Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study highlights snowball effect of overfishing

08.01.2014
Florida State University researchers have spearheaded a major review of fisheries data that examines the domino effect that occurs when too many fish are harvested from one habitat.

The loss of a major species from an ecosystem can have unintended consequences because of the connections between that species and others in the system. Moreover, these changes often occur rapidly and unexpectedly, and are difficult to reverse.

“You don’t realize how interdependent species are until it all unravels,” said Felicia Coleman, director of the Florida State University Coastal and Marine Laboratory and a co-author on the study.

Coleman and her co-authors, led by FSU biological science Professor Joseph Travis, examined case studies of several distressed ecosystems that had been thoroughly changed over the years because of overfishing.

For example, in the Northern Benguela ecosystem off Namibia, stocks of sardine and anchovy collapsed in the 1970s from overfishing and were replaced by bearded goby and jellyfish. But the bearded goby and jellyfish are far less energy-rich than a sardine or anchovy, which meant that their populations were not an adequate food source for other sea animals in the region such as penguins, gannets and hake, which had fed on the sardines and anchovies. African penguins and Cape gannets have declined by 77 percent and 94 percent respectively. Cape hake and deep-water hake production plummeted from 725,000 metric tons in 1972, to 110,000 metric tons in 1990. And the population of Cape fur seals has fluctuated dramatically.

“When you put all these examples together, you realize there really is something important going on in the world’s ecosystems,” Travis said. “It’s easy to write off one case study. But, when you string them all together as this paper does, I think you come away with a compelling case that tipping points are real, we’ve crossed them in many ecosystems, and we’ll cross more of them unless we can get this problem under control.”

The full study appears in the Dec. 23 issue of “Proceedings of the National Academy of Sciences. ”

Travis, Coleman and their colleagues are hoping that their research will accelerate changes in how fisheries scientists approach these ecosystem problems and how fisheries managers integrate system issues into their efforts. They hope that more effort will be devoted to understanding the key linkages among species that set up tipping points in ecosystems and that managers look for data that can show when a system might be approaching its tipping point.

“It’s a lot easier to back up to avoid a tipping point before you get to it than it is to find a way to return once you’ve crossed it,” Travis said.

Fishing experts do generally understand how overfishing affects other species and the ecosystem as a whole, but it “needs to be a bigger part of the conversation and turned into action,” Coleman said.

Travis and Coleman were joined in their research by eight other scientists from the University of Connecticut, University of California-Berkeley, University of California-Santa Cruz, University of Chicago, University of North Carolina at Chapel Hill, University of Maine and Centre de Recherche Halieutique Méditerranéenne et Tropicale in France.

Tom Butler | EurekAlert!
Further information:
http://www.fsu.edu

Further reports about: Cape Verde Islands Overfishing domino effect ecosystem snowball effect

More articles from Ecology, The Environment and Conservation:

nachricht Traffic emissions may pollute 1 in 3 Canadian homes
22.04.2015 | University of Toronto Faculty of Applied Science & Engineering

nachricht Engineers purify sea and wastewater in 2.5 minutes
17.04.2015 | Investigación y Desarrollo

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Fast and Accurate 3-D Imaging Technique to Track Optically-Trapped Particles

KAIST researchers published an article on the development of a novel technique to precisely track the 3-D positions of optically-trapped particles having complicated geometry in high speed in the April 2015 issue of Optica.

Daejeon, Republic of Korea, April 23, 2015--Optical tweezers have been used as an invaluable tool for exerting micro-scale force on microscopic particles and...

Im Focus: NOAA, Tulane identify second possible specimen of 'pocket shark' ever found

Pocket sharks are among the world's rarest finds

A very small and rare species of shark is swimming its way through scientific literature. But don't worry, the chances of this inches-long vertebrate biting...

Im Focus: Drexel materials scientists putting a new spin on computing memory

Ever since computers have been small enough to be fixtures on desks and laps, their central processing has functioned something like an atomic Etch A Sketch, with electromagnetic fields pushing data bits into place to encode data.

Unfortunately, the same drawbacks and perils of the mechanical sketch board have been just as pervasive in computing: making a change often requires starting...

Im Focus: Exploding stars help to understand thunderclouds on Earth

How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was discovered, more or less by coincidence, that cosmic rays provide suitable probes to measure electric fields within thunderclouds. This surprising finding is published in Physical Review Letters on April 24th. The measurements were performed with the LOFAR radio telescope located in the Netherlands.

How is lightning initiated in thunderclouds? This is difficult to answer - how do you measure electric fields inside large, dangerously charged clouds? It was...

Im Focus: On the trail of a trace gas

Max Planck researcher Buhalqem Mamtimin determines how much nitrogen oxide is released into the atmosphere from agriculturally used oases.

In order to make statements about current and future air pollution, scientists use models which simulate the Earth’s atmosphere. A lot of information such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

HHL Energy Conference on May 11/12, 2015: Students Discuss about Decentralized Energy

23.04.2015 | Event News

“Developing our cities, preserving our planet”: Nobel Laureates gather for the first time in Asia

23.04.2015 | Event News

HHL's Entrepreneurship Conference on FinTech

13.04.2015 | Event News

 
Latest News

Electrons Move Like Light in Three-Dimensional Solid

24.04.2015 | Materials Sciences

Connecting Three Atomic Layers Puts Semiconducting Science on Its Edge

24.04.2015 | Materials Sciences

Understanding the Body’s Response to Worms and Allergies

24.04.2015 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>