Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Blue marlin blues: Loss of dissolved oxygen in oceans squeezes billfish habitat

15.12.2011
Study focuses on oxygen minimum zones in NE Atlantic and effects on pelagic species

The science behind counting fish in the ocean to measure their abundance has never been simple. A new scientific paper in Nature Climate Change shows that expanding 'ocean dead zones' (areas of low oxygen) driven in part by climate change makes that science even more complex.


This is a blue marlin with a PSAT (Popoff Satellite Archival Transmitting) tag used to monitor horizontal and vertical habitat use in a new study in Nature Climate Change. Credit: B. Boyce www.savethefish.org

Blue marlin, other billfish and tropical tuna are high energy fish that need large amounts of dissolved oxygen. Scientists from the disciplines of oceanography and fisheries biology are sounding an alarm that the expansion of dead zones is shrinking the useable habitat for these highly valuable pelagic fish in the tropical northeast Atlantic Ocean. And as dead zones shrink habitat by depriving fish of areas with enough dissolved oxygen for them to thrive, they squeeze these species into surface waters where they are more vulnerable to fishing.

"The shrinking of habitat due to expanding hypoxic zones needs to be taken into account in scientific stock assessments and management decisions for tropical pelagic billfish and tuna," said Dr. Eric Prince, fisheries scientist and principal investigator representing NOAA's Southeast Fisheries Science Center on the project. "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 these fisheries."

The data on blue marlin, one of the most valuable and storied fish on the planet, were collected using pop up satellite tracking devices. These devices recorded the horizontal and vertical movement of these fish. The information on fish movement was then compared to detailed oceanographic maps of the same ocean areas showing the location of low-dissolved oxygen zones. By comparing the movement of the blue marlins and the location of low-oxygen areas, the study shows that blue marlin ventured deeper when dissolved oxygen levels are higher and remain in shallower surface waters when low dissolved oxygen areas encroach on their habitat from below, squeezing them into surface waters.

"We found that the blue marlin's habitat is being compressed, while the threats from human activity are increasing. In human terms, you might describe it as if you were in a house on fire with all of the doors and windows were locked, leaving only one exit, then discovering you have a robber inside the house at the same time," said Dr. Jiangang Luo, scientist at the University of Miami's Rosenstiel School of Marine & Atmospheric Science, who processed and analyzed the popup satellite tagging data for the research team.

"Working closely with oceanographers, 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. The alarming picture painted by this study will hopefully inform our management decisions, improving the long-term health of blue marlin and other billfish and tropical tuna fisheries in the central Atlantic," said Luo.

The oceanographic data were collected and analyzed by co-author Lothar Stramma and colleagues at the Leibniz Institute of Marine Science in Kiel, Germany.

While the new paper focuses on the tropical northeast Atlantic Ocean in the waters off West 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.

About the University of Miami's Rosenstiel School

The University of Miami's mission is to educate and nurture students, to create knowledge, and to provide service to our community and beyond. Committed to excellence and proud of the diversity of our University family, we strive to develop future leaders of our nation and the world. Founded in the 1940's, the Rosenstiel School of Marine & Atmospheric Science has grown into one of the world's premier marine and atmospheric research institutions. Offering dynamic interdisciplinary academics, the Rosenstiel School is dedicated to helping communities to better understand the planet, participating in the establishment of environmental policies, and aiding in the improvement of society and quality of life. For more information, please visit www.rsmas.miami.edu.

Barbra Gonzalez | EurekAlert!
Further information:
http://www.rsmas.miami.edu

More articles from Ecology, The Environment and Conservation:

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

nachricht Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>