Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cod resurgence in Canadian waters

28.07.2011
Cod and other groundfish populations off the east coast of Canada are showing signs of recovery more than 20 years after the fisheries collapsed in the early 1990s, according to research published today in Nature.

“This early-stage recovery represents a long ecological transition for an ecosystem that was pushed out of balance and that is gradually moving back into balance,” says William Leggett, a professor in the Department of Biology, former principal at Queen’s, and an expert in the dynamics of large marine ecosystems.

This study is the first to show evidence of a recovery at the multi-species level and delve into the underlying ecological mechanisms facilitating the recovery.

The researchers hypothesize that the 20-year delay in recovery was caused by a reversal of fish predator and prey roles. When large-bodied fish like cod were dominant, they fed on smaller forage fish species. However, the overfishing of cod and other groundfish populations meant that these smaller forage fish had the opportunity to prey on large-bodied fish species in their earliest life-stages, preventing these populations from recovering their numbers.

This absence of large-bodied fish predators resulted in the forage fish population ballooning by 900 per cent and ultimately outstripping its food sources. The subsequent decline in forage fish numbers has been vital for the recovery of the cod and haddock populations.

While this recovery is positive and bodes well for other collapsed fisheries, Dr. Leggett and research colleague Jonathan Fisher are quick to note that the process is not straightforward. Cod populations are now at around 34 per cent of the level that was typical when commercial fishing was flourishing in the 1970s and 1980s. Haddock, on the other hand, now exceeds its historical levels and is playing a more dominant role.

“It’s difficult to say if this switch may have any long-term implications,” explains Dr. Fisher, a postdoctoral fellow in the Department of Biology. “This system may return to its historical character, but there’s also the possibility that it won’t and that another species will dominate. Only time will tell.”

This research was conducted in collaboration with Kenneth Frank and Brian Petrie from the Bedford Institute of Oceanography and was funded by the Natural Sciences and Engineering Research Council of Canada.

Christina Archibald | EurekAlert!
Further information:
http://www.queensu.ca

More articles from Ecology, The Environment and Conservation:

nachricht Minimized water consumption in CSP plants - EU project MinWaterCSP is making good progress
05.12.2017 | Steinbeis-Europa-Zentrum

nachricht Jena Experiment: Loss of species destroys ecosystems
28.11.2017 | Technische Universität München

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: Towards data storage at the single molecule level

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...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

Im Focus: Virtual Reality for Bacteria

An interdisciplinary group of researchers interfaced individual bacteria with a computer to build a hybrid bio-digital circuit - Study published in Nature Communications

Scientists at the Institute of Science and Technology Austria (IST Austria) have managed to control the behavior of individual bacteria by connecting them to a...

Im Focus: A space-time sensor for light-matter interactions

Physicists in the Laboratory for Attosecond Physics (run jointly by LMU Munich and the Max Planck Institute for Quantum Optics) have developed an attosecond electron microscope that allows them to visualize the dispersion of light in time and space, and observe the motions of electrons in atoms.

The most basic of all physical interactions in nature is that between light and matter. This interaction takes place in attosecond times (i.e. billionths of a...

Im Focus: A transistor of graphene nanoribbons

Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years' time. An international research team working with Empa has now succeeded in producing nanotransistors from graphene ribbons that are only a few atoms wide, as reported in the current issue of the trade journal "Nature Communications."

Graphene ribbons that are only a few atoms wide, so-called graphene nanoribbons, have special electrical properties that make them promising candidates for the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

Blockchain is becoming more important in the energy market

05.12.2017 | Event News

 
Latest News

Making fuel out of thick air

08.12.2017 | Life Sciences

Rules for superconductivity mirrored in 'excitonic insulator'

08.12.2017 | Information Technology

Smartphone case offers blood glucose monitoring on the go

08.12.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>