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!
Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research