Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Overfishing leaves swaths of Mediterranean barren

02.03.2012
Unprecedented study also finds fish teeming in fully protected areas

Centuries of overexploitation of fish and other marine resources — as well as invasion of fish from the Red Sea — have turned some formerly healthy ecosystems of the Mediterranean Sea into barren places, an unprecedented study of the Mediterranean concludes.

Research by an international team of scientists designed to measure the impact of marine reserves found that the healthiest places were in well-enforced marine reserves; fish biomass there had recovered from overfishing to levels five to 10 times greater than that of fished areas. However, marine "protected" areas where some types of fishing are allowed did not do better than sites that were completely unprotected. This suggests that full recovery of Mediterranean marine life requires fully protected reserves, the scientists write in a paper published Feb. 29, 2012, in the journal PLoS ONE.

"We found a huge gradient, an enormous contrast. In reserves off Spain and Italy, we found the largest fish biomass in the Mediterranean," said National Geographic Explorer-in-Residence Enric Sala, the paper's lead author. "Unfortunately, around Turkey and Greece, the waters were bare."

The authors made hundreds of dives over three years off Morocco, Spain, Italy, Greece and Turkey, setting up transects to count fish and take samples of plants and animals living on the seafloor in 14 marine protected areas and 18 open-access sites. The result is information on the Mediterranean at an unprecedented scale.

While the level of protection was the most important factor in determining the biomass of fish, the health of the algal forests that support the fish depended on other factors, the authors write. Recovery of formerly abundant algal forests takes longer than recovery of fish. "It's like protecting a piece of land where the birds come back faster than the old trees," Sala said.

The study also provides the first baseline that allows evaluation of the health of any Mediterranean site at the ecosystem level — not only its fish but the entire ecological community. The trajectory of degradation and recovery found by the authors allows for evaluation of the efficacy of conservation at the ecosystem level for the first time.

Sala believes the results about fully protected marine reserves give reason for hope in waters well beyond the Mediterranean. "If marine reserves have worked so well in the Mediterranean, they can work anywhere," he said.

Often called the "cradle of civilization," the Mediterranean is home to nearly 130 million people living on its shores, and its resources support countless millions more. A variety of pressures keep the organisms that live in the sea in a permanent state of stress. "It's death by a thousand cuts," said Enric Ballesteros of Spain's National Research Council and coauthor of the study. Among them are overexploitation, destruction of habitat, contamination, a rise in sea surface temperatures due to climate change and more than 600 invasive species. On the southwest coast of Turkey, for example, an invasive fish from the Red Sea called the dusky spinefoot has left Gokova Bay's rock reefs empty.

A series of marine reserves that shelter slivers of the sea allows certain ecosystems to recover and their all-important predators to eventually reappear. "The protection of the marine ecosystems is a necessity as well as a 'business' in which everyone wins," Sala said. "The reserves act as savings accounts, with capital that is not yet spent and an interest yield we can live off. In Spain's Medes Islands Marine Reserve, for example, a reserve of barely one square kilometer can generate jobs and a tourism revenue of 10 million euros, a sum 20 times larger than earnings from fishing."

"Without marine reserves, fishing has no future," said fisherman Miquel Sacanell, who fishes near the Medes reserve.

The research was supported by Spain's National Research Council, the Pew Charitable Trusts, the Oak Foundation, the Lenfest Ocean Program and the National Geographic Society.

Note: Pictures are available from Carol King Woodward at National Geographic, ckingwoo@ngs.org.

Barbara Moffet | EurekAlert!
Further information:
http://www.ngs.org

More articles from Ecology, The Environment and Conservation:

nachricht Innovative grilling technique improves air quality
01.07.2020 | Fraunhofer Institute for Building Physics IBP

nachricht Traffic density, wind and air stratification influence the load of the air pollutant nitrogen dioxide
26.06.2020 | Leibniz-Institut für Troposphärenforschung e. V.

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Excitation of robust materials

Kiel physics team observed extremely fast electronic changes in real time in a special material class

In physics, they are currently the subject of intensive research; in electronics, they could enable completely new functions. So-called topological materials...

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

Im Focus: ILA Goes Digital – Automation & Production Technology for Adaptable Aircraft Production

Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Contact Tracing Apps against COVID-19: German National Academy Leopoldina hosts international virtual panel discussion

07.07.2020 | Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

 
Latest News

Shock-dissipating fractal cubes could forge high-tech armor

08.07.2020 | Materials Sciences

Scientists use nanoparticle-delivered gene therapy to inhibit blinding eye disease in rodents

08.07.2020 | Health and Medicine

'Growing' active sites on quantum dots for robust H2 photogeneration

08.07.2020 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>