Featured Research

from universities, journals, and other organizations

Increased protection urgently needed for tunas, experts urge

Date:
July 9, 2011
Source:
International Union for Conservation of Nature (IUCN)
Summary:
For the first time, all species of scombrids (tunas, bonitos, mackerels and Spanish mackerels) and billfishes (swordfish and marlins) have been assessed for the IUCN Red List of Threatened Species. 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.

Bluefin tuna (Thunnus thynnus).
Credit: © lunamarina / Fotolia

For the first time, all species of scombrids (tunas, bonitos, mackerels and Spanish mackerels) and billfishes (swordfish and marlins) have been assessed for the IUCN Red List of Threatened Species™. 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.

The results show that the situation is particularly serious for tunas. Five of the eight species of tuna are in the threatened or Near Threatened IUCN Red List Categories. These include: Southern Bluefin (Thunnus maccoyii), Critically Endangered; Atlantic Bluefin (T. thynnus), Endangered; Bigeye (T. obesus), Vulnerable; Yellowfin (T. albacares), Near Threatened; and Albacore (T. alalunga), Near Threatened.

This new information will be invaluable in helping governments make decisions which will safeguard the future of these species, many of which are of extremely high economic value, and is a timely input for the 3rd Joint Meeting of the Tuna RFMOs (Regional Fisheries Management Organizations) being held in La Jolla, California, July 11-15.

"This is the first time that fishery scientists, ichthyologists and conservationists have come together to jointly produce an assessment of the threats facing a commercially important group of fishes," says Dr Bruce B. Collette, Chair of the IUCN Species Survival Commission's (SSC) Tuna and Billfish Specialist Group, Senior Scientist of the U.S National Marine Fisheries Service, and lead author of the paper.

There is growing concern that in spite of the healthy status of several epipelagic fish stocks (those living near the surface), some scombrid and billfish species are being heavily overfished, and there is a lack of resolve to protect against overexploitation driven by high prices. Many populations are exploited by multinational fisheries whose regulation, from a political perspective, is exceedingly difficult.

"All three bluefin tuna species are susceptible to collapse under continued excessive fishing pressure. The Southern Bluefin has already essentially crashed, with little hope of recovery," says Dr Kent Carpenter, Professor at Old Dominion University, manager of IUCN's Marine Biodiversity Unit and an author of the paper. "If no changes are made to current fishing practices, the western Atlantic Bluefin stocks are at risk of collapse as they are showing little sign that the population is rebuilding following a significant reduction in the 1970s."

Three species of billfishes are in threatened or Near Threatened categories: Blue Marlin (Makaira nigricans), Vulnerable; White Marlin (Kajikia albida), Vulnerable; and Striped Marlin (Kajikia audax), Near Threatened.

Most of the long-lived economically valuable species are considered threatened. They mature later than short-lived species and their reproductive turnover is longer, and as such recovery from population declines takes more time. As these scombrids and billfishes are at the top of the pelagic food web, population reductions of these predators may cause significant negative effects on other species that are critical to the balance of the marine ecosystem and that are economically important as a source of food.

The future of threatened scombrids and billfishes rests on the ability of RFMOs and fishing nations to properly manage these species. Southern and Atlantic Bluefin populations have been so reduced that the most efficient way to avoid collapse is to shut down the fisheries until stocks are rebuilt to healthy levels. However, this would cause substantial economic hardship and hinder the ability of RFMOs to control fishing because of the increased incentive for illegal fishing that would be created under these circumstances.

"Temporarily shutting down tuna fisheries would only be a part of a much needed recovery programme. In order to prevent illegal fishing, strong deterrents need to be implemented," says Jean-Christophe Viι, Deputy Director, IUCN's Global Species Programme. "This new study shows that there is an urgent need for effective management. Scientific findings should not be discarded in order to maintain short-term profit. Marine life and jobs for future generations are both at stake."

The recovery of fish stocks is possible through reducing fishing-induced mortality rates to well below the maximum sustainable yield (MSY), as shown in the case of the highly valued eastern population of the Atlantic Bluefin. Recently exploited at three times the MSY, a decrease in the total allowable catch and stricter monitoring and compliance measures have led to recent catch reductions of almost 75% over the past few years. This will enable the species to recover to sustainable levels as long as the current fishing controls are maintained.


Story Source:

The above story is based on materials provided by International Union for Conservation of Nature (IUCN). Note: Materials may be edited for content and length.


Journal Reference:

  1. B. B. Collette, K. E. Carpenter, B. A. Polidoro, M. J. Juan-Jordα, A. Boustany, D. J. Die, C. Elfes, W. Fox, J. Graves, L. Harrison, R. Mcmanus, C. V. Minte-Vera, R. Nelson, V. Restrepo, J. Schratwieser, C.-L. Sun, A. Amorim, M. Brick Peres, C. Canales, G. Cardenas, S.-K. Chang, W.-C. Chiang, N. De Oliveira Leite, Jr., H. Harwell, R. Lessa, F. L. Fredou, H. A. Oxenford, R. Serra, K.-T. Shao, R. Sumaila, S.-P. Wang, R. Watson, E. Yαρez. High Value and Long Life—Double Jeopardy for Tunas and Billfishes. Science, 2011; DOI: 10.1126/science.1208730

Cite This Page:

International Union for Conservation of Nature (IUCN). "Increased protection urgently needed for tunas, experts urge." ScienceDaily. ScienceDaily, 9 July 2011. <www.sciencedaily.com/releases/2011/07/110707141201.htm>.
International Union for Conservation of Nature (IUCN). (2011, July 9). Increased protection urgently needed for tunas, experts urge. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2011/07/110707141201.htm
International Union for Conservation of Nature (IUCN). "Increased protection urgently needed for tunas, experts urge." ScienceDaily. www.sciencedaily.com/releases/2011/07/110707141201.htm (accessed August 21, 2014).

Share This




More Plants & Animals News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) — An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Newsy (Aug. 21, 2014) — According to a new study, spiders that live in cities are bigger, fatter and multiply faster. Video provided by Newsy
Powered by NewsLook.com
Lost Brain Cells To Blame For Sleep Problems Among Seniors

Lost Brain Cells To Blame For Sleep Problems Among Seniors

Newsy (Aug. 21, 2014) — According to a new study, elderly people might have trouble sleeping because of the loss of a certain group of neurons in the brain. Video provided by Newsy
Powered by NewsLook.com
Ramen Health Risks: The Dark Side of the Noodle

Ramen Health Risks: The Dark Side of the Noodle

AP (Aug. 21, 2014) — South Koreans eat more instant ramen noodles per capita than anywhere else in the world. But American researchers say eating too much may increase the risk of diabetes, heart disease and stroke. (Aug. 21) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

More Coverage


Double Jeopardy: Tuna and Billfish

July 25, 2011 — Scientists present an alarming assessment of several economically important fish populations. The analysis of 61 commercially important species classified 7 species as threatened with extinction and ... read more
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins