Fish traps, commonly called weirs, were typically built during low season runs because there were fewer fish running and fishermen had better control over how the weirs affected their catch. However, some types of weir traps were used with varying efficacy year-round. Fishing technology included harpoons, dip nets, spears, arrows, bone gorge hooks (sometimes barbed or poison-tipped), weir traps or baskets in rivers/creeks to trap salmon as they swam upstream, set nets that utilized rocks and currents, gill nets made with bark fibers or gut lines, rakes that speared bottom dwelling crustaceans and shellfish to harvest clams and shellfish during low tides near beaches and mudflats along shorelines in coastal regions