Although the species is native to Japan, Manila clams have been farmed along the Pacific coast of U.S. and Canada since the 1930s so there are no negative impacts on native ecosystems. Manila clams are farmed at high densities, but these volumes do not surpass what the beaches can handle. However, outside pollution and contamination from bacteria as well as brown tides have forced beach closures, causing farms to close as well. The mesh netting used to deter predators is not considered harmful. Manila clams are usually collected with tongs, rakes, and handheld dredges that don’t harm the seafloor the way large hydraulic dredges used for collecting other clams can, according to the Seafood Choices Alliance and the Monterey Bay Aquarium.