Featured Research

from universities, journals, and other organizations

Early-warning system to prevent fishery collapse

Date:
September 16, 2013
Source:
University of Minnesota
Summary:
Threats from overfishing can be detected early enough to save fisheries -- and livelihoods -- with minimal adjustments in harvesting practices, a new study shows.

This is a yellowfin tuna (Thunnus albacares).
Credit: UCSB

Threats from overfishing can be detected early enough to save fisheries -- and livelihoods -- with minimal adjustments in harvesting practices, a new study by researchers in the University of Minnesota's College of Biological Sciences shows.

Related Articles


The work indicates that a healthy fishery can be maintained the way a skillful captain steers an oil tanker: by small course corrections that prevent disaster far ahead.

The study, by Ecology, Evolution and Behavior (EEB) graduate student Matt Burgess and co-advisors Stephen Polasky (EEB and Applied Economics in the College of Food, Agricultural and Natural Resource Sciences) and David Tilman (EEB), was published on September 16 in the Early Edition of Proceedings of the National Academy of Sciences.

Specifically, the work demonstrates how extinction and overfishing threats from multispecies fisheries can be identified decades before valuable species are over-harvested and populations decline.

Most of the world's large fisheries use nets or lines with multiple hooks, which catch multiple species simultaneously and have serious ecological consequences. Past population declines and current increases in harvest rates can be used to assess current threats of overfishing and extinction, but this approach doesn't apply to future threats. By predicting future threats, the researchers' new method would enable conservation measures to prevent overfishing and extinction.

The "Eventual Threat Index," presented in the study, uses minimal data to identify the conditions that would eventually cause a species to be harvested at an unsustainable rate. The central premise of the Eventual Threat Index is that because multispecies fisheries impact many species with the same effort, the long-term fates of all species can be predicted if the fate of any one species can be predicted. In any multispecies fishery, there are a few 'key' profitable or managed species, which are easy to identify and whose socio-economic importance makes their long-term harvest rate somewhat predictable. Threats to other species are predicted by measuring their harvest rates relative to these key species.

"The data we collect includes estimates of the relative population sizes, catch rates and the growth rates of different fish populations," Burgess says. "This index uses what we know about what tends to happen to economically important fish to predict the fate of other species caught along with them."

The approach was tested on eight Pacific tuna and billfish populations; four of which have been identified recently by conventional methods as in decline and threatened with overfishing. The study found that the severe depletion of all four populations could have been predicted in the 1950s using the Eventual Threat Index. These results demonstrate that species threatened by human harvesting can be identified much earlier, providing time for adjustments in harvesting practices before consequences become severe and fishery closures or other socioeconomically disruptive interventions are required to protect species.

Burgess says the index is easy and inexpensive to use. He hopes fisheries will adopt it soon.

"In many fisheries, managers could calculate this index tomorrow using the description in the paper and data they have already collected," Burgess says.

The study is based on marine fisheries but could be applied to multispecies fisheries in large bodies of fresh water, such as Lake Superior.


Story Source:

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


Journal Reference:

  1. Matthew G. Burgess, Stephen Polasky, and David Tilman. Predicting overfishing and extinction threats in multispecies fisheries. PNAS, September 16, 2013 DOI: 10.1073/pnas.1314472110

Cite This Page:

University of Minnesota. "Early-warning system to prevent fishery collapse." ScienceDaily. ScienceDaily, 16 September 2013. <www.sciencedaily.com/releases/2013/09/130916161744.htm>.
University of Minnesota. (2013, September 16). Early-warning system to prevent fishery collapse. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2013/09/130916161744.htm
University of Minnesota. "Early-warning system to prevent fishery collapse." ScienceDaily. www.sciencedaily.com/releases/2013/09/130916161744.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
Anglerfish Rarely Seen In Its Habitat Will Haunt You

Anglerfish Rarely Seen In Its Habitat Will Haunt You

Newsy (Nov. 22, 2014) For the first time Monterey Bay Aquarium recorded a video of the elusive, creepy and rarely seen anglerfish. Video provided by Newsy
Powered by NewsLook.com
Birds Around the World Take Flight

Birds Around the World Take Flight

Reuters - Light News Video Online (Nov. 22, 2014) An imperial eagle equipped with a camera spreads its wings over London. It's just one of the many birds making headlines in this week's "animal roundup". Jillian Kitchener reports. Video provided by Reuters
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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