Fishing trawler

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A fishing trawler is a boat designed to pull fishing nets, called trawls, through the water. Trawling can happen near the sea bottom or higher up in the water column at a chosen depth. Some boats tow more than one net at the same time.

Sizes and gear
- Tractors of many sizes exist, from small open boats with modest power to large factory ships with very powerful engines.
- There are many kinds of trawling gear. Some nets are towed along the bottom, some are used in midwater, and some are designed to open wide for a big catch.
- Some trawlers use special gear to work over rocky bottoms or in difficult seabeds.

A short history
- In the 17th century, a sailing trawler called a Dogger developed in the North Sea. It was slow but sturdy and could fish in rough conditions.
- The modern fishing trawler began in the 19th century in Brixham, England. Fishermen there needed a fast, strong boat to reach far-away fishing grounds as fish stocks near shore were depleted.
- The Brixham trawler’s sleek design helped spread deep-sea trawling to other English ports and beyond. Grimsby, another key town, grew into the world’s largest fishing port in the 1800s.
- In the late 1800s, steam-powered trawlers appeared, letting boats go farther and fish longer without relying on wind. This era also saw the first purpose-built steam trawlers and big improvements in nets and processing.
- By the mid-20th century, trawlers moved from sailing or steam to diesel-powered and then turbine-powered engines. The method of hauling nets also shifted, with stern trawlers (nets hauled from the back) becoming common.

From nets to modern gear
- After World War II, trawlers began to use more electronic tools. Radios, radar, and fish-finding devices helped boats sail safely and find fish more easily.
- Some trawlers were used for military purposes during the Cold War, after being equipped with extra gear.
- Today’s trawlers are sturdy decked ships with advanced navigation, sonar, and other electronics. The gear is controlled from the wheelhouse or bridge, and smaller boats may keep most controls close to the skipper.

How trawling works on the boat
- Trawl nets are hauled in and out of the water by winches and other equipment on deck.
- Nets and gear can be arranged in several ways, depending on the type of trawling:
- Outrigger or beam trawlers use booms to tow nets to the sides.
- Otter trawlers use boards (otters) to keep the nets open as they move.
- Side trawlers deploy nets from the side of the boat.
- Stern trawlers pull nets from the back, often with a ramp to help bring the catch aboard.
- Pelagic trawlers target fish higher in the water and may use pumps to move the catch.
- Many trawlers also process some of the catch aboard, at least washing and sorting, and larger ships may ice, freeze, or can the fish.

Safety and work
- Working on a trawler can be dangerous. Fishing crews face serious risks, and accidents have led to fatalities in the past.

In short, fishing trawlers are diverse boats designed to pull nets through the water, with a long history from early sail-powered ships to today’s highly equipped, high-tech vessels that fish worldwide.