Trawling is changing seafloor habitats: study

September 5, 2012
A trawling boat passes the shore in Hong Kong in 2011. Bottom trawling is dramatically altering the ocean floor and harming habitats, similar to the way that farming has permanently changed the landscape, a study said on Wednesday.

Bottom trawling is dramatically altering the ocean floor and harming habitats, similar to the way that farming has permanently changed the landscape, a study said on Wednesday.

Much has been written about trawling's indiscriminate destruction of fish stocks, but a team of in Spain, writing in the journal Nature, said some of its practices damaged the fabric of the ecosystem.

Continental slopes, the gradients that connect the shoreline with the ocean floor, are being smoothed out in areas that are intensively bottom-trawled, the team said.

entails dragging heavy nets and gear along the ocean floor to haul up fish species that feed near the sea bed.

But it leads to vast displacement of sediment and changes to the submarine landscape, the team said.

This disturbs complex ocean floor habitats, "potentially affecting " in a manner comparable with , it said.

In the northwestern Mediterranean, where industrialised trawling has been taking place since the mid-1960s, the scientists found the practice displaced 5,400 tonnes of sediment in just 136 days they monitored.

"Trawled continental-slope environments are the underwater equivalent of a gullied hill slope of land, part of which has been transformed into crop fields that are ploughed regularly, thus replacing the natural contour-normal drainage pattern by levelled areas," they wrote.

And while farmers ploughed a few times per year, sea trawling can occur almost daily.

The paper argued that trawling be added to the list of Man's damaging ocean legacies along with such phenomena as sea-level rise and acidification.

Conservationists say a trawling ban will not just conserve but give soft corals, sponges and other bottom-dwelling creatures a chance to recover.

Explore further: Hong Kong bans trawling to save fish stocks

More information: DOI: 10.1038/nature11410

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5 / 5 (1) Sep 05, 2012

This form of fishing destroys so much sealife that they alone are responsable for probably 30% of fish decline. Sadly little of this is used, like 5%, wasting 95%. And they wonder why the fish are gone!!

We need to stop destorying the habitat that makes the seafood we want. If done right we could harvest 3x's our current rates forever.
5 / 5 (1) Sep 05, 2012
Seriously, why do they not try and get the message out! 90% of the fish in the ocean are GONE DEAD GONE! compared to per-industrial fish stock levels.

Sickening. Fish may be good for you and healthy and whatever but we need to stop before it's all over. Permanent damage is relatively easy to incur on our planet than anyone ever realized. But if mankind were smart enough we could have everything we want and not touch a single bit of the wild earth.

I would love to live in a space habitat and grow food. Solar panels and asteroids or moon material is all you would need.

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