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 Treatment of saline wastewater during algae utilization
14.05.2019 | Jacobs University Bremen gGmbH

nachricht Plastic gets a do-over: Breakthrough discovery recycles plastic from the inside out
07.05.2019 | DOE/Lawrence Berkeley National Laboratory

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: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

Im Focus: A step towards probabilistic computing

Working group led by physicist Professor Ulrich Nowak at the University of Konstanz, in collaboration with a team of physicists from Johannes Gutenberg University Mainz, demonstrates how skyrmions can be used for the computer concepts of the future

When it comes to performing a calculation destined to arrive at an exact result, humans are hopelessly inferior to the computer. In other areas, humans are...

Im Focus: Recording embryonic development

Scientists develop a molecular recording tool that enables in vivo lineage tracing of embryonic cells

The beginning of new life starts with a fascinating process: A single cell gives rise to progenitor cells that eventually differentiate into the three germ...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Synthesis of helical ladder polymers

21.05.2019 | Materials Sciences

Ultra-thin superlattices from gold nanoparticles for nanophotonics

21.05.2019 | Materials Sciences

Chaperones keep the tumor suppressor protein p53 in check: How molecular escorts help prevent cancer

21.05.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>