Water Pollution:

Organic wastes such as sewage impose high oxygen demands on the receiving water leading to oxygen reduction with potentially severe impacts on the whole eco-system. Industries release a variety of pollutants in their wastewater including heavy metals, organic toxins, oils, nutrients, and solids. Discharges can also have thermal effects, particularly those from power stations, and these too decrease the available oxygen. Silt-bearing overflow from many activities including construction sites, deforestation and agriculture can inhibit the penetration of sunlight through the water column, restricting photosynthesis and causing blanketing of the lake or river bed, in turn damaging ecological systems.

Doves as food:

Several species of pigeon or dove are used as food, and most likely any could be; the powerful breast muscles characteristic of the family make superb meat. In Europe the Wood Pigeon is normally shot as a game bird, while Rock Pigeons were initially domesticated as a food species, and many breeds were developed for their meat-bearing qualities. The extinction of the Passenger Pigeon was at least partially due to shooting for use as food.
Doves are Kosher, and they and Turtle Doves are the only birds that may be used for a Korban. Other kosher birds may be eaten, but not brought as a Korban.