“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!
Bioinvasion on the rise
15.02.2017 | Universität Konstanz
Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
21.02.2017 | Earth Sciences
21.02.2017 | Medical Engineering
21.02.2017 | Trade Fair News