Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions. Large-scale commercial fishing is also known as industrial fishing. This profession has gained in popularity with the development of shows such as Deadliest Catch, Swords, and Wicked Tuna. The major fishing industries are not only owned by major corporations but by small families as well. The industry has had to adapt through the years in order to keep earning a profit. A study taken on some small family-owned commercial fishing companies showed that they adapted to continue to earn a living but not necessarily make a large profit. It is the adaptability of the fishermen and their methods that cause some concern for fishery managers and researchers; they say that for those reasons, the sustainability of the marine ecosystems could be in danger of being ruined.