The Southern California Bight: Ecological Impacts due to
Anthropogenic Factors and Possible Sustainability Tactics
Jamison Sung


    This study examined the effects of anthropogenic pollution, primarily wastewater discharge, and its negative alterations on the Southern California Bight (SCB). Alterations such as a decreasing biodiversity, habitat degradations, and an increasing sickness rate are just some of the impacts upon the SCB. Sustainable measures, such as membrane technology, are also examined to observe their efficiency in the reduction of pollutant levels. The social, technical, and political aspects of the SCB will be addressed as well. Many recent journal articles, books, and internet sources were utilized in comprising this study of the SCB.


    The Southern California Bight (SCB) is a coastal region of unique oceanographic conditions, marine ecosystems and biodiversity. The Southern California Bight extends from Point Conception in Southern California to Cabo Colonett and Bahia de San Quintin in Baja California. In the region of the Bight there are nearly twenty million U.S. residents who live in its vicinity. There are more than three and a half million Mexican residents who inhabit the Tiajuana/ San Diego border region of the Bight as well (Beyeler et al.,1996). With the large number of people living in this area there has been a great demand upon this ecological resource.

    With the increasing population of people who reside near the Bight many environmental, social, economic, and political problems are occurring. The Bight is being polluted by anthropogenic means, mainly in the form of non-point pollution from all the various municipal and industrial waste as well as runoff from various sources. The Southern California Bight and its valuable ecosystems are being threatened by this pollution from rapid population growth, industrial growth, and lack of stringent environmental protection.

    Besides being the home to many aquatic communities the Southern California Bight has many other anthropogenic uses. People and industries that reside near the Bight have put a great demand on this ecosystem. People create a great deal of contamination and pollution in these waters such as municipal waste, river runoff, atmospheric fallout, harbor discharges, thermal discharges, and marine transportation (Kennish, 1998).

    Municipal waste outfalls are the worst source of pollution and outweigh all other sources.

    Industries are not the only ones utilizing the Bight. Residents of the area as well as visitors come to this area for fishing and other recreational uses of its waters. This is the same water that is receiving effluents from wastewater treatment plants of four major sanitation districts, the city of Los Angeles, Los Angeles County, Orange County, and the City of San Diego. Nearly seventy-five percent of California's population dumps its wastewater into the Bight. Wastewater discharge has been going on for quite some time, for instance, primary treated sewage was first discharged off LA in the mid-1930's (Bakus,1989).

    Due to more environmental protection laws, water quality standards have been set and the quality of wastewater discharges have improved since the 1970's. Some areas of the Bight are beginning to show environmental and biological recovery from wastewater discharges (Kennish,1998). We as a society should have never damaged our precious resource to begin with. However, since the ecological damage has already been done we must learn how sustain and manage the ecosystems wisely.

    The polluters of the Southern California Bight must realize that the ecological threshold of this area must not be crossed or the entire ecosystem will collapse. The industries and wastewater facilities must understand the concept of the output rule. This rule states that the wastes emitted from a project should be within the assimilative capacity of the local environment to absorb without unacceptable degradation of its future absorptive capacity and other services (Goodland & Daily,1996). Society must learn how to manage resources, reduce wastes and pollution, use energy and materials efficiently, and repair our Mother Earth by "unthinking" industrialization (Goodland & Daily,1996).

    In this research of the Southern California Bight the overall issue is to examine the anthropogenic or human made impacts of pollution, primarily non-point source pollution from municipal wastewater treatment facilities. I would also like to look beyond the examination of the region but maybe develop some type of plan for a sustainable Southern California Bight for future generations.


    Social capital is defined as the institutional and cultural basis for a society to function (Goodland & Daily,1996). In terms of the social capital the Southern California Bight is of great importance to the millions of people residing in its nearby vicinity. It is clear that we, as a society have not been putting a tremendous amount of input to our social capital or we would of never allowed all the ecological impacts upon the Bight to occur.

    There are programs and projects run by certain commissions which are trying to aim for a more pleasant, less polluted, and more sustainable Southern California Bight. For example, there is already a project in progress that is run by the Southern California Coastal Water Research Project Commission (SCCWRP) and the US Environmental Monitoring Assessment Program (USEMAP) called the Southern California Bight Pilot Project (SCBPP). This project monitors and performs tests on the waters of the Bight. The SCBPP is focusing on the spatial extent and magnitude of ecological change on the mainland shelf as well as comparing the degree of change throughout the Bight. The SCBPP is also examining changes in the Bight and its association with identifiable sources of pollution and if it differs in different portions of the Bight. The State Water Resources Control Board (SWRCB) along with the Coastal Commission has been developing pollution control strategies focusing on non-point source pollution (Beyeler et al.,1996).

    The Bight is of great importance to the various communities and cultures surrounding it. We all depend on its waters to dilute our various discharges. We also use these waters for its aesthetic and recreational purposes. In order to sustain this valuable ecosystem we must educate the public and let them become aware of the ecological and public health problems that the Bight encounters. Most importantly we must learn how to sustain our population growth around this area. The more wastes we dump into the Bight the more we cross its ecological threshold which leads to risk for the Southern California Bight.

    We constantly rely on the waters of the Bight for many reasons, from recreation to sanitation. Therefore, we need to learn how to manage and sustain this ecologically rich area. The actions by the various Commissions are good to ensure safety to our cultures of the region. However, we must go further and educate the public in order to truly make the area socially sustainable.


    The Southern California Bight is home to many ecosystems and organisms within it. There are various ecosystems of bays, estuaries, salt marshes, and kelp forests all containing an abundance of biodiversity. The rich biodiversity within the Southern California Bight is of great importance and must be treated in an environmentally sustainable fashion. The Bight is detrimental to us because it provides many goods and services to humans or a "natural capital". "Natural capital" as defined by Goodland & Daly, is our natural environment or "the stock of environmentally provided assets (the components comprising the environment) that provides a flow of useful goods or services (Goodland & Daly,1996). Society must learn to maintain and not abuse this precious capital and region.

    The geology of the Southern California Bight is complex with islands, banks, ridges, basins, several troughs and numerous submarine canyons (Bakus,1989). However, the geology and geography of the Southern California coastal region is being replaced by intense urbanization. The Southern California coastal region has been consistently experiencing rapidly expanding urbanization and population growth. Currently about 75 percent of California’s population reside in the southern regions, which place a great ecological demand upon the ecosystems of the SCB and the areas that surround it. All of the intense development of urbanization has clearly influenced the coastal waters with various anthropogenic wastes (Dailey,1993). The damage which society is inflicting upon the Bight is linked to urbanization and its counterparts, industrialization and agriculture. There is relatively little coastal space that has not been subjected to construction and resource depletion. These activities resulted in extensive habitat alterations and marine pollution to the Southern California Bight (Beyeler et al.,1996).


    Marine pollution is defined as, "The introduction by humans of substances or energy into the ocean that changes the quality of the water or that affects the physical and biological environment" (Garrison,1993). The Southern California Bight has been the dumping grounds for municipal and industrial waste discharges for many years. Other sources of contamination in these waters include river runoff, atmospheric fallout, harbor discharges, thermal discharges, and marine transportation. However, the effects of municipal waste outfalls far outweigh all other pollutant sources in the Southern California Bight (Kennish,1998).

    The Southern California Bight marine environment is constantly being subjected to large amounts of pollution entering the environment from many sources. Various wastes of sewage effluent, trace metals, fertilizers, iron waste deposits, sludge deposits, even DDT and PCB's have entered the Bight through river runoff, sewage treatment plants, and storm drains. All of these toxic pollutants enter the ocean on a daily basis. These pollutants then begin to harm the variety of species that inhabit the region. "Pollution provides an example of such human influence, and the affects of contaminants upon other species" (Lenihan,1977).

    The Southern California Bight receives many contaminants and nutrients from various sources. While there are about two hundred discrete sources, they usually fall into five major categories (listed in order of importance): wastewater outfalls, river and storm runoff, atmospheric fallout, ocean dumping, and current advection (Dailey,1993). The main transport route of contaminants from the land to the Southern California Bight are wastewater outfalls, river and storm runoff, atmospheric fallout, and ocean dumping these are all examples of non-point pollution. There are other sources of contaminants which include direct or point source pollution to the Bight in the form of industrial wastes and thermal effluent discharge from various power plants. However, these discharges are still relatively small in comparison to the discharges of municipal outfalls (Dailey, 1993). In this report, I will focus upon non-point source pollution of municipal waste treatment plants, the historical aspects and its effects on the Southern California Bight environment.


    Non-point source pollution such as municipal wastewater outfalls is still the dominant source of pollution in the Southern California Bight. Even though runoff is classified as a pollution source of the Bight approximately one-third of the volume of municipal wastewater discharge is surface runoff (Dailey, 1993). Inputs of metals and oils from waste outfalls is much greater than runoff. A majority of the water utilized for domestic and industrial purposes as well as some agriculture enters the municipal wastewater plants creating a "soup" of contaminants and is dumped into the Bight. Municipal wastewater facilities not only takes wastes from humans but from human activities as well.

    Historically, primary treated sewage was first discharged off Los Angeles in the mid 1930's (Bakus,1989). Primary treated sewage killed rich giant kelp beds, an ecosystem which many aquatic organisms depend upon. Primary treated effluent is the most basic form of wastewater treatment and does not filter out much of the wastes. It was not until the 1960's that both the private and public sector of the population realized that "the oceanic waters of the world cannot assimilate an infinite amount of waste" (Dailey,1993).

    Submarine outfalls release billions of liters of municipal wastewater everyday in the Bight's shelf waters. Four sanitation districts (City of LA, LA County, Orange County, and the City of San Diego) have the largest wastewater outfalls. Of the municipal wastewater discharged directly into the Bight about 90% of the effluents are from these four districts (Kennish,1998). These treatment plants are the:

    • Hyperion Treatment Plant (HTP), City of LA
    • Joint Water Pollution Control Plant (JWPCP), LA County
    • Wastewater Treatment Plant 1 and 2, Orange County
    • Point Loma Wastewater Treatment Plant (PLWTP), City of SD.
There are also 15 smaller municipal wastewater treatment plants which discharge into the waters of the SCB. Research has shown that todays wastewater effluent has reduced significantly in mass emissions of contaminants when compared to wastewater effluent of the past.

Contaminants in Wastewater

    There are still many contaminants in the effluent of municipal waste treatment plants. These contaminants in the mass emissions of effluent have been declining within a 24 year period, for example, mass emissions of chlorinated hydrocarbons (DDT & PCB's) and trace metals decreased 99%and 95%, respectively (Kennish,1998). The drop in DDT and PCB's was mainly due to the Clean Water Act and the ban on these chemicals in the 1970's. The Clean Water Act has been the primary law in the protection of the precious waters. Congress amended the Clean Water Act in 1977 to require federal wastewater discharges to procure state permits.

    The mass emissions of suspended solids, grease and oil, and biological oxygen demand (BOD) have also dropped 77%, 69%, and 53%, respectively (Kennish,1998). In 1971 before mass emissions began declining there was contaminants of silver (Ag), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), and DDT that were highest in concentration in municipal wastewater discharges. Despite increases in urbanization, population, and volume of wastewater discharged in the past 24 years the amount of marine contaminants have declined. The SCCWRP feels that this decline in contaminants is a result of control strategies or different production practices (Beyeler et al.,1996).

    Although the various contaminant levels have declined since the 1970's there are still contaminants present in the waters that enter the Bight. There are many outfalls all of which discharge billions of liters a day which adds up to a great amount of pollution. For example, the Point Loma discharge outfall in San Diego can account for essentially all of the silver in coastal waters along the U.S./Mexico boarder in the summer (Wilhelmy & Fiegal, 1992). Anthropogenic Silver is a concern because it is one of the most toxic elements for marine invertebrates. The wastewater discharges of silver into the Southern California Bight has remained relatively constant over the past two decades (Wilhelmy & Fiegal,1992). The SCCWRP has been monitoring contamination gradients and species diversity since the 1970's to preserve and protect our natural capital of various biodiversity.

Wastewater Impacts on the Ecosystem

    There are many organisms that inhabit the Southern California Bight. The Bight is home to a variety of benthic organisms, invertebrates, over 485 species of fish, 80 species of seabirds, and various marine mammals (Bakus,1989). All of the wildlife within the Bight is of great importance in order to have a properly functioning ecosystem. The Bight has a large macrobenthic community, which helps drive the food web. However, macrobenthic community stimulation and degradation has occurred due to organic enrichment and chemical pollution from the LA County Sanitation Districts discharge (Ferraro,1994). Other larger organisms, such as fish, are directly affected by pollution and can cause biological and physical changes and mutations. An example of this would be fin erosion of the Dover sole caused by sewage disposal (Bakus,1989).

    Wastewater discharge clearly impacts the area in which it is discharged. An area seriously impacted by wastewater disposal occurs in the Santa Monica Basin (Kennish, 1998). Humans have become sick just by swimming in these waters (Dailey,1993). Wastewater deposits could drastically alter the ecosystem by changing it from a typically non-polluted environment with non-pollution tolerant organisms to an ecosystem with characteristics of polluted water. Impacts of sewage discharge on rocky intertidal organisms in some areas of the Bight include a decrease in spatial heterogeneity and diversity and enhancement of rapid colonizer, sewage tolerant species (polychaete worm), and suspension and omnivore feeders (Bakus,1989). This ecological change must be kept under control and maintained properly or an ecosystem collapse could occur.

    The "output rule" must be always considered when regarding pollutants in the Southern California Bight. That the wastes emitted from a project should be in the capacity of assimilation of the surrounding local environment to absorb without unacceptable degradation of its waste absorptive properties (Goodland & Daly,1996). Although the amount of pollutants in the Bight has been improving since the 1970's, anthropogenic disposal upon the marine environment has diminished the quality of our local ocean.

    We willingly visit the ocean for recreation, relaxation, and spiritual renewal, yet by our actions we are destroying it. Our society has always exercised its capacity to consume resources and pollute its surrounding, but only in the last few generations has it become visible. Society must be educated of the impacts it has upon the SouthernCalifornia Bight in order to have an environmentally sustainable region.


    Wastewater effluent discharge combined with the other various sources of pollution clearly leads to problems in marine environment. The marine ecosystem along with all the abundant organisms is undergoing changes for the worse. The areas of effluent discharge are becoming more degraded and contaminating all life around it. Then trace metals, ecosystem alteration, bacterial contamination, biodiversity loss, eutrophication, and harmful impacts upon fish and wild life all pose great problems upon the Southern California Bight.

Trace Metals

    One of the problems from wastewater effluent discharge is the bioaccumulation of trace metals in bottom dwelling macrobenthos organisms. Trace metals (Ag, Cd, Cr, Cu, Ni, Pb, Zn) make their way through various industrial and other pathways which lead into treatment plants. These metals then get discharged into the waters of the Bight and settle on top of the various invertebrates and other bottom dwelling organisms. There are many types of shellfish becoming tainted by absorbing the metals into their tissues. Shellfish contamination can lead to bioaccumulation and biomagnification of the contaminants up the food chain eventually making its way to humans. Mercury is the primary toxic metal that is bioconcentrated up marine food chains (Bakus,1989). Mercury is very dangerous because it could lead to serious neurological damage as well as genetic defects. Society must be concerned about the trace metal problem because there are many types of shellfish consumed throughout the world.

Environmental Degradation & Biodiversity Loss

    Wastewater effluent creates another potential problem where discharge occurs. After prolonged exposure this environment can undergo alterations and changes from an area with abundant spatial heterogeneity and biodiversity to an area of rapid colonizers, sewage tolerant species, and decreased diversity (Bakus,1989). An example of this is an area of clean waters characterized by the presence of the brittle starfish that has been replaced by polluted waters inhabited by the sewage tolerant polychaete worm. This shift in ecosystems can greatly decrease the amount of biodiversity present.

Bacterial Contamination

    Besides trace metal pollution and ecosystem and biodiversity loss, bacterial contamination of marine waters is occurring as well. Sewage pollution is a health hazard for people who are swimming or surfing in the waters that have been contaminated by the effluent. Pathogenic micro-organisms found in wastewater can cause serious diseases such as hepatitis and meningitis, and less serious conditions such as diarrhea, skin and ear infections (Nantel/Environ.Probe/4-21-87). Red tides, bacteria, protozoans, and viruses occur in the waters of the Southern California Bight. These conditions are harmful for humans and must be controlled for public health and safety reasons. The marine waters of the Santa Monica Bay has been affected by the daily discharge of the Hyperion Treatment Plant and the Joint Water Pollution Control Plant (Kennish,1998).

    A variety of biological hazards may also exist at municipal wastewater treatment facilities. This is because biological hazards will exist at any location where contaminated wastewater and treated sludge are present. Many potential biohazards (bacteria, viruses, and parasites) may confront wastewater workers due to their daily contact and possible exposure to infectious wastes.


    The addition of nutrients into marine waters from wastewater effluent is another big problem. Eutrophication is the addition of nutrients (nitrogen & phosphorous) which stimulate excessive and undesirable plant growth such as algal blooms. This type of growth is undesirable because it places additional pressures of dissolved oxygen levels due to an increased number of oxygen consuming micro-organisms required to decompose the aquatic plants (Nantel,Environ.Probe,4-21-87). If the dissolved oxygen level required by aquatic life becomes depressed too much then fish kills will occur.

Effects on Fish

    Fish are greatly affected by sewage effluent. The effects have many forms that include physiological, biochemical, pathological, and behavioral changes. The physiological changes of fish include reduction or inhibition of reproductive capacity, growth retardation, and reduced resistance to pathogens. Biochemical disturbances cause alterations in the metabolism, body fluids, and enzyme activities, all leading to organ impairments and physical defects in developing young fish. Common pathological disturbances include fin erosion, ulcerations, liver tumors, and skeletal abnormalities caused by damaged genetics. Behavioral changes in fish are altered feeding and migration patterns usually due to the sensory equipment of the fish. All of these factors play an important role both environmentally and economically because at one point in time California used to have great fishing. This is now declining due to the harm inflicted upon the ecosystem and the changes in fish.


    There have been several techniques developed for the removal of additional nutrients and metals from wastewater treatment plants. These techniques are needed in order to create not only a sustainable Southern California Bight but also sustainable coasts around the world. The techniques are fairly recent and primarily consist of the various types of membrane filtration as well as biological nitrogen filters.

Membrane Technology

    Membrane technology for the treatment of water requires pressure driven processes (diffusion, osmosis). There are three major commercial applications for the membrane technique: the treatment of effluents from sources of wastewater; potable water from substantial sources such as sea water; and production of process water for industrial use (Cheremisinoff,1993). The pressure driven processes can be divided into membrane filtration, ultrafiltration, nanofiltration, and reverse osmosis.

    Membrane filtration is utilized in particulate removal of wastewater effluent. Basically in all processes of membrane treatment the membrane filters out the solids through diffusion. Ultrafiltration utilizes a membrane and an ion exchange resin and is efficient for the removal of larger organic molecules and metal ions. Nanofiltration separates ionic species on coulombic interactions or hydrated in size (Fane et al.,1992).

    Reverse osmosis is used in desalination procedures such as nitrogen removal and softening. The advantages of reverse osmosis membranes are primarily related to economics and high rates of removal efficiency. The two major operating costs of membrane plants are electrical power and membrane replacement (Cheremisinoff,1993). Membrane technology in addition with wastewater treatment can make a big difference upon the marine environment of the Southern California Bight.


    There are also recent innovative treatment solutions available which allow the upgrading of treatment plants. A new biofilter has recently been developed and has been tested in Europe. This biofilter allows for denitrification or nitrification in one reactor. Biofilters are a solution for nitrogen removal in the post-denitrification stage using an external carbon source (Jepsen & Jansen,1993). These filters are capable of serving as denitrification reactors to remove nitrogen and phosphorous nutrients to the most stringent effluent standards achieved in two to three hours. This biofilter will help decrease eutrophication, particularly in warm climates and areas of high population.


    The techniques described above aid in the sustainability of the Southern California Bight and other coastal regions. However, prevention and education of the public can play a big role of sustaining the Bight. If society could manage to prevent pollution from oils, run-off, storm-drains, etc. from the start it would lessen the ecological impacts of the habitat. Educating the public of the precious resource and making them aware of what is happening to our coasts could possibly change societies utilitarian views of the environment.

    If more sustainability measures are utilized this would allow the possibility of more job openings in this newly expanding field. Society in turn would be helping the economy and the environment. The realization must occur that if we do not sustain our coastal regions our coastal regions eventually will not be able to sustain the human population.


    The Clean Water Act and other water related laws have been undergoing many reauthorizations and amendments since the 1970’s, in order to improve water quality. Many new standards have been set regarding the topic of non-point source pollution. Even though wastewater effluent discharge standards have been set, the standards are not good enough. We must go further, by incorporating new waste removal technology, in order to have a Southern California Bight that will maintain its "natural capital". Politics also play a crucial role in the protection of the various water sources. The many industries that pollute the SCB must be watched carefully so that they do bribe corrupt politicians or try secretly dumping more wastes into the waters of the SCB.


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