With fishing pressures high and stock size low, there is already major concern over the current sustainability of cod and other fisheries. The new findings, published in the journal, Proceedings of the Royal Society B, show that natural climate change has previously reduced the range of cod to around a fifth of what it is today, but despite this, cod continued to populate both sides of the North Atlantic.
The researchers used a computer model and DNA techniques to estimate where cod could be found in the ice age, when colder temperatures and lower sea-levels caused the extinction of some populations and the isolation of others.
The computer models used to estimate ice-age habitats suitable for cod were developed by Professor Grant Bigg, Head of the University of Sheffield’s Department of Geography. These climatic analyses were combined with genetic studies by US researchers at Duke University and the University of California, and ecological information prepared by colleagues at the University of East Anglia and the Institute of Marine Research in Norway.
On land, plants and animals (including humans) are known to have moved further south when the northern ice sheets reached their maximum extent around 20,000 years ago. Similar migrations must have happened for plankton and fish in the sea. But there were two added complications: firstly, greatly reduced sea levels meant that many shallow and highly productive marine habitats around Europe and North America ceased to exist. Secondly, the ice-age circulation patterns in the North Atlantic caused the temperature change between tropical and polar conditions to occur over a much shorter north-south distance, reducing the area suitable for temperate species – such as cod.
The new analyses included these effects, together with other environmental and ecological information, in order to estimate where it was possible for Atlantic cod to reproduce and survive.
The results indicated that the ice-age range of Atlantic cod extended as far south as northern Spain, but the total area of suitable habitat was much more restricted. Nevertheless, populations of cod continued to exist on both sides of the North Atlantic. These findings were confirmed by genetic data, based on over a thousand DNA analyses of present-day cod populations, from Canada, Greenland, Iceland and around Europe.
Professor Bigg said: “This research shows that cod populations have been able to survive in periods of extreme climatic change, demonstrating a considerable resilience. However this does not necessarily mean that cod will show the same resilience to the effects of future climatic changes due to global warming.”
Predicting unpredictability: Information theory offers new way to read ice cores
07.12.2016 | Santa Fe Institute
Sea ice hit record lows in November
07.12.2016 | University of Colorado at Boulder
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Life Sciences
08.12.2016 | Physics and Astronomy
08.12.2016 | Materials Sciences