Nutrients Management

I’ll Trade You: Water Quality Science Edition

By Marguerite Huber

Landsat image of Chesapeake Bay

Chesapeake Bay watershed includes six states and the District of Columbia. Image: NASA/Goddard Space Flight Center Scientific Visualization Studio

The outcome of a trade can sometimes be the luck of the draw. You may not have gotten a better sandwich for the one you traded at lunch, or the all-star pitcher your team acquired in that mid-season trade may turn out to be a bust.

On the other hand, the best kind of trade is one where everybody wins. EPA researchers are helping bring just that kind of trade to improve water quality.

Chesapeake Bay is an expansive watershed that encompasses some or all of six states and the District of Columbia. High levels of nutrients flowing in from all over that expansive watershed decrease oxygen in the water and kill aquatic life, creating chronic and well-known dead zones.

To help, EPA established the Chesapeake Bay Total Maximum Daily Load (TMDL), which sets a cap on nutrient and sediment emissions to restore water quality, ensure high quality habitats for aquatic organisms, and protect and sustain fisheries, recreation and other important Bay activities.

Recent innovations in Chesapeake Bay and elsewhere have promoted a new type of trading, called water quality trading, to meet watershed-level reductions in nutrient pollution. The goal is to facilitate individual flexibility and responsiveness while creating incentives to reduce overall nutrient flow from both agricultural and urban areas.

Here is how water quality trading would work…

Farmers and wastewater treatment plants have the opportunity to team up to collectively meet the water quality goal by reducing nutrients. While both entities have their own baseline nutrient emission level they must shoot for, they can gain tradable credits if they do better. A farmer that plants nitrogen-absorbing crops such as barley and wheat can sell the credits they gain to a wastewater treatment plant that needs to reduce its own emissions.

Silhouette of kids on dock at sunset

A healthy Chesapeake is a win for everybody!

Trading is based on the widely different costs it can take to control the same kind of pollutant, depending on its source and location. For example, upgrading wastewater treatment plants and ripping up urban streets to replace leaky stormwater drainage pipes could cost billions of dollars. On the other hand, planting new or different crops is much less expensive.

Like the TMDL itself, the development of the water trading system began with science. EPA-supported scientists and economists developed a computer model to find the least costly mix of pollution-reduction options across the watershed for meeting the TMDL. The model also has been used to explore how different trading policies could help to meet TMDL requirements, and as the basis for analyzing policies leading to the nutrient trading guidelines for Chesapeake Bay.

Overall, water quality trading depends on cooperation across the watershed to help achieve faster, less expensive pollutant reductions that improve the Bay’s water quality. It’s a win-win for everybody.

About the Author: Marguerite Huber is a Student Contractor with EPA’s Science Communications Team.

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Nutrient Management: Always on My Mind

By James R. Mihelcic, PhD, BCEEM

EPA-grantee and guest blogger James R. Mihelcic

EPA-grantee and guest blogger James R. Mihelcic

I am inspired to solve the complex problem of nutrient (nitrogen and phosphorus) management every day.  I think about solving this problem when I tend my winter garden of lettuce and peppers, around my neighborhood as I watch stormwater race from lawns to the Hillsborough River, in the classroom, and when I spend time outdoors enjoying our nation’s waters.

And I am in good company with my thoughts. You see, the National Academy of Engineering has identified managing the nitrogen cycle as one of their Grand Challenges.

I even started my New Year by canoeing in the Chassahowitzka National Wildlife Refuge and got to thinking about nutrients.  This was because some of the springs that feed the refuge have developed the tell-tale signs of nutrient pollution (green, slimy-looking plant growth) from on-site wastewater generation and lawn runoff from surrounding homes.  On that day we were also welcomed into the winter home of a group of manatees.  Manatees depend on sea grass for survival, and excessive nutrients cloud coastal waters, preventing sea grass growth. 

With support from an EPA Science to Achieve Results (STAR) grant, we established our Center for Reinventing Aging Infrastructure for Nutrient Management, which is transforming my daily thinking to everyday reality.  We are reimagining aging coastal urban infrastructure systems to consider nutrient recovery and management that contribute to sustainable and healthy communities.

Manatee at a U.S. Wildlife Refuge, Florida. Image courtesy of U.S. Fish and Wildlife Service.

Manatee at a U.S. Wildlife Refuge, Florida. Image courtesy of U.S. Fish and Wildlife Service.

I have great expectations for our Center research and demonstrations.  Our goals are to develop the science behind new technology and management innovations, and to develop a deep understanding of integrated systems.  We will demonstrate and assess innovations to provide new knowledge for students, community members, practitioners, and other stakeholders.

We are even transforming how we educate new engineers. For example, our new textbook, Environmental Engineering: Fundamentals, Sustainability, Design integrates sustainability and nutrient concepts into every chapter, and has the potential to reach over 10,000 undergraduate engineers every year.

Our research will benefit the public because poor water quality lowers the economic, social, and environmental value of our nation’s waters for current and future generations. 

In Florida, our springs, rivers, estuaries, coastal waters, and the Everglades all suffer because of nutrient pollution.  We have already come up with some ways to help manage nutrient pollution while also meeting the agricultural needs to provide national and global food security. For example, we have shown that 22% of the global demand for phosphorus could be met if we just recovered this valuable resource from domestic wastewater. We’ve also shown how wastewater infrastructure that serves a rapidly urbanizing world can be integrated with recovery of valuable water and nutrients to improve food security.

You can see why nutrients are always on my mind.  I hope they are now on yours.

About the author: EPA-grantee and guest blogger James R. Mihelcic is a Professor of Civil & Environmental Engineering and State of Florida 21st Century World Class Scholar at the University of South Florida (Tampa), where he directs the Center for Reinventing Aging Infrastructure for Nutrient Management

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

A New Beginning: Headwater Research

By Marguerite Huber

I like beginnings. They are a fresh start and influence our lives further down the road. Just like how we have new beginnings, all rivers have influential beginnings too. In a network of rivers up in the mountains, headwater streams are the uppermost streams furthest from the river’s endpoint or merger with another stream. They are the very beginning of miles and miles of rivers and have a great impact on what flows downstream.headwaterstream

Headwater streams and their catchments, or drainage basins, are necessary for the maintenance of healthy and productive streams and rivers. Headwater catchments also provide numerous ecosystem services to humans and the surrounding environment. These benefits include biodiversity, climate regulation, recreation, timber and crop production, and water supply and purification.

EPA researchers studied the importance of headwater catchments by focusing on the quantity and value of a few ecosystem services, and then projected that importance from a regional to national scale. They focused on three ecosystem services (water supply, climate regulation, and water purification) for 568 headwater streams and their catchments.

To assess the potential economic value of headwater catchments’ ecosystem services, researchers used published economic value estimates based on commodity price (water supply), market value (climate regulation), and damage cost avoidance (water purification).

They found the economic value of each ecosystem service as follows:

  • $470,000 – The average yearly value of water supplied through each headwater catchment.
  • $553, 000 – The average yearly value of climate regulation (through carbon sequestration) of each headwater catchment.
  • $29,759,000 – The average yearly value of improving water quality by reducing nutrient pollution.

Overall, the weighted average economic value for headwater catchments in the United States was $31 million per year per catchment. It is essential to note that the national importance of headwater catchments is even higher since the 568 catchments studied are only a statistical representation of the more than 2 million headwater catchments in the continental United States. I think it’s safe to say these beginnings provide some serious benefits!

About the authorMarguerite Huber is a Student Contractor with EPA’s Science Communications Team.

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Take Cover! (With Vegetation)

By Marguerite Huberbuffer

Take cover!

It’s a phrase you yell to protect against something headed your way. But did you ever think that phrase could be applied to pollutants? Well, it can – vegetative cover acts as a defense against non-point source (NPS) pollutants, protecting our lakes, streams, and water bodies.

Vegetative filter strips and riparian buffers  are conservation practices that help control the amount of sediment and chemicals that are transported from agricultural fields into water bodies. They slow down the speed of runoff and capture nutrients, keep more nutrient-rich topsoil on farmers’ fields, and reduces impacts on downstream ecosystems.

To improve water quality in large watersheds, conservation managers need to know what the problems are, where the pollutants originate, and what conservation practices work best.  However, investigating all of these factors at the watershed-wide level is a very difficult and complex task. This is why EPA is working with partners to supplement an existing watershed simulation model to estimate the efficiency of riparian buffers.

USDA’s watershed simulation model, Annualized Agricultural Non-Point Source Pollution (AnnAGNPS), is used to evaluate the effect of farming and conservation practices on pollutants and help decide where to put these practices.  AnnAGNPS also predicts the origin and tracks the movement of water, sediment, and chemicals to any location in the watershed.

To supplement this model, researchers from EPA, USDA, and Middle Tennessee State University developed a Geographic Information Systems–based technology that estimates the efficiency of buffers in reducing sediment loads at a watershed scale.

With the addition of this AGNPS Buffer Utility Feature  technology to the USDA model, researchers and watershed conservation managers can evaluate the placement of riparian buffers, track pollution loads to their source, and assess water quality and ecosystem services improvements across their watersheds.

Riparian buffers and other vegetative cover, such as filter strips, are considered an important, effective, and efficient conservation practice that has been shown to protect ecosystem services at a local level. However, their full impact on a watershed-scale is still subject to ongoing research.

 

About the Author: Marguerite Huber is a Student Contractor with EPA’s Science Communications Team.

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

SPARROWs, Lakes, and Nutrients?

By Jeff Hollister

Dock extending into a lake with forested background.Based on the title above, you probably think I don’t know what I am talking about. I mean really, what do sparrows, lakes, and nutrients have in common? In this case, a lot. So much so, an inter-agency team of EPA researchers in Narragansett RI, and a colleague from the U.S. Geological Survey (USGS) in New Hampshire have been working together to better understand how these three seemingly disparate concepts can be linked together. Some of the results of this work are outlined in a recent publication in the Open Access journal, PLos One

The sparrow I am referring to isn’t small and feathered, it is a model developed and refined by the USGS. Since the late 1990’s, USGS has been developing SPARROW models which have been widely used to understand and predict the total amount of nutrients (among other materials) that streams are exposed to over the long-term. This is known as “nutrient load.” The models are important because they provide a picture over a very large extent of where nutrients might be relatively high.

However, when it comes to lakes, SPARROW doesn’t directly provide the information we need. For our research on lakes, we need reasonable estimates of the quantity of nutrients in a given volume of water (i.e., nitrogen and phosphorus concentration), not long term nutrient load for the year. This is important, because the higher the nutrient concentrations at any given time, the greater the chance of triggering algal blooms—and more blooms mean a greater probability of toxins released by algae reaching unhealthy levels.

In order to better estimate the nutrient concentrations, we needed to use the SPARROW model for total load, but also account for the differences between load and concentration. Our solution: combining field data, data on lake volume and the SPARROW Model.

In our paper “Estimating Summer Nutrient Concentrations in Northeastern Lakes from SPARROW Load Predictions and Modeled Lake Depth and Volume,” recently published in PLoS One, we describe how we combined modeling information from SPARROW, summertime nutrient concentrations collected during EPA’s 2007 National Lakes Assessment, and estimated lake volume (see this and this for more).

The end result of this effort is better predictions, by an average of 18.7% and 19.0% for nitrogen and phosphorus, respectively.

What is the meaning of this in terms of our environment, and importantly, the potential human health impacts? If we are able to better predict concentrations of nutrients it will hopefully also improve our ability to know where and when we might expect to see harmful algal blooms, specifically harmful cyanobacterial algal blooms. Cyanobacteria have been associated with many human health issues, from gastro-intestinal problems, to skin rash, and even a hypothesized association with Lou Gehrig’s Disease (for example, see this). So, in short, better predictions of nutrients, will, in the long run, improve our understanding of cyanobacteria and hopefully reduce the public’s exposure to a potential threat to health.

About the author: Jeff Hollister, a co-author on the study outlined in this blog post, is a research ecologist with an interest in landscape ecology, Geographic Information Systems (GIS), the statistical language R, and open science. The focus of Jeff’s work is to develop computational and statistics tools to help with the cyanobacteria groups research efforts. Jeff is also an outspoken advocate for open science and open access among his colleagues.

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Join us for a nutrient Twitter chat today at 2:00 pm (ET)!

Questions and AnswersReminder: Join us for a Twitter chat today at 2:00 pm (ET)!
Got questions about how nutrient pollution affects our water? Join EPA scientist Anne Rea and other Agency experts today at 2:00 pm (ET).

Use #waterchat to ask a question or participate.

To get you started and introduce you to Anne, we’ve asked her to answer a few questions.

What is your educational background?
I have a Ph.D. in Environmental Health Sciences from the University of Michigan. I studied the biogeochemical cycling of mercury and trace elements in forested ecosystems. Since little work existed in the mercury realm, most of the literature and experts I worked with focused on nitrogen pollution.

How did you become interested in nutrient pollution?
After joining EPA, I wanted to work on the ecological side of things (versus human health) and spent several years doing ecological risk assessments. I then led a joint review of two air pollutants, nitrogen dioxide and sulfur dioxide, for the National Ambient Air Quality Standards. This was the first time two pollutants were reviewed together, and the first time a “secondary” (public welfare) standard was separated from the “primary” standard (human health effects). I’ve always worked on multi-pollutant, multi-media problems, so was uniquely suited to lead the risk assessment for that review.

What’s the most interesting thing you have learned trying to solve this problem?
The dedication and commitment of staff across EPA is amazing. This is one problem the Agency is uniquely suited to solving from a scientific and regulatory perspective—but we can only do it together—across offices, regions and research programs in the Agency, and in collaboration with the states and other federal partners.

How can technology and innovation help solve the problem?
We’ve struggled to solve this problem for more than 40 years, and I think as an Agency we’ve made some progress. As the world’s population increases, there is a demand for increased food production and increased energy use—all of which releases nitrogen (and sometimes phosphorus, sulfur, and carbon) into the environment.

We are working across the Federal government to develop a ‘nutrients challenge’ which will challenge teams globally to come up with innovative ideas to reduce nutrients—either from the emissions source or from the waste stream.

We know we can’t solve nutrient pollution alone. What other federal agencies are we partnering with?
We are working with the National Oceanic and Atmospheric Administration (NOAA) the U.S. Geologic Survey (USGS), the U.S. Department of Agriculture (USDA) the U.S. Fish and Wildlife Service (FWS), the National Park Service (NPS), and others, through jointly funded research, collaborations, cooperative agreements, etc. We work hard to share and use each others data and models as we work collectively to make an impact on nutrient pollution for the country.

Join us at 2:00 pm (ET) to Learn More!
Got more questions? Want to learn more? Don’t forget to join us for a Twitter chat today at 2 pm (ET). Use #waterchat to ask a question or participate. Not on Twitter but have a question? Please add it to the comments section below.

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Diving into Nutrients: How much is too much?

By Sean Sheldrake

An EPA diver kept isolated from contaminants.

An EPA diver kept isolated from contaminants.

There’s a nutrient “problem”?

Did you know nutrient pollution, primarily in the form of too much nitrogen and phosphorus, is one of the nation’s most widespread, costly and challenging environmental problems?  Some 16,000 waterways are impaired, and 78 percent of assessed coastal waters suffer from nutrient pollution, affecting water used for drinking, fishing, swimming and other recreational purposes.  These impacts also threaten tourism, home and property values and public health.

Nitrogen and phosphorous are food for some plants, like algae, and too much can spark a large algal bloom that can end up consuming all the dissolved oxygen in a waterway, causing fish to be starved for that critical gasp of O2.  Fish die-offs are common with extreme nutrient problems.

Where does it come from?

Excessive nitrogen and phosphorus are often the result of human activities. Primary sources include agriculture (manure, excess fertilizer and soil erosion), inadequately treated wastewater, stormwater runoff, air pollution from burning fossil fuels and—us! Huh? Whenever we do things around the house that add nitrogen and phosphorus to the local watershed we are part of the problem. That can include not cleaning up after your dog, using too much fertilizer on the lawn or garden, or washing your car on the driveway (most soaps contain nutrients).

How can I help?

Washington Department of Ecology Image.

Washington Department of Ecology Image.

The good news is that since we are all part of the problem, we can all be part of the solution.

Bag the dog waste, apply fertilizer according to the label (or better yet, switch to using some backyard compost!) and park your car on the lawn instead of the driveway when you wash it, or go to a carwash. We can really make a dent in the problem.

How about a little science to help out?

But it’s not all up to individuals alone. EPA scientists are working on solutions, too.

EPA divers help deploy and retrieve scientific instruments, such as Acoustic Doppler Current Profilers (ADCPs), to help study nutrient pollution.  For example, in one project in Puget Sound we deployed ADCPs to collect information on water flow, a critical first step that EPA computer modelers use to calculate the level of nutrients a water body can tolerate.  Ensuring the proper placement for data collection is paramount for data quality.

EPA diver deploys an ADCP.

EPA diver deploys an ADCP.

Getting into the water can be a challenge though!  Divers may have to upgrade to protective equipment and do a decontamination wash after the dive to ensure the safety of each diver getting in the water to collect data.

Read more about the latest in EPA scientific diving at facebook.com/EPADivers.

 

About the AuthorSean Sheldrake is part of the Seattle EPA Dive unit and is also a project manager working on the Portland Harbor cleanup in Oregon.  He serves on the EPA diving safety board, responsible for setting EPA diving policy requirements.  

Join us for a Twitter Chat to Learn More!
Got questions? Want to learn more? Join us for a Twitter chat this Thursday (July 18, 2013) at 2 pm ET on nutrient pollution and harmful algal blooms. Use #waterchat to ask a question or participate. Not on Twitter but have a question? Please add it to the comments section below. 

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Discovering Silica Cycling

By Joanna Carey

Rivers draining more forested watersheds contain significantly less silica than those draining more developed watersheds.

I am standing, engrossed in quiet, on a wooden bridge in Northern Massachusetts, with a perfect view of the Ipswich River.  I can see it meander once before it eventually opens up to form a babbling riffle. This river is alive, performing complicated metabolic processes as the water moves downstream.

Thanks to my EPA Science To Achieve Results (STAR) Graduate Research Fellowship, I went to this bridge (among others) weekly for a year, sampling the river for nutrients. While filtering my water samples here, people walking by would often ask, ‘how is the river doing?’

Before answering, I would hesitate; it turns out this is a complicated question!

From a human health perspective, most of the rivers I studied were in fine shape (thanks to the Clean Water Act and EPA), meaning that people could swim in the river without getting sick. However, other aspects of the river condition could use improvement.

Human activities, such as wastewater discharge, use of fertilizers, and fossil fuel combustion, are increasing the amount of nutrients flowing into rivers, which can spark excess algal growth and other negative repercussions on the entire ecosystem.

As an EPA STAR Fellow, I had the opportunity to be one of the first in the world to examine how watershed land use impacts the amount of silica in the rivers. Silica, or SiO2, is a required nutrient for diatoms, a common type of phytoplankton (tiny photosynthetic organisms) in temperate waters.

Why is the amount of silica in the rivers important?

Well, it all goes back to the fact that rivers supply over 80% of the silica that’s found in marine waters. And the amount of silica directly controls the amount and type of phytoplankton that grow in the ocean. Because phytoplankton makes up the base of the marine food chain, their type and abundance directly impacts organisms higher up on the food chain, such as commercial fisheries.

My research resulted in the discovery that land use type is indeed an important driver of the amount of silica in rivers.

I found that rivers draining more forested watersheds contain significantly less silica than those draining more developed watershed, which may be because of the large amount of silica taken up by land plants. It appears that lack of vegetation in urbanized landscapes results in more silica entering river systems. While more silica in rivers is not a bad thing, the research highlights a previously unrecognized way in which human actions are altering the environment.

For the last three years, I have been honored to be an EPA STAR Fellow. The award not only allowed me to perform the research of my dreams, but highlighted for me the importance of these fellowships for training the next generation of scientists. Thanks to the EPA, I can now count myself among the experts in aquatic biogeochemistry!

About the Author: Joanna Carey, a former STAR Fellow, is currently an ORISE post-doctoral fellow with the EPA Atlantic Ecology Division in Narragansett, RI studying the impact of oysters on nitrogen cycling in Southern New England.

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Around the Water Cooler: Seagrasses are the nurseries of our coastal waters

By Lahne Mattas-Curry

Coatal SeagrassesDo you like seafood? I love it. I live in Maryland, home of the best crabcakes in America. You know what helps make those crabcakes delicious? Seagrass.

Well, maybe not directly, but seagrass provides shelter and a nursery area where many economically important (and tasty!) fish and shellfish start life.

Seagrasses also provide us with other important benefits such as stabilizing sediment along the shoreline and providing protection from storms and hurricanes. They are found primarily in shallow and sheltered waters on our coastlines.

But nutrient pollution, one of the most challenging environmental problems of our time, is smothering seagrass beds. When there are too many nutrients in our water – nitrogen and phosphorus to be specific – we get blooms of tiny marine organisms called phytoplankton in the water, reducing clarity.  Algae growing on the seagrasses can also reduce the amount of light reaching seagrass leaves.  

Where seagrasses are stressed by nutrient pollution, they can eventually disappear. Since so many people love to eat fish and crabs, the decrease in production of seafood will make it more expensive and harder to find.  That’s a tough pill to swallow.

EPA marine ecologist Jim Hagy is using historical and recent maps of seagrass along the Florida coast to figure out how deep they once grew and how deep they are growing today.  This will help us figure out how clear the water should be in order to protect this important aspect of our coastal ecosystems.

A map of seagrass depth colonization may not sound too exciting, but the research is important because it is the basis “to develop biological endpoints to support nutrient criteria in Florida estuaries,” says Hagy. “Florida estuaries will soon enter a new chapter in their history, one that we hope will include reliable protection for the State’s high quality waters and a credible path to restoration for impaired waters.”

And for the rest of us, healthy seagrasses will help ensure that we can still get a really good crabcake or seafood dinner!

About the Author: Lahne Mattas-Curry works with  EPA’s Safe and Sustainable Water Resources team, drinks a lot of water and  communicates water research to anyone who will listen.

Editor's Note: The opinions expressed herein are those of the author alone. EPA does not verify the accuracy or science of the contents of the blog, nor does EPA endorse the opinions or positions expressed. You may share this post. However, please do not change the title or the content. If you do make changes, please do not attribute the edited title or content to EPA or the author.

EPA's official web site is www.epa.gov. Some links on this page may redirect users from the EPA website to a non-EPA, third-party site. In doing so, EPA is directing you only to the specific content referenced at the time of publication, not to any other content that may appear on the same webpage or elsewhere on the third-party site, or be added at a later date.

EPA is providing this link for informational purposes only. EPA cannot attest to the accuracy of non-EPA information provided by any third-party sites or any other linked site. EPA does not endorse any non-government websites, companies, internet applications or any policies or information expressed therein.

Around the Water Cooler: Riparian Buffers

Vegetation benefits more than just creating fun ways to catch fish!

By Lahne Mattas-Curry

I can remember my little brother hanging on tree branches over the top of the stream that ran through our property growing up. He would reach in to catch fish with his bare hands. He was quite successful, amazingly. This was pretty much a daily occurrence much to my mother’s chagrin.

We were always playing in or around that stream. Back then we didn’t know that  much of the fun  was thanks to a riparian buffer—the bank of the stream sprinkled with native trees, shrubs, and grasses that “buffer” the stream from all kinds of pollutants that flow across the land.

These trees and plants provided more than just fun for us and the other kids in the neighborhood, they also stabilized the stream bank from soil erosion and created a healthy habitat for wildlife—like the fish my brother constantly harassed.

Today, EPA researchers, recognizing the scientific value of nature, have been studying riparian buffers. They find that the wider the buffer, the more likely it will substantially reduce the polluted runoff—including excess nitrogen and phosphorus, sediment and pesticides—from reaching a stream. Even in cities, urban greenways and other narrow bands of vegetation can make some improvements in water quality and quantity. The “buffer” also can reduce floodwaters, helping to maintain stable streambanks and protecting downstream properties. More trees, shrubs and plants create a more beautiful aesthetic and certainly don’t hurt property values.

So, before you decide to clear the way for a view of a stream or river, or expand your lawn for that fresh golf course look, consider the fact that these plants and trees protect your property and are cost-effective “flood insurance” for your home. A buffer with native trees and vegetation can even cut your heating costs in winter by cutting the wind before it chills your home. Plus, think about the birds, fish, frogs, and butterflies that will love to call your property home too.

Some of my fondest memories come from playing along the stream and I am glad my parents chose to keep our house in the natural habitat, protecting our water.

About the Author: A regular “It All Starts with Science” blogger, Lahne Mattas-Curry works with EPA’s Safe and Sustainable Water Resources team.

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