According to a new study, dog urine and feces are being dumped in nature reserves in such large quantities that it could be threatening wildlife.
The analysis showed that the overfertilization of the ground with nitrogen or phosphorus by footpaths could lead to levels that would be illegal on farmland.
The scientists arrived at their conclusions after counting the dogs over 18 months in four nature reserves near Ghent in Belgium. They predicted the same situation across Europe, home to approximately 87 million dogs.
The research found that dogs are fed at their homes and then excrete nutrients when they go on walks. It is estimated that this results in an annual average of 11kg per hectare of nitrogen and 5kg of protein per year. This is the same level of pollution that is known to be transported through air from industry, farming, and traffic fumes. It is between 5kg and 25kg of Nitrogen. Dog faeces and urine have a significant impact on the environment.
Many dog owners believe that leaving pet excrements in the wild will not cause harm. Overfeeding can cause ecosystems to become degraded.
Professor Pieter De Frenne, Ghent University’s lead researcher, stated that we were surprised at the high nutrient inputs dogs could provide. Dogs are often overlooked in this regard.
Researchers determined the illegal levels for nitrogen and phosphorus in situations when dogs must be led and cannot wander more than 2m from a path. These levels are quite shocking, as our study involved nature reserves, he stated. Of course, there are many beneficial effects. [to walks in nature]Owners and their dogs will benefit both psychologically and physically from this, but there are some drawbacks to bringing in large amounts of nutrients.
De Frenne said that the level and frequency of dog ownership is similar in many western European countries, so there is no reason to believe that it would be different in Ghent. British charity Plantlife has warned about nitrogen pollutionIt is one of the most serious threats to wild plants, lichens, and fungi, but little is being done.
The research Published in Ecological Solutions and EvidenceDuring 500 nature reserve visits, more than 1,600 dogs were counted, at all hours of the day and on all days of week. These data were combined with the dog’s excretion of nitrogen and phosphorus to calculate the total nutrients.
Scientists had kept track of whether the dogs were walking on leads. This allowed them to calculate that 126kg/ha/year of nitrogen was lost by paths and 4kg/ha/year was lost to the rest of nature reserves. If all the dogs were kept on leads, the amount of nitrogen deposited by paths rose to 175kg/ha/year, with a similar increase in phosphorus.
It was easy to pick up dog faeces, but it took away almost all of the phosphorus. Only half of the nitrogen was removed, as dog urine has significant nitrogen, but little phosphorus. De Frenne said that urine is difficult to remove. Research has shown that high levels of nutrients can persist for up to three years even after dogs are killed.
De Frenne said that dog owners need to be made aware of the fertilisation effect. I believe that most people will just pick up the urine. The urine would not be removed and managers of nature reserves with sensitive ecosystems might consider banning dogs. This is already happening in some places to protect birds.
Rob Stoneman, director for landscape recovery at The Wildlife Trusts UK, stated: Nature reserves are special places where nature conservation is possible, where fragile habitats and wildlife are protected. Although poo is part of nature, dog poo can cause damage to the ecology of fragile habitats. It is important that you pick up and bag dog poo wherever you take your dog. This will help protect these wild areas for all of us to enjoy.
De Frenne indicated that soil analysis could be used to confirm the results of the current study, and the extension of the analysis for pet cats.