Many different types of wild birds live near rivers, lakes, estuaries, beach shores and various wetlands. These birds eat a variety of smaller animals that live in water such as insects, worms, aquatic invertebrates, and fish. Some also eat waterweeds and grass. Because they build nests and hunt for food in wet areas, it is inevitable that they also leave their droppings behind. Bird poop can carry a host of diseases that can be spread to humans. Thus the huge concentration of bird fecal bacteria in the recreational waters can pose health risks to its users as well as negatively affect industries relying on these waters.
Point Sources of Bird Fecal Pollution
Bird droppings are discharged from a single, identifiable source.
Many bird species are sociable and like to form large flocks. There are more than a handful of reasons why birds find flocking advantageous. They nest together, they fly together, the sleep together and they eat together. Nesting as a flock enables them to raise their young under the protection of the group against predators. Roosting as a flock also gives them the same semblance of protection. Foraging as a group allows birds to find a food source located by one of its members. They don?t necessarily compete for the food since foraging flocks do not necessarily comprise of birds of the same feather. Some may be interested in mollusks while others may target small fishes. After all the eating, the birds eventually poop. Many flocks of birds nest and roost near surface waters and even over a water system (nests have been found under bridges) can generate a lot of bird droppings and can be considered as a point source of water pollution. It is not uncommon to read reports about thousands of seagulls roosting on a lake. A director at the State Water Research Center in Washington State University had equated the amount of waste generated by three birds as the same as that produced by one human.
Non-Point Sources of Bird Fecal Pollution
Fecal matter from birds winds up in water bodies in a diffuse manner.
There are also many bird species that prefer nesting and roosting on land and in trees. Flightless birds and domesticated birds are just some of those birds that fall into this category. Dried feces from large groups of birds nesting over land could be flushed into stream by runoff.