Dog poop can damage ecosystems

by MikeB · February 7, 2022

Both in the USA (depending upon the state) and in the UK, it is mandatory to pick up your dog’s poop. In the USA it is known as the “pooper scooper law”. In most states in the USA, it is illegal to let your dog poop in someone’s yard as well. Essentially in the USA the law states that a cat and/or dog caregiver must clean up after their cat or dog has pooped on private or public property.

Dog poop waster bin in a public place. Photo: Pixabay.

In the UK you will see the vast majority of people picking up their dog poop. This is for health reasons by which I mean the health of people. But now we have a research project which suggest that dog poop can damage ecosystems as well.

It is the nitrogen and phosphorus in dog poop which can damage fragile ecosystems. When dogs are allowed into nature reserves and their owner leaves behind dog poop they leave behind enough nitrogen and phosphorus, it is believed, to affect the ecosystem.

These chemicals act as fertilisers. That might sound like a good thing as certain common plants thrive in nutrient-rich environments. However, rare plants sometimes require low-nutrient conditions. These plants can be crowded out.

Professor Pieter De Frenne of Ghent University, the lead researcher in this project, said: “Our findings suggest that the neglected inputs of dogs in nature reserves could delay restoration goals.”

The professor also said that “In many nature reserves: the management is specifically directed towards lowering nutrient levels to enhance plant and animal biodiversity.”

The research took place at four nature reserves near the Belgian city of Ghent. They estimated that dogs left an average of 11.5 kg of nitrogen and 5 kg of phosphorus per hectare, annually. They decided that this was high enough to influence biodiversity.

They concluded that if all the dog mess was picked up it would cut the amount of nitrogen by 56% and phosphorus by 97% that was introduced into the ecosystem.

They believe that some ecosystems are so finely balanced and delicate that a dog’s urine may upset it.

De Freene suggested that if dogs were always on a leash the problem would be confined to areas next to a footpath. In such areas they found (through modelling?) that the nitrogen and phosphorus nutrient inputs to the area would exceed the legal limit for fertilisation of agricultural land. They thought that this was staggering considering they were looking at nature reserves not farmland.

It was suggested that dogs should be banned from the most sensitive nature reserves and where ecologists are trying to create low-nutrient conditions.