A fishing sinker or knoch is a weight used in conjunction with a fishing lure or hook to increase its rate of sink, anchoring ability, and/or casting distance. Fishing sinkers may be as small as for applications in shallow water, and even smaller for fly fishing applications, or as large as several pounds (>1 kg) or considerably more for deep sea fishing. They are formed into nearly innumerable shapes for diverse fishing applications. Environmental concerns surround the usage of lead and other materials in fishing sinkers.
