Researchers studying the wallop of deep - sea fishing have arrived at a understandably defined depth bound for trawl in Europe : 600 meters ( 2,000 feet ) . deep than that , ecological impacts increase while catch value fall . The findings , published inCurrent Biologythis week , add up just as the European Union is consider disputatious statute law to manage cryptical - ocean fishing and limit trawling , the practice of harvest home seafood by dragging giant net income along the seafloor .
The deep sea is Earth ’s large ecosystem . While biodiversity levels are eminent down there , many species have unique animation history trait that make them especially vulnerable to exploitation by overfishing . Compared to shallow - water species , they tend to experience longer , spawn slower and have fewer young , for instance . Previous studies have plant that bottom trawling takes a toll on ecosystems , and since deep - sea fish sequester bombastic amount of carbon every year , there are also huge implications for our thaw world .
To see if there should be a depth limit – and if so , where – a squad led by the University of Glasgow’sJoanne Clarkestudied how taking into custody composition trends change with depth . The research worker collect data point from trawl study conducted between depths of 240 and 1,500 meters ( 800 and 5,000 feet ) at various locations in the northeasterly Atlantic between 1978 and 2013 .
They found a exculpated transition in catches at profoundness of 600 to 800 meters ( 2,000 to 2,600 foot ) , including major increases in biodiversity , the portion of ( threatened ) shark and rays , and the ratio of discarded biomass to commercial biomass . At this profoundness range , " collateral ecological wallop are significantly increasing while the commercial addition per building block effort is decreasing , " Clarke said in astatement . " go deeper causes slap-up and expectant damage for a reducing welfare to fishermen . " Below 400 meters ( 1,300 feet),New Scientistreported , 18 unexampled species are caught in the nets every 100 meters ( 330 animal foot ) .
" deepness limitations are often mark as a ' blanket ' mensuration , unsophisticated and ill thought out,“Clarke bestow . " In this case , however , it come along that there would be some very specific conservation benefit to a depth demarcation at around 600 meters . "
