March 19, 2013
Minerals found in Los Angeles’ coastal waters are now being used to determine the extent of pollution from stormwater runoff. These minerals provide evidence that the Clean Water Act is effective, though more needs to be done to protect water resources.
The Clean Water Act was amended from the 1948 Federal Water Pollution Control Act in 1972 and has since become one of the most important pieces of environmental legislation. The amended act allowed the EPA to implement pollution control programs around the country by setting water quality standards and managing stormwater and factory runoff. The goals stated in the 2008-2010 report (http://www.epa.gov/compliance/data/planning/priorities/cwastorm.html) included reducing primary pollutants by managing stormwater runoff.
Stormwater runoff is the largest source of water pollution in Los Angeles. Over 90% of stormwater runs off into the ocean without treatment of any kind. Runoff accumulates from off rooftops, agricultural lands, roadways, and urban areas. Pesticides, petroleum products, metals, and acids are among the common pollutants found in stormwater runoff. These chemicals negatively impact the health of wildlife living in coastal waters. Furthermore, these chemicals pose a risk to organisms drinking water contaminated with runoff.
Among these contaminants are heavy metals like cadmium, nickel, and lead. Due mainly to anthropogenic sources, these metals are frequently carried by runoff into coastal waters. There they are taken up by small marine organisms and stored in the animals’ fatty tissue in a process called bioaccumulation. As larger organisms consume contaminated prey, more metals accumulate up the food web. Contaminated fish may eventually reach our plates.
Scientists use these metals to track the presence of other contaminants and to quantify any changes in contaminant levels as a result of clean water legislation.
In a study published in 2012, data of coastal contaminants off California before the enactment of the Clean Water Act was compared to the data from after its enactment (Smail). Samples taken in the 1970s showed high concentrations of toxic metals including cadmium, silver, nickel, copper, lead, and barium (Image 1). The study found a significant decrease in metal contaminants found off the coast of California after the implementation of the Clean Water Act.
The decrease in contaminants was a result of California monitoring anthropogenic sources of metals and employing policies to reduce stormwater runoff that has the potential to carry the metals into coastal waters.
A significant amount of metal-laced runoff comes from California’s extensive highway system. Degraded pavement is a leading source of metals in highway runoff, along with metals leached out of asphalt and metals deposited by vehicles (Minervini). Copper-containing residue from brake pads is another significant source of metal contamination on highways (“Stormwater Runoff Management at Caltrans”). When inundated with rainwater, metals and other pollutants are carried quickly off the roadways and directed toward the ocean.
Another common pollutant in stormwater runoff is suspended particulate matter. The fact that metals easily bind to particulate matter provides a window of opportunity for a solution. A 2007 study by Kayhanian et al. estimated that at least 50% of metals could be removed from runoff—and kept out of the oceans—by managing and removing particulate matter.
Beginning in 1994, California’s highway agency, Caltrans, was ordered by a federal court to better manage large volumes of runoff from highways and other sources to comply with the Clean Water Act. Contracting with the environmental engineering group Brown and Caldwell, Caltrans developed a series of water-retention basins fitted within the highway system. These clay- and concrete-lined basins hold water for up to three days, allowing suspended particulate matter and associated metals to settle and drain out of the basins (Image 2). This project enhanced the understanding of runoff management and successfully decreased the amount of pollution that would eventually reach the ocean.
Stormwater runoff pollution continues to pose a major threat to wildlife and human health in the Los Angeles area. While conditions have greatly improved due to the Clean Water Act, more needs to be done to protect coastal waters. The Brown and Caldwell project is one example of innovations to manage runoff pollution. More projects will be needed in the future to collect, treat, or otherwise manage stormwater runoff.
Sydney Fishman is a freshman from Chicago majoring in Environmental Studies. She eventually wants to pursue studies in coastal environmental policy and management.
Brittany Hoedemaker is also a freshman in USC’s Environmental Studies program from Bellevue, Washington, a suburb across the water from Seattle. She hopes to study the impacts of declining shark populations on marine ecosystems, work to promote shark conservation and enact policies to stop shark finning.
“Clean Water Act (CWA) Storm Water National Priority | Compliance and Enforcement | US EPA.” EPA. Environmental Protection Agency, n.d. Web. 26 Feb. 2013. <http://www.epa.gov/compliance/data/planning/priorities/cwastorm.html>
Kayhanian, M.; Suverkropp, C.; Ruby, A.; Tsay, K. (2007) Characterization and Prediction of Highway Stormwater Pollutant Event Mean Concentration. J. Environ. Manage., 85 (2), 279–295.
Minervini, William P., et al. “Characteristics of Highway Stormwater Runoff in Los Angeles: Metals and Polycyclic Aromatic Hydrocarbons, S. Lau, Y. Han, J. Kang, M. Kayhanian, M. K. Stenstrom, 81, 308-318 (2009).” Water Environment Research 82.9 (2010): 861-2. Web.
Smail, Emily A., et al. “Status of Metal Contamination in Surface Waters of the Coastal Ocean Off Los Angeles, California since the Implementation of the Clean Water Act.” Environmental science & technology46.8 (2012): 4304-11. Web.
“Stormwater Runoff Management at Caltrans.” Brown and Caldwell. 2011. Web. <http://www.bcwaternews.com/waterresources/P-635-0502a_(Stormwater%20Runoff%20Mgmt).pdf>
Soil Biodiversity and Conservation Ecology: U.S. Soil Degradation and the Implementation of Organic Farming Methods
Many factors contribute to the classification of healthy soil which are comprised of, but not limited to, composition, fertility, nutrients, organic matter, as well as, diversity and abundance of soil organisms. These components combine to solidify basic definitions of what can be referred to as soil biodiversity and conservation ecology.
Soil Biodiversity is the composition, heterogeneity, and abundance of soil organisms for sustained soil fertility. Examples of this are microorganisms, nutrients, and organic matter. Conservation Ecology is the study of nature and the status of biodiversity on planet Earth. This field aims at protecting species, habitats, and ecosystems through such projects as landscape preservation and the prevention of species extinction.
The United States, in its current practice, implements industrial farming methods in order to maximize efficiency and decrease expenditures. A primary example of these methods is the segregation of crop production to single cash crops. Therefore, individual farms are responsible for specific agricultural sectors which increases efficiency, but constrains soil resources. According to Diana Wall of Colorado State University, “the use of insecticides, nematicides, and herbicides for control of soil pathogens and pests rather than on biocontrol of pathogens, herbivore-resistant crop varieties, or other management strategies has furthered the impression that soil biodiversity is of little relevance to agricultural production.”
Lack of crop rotation leads to soil degradation, resulting in unforeseen effects on soil quality. In the long run, soil degradation substantially decreases crop yields and quality, further exacerbating critical food insecurities. In addition to adverse effects on human nutrition and health, soil degradation increases environmental susceptibility to droughts and elemental imbalance leading to desertification and devastating events such as the dust bowl.
An alternative to U.S. industrial farming methods is the use of organic farming. According to a 21-year study, that was published in Science, on various farming methods in Central Europe, researchers found that organic farms produced 20% fewer yields. Fertilizer and energy use, however, was reduced by 34-53% and pesticide use was cut by 97%. This led to increased soil biodiversity and fertility for future growing seasons.
Organic farming differs from industrial agriculture methods because of its focus on decomposition and nutrient management. It emphasizes maintaining nutrient levels and soil fertility with the use of crop rotation practices. Organic farms are more dependent on soil chemical content and biological processes for nutrients to sustain crop health and yield than conventional industrial U.S. agriculture.
Integrated-livestock farming is the unification of livestock and grazing land in order to negate the impacts of industrial soil degradation. This purported solution is considered an alternative to organic farming methods in that it requires no change to current crop production and claims to show an improvement in soil quality.
A study conducted in central North Dakota sought to evaluate these claims due to the lack of documentation on the subject. A Soil Quality Index (SQI) was developed using the Soil Management Assessment Framework, and was used to judge treatment effects on soil conditions over a 9 year span. Aggregated SQI values over 9 years showed no significant change in soil quality, implying no differentiation in the capacity for each system to perform critical soil functions. As a result, the study concluded that integrated-crop management systems provide limited benefit to soil quality and nutrient abundance. However, the results of this study are specific to the geographic region to which they were performed, and the climatological as well as topographical characteristics of the region likely played a role.
About the Authors:
Sara Carlson is a sophomore at the University of Southern California studying International Relations Global Business and Environmental Studies.
Jacob Leonard is a sophomore at the University of Southern California and is currently pursuing a Bachelors of Arts degree in Mathematics with a minor in Environmental Studies.
J.F. Karn, et al. “Integrated Crops And Livestock In Central North Dakota, USA: Agroecosystem
Management To Buffer Soil Change.” Renewable Agriculture & Food Systems 27.2 (2012): 115-124. GreenFILE. Web. 28 Feb. 2013. http://search.ebscohost.com/login.aspx?direct=true&db=8gh&AN=75166043&site=ehost-live
Lal, Rattan. “Soil Degradation as a Reason For Inadequate Human Nutrition.” Food Security
(2009): n. pag. Springer Link. Web. 28 Feb. 2013. http://link.springer.com.libproxy.usc.edu/article/10.1007%2Fs12571-009-0009-z
Mader, Paul, Andreas Filesbach, David Dubois, Lucie Gunst, Padruot Fried, and Urs Niggili.
“Soil Fertility and Biodiversity in Organic Farming.” Science 296 (2002): 1694-697. JSTOR. Web. 28 Feb. 2013.
Systems.” Renewable Agriculture and Food Systems 24.4 (2009): 308-18. ProQuest
Research Library. Web. 28 Feb. 2013.
Wall, Diana H. “Chapter 10: Making Soil Biodiversity Matter For Agriculture.” Microbial
Ecology in Sustainable Agroecosystems. By Tanya E. Cheeke and David C. Coleman. Boca Raton: CRC, 2013. 267. Print. http://books.google.com/books?hl=en&lr=&id=92fbRsUSWTgC&oi=fnd&pg=PA267&dq=definition+of+soil+biodiversity&ots=-OyVeDJUoW&sig=-2klu3oSseuuhhaS7YXDFEx7RA8#v=onepage&q=definition%20of%20soil%20biodiversity&f=false
In the event of being isolated on a life boat in the middle of the Pacific after the tragic sinking of your ship, we all know one universal fact: do not drink the salt water. While those of us living in Southern California may not feel as geographically isolated as Pi did, we truly are equally as isolated to natural water resources. However, despite this, one concept still rings true, do not drink the salt water. Right now, in a time of worry about the future of our water security in Southern California, the largest reservoir of water that lay in our backyard is being looked at as the solution to those very legitimate concerns. However, the grand Pacific is not the answer.
Right now, many believe that for Southern California to solve its fresh water problem we must invest more money and energy into desalinating water from the Pacific. As of 2004, there were sixteen small desalination plants in operation throughout Southern California, with plans for an additional nineteen plants to be built in the next decade (Starratt, 2004). The most recently approved plans come from Huntington Beach where they will begin building a $350 million desalination plant into the same small beach city that is already home to a nearly $500 million groundwater replenishment plant (Shankman, 2009). It is these kinds of fiscally irresponsible decisions that will continue to doom Southern California’s water needs in the future.
Further south, in San Diego County, plans for a $984 million desalination plant to be built in Carlsbad are in the works. Despite this enormous cost to build, the plant will provide for less than 8% of California’s water needs. Also, the water produced in these plants costs twice as much to produce as it does to import equal amounts of water from Northern California and the Colorado River (Boxall, 2013).
It is important to keep in mind that the costs for putting in these types of large-scale desalination plants are only this low because it will be using the infrastructure already in place from pre-existing offline power plants. To build a desalination plant of this size from scratch, which is what will be needed if that is the route we are going to take to answer our demands for water, it will cost nearly double. A desalination plant that is being proposed, which will be located near Camp Pendleton, is estimated to cost the state $1.9 billion dollars (Shankman, 2009).
These plants are
also extremely wasteful, as it takes three gallons of seawater to produce one gallon of potable, drinking water. The other two gallons become salty brine that is dumped back into the ocean (Greenlee, 2009). This is disastrous for marine life directly off the coast as it causes harmful algal blooms, which in turn create harmful neurotoxins that negatively affect marine ecosystems along with human health (Caron, 2010). These algal blooms, created by the plants themselves, can turn these multi-billion dollar plants offline, and in some cases, permanently. That has to make one wonder whether or not it is a wise decision to invest so much money into such unstable facilities.
Not only do these plants cost the state billions, but also cost the coastal regions in which they are located tens of millions of dollars annually (Caron, 2010). These coastal towns, which rely on their summer revenue created by tourism and hoards of people from all over Southern California coming to their beaches, will be crippled. Along with creating unusable beaches and killing off local wildlife indigenous to Southern California, these plants are flat-out ugly.
The scariest part of all though, is that if we follow through with these plans to build these polluting, energy intensive, and costly facilities, California’s water future will be even uglier than the desalination plants themselves.
By: Faith Sugerman and Alex Creem
Desertification is defined as the dilapidation of biological productivity, which ultimately leads to desert-like conditions. The deterioration of land due to desertification is closely linked to climate change and other anthropogenic activities. Although the relationship between climate change and desertification is not fully understood, studies conducted by the United Nations Convention to Combat Desertification Secretariat (UNCCD) and the Millennium Ecosystem Assessment suggest that unsustainable agricultural practices paired with increased greenhouse gas emissions and a reduced carbon sink could lead to prolonged periods of extreme drought. Such events can have a dramatic impact on soil already depleted of nutrients, and freshwater availability.
Unsustainable agricultural practices that contribute to desertification include over-cultivation, overgrazing and poor irrigation practices. Deforestation also plays a role, as a decrease in vegetation results in a loss of topsoil. All of these activities are the result of the increasing imbalance between an expanding human population and an environment ill equipped to sustain it. The growing population is not the direct cause of desertification but it has led to the misuse of the land on a massive scale. Our rapidly increasing population has changed the former balance upon which the survival of agriculture depends, such as long uncultivated periods to allow the land to regain its fertility.
In California, the effects of natural drought are exacerbated by climate change and other anthropogenic influences. Increased desertification in an area already scarce in resources does not bode well for the region’s ecosystems or its growing human population. From an ecological standpoint, desertification leads to a decrease in plant biodiversity, as topsoil is lost. This loss of vegetation also impacts the carbon cycle as less carbon sequestration occurs. Water scarcity is also a major concern as Southern California already relies heavily on water pumped from the north. Overdrawing even more groundwater from aqueducts can lead to land subsidence, as has already occurred in the some areas. Water shortages and soil depletion can have a crippling effect on agriculture and food security by leading to increased food prices and unemployment. The most recent drought in California occurred from 2007-2009. In 2008 alone, an estimated $300 million was lost as a result of the drought.
While California has survived periods of drought in the past, scientists believe that these dry spells may become the new norm. A study published in 2011 by a group of researchers at Columbia University predicted that California and the rest of the American Southwest will experience conditions similar to the dust bowl of the 1930s by the year 2080. A similar period of prolonged drought and dust storms will have dire consequences for the region’s food supply and air quality. Is there a way to prevent this crisis? It is possible to combat desertification through sustainable agricultural practices and environmental restoration, but there is still climate change to take into account. Unfortunately, it’s unlikely we can reverse the massive amount of damage done. It will take a drastic change in human behavior and resource use to save California from further drying.
By: Molly Sullivan and Renee Daniels
Aldhous, Peter. “Dust Bowl Looms If US Southwest Drought Plans Fail.” New Scientist. N.p., 2 Nov. 2011. Web. 22 Feb. 2013.
Schesinger , William H., and James F Reynolds. “Biological Feedbacks in Global Desertification.” Articles. Academic Research Library, 02 Mar 1990. Web. 22 Feb 2013. <http://www.planta.cn/forum/files_planta/biological_feedbacks_in_global_desertification_541.pdf>.
Seager, R., M. Ting, I. Held, Y. Kushnir, J. Lu, G. Vecchi, H.-P. Huang, N. Harnik, A. Leetmaa, N.-C. Lau, C. Li, J. Velez, and N. Naik. “Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America.” Science 316.5828 (2007): 1181-184. Web.
Reynolds, James F, and Mark Stafford Smith. “Global Desertification: Building a Science for Dryland Developement.” Science. Science Magazine, 11 May 2007. Web. 22 Feb 2013. <http://www.sciencemag.org/content/316/5826/847.short>.
In October 2010, four major European stakeholders partnered with several groups, such as the European Landowners Organization (ELO) and the European Crop Protections Association (ECPA) to release an extensive publication on soil biodiversity and agriculture. Together, these individuals brought the importance of soil and its relationship to agriculture, climate, and our own health. 2010 was labeled the International Year of Biodiversity, hence the reason for this publication. And now, it is 2013, so where do we stand on this issue of soil biodiversity and conserving the most critical element in our global environment?
Not many people have heard of soil biodiversity but it’s one of the best kept secrets to the well-being of the human population. So what exactly is it?
Soil biodiversity is the variants of species in the soil of a given area. To go deeper, it is not just the number of species, but the complexity of the food web within the ecosystem. Soil isn’t just the abiotic dirt that most people assume it is, but rather it is teeming with life, including bacteria, microbes and fungi. More than one fourth of the known species on earth strictly inhabit the soil. These microorganisms provide many services to humans and the surrounding ecosystem such as nutrient cycling, water regulation, detoxification, and pollination of plants and crops. In terms of creepy critters in the soil, the phrase “the more the merrier” rings true; the more organisms inhabiting the soil, the more services can be performed for human benefit.
Some of the most important organisms found in soil worldwide are from the family of mycorrhizal fungi. In fact, more than 90 percent of all plant species benefit from a relationship with these particular fungi. Because of the symbiotic relationship they share with plant roots, the fungi act as an extension of the plant by increasing the surface area of the root system. This helps the plants absorb more water and nutrients than the roots would on their own.
Most importantly, they serve as an indicator species of changing ecosystems. Because the mycorrhizal fungi and the plant act as one, any contaminants found in the soil will be grabbed by the fungi and thus killing the plant. Similarly, air pollutants or chemicals that can harm the plant will in turn kill the fungi. In this way, the mycorrhizal fungi are sensitive to any environmental change, which makes them a valuable representation of the ecosystem health.
The most prominent genus of mycorrhizal fungi in Southern California is ectomycorrhizal (EM) fungi, which encompasses a high diversity of species. In general, EM fungi attach themselves to Coast Live Oak, pines and other wild trees. According to a decade-long study at San Diego State University, there are 74 species of EM fungi associated with the Coast Live Oak alone! Their main role is to serve as an indicator of the changing dynamics of the oak groves.
Arbuscular mycorrhizal (AM) fungi are a type of EM fungi specific to small plants, grasses, and agriculture. The presence the AM fungi on the roots of crops positively impact the growth and health of the crops. Organic agriculture is the best example of utilizing AM fungi in farming practices.
In addition, organic farming embraces the idea that a complex food web in the soil is more effective in providing services than a high number of species. These farmers maintain the variety of organisms in the soil, welcoming arthropods, earthworms, microbial carbon, and fungi. Sustaining this food web allows more nutrients to be cycled and soil to be rejuvenated with the organic matter from these organisms.
To put it simply: more diverse soil leads to more food, which results in happier and healthier humans.
The European publication mentioned above, states that “soil is a limited and increasingly finite resource,” which puts anthropogenic uses of the soil under stress. Conservation ecology is the concept of preserving ecosystems so that we as humans can continue to enjoy their services. This idea consists of implementing appropriate methods for maintaining soil biodiversity, in particular importance for organic farming.
First, humans should be more aware and practice proper farming techniques in order to reduce anthropogenic causes of soil degradation. A mere 10 percent of agricultural land worldwide is labeled as improving their soil conditions. In order to combat erosion, chemical pollution and nutrient depletion, farmers must supply organic matter, increase plant varieties and protect soil organisms. Reducing tillage, a technique that is being employed more and more, increases the vegetation covering the soil, which not only adds nutrients, but also increases carbon storage.
Second, farmers must reduce their dependence on pesticides and chemicals because it acts as a positive feedback loop. Using chemicals to improve crops decreases the biodiversity in the soil, therefore causing a lower crop yield, and thus the use of even more chemicals. The European publication points out that the practice of crop rotation is a natural and effective way to reduce pest pollutions. Increasing soil biodiversity saves farmers money while naturally improving the health of crops and humans.
Third, soil is the basis for an array of services, which are interconnected with environmental components beyond agriculture. Just as mycorrhizal fungi are affected by the slightest environmental change, soil biodiversity is disturbed by seemingly unrelated factors. Soil is directly influenced by carbon dioxide levels, nitrogen cycling, temperature and precipitation. These are also the agents that induce climate change. Consequently, managing human affects on the atmosphere will improve the health of soil.
Even though the International Year of Biodiversity has come and gone, soil biodiversity is still a pressing issue that will not disappear anytime soon. Humans must recognize the importance of soil and actively work to conserve it in order to maintain a healthy and happy Earth.