Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Expanding dead zones shrinking tropical blue marlin habitat

12.12.2011
The science behind counting fish in the ocean to measure their abundance has never been simple. A new scientific paper authored by NOAA Fisheries biologist Eric Prince, Ph.D., and eight other scientists shows that expanding ocean dead zones – driven by climate change – have added a new wrinkle to that science.

In the December 4 paper published in the scientific journal Nature Climate Change, these scientists sound an alarm that expanding ocean dead zones are shrinking the habitat for high value fish such as marlins in the tropical northeast Atlantic Ocean. As dead zones expand, marlins, other billfish and tunas move into surface waters where they are more vulnerable to fishing. Dead zones are areas in the ocean where oxygen levels are so low that creatures cannot survive over the long term.

“By combining the disciplines of oceanography and fishery biology, we are getting a much clearer picture of how climate driven dead zones are shrinking the habitat for some of the world’s most valuable fish to commercial and recreational fishermen,” Prince said. “With a clearer picture, we will be able to make better management decisions for the long-term health of these species and their ecosystems.”

In the past, Prince has studied the movement of marlins and other billfish in ocean waters off Florida and the Caribbean as well as in the tropical waters of the eastern Pacific. The new paper combines Prince’s research on marlins in the northeast tropical Atlantic Ocean off Africa with oceanographic research in the same waters by Lothar Stramma and his colleagues at the Leibniz Institute of Marine Science in Kiel, Germany, as well as scientists at the University of Miami Rosensteil School of Marine and Atmospheric Science.

Prince tagged blue marlin, one of the most valuable recreational species on the planet, with pop up satellite tracking devices to record their horizontal and vertical movement. He compared this information on fish movement with detailed oceanographic maps developed by Stramma and his colleagues on the same ocean areas showing the location of zones with low dissolved oxygen. Prince, Stramma and Sunke Schmidtko, who was at NOAA’s Pacific Marine Environmental Laboratory in Seattle at the time of the research, are the three equally contributing first authors of the paper.

Blue marlins and many other billfish are high energy fish that need large amounts of dissolved oxygen. By comparing the movement of the blue marlins and the location of low-oxygen areas, the scientists show that blue marlins venture deeper when dissolved oxygen levels are higher and remain in shallower surface waters when low dissolved oxygen areas encroach on their habitat from below.

“The shrinking of habitat due to expanding dead zones needs to be taken into account in scientific stock assessments and management decisions for tropical pelagic billfish and tuna,” said Prince. “Without taking it into account, stock assessments could be providing false signals that stocks are healthy, when in fact they are not, thus allowing overfishing that further depletes these fish stocks and threatens the sustainability of our fisheries.”

While the new paper focuses on the tropical northeast Atlantic Ocean off Africa, the expansion of low-oxygen zones is occurring in all tropical ocean basins and throughout the subarctic Pacific, making the compression of habitat a global issue. The problem for pelagic fishes in the tropical Atlantic is particularly acute, the authors note, because many of these fish species and the unintended catch, called bycatch, are already fully exploited or overfished.

The new paper follows earlier research by Prince published in 2010 in Fisheries Oceanography based on tagging of marlins and sailfish in the waters off Florida and the Caribbean, which also showed these billfish prefer oxygen-rich waters close to the surface and move away from waters low in dissolved oxygen.

To read the new paper, “Expansion of oxygen minimum zones may reduce available habitat for tropical pelagic fish,” visit the Nature Climate Change website.

You can also visit NOAA Fisheries’ website to learn more about related programs, including international activities or our regional saltwater recreational fishing action agendas.

Monica Allen | EurekAlert!
Further information:
http://www.noaa.gov

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

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: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

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...

Im Focus: Quantum Particles Form Droplets

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...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

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,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>