; Hunt et al., 2002) and Santa Maria watersheds (Anderson et al., 2006). Contaminants are eventually transported to the ocean, where they can pose risks to human health and collect in the tissues of marine animals.

Recent studies have found high concentrations of persistent pesticides in mussels and sediments collected at The Hook in Capitola and Laguna Creek (CCLEAN Report, 2005). Concentrations of metals, such as copper and zinc, have been detected over the past few years in runoff from urbanized areas of Monterey that drain directly to the ocean (First Flush Report, 2005).

Storm drain
Legacy pesticides such as DDT bind to sediments and have been found concentrated at the coastal confluences with watersheds in our region. Excessive sedimentation can bury the gravel river bottoms where salmonids such as Coho and Steelhead spawn.

High nutrient loadings have been identified in Monterey Bay and may be attributed to nitrate runoff associated with fertilizer use in the area. High nitrate levels can result in harmful algal blooms with impacts to native species.

Over the past decade, ocean water has frequently exceeded standards for safe recreation due to bacterial contamination and the potential risk to human health posed by associated pathogens.

The contaminants often derive from runoff that comes directly from urban centers and rural residential areas through storm drains. These drains carry bacteria and detergents in part because of an aging sewer infrastructure.
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