Bottom Trawling and Dredging:
Increasing the destructive powers of trawling, many fishing fleets use a method known as bottom trawling in which these heavy massive nets are drug along the sea bottom in order to catch even more fish and marine life which have now where to swim to get out of harms way.
The nets are not only large in size and thus the scope of marine life in its path is more indiscriminate, but they are also equipped with large chains, weights, or other equipment that can weigh thousands of pounds which crush everything they encounter. So when these nets pass through an area the not only catch and kill everything in the path of the net, but they leave a path of destruction along the the bottom of the sea floor as well. Where there was once a thriving community of marine life rich in biodiversity, a wasteland takes its place after a pass of a bottom trawler.
Dredging is a method fairly similar to bottom trawling and often used in conjunction with trawling where large heavy dredges, often up to 4.5 meters wide, are forced along the sea floor to disturb any fish or marine life in the area making it easier for the nets to catch them. There are many damages to the environment from dredging.
These methods are among the most intrusive, destructive, and wasteful methods of fishing. Out of an average catch, only a portion of that is usable. Target fish species that do not meet with regulations are tossed back, usually dead. Likewise, sea turtles, coral, crabs, dolphins, non-target fish species and other marine life are also thrown back into the water dead or dying.
This non-targeted and unused product of trawling, called bycatch, is one of the biggest dangers to many species that are already threatened with extinction. Additionally, the fragile ecosystems, such as those built around slow growing deep water coral, are so devastated that it will take years for them to ever recover, and some may be unable to do so. So the impact is not just taking too much fish that does not support a sustainable rate, but the parts of the oceans that are being destroyed will not begin to support life again for quite sometime making the availability of fish disappear even faster.
The illustrations below (provided courtesy of Oceana) show you an active sea bottom community before dredges and bottom trawlers passed through. Next to them, you see the barren wasteland that is left after the fishing fleet has ransacked the area. Click on an image to enlarge.
Some of the coral ecosystems that are being destroyed are thousands of years old, and the destruction of bottom trawling is so profound that it can actually be seen from space. This is far more than merely over fishing. Trawling is literally wiping out our oceans.
Although trawling is among the worst and most widely used method employed by the fishing industry, it is not the only harmful method used. In part three of this series exposing the fishing industry we will look at some other practices that fleets use to declare war on our oceans.