Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Scientists question fisheries health test

A measure widely advocated as a means of assessing the health of marine ecosystems is an ineffective guide to trends in biodiversity, and more direct monitoring is needed, a new study has found.

The findings – published this week in Nature – followed an examination of whether changes in fishery catches reflect changes in the structure of marine food webs, and therefore are a suitable guide to assess the impacts of fishing on marine ecosystem health.

CSIRO Wealth from Oceans Flagship scientist, Dr Beth Fulton, and Dr Sean Tracey from the Tasmanian Aquaculture and Fisheries Institute at the University of Tasmania, were members of the international team involved in the study.

“Biodiversity indicators are used to track the impacts of fishing as a guide to management effectiveness,” Dr Fulton said.

“The most widely adopted indicator of biodiversity in the ocean at a global scale is the ‘average trophic level’ (position in the food chain) determined from fishery catches.

“This is intended to detect shifts from high-trophic-level predators such as Atlantic cod and tunas to low-trophic-level fish, invertebrates and plankton-feeders such as oysters.”

“We also found that average trophic level determined from fishery catches does not reliably measure the magnitude of fishing impacts or the rate at which marine ecosystems are being altered by fishing.”

Dr Beth Fulton, CSIRODr Tracey said the study was the first large-scale test of whether average trophic level determined by fishery catch is a good indicator of ecosystem average trophic level, marine biodiversity and ecosystem status.

“We looked at average trophic level determined from a range of sources including global fishery catches, long-term surveys, stock assessments and complex computer modelling for marine ecosystems around the world,” Dr Tracey said.

“In contrast to previous findings, which reported declines in catch average trophic level thought to be due to the loss of large fish and the increasing catch of small fish, we found that catches are increasing at most levels of marine food webs and that the average trophic level has actually increased in the past 25 years.

“We also found that average trophic level determined from fishery catches does not reliably measure the magnitude of fishing impacts or the rate at which marine ecosystems are being altered by fishing.”

Dr Tracey says global fisheries are at a crucial turning point, with high fishing pressure being offset in some regions by rebuilding efforts. Relying on the average trophic level of catch could mislead policy development.

Dr Fulton said that, to target limited resources in the best way, researchers should focus on assessing species vulnerable to fishing that are not currently assessed effectively

“We also need to develop and expan trend-detection methods that can be applied more widely, particularly to countries with few resources for science and assessment.

“Through such efforts we can better detect and convey the true impact of fisheries on marine biodiversity,” Dr Fulton said.

Led by University of Washington fisheries scientist, Trevor A. Branch, the study’s findings are published in a letter in Nature entitled: “The trophic fingerprint of marine fisheries”.

Bryony Bennett | 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: 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...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

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

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>