Bottom trawling is a highly destructive fishing technique in which huge, heavy nets attached to large metal plates and rubber wheels are dragged across the sea bed; they destroy everything in their path.
1376 – First notice on the existence of beam trawling
The first known record of trawling is found in a request made to King Edward III of England in 1376 to ban the destructive fishing gear.
"The commons petition the King, complaining that where in creeks and havens of the sea there used to be plenteous fishing, to the profit of the Kingdom, certain fishermen for several years past have subtly contrived an instrument called 'wondyrechaun' [beam trawl] made in the manner of an oyster dredge, but which is considerably longer, upon which instrument is attached a net so close meshed that no fish, be it ever so small, that enters therein can escape, but must stay and be taken. And that the great and long iron of the wondyrechaun runs so heavily and hardly over the ground when fishing that it destroys the flowers of the land below water there, and also the spat of oysters, mussels and other fish upon which the great fish are accustomed to be fed and nourished."
1880's – Trawlers gain steam power
Wherever trawling spread it was met with controversy. In 1499, just a century after the English petition, the fishermen of Flanders were successful in protecting fishing habitats from trawl damage. A decree was passed that banned trawls that "rooted up and swept away the seaweeds which served to shelter the fish". In 1583, the Dutch banned trawling for shrimp in their estuaries. France also made the practice of trawling a capital offence the following year, and in England two fishermen were executed for using metal chains on their beam trawls to help scare fish off the bottom and into the nets. Such chains are standard on the beam trawls of today.
And the damage that trawling caused in 1376 is not comparable to the devastation that results from the practice today - not just fish species but entire ancient ecosystems are destroyed in minutes.
With the advent of the industrial revolution, fishing vessels started to use engines that greatly increased their power and range. Net sizes increased at the same time. Fishing vessels were now able to stay out in almost all weather conditions. Later, as refrigeration replaced traditional salting, industrial vessels were able to go further and stay out for longer, all the while bringing increasing fish yields to the market.
Late 20th century – The deep sea comes within reach of the trawl.
The development of satellite-based navigation systems allowed ships to locate fish stocks more and more efficiently and to fish closer to precarious areas such as shipwrecks and reefs. Net material "progressed" from tarred cotton twine to fibres stronger than steel. Increased cable sizes and larger rollers meant that no habitats were off limits. Fish no longer had any safe havens.
Fishing fleets even started to target coral and sponge habitats and other deep water reefs that previously would have torn their nets. Large metal plates and rubber wheels attached to the nets move along the bottom and crush nearly everything in their path. Deepwater life forms are very slow to recover from such damage, taking decades to hundreds of years - if they recover at all.