How Your Diet Contributes to Nutrient Pollution and Dead Zones in Lakes and Bays

By Donald Scavia
Every year in early summer, scientists at universities, research institutions and federal agencies release forecasts for the formation of "dead zones" and harmful algal blooms in the Gulf of Mexico, the Chesapeake Bay and Lake Erie. This year the outlook is not good.
The dead zone that forms annually in the Gulf of Mexico is likely to approach, if not surpass, record size at roughly 7,250 square miles. Another dead zone in the Chesapeake Bay is projected to be within the top 20% recorded over the past 20 years — about 2.1 cubic miles, equivalent to over 3.5 million Olympic-size swimming pools. And Lake Erie is also projected to set records, with almost 50,000 tons of potentially toxic algae.
The key factor driving these forecasts is winter and spring rainfall considerably above normal across the central U.S. The winter of 2018-2019 was the wettest on record across the nation, and May was the second-wettest month on record.
Predicting the results isn't rocket science. More rain means more flooding and more runoff from farmlands. These waters carry heavy loads of nutrients, mainly from fertilizer, that fuel algal blooms. The end results include fish kills, closed beaches, possible drinking water alerts and loss of coastal property value.
Treading Water
Algal blooms occur when water bodies become overloaded with nitrogen and phosphorus from farms, water treatment plants and other sources. Warm water and nutrients promote rapid growth of algae. Some strains can be toxic or even fatal to aquatic life and humans.
Eventually algae settle to the bottom and decay. This process depletes dissolved oxygen in the water, creating "dead zones" where oxygen levels are low enough to kill fish.
Scientists and public officials have understood this problem for decades, but progress toward addressing it has been painfully slow. Nutrient loads, dead zones and harmful algal blooms in these systems dominated by agriculture have increased or held grudgingly steady for decades.
Dead zone and harmful algal bloom trends with 2019 forecasts in red.
From http://scavia.seas.umich.edu/hypoxia-forecasts/
The main policy tool available now to combat nutrient losses from agricultural lands is the Farm Bill, enacted about every five years, which provides funds for voluntary conservation efforts. Between 1995 and 2015, the U.S. Department of Agriculture provided almost $32 billion in conservation incentive payments. U.S. water quality would be much worse without these programs, but they simply have not been sufficient to reduce nutrient loads over time.
Nutrient load trends; 2019 loads in red.
From: http://scavia.seas.umich.edu/hypoxia-forecasts/
Warmer and Wetter
Scientists predict that as the climate warms, this problem is likely to get worse.
Most climate models forecast increased precipitation, especially intense spring rains, for most of the Midwest, the Great Lakes basin and the mid-Atlantic. As air warms, it can hold increasing amounts of water vapor, which contributes to more precipitation during extreme weather events. In turn, heavier rainfall will impact nutrient runoff and dead zone formation.
Under a worst-case climate change scenario, in which global temperatures rise nearly 5 degrees Celsius above preindustrial levels by 2100, very heavy precipitation events in the Midwest, Great Plains and Southeast regions would increase sharply.
NOAA
A Dietary Strategy
Farm-based conservation programs are important, and some new practices could improve nutrient management. For example, farmers can widen drainage ditches to create two-stage ditches, which allow water to flow onto vegetated side "benches" that capture nutrients during periods of heavy rainfall.
A two-stage ditch has a low-flow channel and a vegetated side 'benches' that are flooded during higher flows. The grass slows water flow and allows nutrients to settle out.
Ohio State University Extension, CC BY
But even these measures would have to be implemented at unprecedented scales to be effective. The challenge is even more daunting when recognizing that, for example, while the annual total phosphorus load to Lake Erie is large, it is only 10% of the amount applied in fertilizer each year. In addition, as with the Chesapeake and Mississippi watersheds, soils around Lake Erie are already laden with nitrogen and phosphorus.
In my view, part of the solution could be using markets to drive a shift away from industrial-scale corn production, which is a major source of nutrient pollution. One major step would be eliminating the federal mandate requiring oil companies to blend corn-based ethanol into gasoline, which consumes 40% of U.S. corn production.
This will be politically difficult as long as presidential primaries start in Iowa. But other strategies may be more feasible, such as encouraging private-sector companies to demand corn raised through more sustainable practices.
Reducing meat consumption, which consumes another 36% of U.S. corn production for animal feed, could also have a significant impact. Studies have shown that reducing this demand for row crops reduces nutrient pollution.
This idea has gained momentum with the growth of the alternative meat industry. The success of startups like Beyond Meat and Impossible Foods is luring giants like Tyson and Perdue into the game. Some are even struggling to keep up with demand for plant-based meat alternatives, particularly in China. One recent market analysis suggests that plant-based "meat" will surpass animal sources globally by 2040.
AT Kearney, CC BY-ND
Shrinking Agriculture's Footprint
Scientists have understood for decades that excess nitrogen and phosphorus degrade Lake Erie, the Chesapeake Bay and the Gulf of Mexico. Nutrient inputs from sewage treatment plants and other discreet, easily identifiable sources have declined because they are regulated under the Clean Water Act.
But the nutrients fouling these water bodies now come mostly from diffuse sources, particularly industrial-scale row crop agriculture. Those operations are not subject to the Clean Water Act, and voluntary conservation programs seem to have at best kept pace with the expansion of large-scale farming.
After analyzing these issues and providing policy advice on them for much of my 45-year career, it's frustrating to see so little change. But I am hopeful that current work that addresses agricultural pollution in broader contexts may have an impact.
For example, recent reports connecting reduced meat consumption to both positive environmental effects and improved health should provide additional incentives for change. Research institutes and scholars are laying out comprehensive global pathways to more sustainable agriculture that are designed to feed the world and protect and restore natural ecosystems.
My hope lies in the combination of health- and market-driven movement toward plant-based meat substitutes and enlightened policies that support more sustainable practices in agriculture's critical role of providing food and fiber to the world.
Near Record ‘Dead Zone’ Predicted for Gulf of Mexico https://t.co/glpoleJ4ih
— Enviro Voter Project (@Enviro_Voter) June 12, 2019
Donald Scavia is professor emeritus at the School for Environment and Sustainability, University of Michigan.
Disclosure statement: Donald Scavia has received funding from the National Science Foundation, the Environmental Protection Agency, the National Oceanic and Atmospheric Administration, Environment and Climate Change Canada, the Erb Family Foundation, the Joyce Foundation, and the C.S. Mott Foundation.
Reposted with permission from our media associate The Conversation.
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In celebration of Earth Day, a star-studded cast is giving fans a rare glimpse into the secret lives of some of the planet's most majestic animals: whales. In "Secrets of the Whales," a four-part documentary series by renowned National Geographic Photographer and Explorer Brian Skerry and Executive Producer James Cameron, viewers plunge deep into the lives and worlds of five different whale species.
<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="b102b19b2719f50272ab718c44703dd0"><iframe lazy-loadable="true" src="https://www.youtube.com/embed/xOySOlB78dM?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Herring are a primary food source for Norway's orcas. Luis Lamar / National Geographic for Disney+
Belugas are extremely social creatures with a varied vocal range. Peter Kragh / National Geographic for Disney+
A Southern Right whales is pictured in the accompanying book, "Secrets of the Whales." Brian Skerry / National Geographic
The coronavirus has isolated many of us in our homes this year. We've been forced to slow down a little, maybe looking out our windows, becoming more in tune with the rhythms of our yards. Perhaps we've begun to notice more, like the birds hopping around in the bushes out back, wondering (maybe for the first time) what they are.
A Coeligena helianthea hummingbird is photographed during a birdwatching trail at the Monserrate hill in Bogota on November 11, 2020. Colombia is the country with the largest bird diversity in the world, home to about 1,934 different bird species, a fifth of the total known. JUAN BARRETO / AFP / Getty Images
1. Choosing the Right Binoculars
<p>Binoculars are a relatively indispensable tool for most birders – but, for those just starting out, it might not yet be worth the several-hundred-dollar investment. If you aren't able to scour the attics of friends or borrow a pair from a fellow bird watcher, some local birding and naturalist groups have <a href="https://vashonaudubon.org/all-about-vashon-birds/binoculars-check-out/" target="_blank">binocular loaning programs</a> for members, allowing you to plan ahead for a day (or week) of birding.</p><p>When you're ready to take the plunge, choosing a pair or binoculars should take some careful deliberation based on your needs and preferences; some <a href="https://www.birdwatchersdigest.com/bwdsite/explore/optics/top-10-tips-buying-binoculars-bird-watching.php" target="_blank">major considerations</a> might include size, ease of use, <a href="https://www.rei.com/learn/expert-advice/binoculars.html" target="_blank" rel="noopener noreferrer">magnification</a>, and price. While professional binoculars can easily run north of $1,000, there are plenty of perfectly suitable entry-level binoculars under $200. You might not get the perfect precision and clarity of more elite models, but a less expensive pair will allow you to strengthen your birding skills while deciding if you're interested in investing in a premium pair.</p><p>For a budget-friendly option, check out resale options on eBay, Facebook marketplace, or neighborhood yard sales: you might find a nicer pair whose retail price isn't within your budget.</p>2. Know What Birds Are in Your Area
<p>When I began to pay more attention to the birds just outside my apartment building, I started to learn what species have always been around me: European starlings, house sparrows, blue jays, black capped chickadees, and the occasional red-bellied woodpecker. They had always been there, but I hadn't ever taken the time to identify them. Once you learn to <a href="https://www.audubon.org/news/get-know-these-20-common-birds_" target="_blank" rel="noopener noreferrer">recognize common birds</a> in your area, you'll be able to identify the typical species right outside your window and in your community. Of course, permanent residential birds in your neighborhood will <a href="https://nestwatch.org/learn/focal-species/" target="_blank" rel="noopener noreferrer">vary by region</a>, as will those migrating through it.</p>3. Get Out and Explore
<p>Venturing elsewhere might allow you to spot some different species beyond those frequenting your backyard. Anywhere with water or greenery offers a place for birding; as an urbanite myself, I've found that even small- and mid-sized parks in New York City allow me to find more elusive birds (although Central Park takes the crown for an afternoon of urban birding).</p><p>If you are able to travel a bit further from home, <a href="https://www.fws.gov/refuges/" target="_blank">national wildlife refuges</a> and <a href="https://www.americasstateparks.org/" target="_blank" rel="noopener noreferrer">state/national parks</a> are excellent places to explore bird habitats and perhaps log some less-common sightings. The American Birding Association also lists <a href="https://www.aba.org/aba-area-birding-trails/" target="_blank" rel="noopener noreferrer">birding trails by state</a>, and Audubon and BirdLife International identify <a href="https://www.audubon.org/important-bird-areas" target="_blank" rel="noopener noreferrer">Important Bird Areas (IBAs)</a> across the country – important bird habitats and iconic places that activists are fighting to protect – where birders can spot birds of significance.</p>4. Finding a Bird: Stop, Look, Listen, Repeat
<p>The National Audubon Society recommends the "<a href="https://www.audubon.org/news/how-find-bird" target="_blank">stop, look, listen, repeat</a>" mantra when seeking and identifying birds.</p><p>First and foremost, spotting birds requires attention. Stopping – getting out of the car, pausing on the sidewalk, trail, or in the backyard to look up – is the most important step.</p><p>When looking for birds, try to avoid gazing wildly around; rather, scan your surroundings, focusing on any odd shapes or shadows, trying to think about where a bird might perch (power lines, fence posts, branches), or keep an eye on the sky for flying eagles and hawks. In open areas like fields and beaches, you might have a more panoramic view, and can take in different sections of the landscape at a time. Look around with the naked eye before reaching for the binoculars to hone in.</p><p>While it can be hard to sift through the noise, listening for birds is perhaps an even more important element of bird watching than looking. Once you spend more time in the field, you'll be able to parse apart the racket and identify specific species, especially aided by Audubon's Bird Guide app or by learning from their <a href="https://www.audubon.org/section/birding-ear" target="_blank">Birding by Ear series</a>.</p><p>Repeat this pattern as you continue on your way, stopping to look and listen for birds as you go, rather than waiting for them to come to you. </p>5. Identification
<p>When you head out for a day of bird watching – especially when you're hoping to spot some new species – you'll want to be armed with the tools to identify what you see. <a href="https://www.audubon.org/news/how-identify-birds" target="_blank" rel="noopener noreferrer">Major considerations when identifying birds</a> are their group (such as owls, hawks, or sparrow-like birds), size and shape, behavior, voice, field marks, season, and habitat.</p><p>The <a href="https://www.sibleyguides.com/about/the-sibley-guide-to-birds/" target="_blank" rel="noopener noreferrer">Sibley Guide to Birds</a> and the <a href="https://www.hmhbooks.com/shop/books/peterson-field-guide-to-birds-of-north-america-second-edition/9781328771445" target="_blank" rel="noopener noreferrer">Peterson Field Guide</a> are widely considered the best books for identifying birds in North America, although many <a href="https://www.audubon.org/news/what-bird-guide-best-you" target="_blank" rel="noopener noreferrer">specialized guides</a> focus on specific species or regions as well.</p><p>Plenty of <a href="https://blog.nature.org/science/2013/05/27/boucher-bird-blog-apps-smart-birder/" target="_blank" rel="noopener noreferrer">bird identification apps</a> have popped up in recent years – including National Geographic Birds, Sibley eGuide to Birds, iNaturalist, Merlin Bird ID, and Birdsnap – which are basically a <a href="https://www.audubon.org/news/the-best-birding-apps-and-field-guides" target="_blank" rel="noopener noreferrer">field guide in your pocket</a>. I'm partial to the Audubon Bird Guide, which allows users to filter by common identifiers, including a bird's habitat, color, activity, tail shape, and general type, adding them all to a personal map to view your sightings.</p>6. Recording Your Sightings
<p><span>As you deepen your commitment to birding, you might join the community of birders that track and quantify their sightings, building their </span><a href="https://www.thespruce.com/what-birds-count-on-a-life-list-386704#:~:text=A%20life%20list%20is%20a,which%20birds%20you%20have%20seen." target="_blank" rel="noopener noreferrer">life list</a><span>.</span></p><p>While a standard notebook noting the date, species name, habitat, vocalizations, or any other data you wish to include will suffice, some birders opt for a more <a href="https://www.riteintherain.com/no-195-birders-journal" target="_blank" rel="noopener noreferrer">structured birder's journal</a> with pre-determined fields to record your encounters, take notes, draw sketches, etc.</p><p>Many birders also choose to record their sightings online and in shared databases (which include many of the field guide apps), often pinpointing them on a map for others to view. Launched by the Cornell Lab of Ornithology and Audubon, <a href="https://ebird.org/home" target="_blank" rel="noopener noreferrer">eBird is one of the largest databases and citizen science projects around birding</a>, where hundreds of thousands of birders enter their sightings, and users can explore birds in regions and hotspots around the world. Users can also record their sightings on the <a href="https://apps.apple.com/us/app/ebird/id988799279" target="_blank" rel="noopener noreferrer">eBird app</a>.</p>7. Attracting Birds to Your Own Yard
<p>Feeding birds is a common phenomenon: more than 40% of Americans maintain a birdfeeder to attract birds and watch them feast.</p><p>Not all birdfeed is created equal, however. Many commercial varieties are mostly made with "fillers" (oats, red millet, etc.) that birds will largely leave untouched. After researching what birds to expect in your area – and which ones you want to attract – you can create your own birdfeed with <a href="https://www.allaboutbirds.org/news/types-of-bird-seed-a-quick-guide/?pid=1142" target="_blank">seeds that will appeal to them</a>.</p><p>Beyond filling a birdfeeder, <a href="https://www.ecowatch.com/eco-friendly-lawn-2651194858.html" target="_self">transforming your yard into an eco-friendly oasis</a> is by far the best way to attract birds. Choosing to forgo mowing your lawn, planting native flowers and grasses, and ditching the pesticides will bring back the bugs that birds feed on, and provide a safe haven in which birds can happily live and eat.</p><p>While it's widely considered acceptable – and even beneficial – to feed birds with appropriate seeds, communal birdfeeders often <a href="https://www.audubon.org/news/to-feed-or-not-feed" target="_blank" rel="noopener noreferrer">foster unlikely interactions between different species</a>, who can then transmit harmful diseases and parasites to one another. Maintaining several bird feeders with different types of seeds might keep different species from coming into contact, and feeders can be <a href="https://www.allaboutbirds.org/news/how-to-clean-your-bird-feeder/" target="_blank" rel="noopener noreferrer">cleaned to prevent the spread of infection</a>.</p>8. Inclusivity and Anti-Racism in the Birding Community
<p>Like all outdoor activities and areas of scientific study, birding communities are subject to racist and discriminatory ideologies. Black birders have long experienced discrimination and underrepresentation in outdoor spaces. The work of organizations like the <a href="https://www.instagram.com/birdersfund/" target="_blank">Black & Latinx Birders Fund</a>, <a href="https://www.instagram.com/birdability/" target="_blank">Birdability</a>, and <a href="https://www.instagram.com/feministbirdclub/" target="_blank">Feminist Bird Club</a> highlight the contributions and importance of birders of color, birders with disabilities, and women and LGBTQ+ birders to the birding community, as do activists and naturalists like <a href="https://www.instagram.com/hood__naturalist/" target="_blank">Corina Newsome</a> and <a href="https://www.instagram.com/tykeejames/" target="_blank">Tykee James</a>. The work of <a href="https://www.audubon.org/news/its-bird-new-comic-written-central-park-birder-christian-cooper" target="_blank">Christian Cooper</a>, <a href="https://camilledungy.com/publications/" target="_blank">Camille Dungy</a> (read her poem <a href="https://www.poetryfoundation.org/poetrymagazine/poems/58363/frequently-asked-questions-10" target="_blank">Frequently Asked Questions: 10</a>), and <a href="https://orionmagazine.org/article/9-rules-for-the-black-birdwatcher/" target="_blank">J. Drew Lanham</a> – including his essay "<a href="https://lithub.com/birding-while-black/" target="_blank">Birding While Black</a>" – are a great place to start.</p><p>Getting involved in birding means educating ourselves on these issues and taking meaningful action; the work of <a href="https://www.audubon.org/news/its-bird-new-comic-written-central-park-birder-christian-cooper" target="_blank">Christian Cooper</a> and <a href="https://orionmagazine.org/article/9-rules-for-the-black-birdwatcher/" target="_blank">J. Drew Lanham</a> – including his essay "<a href="https://lithub.com/birding-while-black/" target="_blank" rel="noopener noreferrer">Birding While Black</a>" – are a great place to start. Just as birders are activists for protecting habitats and natural areas, we must also be active and aware of inclusivity in these spaces.</p>9. Get Involved
<p>To learn from and enjoy the company of other birders, check out local birding groups in your area to join. Many Audubon chapters host trips, meetings, and bird walks for members. The American Birding Association even maintains a <a href="https://www.aba.org/festivals-events/" target="_blank">directory of birding festivals</a> across the country.</p><p>Volunteering for birds is also a great way to meet other birders and take action for birds in your community; local organizations might have opportunities for assisting with habitat restoration or helping at birding centers.</p><p>Like all wildlife, climate change and habitat destruction threaten the livelihood of birds, eliminating their breeding grounds and food sources. A <a href="https://www.audubon.org/climate/survivalbydegrees" target="_blank">2019 report released by the National Audubon Society</a> found that two-thirds of North American birds may face extinction if global temperatures rise 5.4 degrees Fahrenheit by 2100. Staying informed about and taking action for legislation designed to protect birds and our climate – such as the recent <a href="https://www.congress.gov/bill/116th-congress/house-bill/5552/text" target="_blank" rel="noopener noreferrer">Migratory Bird Protection Act</a> – is important for ensuring a livable future for wildlife and humans alike.</p><p><em>Linnea graduated from Skidmore College in 2019 with a Bachelor's degree in English and Environmental Studies, and now lives in Brooklyn, New York. Most recently, Linnea worked at Hunger Free America, and has interned with WHYY in Philadelphia, Saratoga Living Magazine, and the Sierra Club in Washington, DC. </em><em>Linnea enjoys hiking and spending time outdoors, reading, practicing her German, and volunteering on farms and gardens and for environmental justice efforts in her community. Along with journalism, she is also an essayist and writer of creative nonfiction.</em></p>- Study: Birds Are Linked to Happiness Levels - EcoWatch ›
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