oxygen levels of the baltic are so depleted that fish and plant species can’t survive in its waters, making it one of the most polluted seas in the world.

manure and fertilizers from its coastal countries account for large amounts of nitrogen and phosphorus in baltic waters. this induces over-enriched seawater to grow excessive amounts of algae, forming “algal blooms.” as the algae dies and sinks to the seafloor, bacteria use up oxygen as they decompose the material, causing “dead zones” – oxygen-depleted areas, in which fish and plant populations are decimated.

the baltic’s waters are among many gasping for oxygen as a result of this process called “eutrophication.” over the atlantic, u.s. scientists are grappling with similarly-polluted waterways in the chesapeake bay, gulf of mexico and the great lakes. earlier this month, marylanders reported “cloudy, streaky-looking water,” alerting algal blooms in six maryland rivers.

“it’s very deadly, it’s very dangerous,” dr. tara scully, biology professor and head of an oyster research lab at george washington university, said. “it causes fish kills, fish just start washing up on shore because this process has occurred.”

as with many environmental issues, there’s no single culprit, but european countries surrounding the sea are acknowledging responsibility by experimenting with natural water filters and trying to cut down on harmful sea inputs. 

the baltic blue growth (bbg) project, which ended in 2019, connected a network of research facilities in estonia, poland, sweden, latvia and denmark who have been trialing blue mussel farms to fight algal blooms.

blue mussels are filter feeders, meaning they take up nutrients in their environment and naturally clean the waters. once harvested, the nutrients they contain are recycled for food production or fish and poultry feed, which in turn benefits farmers.

jonne kotta, director of estonia marine institute and bbg partner, said that although countries surrounding the baltic sea have lowered their nutrient runoff by 15 to 30 percent since 1995, it is considered that nearly the entire baltic sea was still being affected by eutrophication as late as 2007-2011. 

“the amount of nutrients stored in the baltic sea ecosystem are so huge that even if all land based activities which cause eutrophication in the baltic stopped tomorrow, it would still take generations for the baltic to recover to an acceptable state,” kotta explained.

environmental policy is starting to show that reducing nutrient inputs hasn’t changed the already nutrient-excessive waters. this is an especially salient concern for a body of water with such limited water exchange – water exchange with the north sea takes about 30 years.

“while land-based pollution control measures can and will continue to make an important contribution to solving the baltic sea eutrophication problem, it is a mistake to think they are enough to solve the problem,” kotta said.

dr. scully studies another bivalve – the eastern oyster – as a solution to the chesapeake’s nutrient pollution and algal blooms. the chesapeake oyster alliance, a coalition of organizations aiming to restore the health of the bay, even launched an initiative to add 10 billion oysters to the bay by 2025 to combat algal blooms eutrophication.

the bivalves’ kryptonite 

but nils hedberg, marine ecotoxicologist at stockholm university, believes bivalves are not necessarily the answer for baltic-like environments. 

although he said the blue mussel clean-up method is attractive because it’s pitched as a low-cost solution with potential to stimulate new farming markets, hedberg co-authored a report highlighting the limitations of relying heavily on bivalves to clean the baltic.

it’s unclear if the baltic’s waters can support the large-scale farms that would be required to make a significant difference to the baltic’s nutrient content. examples from the united states, new zealand, sweden, and the netherlands have shown that bivalve cultivation alters the ecosystem in a negative way and can even increase nutrient levels in affected waters.

“the risks will increase with the scale and intensity of the farm, and it is very likely that we need quite large farms to compensate for the slow growth and the high production costs,” he explained. “small farms will not cause any significant problems but will probably not solve any either.”

there is still very little research about the environmental impact of large mussel farms. in theory, hedberg explained mussels will eat most of the plankton in large farming areas, which makes it harder for fish to thrive there. 

he is instead a proponent of external methods which aim to decrease nutrients by changing land conditions so less nutrients reach the sea. 

external methods include agricultural nutrient recycling – farming methods that reduce the amount of nutrient-rich fertilizers. current practices, like intensive animal farming and overusing fertilizers, cause extra nutrients to leach into the soil and, through groundwater and streams, find their way into the baltic.

meanwhile, the baltic’s brackish waters – water with salinity levels between sea water and fresh water – limit bbg’s circular economy plan. blue mussels are native to high-salinity waters: this is true of western baltic waters, but the eastern waters are either brackish or have a lower salinity, which causes the mussels to grow more slowly and be smaller overall.

smaller mussels are harder to sell on the seafood market, making it a challenge for farmers in the east to commercially benefit from a push for mussel cultivation.

kotta said bbg still found ways to cultivate larger volumes of mussels in more areas of the batlic than originally thought possible, through developing farming technologies.for example, kotta said one of the new pieces of equipment was the “fuzzy rope,” which allows more surface area for mussels to grow.

next steps

kotta is now focusing on kicking off a mussel farm off estonia’s coastline, one of the most distant coastlines from the open sea.

hedberg explained one of the biggest issues is the knowledge gap in understanding the baltic’s seascape, like ecosystem habitats and currents. with the little research there is now, it’s hard to predict at the rate negative aspects of mussel cultivation will occur.

it is still unclear if the baltic’s waters can support the large-scale farms that the project requires.

“i think it is safe to say that we researchers never agree on all the details, and in this complex case, with a lot of knowledge gaps and large scale processes, we have a lot to debate,” said hedberg.

“perhaps it is possible to find a perfect balance.”

sediment, runoff, and nutrients all deposit into the gulf of mexico, sometimes originating as far north as minnesota. the large number of pollutants entering the outlet causes massive problems, sometimes in ways that one would not expect. for example, it might be surprising to learn that a large inflow of nutrients like nitrogen and phosphorus have adverse consequences for the ecosystem of the gulf of mexico.

when an excess of nitrogen and phosphorus enter a large body of water, an algal bloom occurs. as these algae blooms grow, two things happen: the algae on the surface prevent light from reaching aquatic plants below the surface, causing these plants to die, and the algae also die. bacteria break down the dead organisms, a process that requires the use of oxygen. this results in a deficit of oxygen, creating a dead zone where plants and animals cannot exist.

such a dead zone exists in the gulf of mexico, and it is at its largest size since measuring began in 1985 — roughly the size of new jersey. the large size is concerning considering the massive impacts the dead zone has on the gulf of mexico and the gulf coast area.

besides disrupting the ecosystem, the dead zone poses economic problems to the area. seafood is a large industry in the region, and fish kills represent a major threat to this industry.

the dead zone is projected to grow, and it certainly will not shrink without some sort of change occurring.

one way to reduce the amount of nutrients that reach waterways is to implement nutrient removal techniques in wastewater treatment facilities.

in washington, d.c., dc water has introduced enhanced nitrogen removal facilities that allow the blue plains treatment plant to significantly reduce the amount of nitrogen discharged into the potomac river; they claim that these new facilities have prevented over 144 million pounds of nitrogen from entering the potomac river.

dc water is also constructing a new tunnel system that will prevent sewer overflows from being flushed into waterways without first being treated. with rising concerns over excess nutrients in water ecosystems, wastewater treatment facilities around the united states are facing pressure from local, state, and federal governments to implement nutrient removal processes similar to those utilized by dc water.

besides discharges from wastewater treatment plants, runoff also represents a major source of nutrients in waterways. phosphorus and nitrogen are the main components of fertilizers and make their way into rivers, lakes, and other bodies of water as a part of agricultural runoff. runoff is classified as a non-source pollution and is therefore unregulated, so it has been difficult to track and prevent the amount of nutrients entering waterways through this route.

however, this does not mean that it is impossible to reduce the amount of runoff that reaches bodies of water.

investing in green infrastructure can prevent an abundance of nutrients in waterways and has other benefits like reducing flooding. green infrastructure includes rain gardens, bioswales, permeable pavements, and rainwater harvesting. incorporating green infrastructure alongside traditional infrastructure can help reduce the amounts of nitrogen and phosphorus reaching waterways.

—

citations:

“gulf of mexico ‘dead zone’ is the largest ever measured.” national oceanic and atmospheric administration. august 2, 2017. https://www.noaa.gov/media-release/gulf-of-mexico-dead-zone-is-largest-ever-measured.

“removing nitrogen from wastewater protects our waterways.” dc water. 2017. https://www.dcwater.com/nitrogen-reduction.

“tunnel dewatering pump station and enhanced clarification facility.” dc water. 2017. https://www.dcwater.com/projects/tunnel-dewatering-pump-station-and-enhanced-clarification-facility.

“what is green infrastructure?” environmental protection agency. july 03, 2018. https://www.epa.gov/green-infrastructure/what-green-infrastructure.

he examines the contents of a series of glass jars. one is full of little brown pellets. the other contains a dark brown liquid and is labeled “raw digestate – non-hazardous.”

“we’re trying to produce sustainable fertilizers,”  explains edalati, a graduate student in the university of california, davis, department of biological and agricultural engineering.

edalati said that each kind of fertilizer has its benefits and its drawbacks. the liquid form can be applied through drip irrigation, a farming method in which the plant roots are slowly watered via small tubes; however, it contains very little nitrogen – in many cases, not even 1 percent. the pellets, on the other hand, contain up to 5 percent nitrogen but cannot be applied through the ease of drip. 

plants need nitrogen to thrive. they use it to make chlorophyll, a compound that aids them in photosynthesis.

“soils need organic matter returned to them to support the soil microbiology that helps in crop cultivation,” edalati says. the fertilizer he is creating helps provide that.

these fertilizers are the byproduct of the renewable energy anaerobic biodigester (read), which make up the four giant silos that tower in the sun behind edalati. the vision behind read is to break down organic waste and produce a recycled product that can be used in farming and agriculture. it can hold up to 50 tons of organic waste like food and manure.

the concept for read was invented by ruihong zhang, ph.d., of the uc davis department of biological and agricultural engineering. she is also the chief technology advisor to cleanworld, a private company with which uc davis partnered to produce the machine.

“the digester is basically a vertical hammer mill,” zhang says, referring to a machine that crushes and shreds material through the repeated blows of little hammers.

read is composed of four tanks. three of them are for breaking up and pulverizing waste. the digester first separates any plastic that does not belong. it then grinds the food waste and organic material into a paste, which is pumped into the first tank.

“the first tank has bacteria that break food waste down into organic acid,” zhang says. “then (it) goes into the second tank, which has high density microbes that convert organic matter into gas.”

the fourth tank is where the digestate, or leftover organic matter, is stored.

“the leftovers have all the nutrients,” zhang says.

zhang developed this technology 10 years ago at uc davis and was able to turn the plans into action with the help of cleanworld, which specializes in biodigesters.  the university took over full operation of the digester in early 2018, with zhang as a liaison between cleanworld and uc davis, and is now investing more into the operation.

it’s also an easy way for local restaurants, farms and communities to dispose of waste for between $35 and $52 per ton.

uc davis is a non-profit, but zhang says her operation “is a full business model.”

“economically, we’re not getting any money back,” she says. “we got funding from [the] state to create these. it’s not about money, it’s about the show and tell, and making it work.”

even though zhang and her team are not making money, that’s not to say others couldn’t.

“this is a great example of taking the technology forward and making a commercial business,” she says.

zhang and her team give the fertilizer they make to area farms who then report the results back to them. a 2-year-long study on digestate fertilized tomatoes yielded results comparable to tomatoes fertilized with uan-32, a popular synthetic fertilizer, which is 32% nitrogen.

“yields for the digestate fertilizers were equal to the uan-32 and even higher in the case of the digestate concentrate,” edalati says. “the digestate fertilized tomatoes had higher soluble sugar content than the uan-32 tomatoes.

“uan-32 is good for providing nitrogen, but does not give you anything else. plants also need more than just nitrogen. digestate can provide that.”

zhang and her team want to ship the digestate farther than they are currently able to.

“the digestate is valuable, but transporting it is not necessarily economically viable,” edalati says of the liquid fertilizer. “the pellets would be one way to be able to transport nutrients far away at a cheaper cost.”

the difficulty lies in nitrogen content. the liquid digestate is 5% to 6% nitrogen – an essential component to fertilizer – whereas the pellet form is only 0.1 percent to 0.3 percent nitrogen. “you’d have to transfer a lot more of this to get the same amount of nitrogen,” edalati says.

neither, though, compare to uan-32, the popular synthetic commercial fertilizer.

“you can literally apply a couple hundred milliliters of uan-32 versus hundreds of gallons of (digestate),” edalati says. “that’s the challenge.”

thankfully, though, they have a virtually endless supply of test material while they work out how to make their fertilizer more nitrogen-rich.

“ice cream, muscle milk, tomato paste and cut tomatoes from campbell’s,” he says with a laugh, listing some of the more frequent items from which he’s made fertilizer. “all of those used to go to a landfill. now they come here.”

“coffee, too,” zhang adds. “we put a lot of coffee in here. maybe those bacteria love it and get energized.”

manure, fish bones and charcoal. ancient native farmers in central america recycled these wastes in an intricate system to sustain water resources as well as replenish the land.

they used fire and ashes as a natural way to fertilize their land. with these sustainable systems, the natives developed their complex and diverse farming techniques and expanded the types of crops they cultivated.  these communities received all that they needed to survive from the land, and did as much as they could to make sure they gave back to their environment.

fast-forward to modern day panama, where the eco-town kalu yala strives to attain levels of sustainability like those who laid the groundwork for them in central america thousands of years ago. in a small valley, high up in the mountains, more than 100 members of the kalu yala community of interns and staff have started to establish irrigation systems for fish and water farming systems. they are also testing new crops that can flourish in the jungle’s hot and sticky climate, or during the daily downpour of the several-months-long rainy season. when it comes to sustainability, the members of kalu yala use the eco-town as a living laboratory for the best ways to reduce their carbon footprint and become as self-sustaining as possible. growing their own food and producing their own fuel from organic wastes helps meet that goal.

“we don’t want to be constantly reactive to (fixing) things that are unsustainable,” says rachael maysels, 26, the assistant director of biology, one of several internship programs at kalu yala. “we want to think about it ahead of time and act in advance of our actions so there is room for mistakes.”

in the conversation surrounding sustainability, carbon footprint and carbon emissions are topics that often come up. a person’s carbon footprint measures the amount of carbon dioxide and other carbon compounds emitted as waste products due to consumption of materials — particularly fossil fuels.

“we’re not just trying to shoot for being carbon neutral at kalu yala. it’s trying to be carbon negative,” maysels says. “that’s something we can do with reforestation, pruning and turning (the plant matter) into charcoal. there are all these ways to kind of take one step further and it’s more of a proactive approach.”

maysels is helping the eco-town through the production of biochar, one of many ongoing programs that involve the interns that come to kalu yala from across the globe.

“it’s a simple idea and a simple method that can make a really big impact,” maysels explains. “it’s the idea of turning waste plant material, organic material into charcoal through a method of pyrolysis,” or the heating of materials without oxygen.

according to the united states department of agriculture, biochar is thought to have been used as a soil supplement in the amazon basin thousands of years ago. indigenous people created areas of “terra protta,” or “dark earth,” to regenerate fertilized soil for planting. by burying biomass, a combination of burnt wood and other organic materials, deep in the ground, the material heats up under pressure and goes through the process of pyrolysis, the thermodynamic decomposition of organic materials.

“almost like if you have a campfire, what’s left at the end is ash” – and char, maysels says. but when the burning process is buried, “you’re releasing all of the other material except for carbon.” this captures the carbon and prevents it from escaping back into the air, slowing down the release of carbon emissions into the atmosphere. this release prevention negates the carbon footprint that the burning of wastes would generate.

the creation of biochar also has other benefits, such as increasing soil fertility and water retention, as the ancients knew. “this really helps when it comes to the rainy season here,” maysels says. “we want to prevent erosion and hold on to as many nutrients as possible.”

but in the jungle, there are many challenges when it comes to accessing resources to make these experimentations with biochar more elaborate. “having a lot of the resources … to keep you going out here can be tough,” says ryan king, the director of biology at kalu yala.

“we’re trying to switch over everything to renewable energy.” biochar is one of the key ways to do so.  

to jump these hurdles, maysels finds that creativity and her college training in indigenous farming help make the process as simple, yet as effective, as possible.

“initially, my first design was a biochar system that took a lot of materials, which took some specific style hardware that couldn’t easily be found,” maysels says. “i think by setting limitations is when you get creative. restricting the ease of things, your brain starts to work around those obstacles.”

the process comes along with a lot of trial and error, but the community at kalu yala emphasizes learning from mistakes in experimentation. “here, they want you to do as much as you can and be creative, passionate, and make mistakes and keep doing it again,” king says. “having sterile and pristine equipment is definitely needed in certain fields of work, but you can’t control our systems. our earth systems have proven to be a lot more complicated with interacting factors. you have to study it through a different type of ecology.”

since joining the kalu yala staff in january and experimenting with biochar, maysels has combined her background knowledge with new and creative adaptations to progress toward reducing carbon from campfires. one solution involves digging a hole for the fires to hold more carbon in place.

“i graduated college in 2012 and did my field research part of my degree in the himalayas,” maysels says. “on a backpacking trip, i studied indigenous agriculture and high mountain ecology. i got launched into agriculture and since then have been to maybe about 20 countries and worked on maybe 18 farms in those countries, just studying internationally different styles of farming, food systems, small scale techniques, indigenous techniques.”

like the indigenous communities thousands of years before, the kalu yala systems are not perfect on the first try, but they strive to utilize what they can from the environment around them, reusing and replenishing as much as possible. the community members like to say it’s a culture of learning. but the learning at kalu yala would not happen without doing.

at sunrise, maysels heads down the dirt path to the area of campus with a large compost pile and stacks of burnt wood and organic waste ready for her to bury. she starts digging.

it looked like a scene out of the musical “oklahoma.” tom linthicum, owner of seneca ayr farms, drove us up the gravel road to his farmhouse in maryland. the bright november day made the recently harvested soybean fields glow and sway, his green-roofed farmhouse perched above with a dog asleep on the porch. i kept expecting farmhands to burst into song.

“looks old, doesn’t it?” he grinned at us. “it’s a trick. i built our house as an exact replica of the one i grew up in, back at the old farmhouse.” 

tradition runs deep in this family: in architecture, profession and values. tom is the seventh generation of his family to farm here, and continues to practice their most valuable lesson:

“if you take care of your land, the land will take care of you.” 

but not even two weeks later, the american farm bureau federation and the fertilizer institute were garnering support from 21 other states to oppose the new plan, saying it was an overstep of the epa’s power and a misrepresentation of the improvement and data around the issue. in fact, the two organizations have led several initiatives against the epa with accusations like this. if the epa sets limits that are higher than needed, farms could spend a lot of money trying to reduce runoff, and fertilizer sales would plummet as they tried to comply to the new rules.

the pennsylvania courts dismissed it, since the states the laws applied to had agreed to them. but the fertilizer institute is still fighting it today.

now, here’s the thing: these 21 states that oppose the bill are not the seven that these laws apply to. so to me, it doesn’t make sense that they’re the ones who could get these new laws overturned. if they succeed, it will be a huge step back for the people of this watershed who rely on the deteriorating bay for their water and commerce.

standing on tom’s porch, i watched the expanse of soybeans sway around us in the chilly breeze. this feels like such a simple, peaceful life. maybe that’s what makes the bitter fight raging over its practices so jarring. but no one seems to know that the fate of the bay rests on a few debated laws and the good intentions of farmers. at any point, those laws may go away.

tom is doing his part to clean up the bay. but who’s to say that every other farmer would follow his lead without incentive? i’m afraid of the answer and what it will mean for this region. 

the energy in wastewater treatment most commonly comes from carbon containing organic matter. bacteria convert organic matter into methane, a combustible fuel that can be burned to generate power. in addition to carbon containing organic matter, there is also nitrogen in wastewater. unfortunately, current treatment processes don’t recover energy from waste nitrogen. but what if we could convert waste nitrogen into a combustible gas, just like converting organic matter into methane? it turns out we can! that’s where the rockets come in. bacteria are capable of converting waste nitrogen into nitrous oxide… yeah, nitrous oxide. the same stuff your dentist gives you, although dentists usually call it “laughing gas”. it’s also the same gas racecar enthusiasts use to supercharge their engines, although they call it “nitrox”. it’s also the same gas that has been used for decades in rockets. in fact, space ship one, the first privately manned spaceplane that is paving the way for sub-orbital space flights open to the public, used nitrous oxide in its rocket motors. it’s powerful stuff and we can get it for free from wastewater! at stanford we are developing a way to get bacteria to convert waste nitrogen into nitrous oxide, thus enabling energy recovery from both waste carbon and nitrogen. by producing nitrous oxide, we could essentially “supercharge” wastewater treatment, kind of like a nitrox turbocharged racecar.

wastewater treatment may not take us to the moon, but it can provide a serious amount of free and clean energy. considering that the treatment of wastewater consumes 3% of u.s. energy supply and wastewater treatment plants are often the highest energy expenditure for cities, generating power from wastes seems like a really good idea.