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
Mike Gravel run for president. Gravel favors abortion rights. During the 2008 campaign, Gravel was a strong supporter of LGBT rights. He supported same-sex marriage and opposed the Defense of Marriage Act and the U.S. military's "don't ask, don't tell" policy. He wrote in 2008 that "depriving gays and lesbians of equal rights is immoral." Gravel is a critic of what he terms American imperialism. Gravel firmly opposes U.S. military action against Iran and Syria. He voiced opposition to the Guantanamo Bay detention camp, the Military Commissions Act of 2006, the use of torture, indefinite detention, and what he called "flagrant ignorance"