Featured Research

from universities, journals, and other organizations

Tuna and mackerel populations have reduced by 60% in the last century

Date:
February 8, 2012
Source:
Plataforma SINC
Summary:
A new study shows that the impact of fishing for tuna and similar species during the last 50 years has lessened the abundance of all these populations by an average of 60%. Experts add that the majority of tuna fish have been exploited to the limits of sustainability.

Bigeye tuna.
Credit: Alicia Delgado de la Molina / IEO

A study shows that the impact of fishing for tuna and similar species during the last 50 years has lessened the abundance of all these populations by an average of 60%. Experts add that the majority of tuna fish have been exploited to the limits of sustainability.

The debate about the impact of fishing on different species has already gone on for 50 years. A recent study concluded that populations of tuna and similar species have been cut by 60% on average throughout the world over the last century.

The project published by the Proceedings of the National Academy of Sciences (PNAS) journal adds that most of these populations have been exploited to the limits of sustainability, and there are many species that have been overexploited.

The populations that have had their abundance most affected are cold water tuna, such as the Atlantic bluefin and the southern bluefin, which have decreased by 80%. These species are big, long-lived and high in economic value.

Mackerel, which are smaller and have shorter life cycles, have also experienced a significant reduction in abundance. According to the project, this information suggests that fishing can be a threat to all species, regardless of their size.

María José Juan-Jordá, researcher at the University of A Coruña (Spain) and main author of the study declared that "the results of this study, which are based on a compilation of more precise estimates, show a global situation of tuna populations that differs from bleaker past interpretations."

A study published in Nature journal in 2003, which concluded that the abundance of pelagic fish, mainly tuna, had reduced by 90% in the past century. Despite this, we are reminded that "there are worrying factors that regional fishing organisations should solve in order to ensure a sustainable future is these fisheries."

In the opinion of the authors, management of tuna populations can work "although with some species, fishing management needs help. The ones with the highest economic value are the most over-exploited. There are clearly still people who benefit economically from illegal fishing of bluefin tuna, a case in which international trade goes beyond international fishing regulations, which are usually effective" states Nicholas Dulvy, a researcher from University of Simon Fraser (Canada), who also participated in the study.

Juan-Jordá adds that "fishing management organisations must not just use their resources to manage high-value species, such as large tuna, but also for species of lower economic value, which are important as they are a big source of protein for many developing countries."

The study suggests that increasing hauls can continue to be risky and that as the demand keeps growing, any global fishing effort should be made with "a lot of care." Iago Mosqueira, a fishing scientist from the European Commission and co-author of the project points out that "therefore everyone must concentrate now on creating a real future for these populations and the fisheries that depend on them."

In the opinion of Juan Freire, Professor from A Coruña University, and participant in the study "serious efforts and effective action are needed to reduce global overfishing, to recover overexploited populations and regulate trade that endangers them. Only then can we guarantee bigger catches, stable financial profits and reduce our impact on marine ecosystems."


Story Source:

The above story is based on materials provided by Plataforma SINC. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. J. Juan-Jorda, I. Mosqueira, A. B. Cooper, J. Freire, N. K. Dulvy. Global population trajectories of tunas and their relatives. Proceedings of the National Academy of Sciences, 2011; 108 (51): 20650 DOI: 10.1073/pnas.1107743108

Cite This Page:

Plataforma SINC. "Tuna and mackerel populations have reduced by 60% in the last century." ScienceDaily. ScienceDaily, 8 February 2012. <www.sciencedaily.com/releases/2012/02/120208103226.htm>.
Plataforma SINC. (2012, February 8). Tuna and mackerel populations have reduced by 60% in the last century. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2012/02/120208103226.htm
Plataforma SINC. "Tuna and mackerel populations have reduced by 60% in the last century." ScienceDaily. www.sciencedaily.com/releases/2012/02/120208103226.htm (accessed September 21, 2014).

Share This



More Plants & Animals News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) — The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) — Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) — The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) — A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) 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:
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