Love meat? If the answer is yes, then your poop is damaging coastal ecosystems like seagrass beds and coral reefs. As a fellow meat-eater, it’s a serious bummer.
We are well aware — or should be — of the harmful environmental impact of a meat-based diet. Each meat-eater is responsible for 1.5 more tons of greenhouse gas emissions than a vegan. But a new study published earlier this month found another way that our obsession with eating fellow animals is harming the planet: through our poop.

The problem with animal-based diets aka diets high in meat consumption is that they greatly increase the amount of nitrogen we consume. The issue is that we pass almost all of this nitrogen back out through the digestive process. Translation: our nitrogen-laced poop is being filtered back into our oceans through our sewage systems and it’s killing coral reefs and seagrass beds.
The Unsanitary Findings
Fun fact: For anyone who doesn’t know, yes, our wastewater (aka any leftover water flushed down the drain) eventually ends up back in our oceans and rivers. We used to dump it on the street but that caused too many health issues. So now, it’s channeled to sewage plants via pipes and heavily treated before a majority of it is pumped back into our oceans.
But all that wastewater is seriously harming our oceans. In 2015 alone, human sewage water (aka water that comes from the toilet) and/or wastewater contributed around 6.8M tons of nitrogen to coastal waters. Only a third of that nitrogen was produced by untreated sewage, which means that even our in-depth treatment processes of human wastewater aren’t enough to remove the dangerous levels of nitrogen.

So, how bad is it? The study found that 88% of seagrass beds and 58% of coral reefs are negatively impacted by wastewater nitrogen pollution.
The study focused on pollution for 135,000 watersheds and identified India, China, and the U.S. as the major contributors to nitrogen-laced poop pollution.
How Your Poop Harms Coastal Ecosystems
Ok, so nitrogen in our poop is bad, but why exactly is it bad for coastal ecosystems?
According to ecologist Megan Huggett,
“It can lead to decomposition of algal cells, which can deplete oxygen and lead to fish kills. [Wastewater] also brings in things like herbicides and pesticides into the system, and plastics of course.”

Translation: our nitrogen-laced poop kills fish because it reduces the amount of oxygen in the water, which they need to survive.
But how is it killing coral reefs exactly? One study found that excess nitrogen in the water makes it particularly harder for coral reefs to survive as water temperatures rise. So, not only are we killing coral reefs with regular climate change, but we’re compounding the negative effects of that with our poop.
Why Should You Care?
What’s the big deal if we kill off some seagrass beds and coral reefs? Aside from providing a crucial ecosystem for thousands of species of marine animals (what’s up biodiversity), coral reefs actually do a lot for us. Over 500 million people rely on coral reefs for food and jobs (think tourism & fishing). Additionally, coral reefs act as barriers that can reduce wave energy by up to 97% which might just save your life from an impending tsunami or hurricane.

How You Can Help
Go meatless for a minimum of one day each week (if not more). You’ve heard it before but that’s because it works.
If every American skipped meat one day per week the environmental impact would be staggering. To put it into perspective, around 1.4B animals would be spared each year, greenhouse gas emissions would be cut by the equivalent of 10B charged smartphones, and 100B gallons of water, 3M acres of land, and 70M gallons of gas would be saved. Not to mention the positive impact it would have on our nitrogen-laced waterways.

Start by eliminating meat from your diet on Mondays and become part of the solution. Your poop and the planet will sincerely thank you.