Common bleak small shellfish and plant detritus. It is found in streams and lakes. The bleak prefers open waters and is found in large numbers where there is an inflow of food from pumping stations or behind weirs. The bleak spawns near the shore in shallow waters. Some are found in deep water. The substrate is not important. The bleak is an important food source for predatory fish. It is more sensitive to pollution than other cyprinids, which might explain the decline in North-Western Europe. Bleak are used as bait for sport-fishing for larger fish. In 1656 in Paris, a Mr. Jaquin
Common species because common species shape ecosystems, contribute disproportionately to ecosystem functioning, and can show rapid population declines, conservation should look more closely at how the trade-off between species extinctions and the depletion of populations. Common species Common species and uncommon species are designations used in ecology to describe the population status of a species. Commonness is closely related to abundance. Abundance refers to the frequency with which a species is found in controlled samples; in contrast, species are defined as common or uncommon based on their overall presence in the environment. A species may be locally abundant without being common. However,