Gravel chub silt and debris. They are more often found in areas with limited macrophytes and larger root aquatic plants, algae and moss. Because of their need of a specialized clean habitats, the gravel chub is especially vulnerable to various forms of pollution, especially from agriculture practices that create erosion and excessive silt. In past sampling surveys the gravel chub had been found as far north in the Upper Iowa River as Le Roy, Minnesota, but because of excessive amounts of sewage, pesticides and sedimentation of rocks and sand, this is no longer the case. The presence of gravel chubs in a
Eye Gravel Pit no public access. Eye Gravel Pit Eye Gravel Pit is a 0.4 hectare geological Site of Special Scientific Interest in Eye Green in Cambridgeshire. It is a Geological Conservation Review site, and part of it overlaps Eye Green Local Nature Reserve. This former gravel quarry in the East Anglian Fens has marine and a few non-marine shells laid down when the area was under the North Sea, probably during the warm Eemian period, 130,000 to 115,000 years ago. It is described by Natural England as important because it lies at the junction between fluvial and glacial deposits. The site is