Bottom trawler with otterboards and nets at the Harbourside Porec in the Adriatic.
Image details
Contributor:
Phillip Thomas / Alamy Stock PhotoImage ID:
DD4XMBFile size:
25.4 MB (1.1 MB Compressed download)Releases:
Model - no | Property - noDo I need a release?Dimensions:
2439 x 3644 px | 20.7 x 30.9 cm | 8.1 x 12.1 inches | 300dpiDate taken:
15 September 2012Location:
Porec, CroatiaMore information:
Bottom trawling is still being practised, although scientific evidence indicates it is an unsustainable technique that causes damage to the seabed resulting in habitat devastation and a reduction in fish stocks. Bottom trawling can be divided into two distinct forms benthic trawling and demersal trawling. Benthic trawling is towing a net at the very bottom of the ocean and demersal trawling is towing a net just above the benthic zone. In Benthic trawling otter boards are positioned in such a way that the hydrodynamic forces, acting on them when the net is towed along the seabed, pushes them outwards and prevents the mouth of the net from closing. They also act like a plough, digging up to 15 cm into the seabed, creating a turbid cloud, and scaring fish towards the net mouth. This process damages the seabed and prolonged trawling will inevitably result in the sea bed becoming a barren environment.