Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Double jeopardy: Tuna and billfish

An international team of scientists assessed the population status of several fish species

A new study by top global fisheries experts presents an alarming assessment of several economically important fish populations. The analysis of 61 species of "scombrids," which include tunas, bonitos, mackerels and Spanish mackerels, and billfishes, which include swordfish and marlins, classified seven as threatened with extinction and four as "near threatened" for the IUCN Red List of Threatened Species.

University of Miami Rosenstiel School of Marine & Atmospheric Science associate professor, and assistant director of NOAA's Cooperative Institute for Marine and Atmospheric Studies (CIMAS) David Die and colleagues scientifically evaluated the species population and conservation status under the IUCN Red List Categories and Criteria, which is the most widely accepted system for classifying extinction risk at the species level.

"The IUCN assessments provide us with a different view of the conservation status of marine resources, when compared to that provided by fishery management organizations," said Die, who has studied highly migratory tuna and billfish for more than 12 years.

Die conducts research on highly migratory tunas and billfish and regularly contributes to assessments of Atlantic billfish and Atlantic tropical tunas. He contributed information on abundance trends and biological parameters for the Atlantic species of large tunas and billfish to this recent IUCN review study.

Of the 61 known species, seven are classified in a "threatened" category, being at serious risk of extinction. Four species are listed as "near threatened" and nearly two-thirds have been placed in the "least concern" category.

According to the IUCN, there is growing concern that in spite of the healthy status of several epipelagic (those living near the surface) fish stocks some scombrid and billfish species are being heavily overfished, and there is a lack of resolve to protect against overexploitation driven by high prices.

Global fish populations are under pressure from overfishing, pollution, habitat degradation, and disease. The U.N. Food and Agriculture Organization (FAO) estimates that 25 percent of the world's commercially important marine fish stocks were overfished or depleted.

Scombrids and billfishes are found throughout the world's oceans, primarily in tropical and temperate coastal and marine regions, and vary greatly in size and lifespan. The largest billfish, the Blue Marlin, and largest scombrid species, the Atlantic Bluefin, can grow to more than four meters (31 feet) long. In contrast, the smallest scombrid species, the Indian Mackerel, only grows to a maximum of 31 centimeters (~ 1 foot).

The health of ocean fisheries is assessed in several different ways. The IUCN review seeks to identify species threatened by extinction where as fisheries management evaluations focus on a population's sustainability in the face of exploitation.

"Our study reaches similar conclusions to those from the FAO," said Die. "Approximately one quarter of the worldwide fish stocks and species of "scombrids" are in an undesirable state of sustainable exploitation or conservation."

The study, titled "High Value and Long Life—Double Jeopardy for Tunas and Billfishes," was published in the July 15 issue of the journal Science.

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

Barbra Gonzalez | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Diagnoses: When Are Several Opinions Better Than One?
19.07.2016 | Max-Planck-Institut für Bildungsforschung

nachricht High in calories and low in nutrients when adolescents share pictures of food online
07.04.2016 | University of Gothenburg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

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

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>