Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Earth Science News .




WATER WORLD
Bottom trawling causes deep-sea biological desertification
by Staff Writers
Barcelona, Spain (SPX) May 22, 2014


This is a microscopic view of nematodes. Image courtesy Cristina Gambi, Marche Polytechnic University.

A study led by scientists from the Polytechnic University of Marche (Ancona, Italy) involving researchers from the Institute of Marine Sciences (ICM, CSIC) and the Autonomous University of Barcelona (UAB), has determined that fishing trawling causes intensive, long-term biological desertification of the sedimentary seabed ecosystems, diminishing their content in organic carbon and threatening their biodiversity.

Trawling is the most commonly used extraction methods of sea living resources used around the world, but at the same time, it is also one of the main causes of degradation of the seabed. This fishing practice originated in the second half of the fourteenth century, and in the last thirty years has grown exponentially, being progressively expanding towards greater depths in the ocean.

The study, published in the latest issue of the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS), focuses on assessing the impact of this activity on the meiofauna (small organisms, between 30 and 500 micrometers) living in marine sediments over the fishing grounds of the continental slope, about 500 meters deep.

The results reveal that trawling, by continuously stirring over the years the soft sediment of seabed, have led to meiofauna being 80% less abundant and to reduce its biodiversity by 50% lower in comparison with similar areas where no trawling occurs.

The negative effects of trawling are also evident in the decrease in the number of species of nematodes (the dominant component of the meiofauna at these depths), which decreases by 25%. The study also revealed that the sediments are impoverished significantly (over 50 %) regarding the content of organic matter (food for organisms that live at these depths) and show lower degradation of carbon (about 40%), one of the main functions of ecosystems in deep marine environments.

The study was conducted in northeastern Catalan coast, in La Fonera, also called Palamos, submarine canyon and is the continuation of a previous work where the impact of this method of fishing on the morphology and sedimentary dynamics of this canyon was evaluated1.

According to Pere Puig, researcher at the ICM-CSIC who participated in the study, "the dragging of the gear on the seabed lifts and removes fine particles of sediment, yet also resuspends small organisms living in the sediment that constitute the base of the food chain at these depths".

Jacobo Martin, also at ICM-CSIC and who currently works at the Centro Austral de Investigaciones Cientificas of Ushuaia, Argentina, adds "in the long run, it causes a steady loss of fine sediments, soft and rich in organic matter, leaving a more depleted and compacted seabed sediment surface that it is more difficult to be colonized again".

The work compares these kinds of impacts of trawling on marine sediments with the loss of fertile soil on land. According to Pere Masque, researcher at the Department Physics and the Institute of Environmental Science and Technology at UAB, "the fishing grounds are compared to agricultural fields in terms of the morphological change caused to the seabed, and may end up becoming barren if the constant loss of superficial sediment endures over time".

The paper concludes by warning about the ecological consequences and effects on ecosystem functioning and biodiversity of deep marine sedimentary environments around the world, where it was believed that the impact caused by this type of fishing were lower. The results of this study, therefore, reinforce the need for immediate action for the sustainable management of trawling in deep marine environments.

Paper, Pusceddu, A., Bianchelli, S., Martin, J., Puig, P., Palanques, A., Masque, P., Danovaro, R. (2014) Chronic and intensive bottom trawling impairs deep-sea biodiversity and ecosystem functioning. Proceedings of the National Academy of Sciences of the United States of America; Cited paper: 1Puig, P., Canals, M., Company, J.B., Martin, J., Amblas, D., Lastras, G., Palanques, A., Calafat, A.M. (2012). Ploughing the deep seafloor. Nature, 489: 286-289, doi: 10.1038/nature11410.

.


Related Links
Universitat Autonoma de Barcelona
Water News - Science, Technology and Politics






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





WATER WORLD
Climate change endangers historic US landmarks
Washington (AFP) May 20, 2014
Climate change and sea level rise are threatening historic US landmarks, from the Statue of Liberty to NASA's coastal rocket launch sites, and the nation needs to prepare, scientists said Tuesday. "The range and scale of impacts are alarming," said the report by the Union of Concerned Scientists that listed more than two dozen landmarks endangered by wildfires, coastal erosion and flooding ... read more


WATER WORLD
China says Vietnam riot killed four people

Malaysia to discuss with Inmarsat on release of "raw data"

Source of Fukushima's nagging radioactive leak finally discovered

Ferry and cargo ship collide in Hong Kong, 33 injured

WATER WORLD
Is there really cash in your company's trash?

Computer simulations enable better calculation of interfacial tension

Professors' super waterproof surfaces cause water to bounce like a ball

New Technique Safely Penetrates Top Coat for Perfect Paint Job

WATER WORLD
Bottom trawling causes deep-sea biological desertification

Better science for better fisheries management

The Role of the 'Silent Killer' inside Deep-diving Animals

Climate change endangers historic US landmarks

WATER WORLD
Antarctica's ice losses on the rise

China glaciers shrink 15 percent in warming: Xinhua

WTO rejects Canada, Norway appeal against EU seal import ban

Greenland will be far greater contributor to sea rise than expected

WATER WORLD
China Bright Food to buy majority stake in Israel's Tnuva

Shrub growth decreases as winter temps warm up

The Added Value of Local Food Hubs

Big drop in wintertime fog needed by fruit and nut crops

WATER WORLD
Catastrophic floods bring down Bosnia ethnic barriers

Deadly floods recede to reveal Balkan desolation

NOAA predicts 'average' Atlantic hurricane season

The next 'Big One' for the Bay Area may be a cluster of major quakes

WATER WORLD
UN Council seeks tighter Somali control of weapons

US troops deploy to Chad in hunt for Nigerian girls

S.Africa elephant park accused of 'horrific' cruelty

New airstrikes target Somalia's Shebab

WATER WORLD
Preschool teacher depression linked to behavioral problems in children

US military opens door to gender treatment for Manning

Longevity gene may boost brain power

Rocks lining Peruvian desert pointed to ancient fairgrounds




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.