In half of the North Atlantic and North Pacific waters under national jurisdiction, fishing has led to a 90-per-cent decrease in top predators since the 1950s, and the impacts are now headed south of the Equator, according to a new study published online today in the journal Marine Ecological progress Series. The study is available at http://www.int-res.com/abstracts/meps/v442/p169-185/.
Funded by the Pew Charitable Trusts, the Natural Sciences and Engineering Research Council of Canada (NSERC), and the French Consulate-General in Vancouver, researchers from UBC’s Fisheries Centre modeled the impact of fishing around the world using global databases of fisheries catches from 1950 to 2006 and satellite images of phytoplankton, which are used to map where predators should be, based on food availability.
The scientists found that the exploitation of marine predators first occurred in coastal areas of northern countries, then expanded to the high seas and to the southern hemisphere. The decline of top-of-the-food-chain predators also means widespread and fundamental changes to both the structure and function of marine systems.
“Species such as tuna have been seriously exploited because of high market demand,” says Laura Tremblay-Boyer, a PhD student at UBC Fisheries Centre and lead author of the study.
“A constant theme throughout our study of global marine ecosystems is that these top predators are today prey for human beings, assisted by some serious technology,” says Tremblay-Boyer. “Top marine predators are more intrinsically vulnerable to the effects of fishing due to their life histories. Bluefin tuna, for instance, cannot reproduce until age nine.”
In addition to low numbers in the northern hemisphere, the study shows a dramatic decline in the south seas, where wild-caught fish are sent to northern markets.
“After running out of predator fish in the north Atlantic and Pacific, rather than implementing strict management and enforcement, the fishing industry pointed its bows south,” says co-author Daniel Pauly, principal investigator of the Sea Around Us Project at UBC. “The southern hemisphere predators are now on the same trajectory as the ones in the northern hemisphere. What happens next when we have nowhere left to turn?”
Under current fishing practices, biomass loss of predatory species is expected to occur in the southern hemisphere, but humans living in the south will not be able to rely on the north for their fish, the research team adds.
The University of British Columbia Fisheries Centre, in the College for Interdisciplinary Studies, undertakes research to restore fisheries, conserve aquatic life and rebuild ecosystems. It promotes multidisciplinary study of aquatic ecosystems and broad-based collaboration with maritime communities, government, NGOs and other partners. The UBC Fisheries Centre is recognized globally for its innovative and enterprising research, with its academics winning many accolades and awards. For more information, visit www.fisheries.ubc.ca.
The Pew Environment Group is the conservation arm of The Pew Charitable Trusts, a non-governmental organization headquartered in the United States that applies a rigorous, analytical approach to improving public policy, informing the public and stimulating civic life.
Brian Lin | EurekAlert!
Listening in: Acoustic monitoring devices detect illegal hunting and logging
14.12.2017 | Gesellschaft für Ökologie e.V.
How fires are changing the tundra’s face
12.12.2017 | Gesellschaft für Ökologie e.V.
DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.
Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
15.12.2017 | Power and Electrical Engineering
15.12.2017 | Materials Sciences
15.12.2017 | Life Sciences