Underwater shellfish farts produce 10 percent of greenhouse gases released in the Baltic Sea, a new study shows. This could be a concern as aquaculture - and the polluting practices that go along with it - expands.
We are already used to hearing jokes about polluting cow farts. But even small underwater shellfish can contribute to global warming.
Indeed, a new study has found that through digestive processes, clams and worms produce 10 percent of greenhouse gases in the Baltic Sea.
But Stefano Bonaglia, the lead author of the study, says that does not mean we should start blaming these organisms for the climate change humans have created.
Bivalves have been releasing greenhouse gases for millions of years without a negative impact on the climate, he points out.
Only after humans began farming them, and once fertilizer runoff has polluted the seas, has impact worsened.
Shellfish are fast-growing and could be a vital source of protein for a rapidly growing global populationImage: Spencer Platt/Getty Images
Humans, not shellfish, are warming the planet
Clams and worms in the Baltic Sea release as much greenhouse gas as 20,000 dairy cows - which seems like a big number. But it's quite relative.
In Germany alone, there were more than 4 million dairy cows in 2016, according to the dairy division of the Agriculture and Horticulture Development Board - 20,000 would represent not even 1 percent of that.
Methane emissions from underwater animals in the Baltic Sea are part of a natural cycle - as opposed to cattle, which are farmed by humans.
These mollusks are not to blame for global warming - humans are, Bonaglia points out.
"When humans interfere with the natural cycle - for example through intensive farming - we may have negative consequences, such as these unwanted emissions," Bonaglia told DW.
Cattle farming is still - by far - among the most polluting of all human activitiesImage: picture-alliance/dpa/A. Heimken
Keep farming, stop polluting
While aquatic clam farming should be controlled to limit greenhouse gas emissions, Bonaglia highlights that fertilizers reaching the seas and the coasts are a much greater threat for the climate.
The Baltic Sea Centre explains that the elements included in fertilizers, such as nitrogen and phosphorus, lead to eutrophication in the Baltic Sea.
Fertilizers increase nutrients, enabling algal blooms and consequent bacterial activity that can potentially increase greenhouse gas emissions.
While clams and worms represent 10 percent of the Baltic Sea greenhouse gas emissions, the other 90 percent comes from bacteria, mainly present in the dead zones of the Baltic Sea - deep waters with low levels of oxygen, suffering an excess of nutrients due to human activities.
A global concern?
The Baltic Sea makes up only about 0.1 percent of the Earth’s oceans - drawing back, the amount of emissions from underwater shellfish around the world could be a concern when the scale of shellfish farming is taken into account.
Bonaglia called again for calm, saying his findings cannot be extrapolated to other seas.
"We don’t know what is going on, for example, in the Adriatic Sea, the Mediterranean Sea or the Black Sea," Bonaglia said.
Each water body has its own characteristics and requires therefore of specific studies, he pointed out. "We need more studies, definitely."
The Atlantic Ocean, for instance, does not generate much methane, since its turbulent waters metabolize it and prevent it from going into the atmosphere.
We hear warnings about climate change on a daily basis. While global leaders dally over policy, what individual actions can we take to reduce global warming? A new study has some very concrete suggestions.
Image: Fotolia/TrudiDesign
Number 10: Upgrade lightbulbs
You just bought a fancy lamp? Make it cooler with efficient lightbulbs. This is one of the small actions that make a difference in the long-term - and let's be honest, it's not a big effort. Some LED bulbs consume up to 90 percent less than traditional ones.
Image: DW/Gero Rueter
Number 9: Hang laundry to dry
In cold or rainy countries, the task might be challenging - but these challenges are nothing compared to the worst consequences of climate change.
Image: picture-alliance/AP/Hussein Malla
Number 8: Recycling
Recycling has become normal behavior for thousands of people around the world. It definitely contributes to making a better world - but unfortunately, it is not enough.
Image: Fotolia/TrudiDesign
Number 7: Wash clothes on cold
Worried about your clothes shrinking in hot water? Here another reason to keep washing with cold water: Since it avoids turning on the water heater, cold-water washing also produces less greenhouse gas emissions.
Image: Fotolia/Kzenon
Number 6: Drive a hybrid
Until you are ready to get rid of your car completely, you could move to a hybrid electric car. But beware: The electricity that powers it is probably still coming from dirty fossil fuels.
Image: picture-alliance/Photoagency Interpress
Number 5: Switch to a vegetarian diet
Beef production is the largest driver of tropical deforestation worldwide, with soy production closely following - mainly to feed animals. The carbon footprint of a meat-based diet is almost double that of a vegetarian one. Even reducing the amount of meat you eat makes a difference.
Image: FOX BROADCASTING/The Simpsons
Number 4: Buy green energy
Renewable energies are the new trend - but we are still largely dependent on fossil fuels such as coal. In countries like Germany, you can choose your energy provider - among some that draw from renewable sources.
Image: Getty Images/AFP/L. Jin
Number 3: Cancel one trans-Atlantic flight
Air travel is a major challenge when it comes to tackling climate change. Policy-makers are exploring ways to reduce the climate impact of flights - but in the meantime, you can start thinking twice before taking a plane. Particularly to cross the pond.
Image: picture-alliance/P. Mayall
Number 2: Don't use a car
Getting rid of your car is the second-most effective action you can take to tackle climate change. And riding your bike also helps keep you fit!
Image: picture-alliance/akg-images
Number 1: Have one less child
Giving birth to a new person consuming and polluting at the current rate of people in industrialized countries is the worst thing you can do for the planet, according to the study. But if you start now with the other nine actions, your kids might be able to live in a better world.
