knots, and its sensitivity can decrease when it is wet. Monofilament degrades with time and can weaken when exposed to heat, sunlight, and/or saltwater. When stored on a spool for a long time, it may come off the fishing reel in coils or loops. It is advisable to change the monofilament line at regular intervals to prevent degradation. Non-fishing uses Monofilament fishing line is sometimes used in medicine as a pricking tool to examine the dermatomal fine touch. The transparency of monofilament fishing line makes it desirable for special effects where objects need to look like they are floating unsupported. It has also been used for string trimmers, musical instrument strings, sewing thread and bent in the shape of a staple for use as a septum piercing retainer. Environmental impact Discarded monofilament lines can present serious environmental problems. These lines are extremely difficult to spot when submerged in water, and fish, birds, and other marine life can easily become entangled, causing starvation, amputation, and death. Ingestion is also a serious threat to wildlife. Monofilament lines also present a risk to swimmers and scuba divers. The breakdown of lines, especially in string trimmers, leads to microplastics which may cause starvation or poisoning of organisms in soil or water. For these reasons, programs have been started to recycle fishing line, to keep it out of the environment. Specialized containers have been designed to collect fishing line for recycling. See also Braided line Multifilament line Ghost net References External links MRRP Monofilament Recovery and Recycling Program Monofilament vs Fluorocarbon vs Braided Fishing Line Fishing equipment