Plastic Waste in the Sea
An incredible 12 million tons of plastic end up in the ocean every year. The equivalent of one garbage truck full of plastic waste is emptied directly into the sea every minute. Plastic drifts with the currents and is slowly decomposed by UV radiation, bacteria, salt, temperature fluctuations or friction. It can be found everywhere in the ocean today in the form of microplastics. Some of it, however, sinks to the bottom and forms thick garbage carpets there.
Over 85 % of the trash on the seafloor, on submarine mounts and ocean ridges, as well as in the Great Pacific Garbage Gyre, is formed by ghost fishing gear. This includes lost or illegally disposed of set nets, trap nets, lobster traps, and fishing lines. Ghost nets damage coral reefs, prevent marine mammals from surfacing, and pose a long-term potential for damage to marine biodiversity.
In the past, fishing nets were made of perishable natural fibers such as hemp, sisal or linen. Loss of hand-knotted nets was a pain, but not a heavy burden on the environment. Since synthetic materials such as polypropylene, polyethylene and nylon (polyamide) are much more durable, they have completely replaced natural materials since the 1960s.
Modern nets are single- or multi-threaded, knotless or knotted, and are made for different types of fishing. Lobster, for which Quebec is a top producer, is caught in baskets; Arctic crab, shrimp, and cod with bottom-set gillnets; and halibut is caught with trawls, which consist of one main vein and many hundreds of secondary veins, each with a fish hook at the end.